City of Fresno SEDA Specific Plan Program EIR
Recycled Water Technical Study Page 15 of 22
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers • Agricultural reuse incudes the direct delivery of both undisinfected secondary and disinfected tertiary treated wastewater, delivering recycled water to the FID via their canal facilities, and delivery of recycled water to other interested parties for agricultural use. • Groundwater recharge affords the City an opportunity to directly augment the City’s potable water supply and provide a use for recycled water during winter. The process involves siting and sizing potential recharge basins, and delivering recycled water to be stored in these basins to percolate down to the groundwater aquifers. • Fisheries enhancement would involve supplementing water released by the United States Bureau of Reclamation (USBR) to maintain fish flows in the San Joaquin River with recycled water; however, the amount of water required for such activities greatly outpaces recycled water production, and this option was deemed impractical and not pursued further.
Two alternatives for recycled water supply and distribution systems were presented in the Master Plan, both with proposed improvements that provided a path to conveying recycled water to the Plan Area. The first alternative was outlined with the idea that the Fresno-Clovis RWRF would be the main source of recycled water for the City, and would supply recycled water to all four quadrants of the recycled water distribution system via numerous pipelines and pump stations.
The second alternative assumed a number of satellite recycled water facilities would be built around the City to assist in providing recycled water supplies, thereby alleviating the FresnoClovis RWRF of the requirement to supply the entire system.
The Southeast Quadrant includes southeast Fresno and the Plan Area. Alternative 1 of the Master Plan included backbone piping that stops short of the Plan Area. Alternative 2 included backbone piping leading to a proposed satellite recycled water facility (scalping plant) within the limits of the Plan Area. The City is still analyzing the two alternative as presented in the Recycled Water Master Plan as well as other options for the use of recycled water in the Plan Area. The construction of a satellite recycled water facility (scalping plant) within SEDA would allow the area to be self-sustaining, and provide a path for wastewater collection and treatment that would directly benefit the Plan Area. Refer to the Recycled Water Master Plan for details on the proposed recycled water infrastructure.
Per the Recycled Water Master Plan, urban reuse provides the City with the best opportunity to implement recycled water projects that directly offset potable water and are highly visible to the community. However, urban reuse is much more distribution system-intensive than other alternatives like groundwater recharge since potential recycled water users are spread out around the City. The Recycled Water Master Plan recommended aligning the distribution system to serve large water users first to ensure efficient use of the recycled water supply. Smaller users can then be connected to the main distribution system at a later time.
The Recycled Water Master Plan includes assumptions of recycled water capacities and demands for each quadrant of the distribution system based on whether they were supplied via the RWRF or satellite RWFs (Alternative 1 vs Alternative 2, respectively). The Southeast Quadrant was projected to have a treatment capacity of 2.8/5.1 MGD (2.8 MGD without residential or commercial reuse/5.8 MGD with residential and commercial reuse) for Alternative 1 and 3.0 MGD for Alternative 2, and a demand of 995/1,820 AFY (acre feet per year) for Alternative 1 and 951 AFY for Alternative 2. It should be noted that the Master Plan Alternative 1 does not include any delivery of recycled water to the SEDA area, and thus the demands presented are not accurate for planning purposes of the Plan Area. Alternative 2 includes the proposed satellite RWF (scalping plant) potentially located within SEDA boundaries, and thus could be used in estimating demands. However, the timeline for recycled water development within the Plan Area has not been fully developed, and thus updates to the Recycled Water Master Plan are required to determine the extent to which recycled water would be available to SEDA users.
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Recycled Water Technical Study Page 16 of 22
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers Engineering Report for the Production, Distribution and Use of Recycled Water (September 2015) The Engineering Report for the Production, Distribution and Use of Recycled Water (included in Appendix C) serves as an update to the Recycled Water Master Plan and discusses further proposed improvements based on the City’s plan for a recycled water distribution system, including the tertiary treatment equipment currently in operation.
The Engineering Report focuses on updating the Recycled Water Master Plan with data and information on the disinfected tertiary treatment process at the Fresno-Clovis RWRF, and establishes phases for its expansion – Phase I is the initial facility, which has a production capacity of 5 MGD; subsequent Phase 2 and 3 expansions are planned to provide an additional 10 MGD and 15 MGD of capacity, respectively, resulting in a final capacity of 30 MGD. With this came the establishment of a recycled water distribution system to convey the recycled water to users throughout the City. The engineering report recommends Alternative 2, which includes a pipeline connecting the Southeast quadrant with the recycled water system, as well as a satellite RWF (scalping plant) within the Plan Area. However, the City is still analyzing prospective options for recycled water system alignments.
The Engineering Report estimates that Phase 1 users will mainly be in the urban reuse category, as established in the Recycled Water Master Plan. The types of urban recycled water uses recommended generally include landscape irrigation and industrial uses. Some examples include:
• Parks
• Golf course and country clubs
• Homeowners Association common areas
• Cemeteries
• Airports
• State highway rights-of-way
• Schools and college campuses
• Municipal facilities such as courthouses and city halls • Water feature impoundments such as Lake Van Ness and Woodward Lake • Fairgrounds
Some examples of industrial uses include:
• Heating and cooling
• Industrial laundries
• Commercial vehicle washing
• Dust control
• Fire protection
• Sanitary, such as toilet flushing at industrial sites • Process water (except for food processes)
• Cleanup/wash down water (except for food processes)
• Boiler feed
The City’s Recycled Water Ordinance requires recycled water use under certain conditions, where recycled water is available, as summarized below:
a) The City may require all customers who connect to the potable water system to use recycled water for all approved uses, including but not limited to dual plumbing for commercial buildings and single family residential irrigation. b) Existing commercial properties, existing industrial properties, existing apartments and condominiums, and all homeowners associations are required to use recycled water for landscape irrigation.
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Recycled Water Technical Study Page 17 of 22
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers c) New commercial projects, new industrial projects, new institutional and governmental projects, and new apartments and condominiums are required to be dual plumbed to provide for internal use of recycled water, and are required to use recycled water for landscape irrigation.
d) New single family residential home projects are required to provide for landscape irrigation with recycled water.
All properties within a Recycled Water Project Area, as is defined in the Recycled Water Ordinance, that host land uses for which recycled water is recommended by the Recycled Water Master Plan, or is required by the Ordinance, are potential recycled water use areas, and the owners or tenants of such properties are potential recycled water users.
City of Fresno Metropolitan Water Resources Management Plan – Phase 2 Development and Evaluation of Future Water Supply Plan (January 2011)
Phase 2 of the City’s Metro Plan for water resources includes a chapter devoted to future recycled water infrastructure (Chapter 7. Future Recycled Water). The Metro Plan discussed current recycled water use and future recycled water use, and includes data on estimated recycled water demands. The Metro Plan estimated that the SEDA Specific Plan area would utilize approximately 5,100 AFY of recycled water – about 18% of the total 2025 projected water demand for the SEDA area (27,800 AFY). These demands were determined with previous land use classifications for the SEDA area, and will thus need to be updated for those land uses being utilized in this Specific Plan. This will be discussed further in Chapter 5. The Metro Plan is also in the process of being updated by the City, and any analysis will need to be revised in accordance with any recommendations included in the revised Metro Plan.
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220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers CHAPTER 5
SPECIFIC PLAN RECYCLED WATER INFRASTRUCTURE
5.1 General
The SEDA Specific Plan area has been reevaluated with revised land use classifications – see Figure 5.1 for the chosen alternative for land use classifications. Of these land uses, there will be several that will be able to utilize recycled water for urban or agricultural reuse, as well as groundwater recharge. The Plan Area presents a unique opportunity to develop the recycled water distribution system along with the area-wide development, allowing recycled water use to be engrained into the Plan Area. However, recycled water is not yet utilized in the Plan Area, and the Recycled Water planning documents (Master Plan, Engineering Report, General Plan) do not account for the development of a recycled water distribution system within the Plan Area until after the planned development of the City’s growth areas.
Figure 5.1 SEDA Proposed Land Use19
19 Southeast Development Area Specific Plan Notice of Preparation, First Carbon Solutions. 02/2022.
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220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers
5.2 Plan Area Land Uses
The land use classifications for the Plan Area have been developed to be unique for the Specific Plan, and differ from those of the City’s General Plan. Many land uses are similar to those of the General Plan, but have been tailored for use in the Specific Plan.
Land uses that would be eligible for recycled water use generally include any with green spaces, landscaping, industrial or agricultural processes. The SEDA Specific Plan document includes information for all specific plan land uses; several promote mixed-use facilities, which may allow recycled water to be utilized in many more ways than original plans would have allotted. Land uses that have landscaping, parks, educational facilities, industrial facilities, or open spaces would all be able to utilize recycled water for irrigation. The Specific Plan includes designated community agricultural and gardening areas, which may also be eligible for recycled water use.
In accordance with the SEDA Specific Plan Draft Policy Document, there will be a large significance placed on open spaces, including parks and other green spaces interspersed throughout its mixed-use centers and neighborhoods. There will also be a focus on community farming and agriculture, especially along buffer zones on the east side of the Plan Area. A system of pedestrian/bicycle trails is planned throughout the area as well. All of these land uses will be eligible to utilize recycled water, mainly for irrigation.
5.3 Plan Area Improvements
Improvements within the Plan Area will be required to facilitate the use of recycled water. Since the recycled water distribution system has not yet been planned for the area, it has been assumed that all land uses that would be eligible for recycled water use will utilize potable water until the recycled water supply and distribution system are available. However, these potable water facilities should be installed in accordance with all recycled water regulations and requirements so as to allow a seamless transition to recycled water. This includes installing purple pipe, purple valve boxes, purple irrigation facilities, and maintaining required clearances with other adjacent utilities.
If the Plan Area is expected to be supplied with recycled water from the Fresno-Clovis RWRF, significant infrastructure will be needed to convey the water from the facility to the Plan Area at a usable flow and pressure. Piping of various sizes and booster pump stations will be required, among other improvements. If a satellite RWF (scalping plant) is planned, then the infrastructure required would mainly consist of a distribution system of pipelines to convey the recycled water to the users, as well as a pipeline to convey solids to the Fresno-Clovis RWRF. Consideration would need to be given to recycled water storage facilities when assessing the demand versus the supply of recycled water produced.
5.4 Projected Baseline Demand
A baseline analysis of the Plan Area was completed to understand a preliminary recycled water demand based solely on estimated area of open space presented in the Specific Plan buildout plan, and only accounting for recycled water that may be used for irrigation of said open space.
According to the plan, each land use classification will encompass some percentage of open space, or “Park Acres.” These are as follows:
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220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers Table 5.1 SEDA Land Use Classifications – Park Acres
SEDA Land Use
Classification
Land Use
Acres
Park Acres
Percentage Park Acres
Regional Center 310 10% 31
Community Center 290 10% 29
Neighborhood Center 520 10% 52
Mixed Residential 1,090 10% 109
Neighborhood Residential 1,520 10% 152
Rural Residential 2,160 0% 0
Rural Cluster 810 0% 0
Institutional 280 5% 14
Office Center 160 5% 8
Flexible R&D 1,380 5% 69
The total minimum park acres in the Plan Area equals 464 acres. Utilizing precipitation data obtained from the Western Regional Climate Center for Fresno20, preliminary irrigation calculations were completed to determine the Estimated Total Water Use (ETWU) of the park acres in the Plan Area. Assuming the landscaping would be warm-season turf, and irrigation would mainly be applied via overhead spray/rotors, an annual ETWU with rainfall included of approximately 283 ac-ft (0.3 MGD) was found for the Plan Area (without rainfall yields an ETWU of 1,572 ac-ft, or 1.4 MGD). This represents the minimum required recycled water demand for the park acres included in each of the land use classifications, and does not account for any designated open spaces, agricultural areas, or other miscellaneous potential recycled water uses.
This has also been completed without knowledge about the available supply of recycled water for the Plan Area, and demands will need to be reassessed once a supply is available. A summary of the calculations completed can be seen in Appendix A.
This demand is not a clear indication of how much recycled water the Plan Area will actually use.
Updates to the Recycled Water Master Plan will be required to fully develop the recycled water distribution system for the Plan Area. Determinations of potential recycled water users will need to be made in order to accurately estimate the anticipated recycled water demand. 20 Western Regional Climate Center. https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?ca3257. 2022.
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220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers CHAPTER 6
IMPACTS AND MITIGATIONS
6.1 SEDA Planning
Improvements within the Plan Area will require modifications to master planned recycled water facilities and infrastructure.
A draft policy document has been completed for the SEDA Specific Plan (March 2022), which includes updated policies for the Plan Area, and proposed improvements to meet the chosen alternative for development of the area. Included among these are policies directly related to recycled water use in the Plan Area. Refer to the SEDA Specific Plan policy document for details on policies related to recycled water.
6.2 Impacts of Significance
The proposed Specific Plan would result in a significant impact if it would:
1. Require or result in the construction of new water or wastewater treatment facilities or expansion of baseline facilities, the construction of which could cause significant environmental effects.
Recycled water may be a significant contributor to the Plan Area’s water supply system.
The principal impact of providing recycled water is the overall water supply rather than direct shortages for end users. This is because the ability exists to trade off and supplement recycled water supply from other sources. The recycled water planning documents do not delve into detailed plans for improvements for the Plan Area. Recycled water is not currently utilized in the Plan Area, and there are no portions of the recycled water distribution system that have been constructed within the area. Thus, any proposed recycled water use would necessitate the expansion of the existing recycled water system, the installation of new recycled water pipelines, and potentially new treatment and storage facilities so as to provide sufficient recycled water at buildout conditions.
However, the lack of planning document details and existing recycled water supply in the Plan Area makes it difficult to assess the necessary mitigation measures to accommodate the impacts of new facilities. Continued evaluation of available capacity and construction of improvements is required. Construction and operation of potential improvements could result in project-specific impacts that are not currently known because said facilities have not yet been designed or planned. Once further environmental evaluations have occurred and further planning is completed, potential impacts would be considered significant without any mitigations. Impacts related to the construction of new recycled water treatment facilities or expansion of baseline facilities would be less than significant with mitigations. At the time discretionary projects are submitted, the City shall require projectspecific environmental evaluations for the expansion of recycled water facilities be completed prior to project approval.
2. Have insufficient recycled water supplies available to serve the proposed Plan from baseline entitlements and resources, and require new or expanded entitlements.
Recycled water supply shortage impacts would be significant in both real impacts and the cost of non-compliance with regulatory requirements and proposed policies. The proposed Specific Plan would result in an increase in density between the Fresno General Plan and the SEDA Specific Plan, which would modify the generation of wastewater. Since the availability of recycled water is directly related to the generation of wastewater, any City of Fresno SEDA Specific Plan Program EIR
Recycled Water Technical Study Page 22 of 22
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers change in wastewater production may affect recycled water availability. There are impacts associated with insufficient recycled water, including utilizing more potable water for nonpotable uses.
The Master EIR (MEIR) prepared for the City of Fresno included several mitigation measures for increasing wastewater treatment capacities for the City of Fresno that are applicable to this plan. These include:
• MEIR Mitigation Measure USS-1: the City shall develop and implement a wastewater master plan update.
• MEIR Mitigation Measure USS-3: Prior to exceeding existing wastewater treatment capacity, the City shall evaluate the wastewater system and shall not approve additional development that contributes wastewater to the wastewater treatment facility that could exceed capacity until additional capacity is provided...
It is also not known how many users will exist in the Plan Area, and what the actual demand will be for recycled water. Continued development of the Recycled Water Master Plan and the recycled water distribution system is required to fully understand the needs of the Plan Area. With continued development and implementation of proposed improvements that will enhance the reliability and availability of recycled water in the Plan Area, impacts with mitigation would be less than significant.
6.3 Conclusions
The Plan Area currently does not utilize recycled water, however the SEDA Specific Plan presents the City with an opportunity to expand its recycled water system and increase the viability of recycled water to improve surface and groundwater conservation.
For the purposes of the Specific Plan, it has been assumed that since no recycled water supply exists in the Plan Area, and the distribution system has not been outlined in the City’s recycled water planning documents, all land use classifications within the Plan Area will utilize potable water for use cases in which recycled water is allowed, with the stipulation that these systems install facilities that meet recycled water standards and regulations to ensure future conversion to recycled water will not require extensive improvements or revisions to the systems.
City recycled water planning documents, including but not limited to the Recycled Water Master Plan and the City Metro Plan, will need to be updated to account for the development of the SEDA, and account for the policies and revisions present in the Specific Plan.
Mitigations for SEDA from the General Plan to the SEDA Specific Plan include:
a) Develop additional water conservation measures in accordance with the City Metro Plan. b) Implement recycled water objectives, goals, and policies as described in Chapter 7 of the City Metro Plan.
c) Develop an update to the Recycled Water Master Plan. d) Develop an update to the Recycled Water Distribution System. e) Develop recommendations and design and construct wastewater treatment facilities, recycled water supply, distribution, and storage facilities for the Plan Area. f) Develop list of potential users in the Plan Area to estimate actual recycled water demand.
Feasibility Evaluation for Recycled Water
Irrigation Use at Fulton Mall
Appendix A
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers Appendix A
Preliminary Irrigation Calculations
Feasibility Evaluation for Recycled Water
Irrigation Use at Fulton Mall Appendix A
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers Evapotranspiration Calculations
Fresno ETo data1 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 0.9 1.7 3.3 4.8 6.7 7.8 8.4 7.1 5.2 3.2 1.4 0.6 51.1 Average Rainfall (WRCC) (in) 2 2.09 1.90 1.89 1.03 0.36 0.16 0.01 0.01 0.15 0.53 1.13 1.64 10.90 Effective Rainfall (25% per AB 1881) 0.52 0.48 0.47 0.26 0.09 0.04 0.00 0.00 0.04 0.13 0.28 0.41 2.73 Adjusted Eto 0.38 1.23 2.83 4.54 6.61 7.76 8.40 7.10 5.16 3.07 1.12 0.19 48.38 1 Appendix A - Reference Evapotranspiration (ETo) Table, MWELO 2 Western Regional Climate Center Estimated Total Water Use (ETWU) = (ETo) x (0.62) x (K) x (PA) / (IE) SEDA Plan Area (PA) – 464 acres Landscape Factor (K): 0.60 (Warm-Season Turf) Irrigation Efficiency (IE): 0.75 (Overhead Spray/Rotor) SEDA Plan Area Jan Feb Mar Apr May Jun Jul
ETWU without rainfall (gal) 9,022,565 17,042,623 33,082,740 48,120,349 67,167,987 78,195,567 84,210,610 ETWU without rainfall (acre-ft) 27.69 52.30 101.53 147.68 206.13 239.97 258.43 ETWU with rainfall (gal) 3,784,465 19,047,638 18,947,387 10,325,825 3,609,026 1,604,012 100,251 ETWU with rainfall (acre-ft) 11.6 58.5 58.1 31.7 11.1 4.9 0.3 SEDA Plan Area Aug Sep Oct Nov Dec Annual
ETWU without rainfall (gal) 71,178,016 52,130,378 32,080,232 14,035,102 6,015,044 512,281,212 ETWU without rainfall (acre-ft) 218.44 159.98 98.45 43.07 18.46 1572.13 ETWU with rainfall (gal) 100,251 1,503,761 5,313,288 11,328,332 16,441,119 92,105,355 ETWU with rainfall (acre-ft) 0.3 4.6 16.3 34.8 50.5 282.66 Annual without rainfall (MGD) = [1,572.13 ac-ft x (325,851 gal / 1 ac-ft)] x (1 year / 365 days) / 106 = 1.4 MGD Annual with rainfall (MGD) = [282.66 ac-ft x (325,851 gal / 1 ac-ft)] x (1 year / 365 days) / 106 = 0.3 MGD Feasibility Evaluation for Recycled Water
Irrigation Use at Fulton Mall Appendix B
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers Appendix B
City of Fresno Recycled Water Master Plan
Feasibility Evaluation for Recycled Water
Irrigation Use at Fulton Mall Appendix C
220320_SEDA_Recycled Water Tech Study_REV Blair, Church & Flynn Consulting Engineers Appendix C
Engineering Report for the Production, Distribution and Use of Recycled Water
CITY OF
DEPARTMENT OF PUBLIC UTILITIES
WASTEWATER MANAGEMENT DIVISION
ENGINEERING REPORT
DISTRIBUTION AND USE OF RECYCLED WATER
Prepared Under the Direction of:
Blair, Church & Flynn
CITY OF FRESNO, CALIFORNIA
DEPARTMENT OF PUBLIC UTILITIES
WASTEWATER MANAGEMENT DIVISION
REPORT FOR THE PRODUCTION,
DISTRIBUTION AND USE OF RECYCLED WATER
SEPTEMBER 18, 2015
Prepared Under the Direction of:
Mr. Kevin Norgaard
Chief of Technical Services
Prepared by:
Blair, Church & Flynn Consulting Engineers
A California Corporation
451 Clovis Avenue, Suite 200
Clovis, CA 93612
(559) 326-1400 ph
(559) 326-1500 fax
bcf-engr.com
FOR THE PRODUCTION,
DISTRIBUTION AND USE OF RECYCLED WATER
Engineering Report for the Production,
Distribution and Use of Recycled Water Page i
215138_rpt01.docx Blair, Church & Flynn Consulting Engineers
TABLE OF CONTENTS
1.0 INTRODUCTION ................................................................................................................................. 1
2.0 RECYCLED WATER PROJECT .............................................................................................................. 5
2.1 General .......................................................................................................................................... 5
2.1.1 Fresno Irrigation District ....................................................................................................... 5
2.1.2 Fresno Metropolitan Flood Control District .......................................................................... 6
2.2 Rules and Regulations ................................................................................................................... 6
2.3 Producer, Distributor and Users of Recycled Water ..................................................................... 7
2.3.1 Producer and Distributor ...................................................................................................... 7
2.3.2 Recycled Water Users ........................................................................................................... 7
2.4 Raw Wastewater ......................................................................................................................... 11
2.5 Treatment Processes................................................................................................................... 12
2.5.1 Existing RWRF Facilities ....................................................................................................... 12
2.5.2 New TTDF Facilities ............................................................................................................. 13
2.5.3 Operation and Maintenance Manuals ................................................................................ 15
2.6 Plant Reliability Features ............................................................................................................ 15
2.6.1 Fine Screens ........................................................................................................................ 16
2.6.2 Bioreactors (Pre-Aeration Basins) ....................................................................................... 16
2.6.3 Aeration System .................................................................................................................. 16
2.6.4 Mixed Liquor Return and Sludge Recirculation Pumps ....................................................... 16
2.6.5 MBR Membrane System ..................................................................................................... 17
2.6.6 Disinfection ......................................................................................................................... 17
2.6.7 Alarm Provisions ................................................................................................................. 18
2.6.8 Facility Hours and Staffing .................................................................................................. 20
2.6.9 Electrical Power Supply ....................................................................................................... 20
2.7 Supplemental Water Supply ....................................................................................................... 21
2.8 Monitoring and Reporting .......................................................................................................... 22
2.9 Contingency Plan ........................................................................................................................ 23
3.0 TRANSMISSION AND DISTRIBUTION SYSTEMS ............................................................................... 24
4.0 RECYCLED WATER USE AREAS ......................................................................................................... 27 Engineering Report for the Production,
Distribution and Use of Recycled Water Page ii
215138_rpt01.docx Blair, Church & Flynn Consulting Engineers
LIST OF FIGURES
FIGURE 1-1 LOCATION MAP .......................................................................................................................................... 2 FIGURE 1-2 OVERVIEW OF PLANNED DISTRIBUTION SYSTEM ....................................................................................... 4 FIGURE 2-1 RECYCLED WATER USER MAP FOR INITIAL CONTACTS ............................................................................. 10 FIGURE 2-2 EXISTING RWRF TREATMENT TRAINS ....................................................................................................... 12 FIGURE 2-3 TTDF SCHEMATIC SITE PLAN ..................................................................................................................... 14 FIGURE 2-4 TTDF SCHEMATIC LINE DIAGRAM ............................................................................................................. 15 FIGURE 3-1 SOUTHWEST QUADRANT RECYCLED WATER TRANSMISSION MAIN PROJECTS ....................................... 26
LIST OF APPENDICES
Appendix A Recycled Water Ordinance
Appendix B Rules and Regulations
Appendix C Recycled Water User Agreement
Appendix D TTDF Design Report
Appendix E Standard Specifications and Drawings for Recycled Water Facilities
LIST OF RELEVANT INTERNET-ACCESSIBLE DOCUMENTS
Construction Plans for Recycled Water Transmission Main Project SW1A https://dl.dropboxusercontent.com/u/79172/215138_RWTM_SW1A_Plans.pdf Construction Plans for Recycled Water Transmission Main Project SW1B https://dl.dropboxusercontent.com/u/79172/215138_RWTM_SW1B_Plans.pdf Industrial Pretreatment Program
https://dl.dropboxusercontent.com/u/79172/Industrial%20Pretreatment%20Program%202009.pdf Recycled Water Master Plan
http://www.fresno.gov/NR/rdonlyres/7B22E4E4-29CF-4C10-B3BEF32C141CBB4B/0/RecycledWaterMasterPlan2013.pdf Recycled Water Ordinance
http://www.fresno.gov/NR/rdonlyres/7AB20689-3E0B-4C1C-A01B67BF9D0B8305/0/RecycledWaterOrdinance.pdf Recycled Water-Related Statutes
http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/Documents/Lawbook/RWstatute s2014-05-01a.pdf
Recycled Water-Related Regulations
http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/lawbook/RWregulati ons_20150716.pdf
Engineering Report for the Production,
Distribution and Use of Recycled Water Page iii
215138_rpt01.docx Blair, Church & Flynn Consulting Engineers Recycled Water User Map for Initial Contacts
https://dl.dropboxusercontent.com/u/79172/Fresno%20RecWat%20User%20Map.pdf TTDF Design Report
https://dl.dropboxusercontent.com/u/79172/TTDF%20Schematic% 20Design%20Final%20Tech%20Memo.pdf
TTDF Construction Drawings
https://dl.dropboxusercontent.com/u/79172/TTDF%20Conformed%20Plans.pdf TTDF Construction Specifications Volume I
https://dl.dropboxusercontent.com/u/79172/TTDF%20Conformed%20Specs%20Vol1.pdf TTDF Construction Specifications Volume II
https://dl.dropboxusercontent.com/u/79172/TTDF%20Conformed%20Specs%20Vol2.pdf TTDF Construction Specifications Volume III
https://dl.dropboxusercontent.com/u/79172/TTDF%20Conformed%20Specs%20Vol3.pdf Engineering Report for the Production,
Distribution and Use of Recycled Water Page iv
215138_rpt01.docx Blair, Church & Flynn Consulting Engineers
ACRONYMS AND ABBREVIATIONS
AFY Acre-Feet per Year
BOD Biochemical Oxygen Demand
CRWQCB California Regional Water Quality Control Board, Central Valley Region CFS Cubic Feet per Second
Clovis ST/WRF Clovis Sewage Treatment / Water Reuse Facility FID Fresno Irrigation District
FMFCD Fresno Metropolitan Flood Control District
FSE Fine Screen Effluent
GFD Gallons per Square Foot per Day
GPM Gallons per Minute
GRRP Groundwater Replenishment Reuse Projects
KVA Kilovolt-Amp
KW Kilowatt
MGD Million Gallons per Day
MVA Megavolt-Amp
MW Megawatt
NFWRF North Fresno Wastewater Reclamation Facility
OIS Operator Interface Station
PGE Pacific Gas & Electric Company
RAS Return Activated Sludge
RWPA Recycled Water Project Area
RWRF Fresno / Clovis Regional Wastewater Reclamation Facility RWTM Recycled Water Transmission Main
SCADA Supervisory Control and Data Acquisition
TSS Total Suspended Solids
TTDF Tertiary Treatment and Disinfection Facility
TTRW Tertiary Treated Recycled Water
UV Ultra-Violet
WAS Waste Activated Sludge
WDRs Waste Discharge Requirements
Engineering Report for the Production,
Distribution and Use of Recycled Water Page v
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DEFINITIONS
1974 Agreement: The 1974 agreement between the City of Fresno and FID to establish a groundwater reclamation system consisting of on-site extraction wells at the RWRF and piping that delivers extracted groundwater to FID's Dry Creek and Houghton Canals.
1976 Agreement: The 1976 agreement between the City of Fresno and FID that provides for the agencies to use FID's distribution system to satisfy their respective water supply rights, and to work together to protect and preserve the groundwater basin.
Guidelines: The California Department of Water Resources March 2001 “Guidelines for the Preparation of an Engineering Report for the Production, Distribution, and Use of Recycled Water” Master Plan: The City of Fresno's 2010 "Recycled Water Master Plan" Metro Plan Update: The City of Fresno's 2011 "Metropolitan Water Resources Management Plan Update, Phase 2"
Recycled Water Ordinance: The City of Fresno Recycled Water Ordinance, adopted July 17, 2014 as Ordinance 2014-32
Rules and Regulations: The City of Fresno "Rules and Regulations of Recycled Water Use" TTDF Design Report: "Tertiary Treatment and Disinfection Facility Technical Memorandum", August 2011
TTDF Construction Plans: "Drawings for the Construction of Tertiary Treatment and Disinfection Facility - Phase I", Conformed Drawings, September 19, 2013
TTDF Construction Specifications: "Fresno-Clovis Regional Wastewater Reclamation Facility, Tertiary Treatment And Disinfection Facility, Specifications", Conformed, Volumes I - III, September 2013, Waste Discharge Requirements: California Regional Water Quality Control Board, Central Valley Region, "Order No. 5-01-254, Waste Discharge Requirements for Cities of Fresno and Clovis Wastewater Treatment Facility, Fresno County", 19 October 2001
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1.0 INTRODUCTION
The City of Fresno is located in the County of Fresno, in California's Central Valley, approximately 220 miles north of Los Angeles and 180 miles south of Sacramento. In partnership with the City of Clovis, the City owns and operates the Fresno-Clovis Regional Wastewater Reclamation Facility (RWRF), which receives and treats the majority of wastewater generated within the Cities of Fresno and Clovis and some unincorporated areas of Fresno County. The RWRF site is located in the area generally bounded by Jensen, Chateau Fresno, Central, and Cornelia Avenues, and its on-site Administration Office building is located at Lat 36°42'14.63" N, Long 119°53'33.50" W. The RWRF is currently operated under California Regional Water Quality Control Board, Central Valley Region, "Order No. 5-01-254, Waste Discharge Requirements for Cities of Fresno and Clovis Wastewater Treatment Facility, Fresno County", dated 19 October 2001 (Waste Discharge Requirements).
The City also owns and operates the North Fresno Wastewater Reclamation Facility (NFWRF), which receives and treats wastewater generated within a small area of the City generally bounded by Copper, Friant, and Willow Avenues. The NFWRF is located on the north side of Copper Avenue, between Cedar and Maple Avenues, at Lat 36°53'46.35" N, Long 119°45'8.01" W. Recycled water produced by the NFWRF is used for irrigation of a golf course at Copper River Country Club, which is situated within the area served by the NFWRF.
The City of Clovis owns the Clovis Sewage Treatment / Water Reuse Facility (Clovis ST/WRF), which is operated under contract by CH2M Hill. The Clovis ST/WRF is located at the northeast corner of Ashlan and Loma Vista Avenues, at Lat 36°47'39.77" N, Long 119°36'50.71" W. The Clovis ST/WRF receives and treats wastewater generated within certain areas of the City of Clovis that are not tributary to the RWRF, and currently has an average daily flow capacity of 2.8 MGD. Recycled water produced by the Clovis ST/WRF is used for landscape irrigation in certain areas of the City of Clovis, and for agricultural irrigation via limited elements of the Fresno Irrigation District distribution system.
Figure 1-1 provides a location map showing the approximate locations of the RWRF, NFWRF and Clovis ST/WRF facilities.
The City of Fresno's 2011 Metropolitan Water Resources Management Plan Update (Metro Plan Update), Phase 2, recommended that the City incorporate tertiary-treated recycled water into its future water supply portfolio to meet non-potable demands in new development areas and existing parts of the City, to offset potable water demands. The Metro Plan Update called for the use of up to 25,000 AFY, approximately equivalent to an average of 22.3 MGD, of tertiary-treated recycled water by 2025.
The City's 2010 Recycled Water Master Plan (Master Plan), although completed prior to the Metro Plan Update, Phase 2, incorporated the same Metro Plan Update recommendation taken from a draft edition, as a minimum. The Recycled Water Master Plan implementation recommendations included the construction of a tertiary-treated recycled water production facility at the RWRF, and a network of recycled water transmission and distribution pipelines to convey recycled water to use areas.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers The City of Fresno is currently constructing a Tertiary Treatment and Disinfection Facility (TTDF) at the RWRF. It will be a Phase 1 facility having an initial recycled water production capacity of 5 MGD.
Subsequent Phase 2 and Phase 3 expansions are planned to provide additional capacity of 10 MGD and 15 MGD, respectively, to result in a Phase 3 capacity of 30 MGD. The TTDF will receive primary effluent from one of the existing RWRF treatment trains, and will produce disinfected tertiary-treated recycled water. A recycled water transmission and distribution pipeline network is planned to convey recycled FIGURE 1-1
LOCATION MAP
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers water from the TTDF to recycled water use areas in the City of Fresno. Figure 1-2 provides an overview of the planned distribution system, taken from the Master Plan.
As generally described in the Master Plan, the City's objectives for its planning and development of a recycled water production and distribution system are:
x Protect and improve groundwater quality by reducing the use of the RWRF percolation ponds that are currently used for effluent disposal.
x Increase the use of recycled water through urban reuse, groundwater recharge and agricultural reuse to help meet increasing water demands in the region. x Offset potable water use, enhancing the sustainability of the City's water supply.
This Engineering Report for the Production, Distribution, and Use of Recycled Water describes the City of Fresno’s planned recycled water production and distribution facilities, and describes how those facilities and the planned uses of recycled water will comply with the State of California Water Recycling Criteria, which are contained in Sections 60301 through 60355, inclusive, of the California Code of Regulations, Title 22, Division 4. The format and content of this report conform to the March 2001 “Guidelines for the Preparation of an Engineering Report for the Production, Distribution, and Use of Recycled Water” (Guidelines).
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OVERVIEW OF PLANNED DISTRIBUTION SYSTEM
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2.0 RECYCLED WATER PROJECT
2.1 General
The City of Fresno, Department of Public Utilities, Wastewater Management Division, is the lead agency and project sponsor for this project, and is ultimately responsible for the design, construction, operation and maintenance of the recycled water production and distribution facilities. Although the City of Fresno owns and operates the RWRF, in partnership with the City of Clovis, the City of Clovis has no ownership in or responsibility for the City of Fresno's planned recycled water production and distribution facilities.
Other agencies that have, or could potentially have, an interest in the City's production, distribution and use of recycled water are Fresno Irrigation District (FID) and Fresno Metropolitan Flood Control District (FMFCD).
2.1.1 Fresno Irrigation District
In 1974, the City entered into an exchange agreement (1974 Agreement) with Fresno Irrigation District (FID) to establish a groundwater reclamation system consisting of on-site extraction wells at the RWRF and piping that delivers extracted groundwater to FID's Dry Creek and Houghton Canals. The extracted ground water typically mixes with a variable amount of surface water prior to use on crops, including fodder, fiber, and food for human consumption (e.g., almonds, beans, peaches, raisins, and wine grapes, etc.). The extracted groundwater is discharged to the canals during the growing season for agricultural use on the western side of FID's service area. Each canal can convey up to 200 cubic feet per second (CFS). There are currently no regulatory restrictions on the use of extracted groundwater.
The 1974 Agreement stipulates the following:
x The City must discharge a minimum of 100,000 AF of extracted groundwater to FID during any ten-year period.
x The City may discharge a maximum of 30,000 AF of extracted groundwater to FID in any given year.
x For every acre-foot of extracted groundwater the City discharges to FID, the City is entitled to receive 0.46 acre-foot of surface water from FID.
x Any increase in the discharge of extracted groundwater to FID beyond that stipulated in the 1974 agreement is subject to FID approval.
x The City cannot extract groundwater from beneath the RWRF in volumes that will cause the groundwater level to drop below levels observed in the previous year.
The City has not historically used its full entitlement of surface water under the 1974 Agreement due to lack of demand and adequate facilities, such as groundwater recharge basins or surface water treatment facilities.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers The City and FID also entered into a separate cooperative agreement dated 1976 (1976 Agreement), that provides for the agencies to use FID's distribution system to satisfy their respective water supply rights, and to work together to protect and preserve the groundwater basin. The 1976 Agreement also stipulates that the City will retain its treated effluent within the boundaries of FID unless written consent to do otherwise is obtained.
The City currently owns, operates and maintains the facilities that deliver extracted groundwater to the FID system, up to the point of delivery. FID currently owns, operates and maintains all elements of the FID system that distribute the extracted water, beyond the point of delivery. There are currently no plans to change responsibility for ownership, operation and maintenance of the respective facilities.
Relative to agricultural alternatives that involve FID, the Master Plan recommends expansion of agricultural exchange via increased delivery of extracted groundwater, and / or the addition of delivery of tertiary-treated recycled water, to expand such agricultural exchange beyond the current limitation of 30,000 AFY. Expansion beyond the current limitation, and / or the addition of tertiary-treated recycled water to the agricultural exchange program, would require modification of the 1974 Agreement. The City and FID are not yet working to modify the 1974 Agreement. Neither the TTDF currently under construction, nor the planned recycled water transmission and distribution pipeline network, include elements that are specifically intended to expand the agricultural exchange program beyond the current limitation, or provide for the addition of tertiary-treated recycled water to the program.
2.1.2 Fresno Metropolitan Flood Control District
The Master Plan recommends that Groundwater Replenishment Reuse Projects (GRRPs) be implemented to the extent practical in the southwest, northwest and southeast quadrants of the City.
The Master Plan identifies numerous potential GRRP sites that are generally situated near or adjacent to FMFCD basin sites, since storm water runoff or surface water in the FMFCD system could be used for groundwater recharge on its own, and could also serve as diluent water for the GRRPs if tertiary-treated recycled water is used in the GRRPs. The Master Plan also identifies three tentative locations for regional groundwater recharge areas, or "super-recharge basins".
If development of any of the GRRPs affects FMFCD basins or other facilities, the City would have to enter into related agreements with FMFCD, whether or not the GRRP incorporates the use of tertiary-treated recycled water. The City and FMFCD are not yet working to develop such agreements. Neither the TTDF currently under construction, nor the planned recycled water transmission and distribution pipeline network, include elements that are specifically intended to supply TTRW to potential GRRP sites.
2.2 Rules and Regulations
The City of Fresno Recycled Water Ordinance was adopted July 17, 2014 as Ordinance 2014-32, and it is appended to this report as Appendix A. The Recycled Water Ordinance specifies that the City will establish Recycled Water Rules and Regulations to govern the operation of the City's recycled water system and the use of recycled water, and to implement the policies and requirements of the Recycled Water Ordinance, the California Code of Regulations Titles 17 and 22; and other State and local rules Engineering Report for the Production,
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers and regulations related to the use of recycled water. The Rules and Regulations have been prepared by the City, and they are appended as Appendix B.
The City will ensure that all parties involved in the distribution and use of its recycled water perform their activities in accordance with the Rules and Regulations, which have been developed by the City’s Public Utilities Department (Public Utilities). The following documents support the Rules and Regulations:
x This Engineering Report
x TTDF Engineering Report
x Recycled Water Ordinance
x Recycled Water User Agreements
The Rules and Regulations cover design, construction, operation and maintenance for recycled water distribution systems and use areas, together with control measures to be implemented for use areas.
They include a cross-connection control program, and provisions for inspection by City personnel. The Rules and Regulations are intended to meet or exceed all of the requirements of applicable State statutes and regulations, including but not limited to those compiled in the 25 June 2015 edition of the State Water Resources Control Board "Recycled Water-Related Statutes and Regulations", which was formerly referred to as "The Purple Book".
The Recycled Water Ordinance specifies that the Director of the City of Fresno Department of Public Utilities (Director), and / or City employees to whom such responsibility is delegated by the Director, shall administer, implement, and enforce the provisions of the ordinance. The Director also bears responsibility for enforcement of the Rules and Regulations. As of the date of this report, Thomas C.
Esqueda is the Director of the City of Fresno Department of Public Utilities.
2.3 Producer, Distributor and Users of Recycled Water
2.3.1 Producer and Distributor
The City of Fresno, Department of Public Utilities, Wastewater Management Division, is the lead agency and project sponsor for this project, and is ultimately responsible for the design, construction, operation and maintenance of the recycled water production and distribution facilities. Although the City of Fresno owns and operates the RWRF in partnership with the City of Clovis, the City of Clovis has no ownership in or responsibility for the City of Fresno's planned recycled water production and distribution facilities. The City of Fresno will be the sole producer and distributor of recycled water.
2.3.2 Recycled Water Users
The Master Plan contains recommendations for three different categories of recycled water use opportunities, namely: Urban Reuse Opportunities, Agricultural Reuse and Exchange Opportunities, and Groundwater Reuse Recharge Opportunities.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers As described earlier in this report, the City and FID are not yet working to modify the 1974 Agreement.
Neither the TTDF currently under construction, nor the planned recycled water transmission and distribution pipeline network, include elements that are specifically intended to expand the agricultural exchange program beyond the current limitation, or provide for the addition of TTRW to the program.
With respect to the use of TTRW, agricultural reuse and exchange involving FID is considered a long term opportunity, and it is not currently planned as a Phase 1 recycled water use.
GRRP opportunities are also considered long term recycled water use opportunities, and are not currently planned as a Phase 1 recycled water use.
The urban reuse opportunities recommended by the Master Plan are considered to be both near term and long term recycled water use opportunities, and it is expected that most or all of the Phase 1 recycled water uses will be in the urban reuse category. Urban reuse provides an opportunity to implement recycled water projects that directly offset potable water use and are highly visible to the community. The types of urban recycled water uses recommended in the Master Plan generally include landscape irrigation and industrial uses. Some examples of the types of users for which recycled water landscape irrigation is planned are listed below.
x Parks
x Golf courses and country clubs
x Homeowners association common areas
x Cemeteries
x Airports
x State highway rights-of-way
x Schools and college campuses
x Municipal facilities such as courthouses and city hall x Water feature impoundments such as Lake Van Ness and Woodward Lake x Fairgrounds
Similarly, some examples of industrial uses for which recycled water use is planned are given in the following bulleted list.
x Heating and cooling
x Industrial laundries
x Commercial vehicle washing
x Dust control
x Fire protection
x Sanitary, such as toilet flushing at industrial sites x Process water (except for food processors)
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x Boiler Feed
The Recycled Water Ordinance requires recycled water use under certain circumstances, where recycled water service is available, as summarized in the following paragraphs. a) The City may require all customers who connect to the potable water system to use recycled water for all approved uses, including but not limited to dual plumbing for commercial buildings and single family residential irrigation.
b) Existing commercial properties, existing industrial properties, existing apartments and condominiums, and all homeowners associations are required to use recycled water for landscape irrigation.
c) New commercial projects, new industrial projects, new institutional and governmental projects, and new apartments and condominiums are required to be dual plumbed to provide for internal use of recycled water, and are required to use recycled water for landscape irrigation. d) New single family residential home projects are required to provide for landscape irrigation with recycled water.
All properties within the Recycled Water Project Area (RWPA), as it is defined in the Recycled Water Ordinance, that host land uses for which recycled water use is recommended by the Master Plan, or is required by the Recycled Water Ordinance, are potential recycled water use areas, and the owners or tenants of such properties are potential recycled water users.
The Rules and Regulations require that no recycled water shall be used on any property or use area not owned or controlled by the City unless a non-transferrable User Agreement has been executed between the City and the recycled water user. User Agreements will contain contractually binding terms requiring conformance with the Rules and Regulations and all applicable local, state and federal regulations, including Title 17 and 22 of the California Code of Regulations. Users will be responsible for constructing and maintaining their own on-site recycled water systems for their use area. Appendix C contains a user agreement template that will serve as the foundation for the individual User Agreements for each recycled water user.
The City of Fresno has begun making initial contacts with potential recycled water users to advise them of the forthcoming availability of recycled water, and to begin making necessary arrangements for them to become recycled water users. Initial contacts are being made with potential users sited within onehalf mile of the planned recycled water transmission main system. Figure 2-1 is a highly reduced scale map graphically identifying the target area for initial contacts, and the locations of potential recycled water use areas. A full scale version of the map may be viewed at the URL address provided in the List Of Relevant Internet-Accessible Documents.
The City of Fresno also plans to install recycled water hydrants along the recycled water transmission main system. The recycled water hydrants could be used to provide TTRW for fire suppression activities, and for construction water uses such as dust control and moisture conditioning for soil compaction.
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RECYCLED WATER USER MAP FOR INITIAL CONTACTS
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2.4 Raw Wastewater
The raw wastewater entering the RWRF, for the last 12-month period ending 30 June 2015, has been characterized by the wastewater chemistry shown in Table 2-1, based on an analysis of data provided by the City. The data provided by the City consisted of laboratory analysis results for 24-hour composite samples.
TABLE 2-1
WASTEWATER CHARACTERISTICS
JULY 1 2014 THROUGH JUNE 30 2015
Property Minimum Maximum Median 95th Percentile
Biochemical Oxygen Demand (BOD, mg/l) 219 598 336 450
Total Suspended Solids (TSS, mg/l) 182 546 294 368
Electrical Conductivity (EC, ȝmhos/cm) 778 1369 1051 1236 Ammonia Nitrogen (NH3-N, mg/l) 21 52 32 38
Total Dissolved Solids (TDS, mg/l) 430 964 605 779
Total Volatile Dissolved Solids (TVDS, mg/l) 108 448 192 285 The wastewater entering the RWRF is ordinary municipal wastewater generated within the majority of the wastewater collection system service areas of the Cities of Fresno and Clovis. The City of Fresno reports that wastewater generated by 46 industrial customers in calendar year 2014 accounted for the flow, BOD and TSS proportions, relative to the total flow received at the RWRF, shown in Table 2-2.
TABLE 2-2
INDUSTRIAL CUSTOMER CONTRIBUTIONS
JANUARY 1 2014 THROUGH DECEMBER 31 2014
Property Total RWRF
Industrial
Contribution
Industrial
Percentage
Wastewater Flow (Million Gallons) 21,537 2,946 13.68%
Biochemical Oxygen Demand (BOD, Pounds) 62,489,056 21,655,376 34.65% Total Suspended Solids (TSS, Pounds) 54,152,862 10,378,756 19.17% The City has developed and rigorously implements an Industrial Pretreatment Program, as required by the Clean Water Act of 1977 (PL 95-217). The program sets forth uniform requirements for the discharge of certain industrial wastewater flows into the wastewater collection system and the RWRF, and enables the City as operator of the RWRF to comply with applicable local, state and federal laws relative to industrial wastewaters. The objectives of the program are to:
x Prevent the introduction of pollutants which will interfere with the operation of the RWRF, including interference with the use or disposal of municipal sludge. x Prevent the introduction of pollutants which will pass through into the RWRF treatment facilities or otherwise be incompatible with the treatment facilities. x Improve opportunities to recycle and reclaim wastewater and related sludges. x Provide for equitable distribution of the cost of the Pretreatment Program among users.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers The City of Fresno Industrial Pretreatment Program may be viewed at the URL address provided in the List Of Relevant Internet-Accessible Documents.
2.5 Treatment Processes
2.5.1 Existing RWRF Facilities
The existing RWRF is currently rated for an annual monthly average daily discharge flow of 80 MGD and a maximum monthly average daily discharge flow of 88 MGD. The annual monthly average daily discharge flow is currently reported to be approximately 60 MGD.
Wastewater is received at the RWRF headworks, which includes an influent pump station, bar screens, grit removal tanks, and grit processing equipment. After the preliminary treatment at the headworks, the wastewater is provided with primary treatment by six clarifiers. The primary effluent from these clarifiers is distributed to three secondary treatment trains, referred to as Trains A, B and C. Figure 2-2 provides a schematic illustration of the three RWRF treatment trains.
FIGURE 2-2
EXISTING RWRF TREATMENT TRAINS
Train A is the oldest of the three treatment trains, and it reportedly has several operational and maintenance issues as identified in the TTDF Engineering Report. Train B is the next oldest of the three treatment trains, and it consists of four rectangular aeration basins and eight rectangular secondary clarifiers. Train C is the newest of the three treatments trains. It consists of two rectangular aeration basins and four rectangular secondary clarifiers. The undisinfected secondary effluent from the RWRF Engineering Report for the Production,
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2.5.2 New TTDF Facilities
Primary effluent destined for treatment at the new TTDF will be diverted from Train C at a point immediately upstream of the Train C aeration basins by connection to an existing pipe stub in the primary effluent piping. The primary effluent will be treated by fine screening at a new fine screen facility situated near the point of diversion. Fine screen effluent (FSE) will be conveyed to the TTDF by a gravity flow FSE pipeline that crosses one of the secondary effluent canals (Canal B) in an inverted siphon configuration.
The TTDF will receive and treat the FSE and produce TTRW using membrane bioreactor (MBR) processes. The TTDF will be all new construction, with bioreactors (pre-aeration basins), membrane tanks and a blower building all having common walls to minimize concrete and piping costs. In the course of the treatment process, flow will progress through two parallel bioreactors that provide both anoxic and oxic zones, and then through the membrane cassette facilities in the membrane tanks.
Membrane permeate will be disinfected by an in-pipe ultra-violet (UV) disinfection system to produce TTRW, meeting Title 22 recycled water quality criteria. Train A Aeration Basin No. 4 will be converted to provide covered recycled water storage.
The initial phase of the TTDF will have a constant flow capacity of 5 MGD, but will be laid out so as to provide for future expansion to have an ultimate design capacity of 30 MGD.
The existing 24 inch diameter aeration air line serving Train A Aeration Basin No. 4 will be used and extended to deliver process air to the bioreactors. Electrical power for the TTDF will be supplied from an existing 12 kV electrical building, located east of the Train A secondary clarifiers, through existing and new extended conduits.
Figure 2-3 provides a TTDF schematic site plan, and Figure 2-4 provides a TTDF schematic line diagram, both taken from the TTDF Design Report.
The most significant key elements of manufactured components of the TTDF are the fine screen equipment, the MBR membranes, and the UV disinfection system. The fine screen equipment will be ROTAMAT Rotary Drum Fine Screens RPPS-PRO, Model RPPS-PRO 1600/2, manufacture by Huber Technology. The MBR membrane facilities will be LEAPmbr, incorporating ZeeWeed hollow fiber membranes, manufactured by GE Water & Process Technologies. The UV disinfection systems will be TrojanUVFit Model 72AL75 UV disinfection system, manufactured by Trojan Technologies.
Chemicals that will be routinely used at the TTDF include sodium hypochlorite (12.5% solution) and citric acid (50% solution) for MBR maintenance and recovery cleans. The chemicals will be stored at an outdoor 30' by 20' containment area that consists of a concrete slab with perimeter containment walls 1' 2" high. Sodium hypochlorite will be stored in two 250 gallon totes, and citric acid will be stored in one 250 gallon tote. The totes will be supported on individual steel tote support frames. Chemical Engineering Report for the Production,
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TTDF SCHEMATIC SITE PLAN
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers metering pumps sited within the containment areas will inject the chemicals into the backpulse pumps discharge header for MBR maintenance and recovery cleans. It is estimated that annual chemical consumption will be 4,000 gallons per year for sodium hypochlorite, and 750 gallons per year for citric acid. The TTDF Design Report, Section 16 - Recommended Project Description in particular, provides a description of the TTDF, including a detailed list of major process equipment and planned chemical use.
The TTDF Design Report is included as Appendix D, and may be viewed at the URL address provided in the List Of Relevant Internet-Accessible Documents. TTDF Construction Drawings may also be viewed at the URL address provided in the List Of Relevant Internet-Accessible Documents.
2.5.3 Operation and Maintenance Manuals
Under the provisions of the construction contract for the TTDF, the construction contractor is responsible for obtaining from the various vendors and suppliers and providing the operation and maintenance (O&M) manuals for all of the key elements of the TTDF. The TTDF design engineer, Parsons Corporation (Parsons) will prepare an overall Process O&M Manual for the TTDF, which will incorporate all of the O&M documentation and will be produced in an electronic format that will be accessible and usable online by computer and other electronic devices, such as iPads and similar tablets.
In a separate but related effort, Carollo Engineers (Carollo), under a contract with the City is assembling all of the existing O&M manuals for the RWRF, exclusive of the TTDF. The existing O&M manuals currently exist only in printed hard copy form. Carollo will combine the existing documentation in an electronic format that will provide similar online accessibility as for the Parsons Process O&M Manual for the TTDF. Although the Parsons Process O&M Manual for the TTDF and the Carollo combined O&M manual for the RWRF will be separate electronic documents, they will both be accessible for plant operators via the same secure online portal.
2.6 Plant Reliability Features
The TTDF Design Report, Section 15 - Selected MBR Alternatives Analysis, and Section 16 - Recommended Project Description in particular, provides a description of the key elements of the TTDF process equipment and their reliability features. The following paragraphs provide a summary of process equipment reliability features described in the TTDF Design Report.
FIGURE 2-4
TTDF SCHEMATIC LINE DIAGRAM
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2.6.1 Fine Screens
Fine screens will be in-channel perforated-plate drum screens. Two fine screens will be installed with one of the units as standby, thereby providing a fully redundant standby primary treatment unit process. Each screen would be capable of handling 5 MGD of flow to provide redundancy. The units will be installed in concrete channels equipped with isolation gates to allow for maintenance without interfering with fine screen and TTDF operation. Each fine screen will be equipped with an integrated washer/compactor for cleaning and concentrating the screenings prior to disposal off site.
The fine screens will be provided with alarms to indicate high differential water level (between upstream and downstream surfaces), high upstream water level, motor overload, low oil level, and emergency stop actuated conditions.
2.6.2 Bioreactors (Pre-Aeration Basins)
Two bioreactors will be constructed, each having a flow capacity of 5 MGD to provide system redundancy, thereby providing multiple biological treatment units capable of producing oxidized wastewater with one unit not in operation. Each bioreactor will be divided into several anoxic and oxic zones, with the first quarter of each bioreactor dedicated to the anoxic zone. Baffles would be placed in the bioreactors to separate the anoxic and oxic zones to minimize back-mixing as the flow passes through in a plug flow regime. Additional baffling would be used to divide each anoxic and oxic zone into 3 compartments to minimize back-mixing. The plug flow conditions increase the efficiency of biological treatment, optimizing carbonaceous matter removal, nitrification and denitrification.
Submersible mixers will provide mixing in the anoxic zones. One submersible mixer will be provided in each anoxic zone compartment, for a total of six mixers, with one additional mixer provided as a shelf spare.
2.6.3 Aeration System
Air will be introduced into the oxic zones in the bioreactors through fine bubble diffusers. Aeration will be tapered so that approximately 70% of the oxygen is provided in the first half of the oxic zone to satisfy the high oxygen demand. The required air will be supplied to the oxic zones by the existing RWRF blowers. The blowers are of single-stage centrifugal type and have enough capacity to serve the biological needs of the MBR process as well as the remaining plant. There are five duty blowers with one standby blower. The existing 24 inch diameter air pipeline of RWRF Train A Aeration Basin No. 4 will be used and extended to supply air to the bioreactors, since that basin will be de-commissioned and converted to provide recycled water storage.
2.6.4 Mixed Liquor Return and Sludge Recirculation Pumps Two recirculation lines will be provided in the MBR system, namely the mixed liquor return and sludge recirculation lines. The mixed liquor return system transfers mixed liquor from the tail end of the oxic zone back to the head of the anoxic zone at an adjustable rate up to four times the average flow. This Engineering Report for the Production,
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers system transfers nitrates resulting from nitrification back to the anoxic zone for denitrification as the oxygen molecules associated with nitrates are used by the biomass. The sludge recirculation system transfers sludge from the membrane tanks to the head of the oxic zone, also at an adjustable rate up to four times the average flow. The recirculation system prevents the solids concentration in the membrane tanks from increasing excessively and plugging the membranes, as permeate is removed from the mixed liquor. Excess sludge will be wasted from the MBR system from the sludge recirculation line.
There will be two duty pumps with one shelf spare pump for the mixed liquor return pumps, one duty pump with one standby pump for the sludge recirculation pumps, and one duty pump with one standby pump for the waste activated sludge (WAS) pumps.
2.6.5 MBR Membrane System
The MBR membrane system will consist of four independent MBR tanks, with each tank containing six installed hollow fiber membrane cassettes with spare room for installation of an additional cassette.
The system will be configured to allow isolation of a tank for maintenance and cleaning. Permeate pumps would draw the MBR membrane system effluent through the membranes, directing it to the TTDF disinfection system.
The total membrane surface area for the four tanks is 417,360 square feet, which provides for a treatment capacity of 5.0 MGD for the design flux rate of 12 gallons/square foot/day (GFD), and for the maximum flux rate of 16 GFD when one tank is out of service. The MBR membrane system facilities will include alarms to signal the production of TTDF effluent that does not meet the quality requirements for disinfected TTRW. The MBR membrane system thus provides alarm systems and multiple MBR tank units capable of treating the entire flow with one unit not in operation.
Key mechanical elements of the MBR membrane system include air scouring blowers, permeate pumps, backpulse pumps, and instrument air compressors. There will be two duty blowers and one standby blower for the air scouring blowers. There will be four duty pumps and one shelf spare pump for the permeate pumps. There will be one duty pump and one standby pump for the backpulse pump. And finally, there will one duty air compressor and one standby air compressor for the instrument air compressor.
2.6.6 Disinfection
Membrane permeate will be disinfected by an in-pipe ultra-violet (UV) disinfection system to produce TTRW, meeting Title 22 recycled water quality criteria. The UV disinfection systems will be TrojanUVFit Model 72AL75 UV disinfection system, manufactured by Trojan Technologies. There will be four reactor trains, with each train having two reactors. Three of the UV disinfection trains will be in service at any given time, with the fourth train being on standby. Each reactor will have a flow treatment capacity of
1.0 MGD, providing an in-service total treatment capacity of 6.0 MGD for the design flow of 5.0 MGD.
The standby train with its two standby reactors will provide 2.0 MGD of standby capacity. The UV Engineering Report for the Production,
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers disinfection system provides multiple UV disinfection units capable of treating the entire flow with one unit out of service, and also provides two standby units.
2.6.7 Alarm Provisions
The TTDF will include a new Supervisory Control and Data Acquisition (SCADA) system with an Operator Interface Station (OIS) in the Control Building. The TTDF will also include many alarm systems that will communicate with facility operators via the SCADA OIS. The OIS will include alarm management screens to display process and control system alarms.
The contents of the alarm management screen will be arranged in a tabular fashion, and entries in the alarm table will be color coded following the same color conventions as used in the existing RWRF SCADA system. The following information, as applicable, will be conveyed in the alarm table: date and time of the alarm, database point designation, type of alarm, value, PLC number and alarm description.
The alarm management screen will provide a means for acknowledging alarms either individually or by page or globally.
If audible alarms are enabled at the intended site, a means will be provided for silencing audible alarms which is at all times accessible or visible to the operator. At physical locations where there is more than one OIS, the operator will not be required to silence the alarm on more than one OIS.
Alarms are categorized by four types listed in order of priority from highest to lowest. a) Major alarm is the highest priority. A major alarm is caused by an abnormal process or equipment condition. A condition which is potentially dangerous to personnel or equipment or violates public health regulatory limits is classified as a major alarm. A major alarm is usually characterized as being a High-High alarm, hardwired alarm, or remote safety shutdown alarm. b) Minor alarm is the next highest priority. A minor alarm is caused by an abnormal process or equipment condition. A condition which is not considered mission critical is classified as a minor alarm. A minor alarm may be a precursor to a major alarm. c) Event alarm is the next to lowest priority. An event alarm is generated by operator action such as changing the control mode.
d) Informational alarm is the lowest priority. An informational alarm provides a means of conveying important process information to the operator. Informational alarms usually take the form of messages.
Table 2-3 provides a very brief summary of alarms that will be provided for key elements of the TTDF process equipment. It is based on information contained in Section 13370 – Programmable Controllers and Panel Instruments in the TTDF Construction Specifications.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers TABLE 2-3
ALARM PROVISIONS FOR SELECTED KEY ELEMENTS
OF THE TTDF PROCESS EQUIPMENT
Process Equipment Item Alarm Description
Fine Screens Common Alarm
Fine Screens High Differential Level
Fine Screens High Upstream Level
Fine Screens Emergency Stop Actuated
Fine Screens Grease Pump No. 1 Reservoir Low Level
Aeration Basins RAS Influent Valve Fail
Aeration Basins Influent Channel Agitation Air Valve Fail Aeration Basins ML Channel Agitation Air Valve Fail
Aeration Basins Anoxic Mixer Fail
Aeration Basins Anoxic Mixer High Winding Temperature
Aeration Basins Anoxic Mixer Seal Leak
Aeration Basins Oxic Zone Aeration Valve Fail
Aeration Basins Mixed Liquor Pump Fail
Membrane Basins Agitation Air Valve Fail
Membrane Basins Membrane Basin Low Level
Membrane Basins Membrane Basin Low-Low Level
Membrane Basins Infeed Slide Gate Fail
Membrane Pump Gallery Permeate Pump Fail
Membrane Pump Gallery Permeate Pump High Winding Temperature Membrane Pump Gallery Backpulse Pump Fail
Membrane Pump Gallery Backpulse Pump High Winding Temperature Membrane Pump Gallery Backpulse Pumps High Discharge Pressure Membrane Pump Gallery Sump Pump Common Alarm
Membrane Pump Gallery Sump Pump Seal Leak
Membrane Pump Gallery Sump High-High Level
Membrane Pump Gallery Floor High Level
Permeate Collector Permeate Collector Low Level
Permeate Collector Permeate Collector Low-Low Level
Permeate Collector Permeate Collector High Turbidity
RAS Pump Station RAS Pump Fail
RAS Pump Station RAS Pump High Winding Temperature
RAS Pump Station RAS Pump High Discharge Pressure
RAS Pump Station RAS Pump Station Low-Low Level
WAS Pump Station WAS Pump Fail
WAS Pump Station WAS Pump High Winding Temperature
WAS Pump Station WAS Pump Seal Leak
WAS Pump Station WAS Pump Station Low-Low Level
UV Train Discharge Valve Fail
UV Reactor High Water Temperature
UV Reactor Low UV Intensity
UV Reactor Ground Fault
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers TABLE 2-3
ALARM PROVISIONS FOR SELECTED KEY ELEMENTS
OF THE TTDF PROCESS EQUIPMENT
Process Equipment Item Alarm Description
UV Reactor Low Priority Alarm
UV Reactor High Priority Alarm
UV Reactor Critical Instrument Failure
UV Reactor UV Dose Failure
Drain Pump Station Drain Pump Fail
Drain Pump Station Drain Pump High Winding Temperature
Drain Pump Station Drain Pump Seal Leak
Drain Pump Station Drain Pump Station Low Level
Drain Pump Station Drain Pump Station High Level
Valve Vault Valve Vault Sump Pump Common Alarm
Valve Vault Valve Vault Sump High-High Level
2.6.8 Facility Hours and Staffing
As for the existing RWRF facilities, the TTDF facilities will be staffed around the clock, 24 hours every day, by certified plant operators. All alarm indicators will be received by plant operators in the facility Control Building via the SCADA system and its OIS interfaces. The Control Building is continuously staffed by RWRF personnel.
2.6.9 Electrical Power Supply
The primary source of electrical power supply for the RWRF, provided by Pacific Gas & Electric Company (PGE) is one 70 KV high voltage power line supplying power via one City-owned 10 MVA power transformer with a secondary voltage of 12 KV. The secondary side of the transformer is connected to two main circuit breakers for the main 12 KV service switchgear, which is equipped with a normally open tie circuit breaker. This switchgear is rated at 12 KV, 2000A, 500 MVA short circuit capacity with Bus “A” and Bus “B” separated by the normally open tie circuit breaker.
A backup source of electrical power supply from PGE exists in the form of a 12 KV line that provides a capacity of 5 MVA for emergency use. This backup line originates at a different PGE substation than the primary source line, and it is considered highly unlikely that both sources would be out of service at the same time. This backup line is tied to the main 12KV service switchgear through a normally open circuit breaker with a "Kirk Key" trapped key interlock, operated manually.
The RWRF also has three backup generators, one of which is a propane fired system that generates 25 KW. The other two backup generators are diesel fired systems that produce 350 KW and 1600 KW, respectively. The total power generation capacity of these three backup generators is thus 1975 KW, or 1975 KVA. Combined with the backup PGE line, this results in a total backup power supply capacity of 6975 KVA.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers The RWRF also has a natural gas fired turbine generator that can produce up to 9.25 MW, equivalent to 9250 KVA. This generator system is not currently configured to provide power to the overall RWRF electrical system, and so it is not available as a near-term backup source of electrical power for the RWRF and the TTDF. However, the City is working to implement the necessary improvements to allow this generator to serve as a backup source of electrical power.
The City reports that the RWRF summer peak electrical power demand is approximately 6500 KVA, and that the estimated peak power demand for the TTDF is approximately 1250 KVA, for a combined total of 7750 KVA. It is evident that the primary power supply provides sufficient capacity for the anticipated combined demand of the RWRF and the TTDF. However, until the natural gas fired turbine generator can be configured to serve as a general service backup generator, the backup power supply capacity of 6975 KVA does not provide sufficient electrical power for the combined demands of the RWRF and the TTDF. The City reports that until such time as the natural gas fired turbine generator can be configured to serve as a general service backup generator, plant operators will shut down non-essential electrical loads facility-wide if necessary for temporary operation under emergency backup power supply conditions.
2.7 Supplemental Water Supply
The City will operate the TTDF and manage its recycled water users such that the recycled water supply can meet recycled water demand at all times. However, if the TTDF becomes unable to produce sufficient recycled water on a short-term basis to meet recycled water demand, supplemental water may be required to meet the recycled water user needs.
Supplemental water could be provided by the following sources. 1) Stored Recycled Water. The covered recycled water storage basin, a converted RWRF Train A aeration basin, will provide 2.7 million gallons of recycled water storage, or approximately 54% of one day's recycled water production capacity of the TTDF. Stored recycled water may be used to provide continued recycled water service for limited periods in the event of a short-term emergency situation resulting in TTDF inability to produce TTRW. 2) Raw Water. Raw water consists of untreated surface water provided by FID. Raw water would not be introduced into and conveyed by the recycled water distribution system, but would be delivered by other conveyance systems, generally the FID pipeline and canal system and private irrigation water pipelines. Thus, utility of this source of supplemental water would be limited to those users who have access to such other systems, and would be subject to supply availability. 3) Potable Water Distribution System. The City's potable water distribution system could serve as a temporary source of supplemental water for recycled water users. This would require an approved temporary disconnection from the City's recycled water distribution system, followed by the establishment of an approved temporary connection to the City's potable water distribution system.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers 4) Private Wells. Some recycled water users will have onsite private wells that have been or are being used for irrigation water supply and/or potable water supply, and could be relied on as a temporary source of supplemental water. As for potable water, the use of this supplemental source would require an approved temporary disconnection from the City's recycled water distribution system, followed by the establishment of an approved temporary connection to the private well system.
5) Reclamation Wells. In the future, the City hopes to be able to use groundwater produced from aquifers beneath the RWRF percolation ponds, disinfected if necessary, as a supplemental water source for the recycled water system. The City estimates that it will be at least two years from the date of this report before the use of this groundwater as a supplemental water supply could be implemented Water quality testing to verify suitability of the groundwater would be done prior to approval of such use, and necessary infrastructure would have to be constructed.
The only supplemental water source of those listed above that has potentially lower general quality than the recycled water itself is the raw (untreated) surface water. In cases where raw water is used as a supplemental source, the City will confirm with the affected users that the raw water quality is adequate for their particular application, which is ordinarily expected to be the case.
Since most recycled water users will have formerly relied on raw water, potable water, or private wells for the same uses for which recycled water is subsequently used, it is expected that the supply and delivery infrastructure for those supplemental water supply sources would generally be adequate for those same uses on a temporary basis.
Cross-connection of any recycled water distribution system, whether the City's recycled water distribution system or any individual user's on-site recycled water system, with any potable water distribution system is prohibited, even as a supplemental water source in the event of a shutdown or failure at the TTDF. The Rules and Regulations contain specific requirements for disconnecting on-site recycled water systems from the recycled water distribution system before making a temporary connection to a potable water distribution system.
2.8 Monitoring and Reporting
The Waste Discharge Requirements (WDRs) for the RWRF include a Monitoring and Reporting Program (MRP) that specifies required monitoring and reporting for RWRF operations. Primary effluent destined for treatment at the new TTDF will be diverted from RWRF Train C at a point immediately upstream of the Train C aeration basins by connection to an existing pipe stub in the primary effluent piping. The diversion point is downstream of the RWRF headworks, and therefore downstream of the influent composite sampling location designated in the WDRs. Influent monitoring and reporting for the TTDF will therefore be done as an integral part of the influent monitoring and reporting done for the RWRF under the provisions of the MRP.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers Monitoring and reporting for disinfected TTRW produced by the TTDF will also be done as specified in the MRP for effluent discharge monitoring. This will involve the introduction of a new effluent composite sampling location at the TTDF discharge, in addition to those currently designated in the WDRs. The new sampling location must be established with concurrence of CRWQCB staff, and a description of the new sampling location must be submitted to the Board and attached to the WDRs.
In addition to the effluent discharge monitoring and reporting required by the WDRs, disinfected TTRW will also be tested for total coliform bacteria and turbidity, as required by Title 22 CCR Section 60321.
The disinfected TTRW will be sampled at least once daily for total coliform bacteria. The samples will be taken from the disinfected TTRW at the new designated effluent composite sampling location, and will be analyzed by the RWRF laboratory.
Disinfected TTRW will also be continuously sampled for turbidity using a continuous turbidity meter and recorder at the new effluent composite sampling location. In the event of failure of the continuous turbidity meter and recorder, grab samples taken at the same location at a minimum frequency of 1.2- hours may be substituted for a period of up to 24-hours.
All monitoring results will be reported as specified in the WDRs, including the additional total coliform bacteria and turbidity monitoring for the TTDF.
2.9 Contingency Plan
For the purposes of this report, "off-spec effluent" is TTDF effluent that does not meet the quality requirements for disinfected TTRW, or partially treated or untreated wastewater that somehow passes through the TTDF. In the event of any circumstance that could result, or does result, in the discharge of off-spec effluent from the TTDF, effluent pumping from the TTDF permeate pumps to the covered recycled water storage basin would be halted, so as to preserve the quality of stored TTRW so that it may be used to provide continued recycled water service while the cause of the problem is investigated and remedied.
In the event that off-spec effluent is delivered into the covered recycled water storage basin, pumping from the recycled water pump station would be halted, so as to prevent the introduction of off-spec effluent into the recycled water distribution system. Provided that the off-spec effluent in storage is of an equivalent or higher quality than the undisinfected secondary effluent produced by the RWRF, the off-spec effluent would be pumped or allowed to overflow via the overflow pipeline to Canal B, which is part of the canal system that delivers undisinfected secondary effluent from the RWRF treatment facilities to the percolation basins. The TTDF facilities will include a dedicated pipeline for pumped conveyance of off-spec effluent under such conditions.
If off-spec effluent in the covered recycled water storage basin is not of an equivalent or higher quality than the undisinfected secondary effluent produced by the RWRF, the off-spec effluent would be pumped from the storage basin via temporary pipelines and returned to the primary effluent stream of Engineering Report for the Production,
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers RWRF Train C. The recycled water storage basin would be flushed clean and disinfected prior to returning the basin to normal recycled water storage duty.
Since the supply of primary effluent for treatment by the TTDF is a diversion from the primary effluent stream of RWRF Train C, the supply can be stopped by simply stopping the diversion. This can be done by operation of a pneumatically operated valve located in a valve vault adjacent to the fine screens.
When the diversion is stopped, the primary effluent that would otherwise be diverted to and treated by the TTDF is instead retained and treated in RWRF Train C.
3.0 TRANSMISSION AND DISTRIBUTION SYSTEMS
Chapter 1 of this report provides a brief description of the Master Plan, and its recommendations for recycled water production, transmission and distribution facilities that are now in the early stages of implementation. Figure 1-2 provides an overview of the planned distribution system, taken from the Master Plan. The initial phase of implementation of the planned distribution system includes the design and construction of certain elements of the recycled water transmission mains referred to as the Southwest Quadrant, together with a related recycled water booster pump station. Figure 3-1 shows the Southwest Quadrant recycled water transmission main and booster pump station projects.
The City is expected to soon award a construction contract for the Southwest Quadrant Project SW1A, and is currently soliciting bid proposals for the construction of Project SW1B. The construction plans for Projects SW1A and SW1B may be viewed at the URL addresses provided in the List Of Relevant InternetAccessible Documents.
Projects SW1C, SW1D, SW4, and SWPS1 are currently under engineering design, at various levels of design completion. The City reportedly is planning to soon issue a Request for Qualifications for engineering design of the Northwest Quadrant and Northeast Quadrant recycled water transmission mains.
The hydraulic design for the recycled water transmission main system is based on a minimum operating pressure of 40 PSI, and a maximum pressure variation between low operating pressure and high operating pressure of 20 PSI.
Pipe materials for the recycled water transmission mains will be cement mortar lined and coated steel pipe (CMLCSP) or cement mortar lined and tape coated steel pipe with a mortar rock shield (CMLTCSP) for pipes 24 inches and larger in diameter. Pipes smaller than 24 inches in diameter will be poly-vinyl chloride pipe (PVC) or ductile iron pipe (DIP).
The City of Fresno has developed and adopted Standard Specifications and Standard Drawings for recycled water facilities. The Standard Specifications include construction specifications as well as design criteria. The Standard Specifications and Standard Drawings are appended to this report as Appendix E. The Standard Specifications and Standard Drawings apply to all construction of recycled water facilities within the City of Fresno.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers With respect to pipe materials, the Standard Specifications and Standard Drawings currently include provisions for PVC and DIP pipe materials. The City of Fresno is also in the process of developing additional standard specification and standard drawing content to include the CMLCSP and CMLTCSP pipe materials, which is expected to be added to the Standard Specifications and Standard Drawings after it is adopted by the City.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers FIGURE 3-1
SOUTHWEST QUADRANT RECYCLED WATER TRANSMISSION MAIN PROJECTS Engineering Report for the Production,
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4.0 RECYCLED WATER USE AREAS
Subchapter 2.3 of this report provides a brief discussion of planned and/or required recycled water uses, restated in part here for the reader's ease of reference. All properties within the Recycled Water Project Area (RWPA), as it is defined in the Recycled Water Ordinance, that host land uses for which recycled water use is recommended by the Master Plan, or is required by the Recycled Water Ordinance, are potential recycled water use areas, and the owners or tenants of such properties are potential recycled water users.
The Rules and Regulations require that no recycled water shall be used on any property or use area not owned or controlled by the City unless a non-transferrable User Agreement has been executed between the City and the recycled water user. User Agreements will contain contractually binding terms requiring conformance with the Rules and Regulations and all applicable local, state and federal regulations, including Title 17 and 22 of the California Code of Regulations. Users will be responsible for constructing and maintaining their own on-site recycled water systems for their use area. Appendix C contains a user agreement template that will serve as the foundation for the individual User Agreements for each recycled water user.
The City of Fresno has begun making initial contacts with potential recycled water users to advise them of the forthcoming availability of recycled water, and to begin making necessary arrangements for them to become recycled water users. Initial contacts are being made with potential users sited within onehalf mile of the planned recycled water transmission main system. Figure 2-1 is a highly reduced scale map graphically identifying the target area for initial contacts, and the locations of potential recycled water use areas. A full scale version of the map may be viewed at the URL address provided in the List Of Relevant Internet-Accessible Documents.
The City is in the process of retaining a recycled water use area consultant (RWUA Consultant) that will work with potential recycled water users and the City to set up recycled water use areas in conformance with the Recycled Water Ordinance, the Rules and Regulations, the Recycled Water User Agreement, and all applicable local, state and federal regulations. The City will pay the cost of the RWUA Consultant.
The recycled water user will be responsible for implementing all onsite improvements, beyond the point of connection to the City's recycled water service, that may be necessary to retrofit or equip the use area for recycled water use. The recycled water user will also be responsible for elimination of any cross connections discovered in the course of the cross connection control survey.
Each recycled water user must designate a Recycled Water Site Supervisor to be responsible for the onsite recycled water system at each use area under their control. The Recycled Water Site Supervisor is required to be responsible for proper installation, operation, and maintenance of the recycled water system, compliance with the Rules and Regulations, prevention of potential hazards, and preservation of the onsite recycled water system plans in “as built” form. Additional specific responsibilities of the Recycled Water Site Supervisor are provided in the Rules and Regulations.
Upon completion of the RWTM facilities that will deliver TTRW to the Roeding Park area, the City plans to implement recycled water use at Roeding Park, including Chaffee Zoo and Rotary Storyland and Engineering Report for the Production,
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers Playland, as the first of the City's own recycled water use areas. A feasibility study has been conducted, and the City is currently making arrangements to retain an engineering and landscape architecture consultant for the design of improvements necessary to retrofit or equip the use area for recycled water use.
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215138_rpt01.docx Blair, Church & Flynn Consulting Engineers
APPENDIX A
RECYCLED WATER ORDINANCE
Engineering Report for the Production,
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APPENDIX B
RULES AND REGULATIONS
Rules and Regulations of
Wastewater Management Division
5607 W. Jensen Ave
Fresno, CA 93706
Recycled Water Use
Rules and Regulations of Recycled Water Use 1
Contents
1. Introduction .......................................... 2
2. Definitions ............................................ 5
3. General City Responsibilities ............... 8
4. General Customer Responsibilities ...... 8
5. Site Supervisor Responsibilities ........... 9
6. Facility Requirements ........................ 11
7. On-Site Recycled Water Systems ...... 13
8. Department of Transportation ............ 14
9. Recycled Water Fill Stations .............. 14
10. Cross Connection .............................. 14
11. Backflow Prevention .......................... 16
12. Obtaining Recycled Water Service .... 16
13. Service Termination ........................... 18
APPENDIX A – Use Area Monitoring Report ....... 22
APPENDIX B – Cross Connection Procedure ..... 26
APPENDIX C – Fill Station Application Form....... 30
............................................................................ 30 Rules and Regulations of Recycled Water Use 2
1. Introduction
The City of Fresno owns and operates a Recycled Water Distribution System (Distribution System) providing Recycled Water for approved uses to Recycled Water Customers (Customer) within the Recycled Water Project Area. This document contains the City of Fresno’s Rules and Regulations governing the design, construction and use of Recycled Water (Rules and Regulations). These Rules and Regulations aim to provide Customers with necessary information to comply with relevant codes, laws, statutes and regulations concerning the use of Recycled Water.
1.1. Authority and Sources
The Rules and Regulations are prepared and administered by the Department of Public Utilities Wastewater Management Division, and may be updated from time to time. The Rules and Regulations apply to all Customers and distributors of Recycled Water and shall govern the design, construction and use of both the Distribution System operated by the City and On-Site Recycled Water Systems operated by Customers. Since codes, laws, statutes and regulations can change without prior approval or knowledge, the City of Fresno does not assume any liability for errors in this document. It is the responsibility of the Customer to check with the City of Fresno before initiating any changes to their On-Site Recycled Water System. It is the intent of these Rules and Regulations to be consistent with the following criteria:
(a) California Code of Regulations, Title 22, Division 4, Chapter 3 (Water Recycling Criteria).
(b) California Code of Regulations, Title 17, Division 1, Chapter 5 Group 4, Article 1and 2 (General and Protection of Water System).
(c) The State Water Resources Control Board (SWRCB) and its Division of Drinking Water (DDW) Guidelines for Use of Recycled Water, and Guidelines for Use of Recycled Water for Construction Purposes.
(d) American Water Works Association (AWWA) California/Nevada section, Guidelines for the Distribution of Non-Potable Water and Guidelines for Retrofitting to Recycled Water or alternate measures that are acceptable to the DDW.
(e) Applicable regulations by the Regional Water Quality Control Board (RWQCB). (f) City of Fresno Municipal Code, Chapter 6, Article 3, Sewage and Water Disposal and Article 9, Recycled Water Ordinance.
Interested parties may contact the Wastewater Management Division for copies of documents referenced in these Rules and Regulations.
1.2. Scope and Severability
If any section, subsection, clause or phrase of these Rules and Regulations is determined to be invalid, the remaining portions of these Rules and Regulations shall remain in effect. If there is any conflict between the provisions of these Rules and Regulations and the provisions of any of the referenced documents, the most stringent guidelines will control.
Rules and Regulations of Recycled Water Use 3
1.3 Planning for Recycled Water Use
The Rules and Regulations outlined in this document provide Recycled Water Customers with information for design, installation, operation and maintenance of an OnSite Recycled Water System. This section provides general information about the City of Fresno’s Recycled Water program.
Eligibility to Use Recycled Water.
(a) The Department of Public Utilities shall review the Recycled Water Master Plan and make a preliminary determination whether the current or proposed use of the property requires service with Recycled Water, or facilities designed to accommodate the use of Recycled Water in the future. This determination is based in part on the property’s location within the existing or proposed Recycled Water Project Area.1
(b) The City of Fresno’s Recycled Water Ordinance requires all new construction, existing and future commercial/ industrial facilities to use Recycled Water for landscape irrigation, if available in the Recycled Water Project Area. (c) Existing sites using Potable Water for irrigation may convert to Recycled Water with approval of the City.
(d) All Recycled Water systems shall be metered separately from the Potable Water supply and must have no Cross Connection to the Potable Water supply.
1.4. Protection of Public Health and the Environment
The use of Recycled Water shall not result in contamination or pollution of any surface water body nor create a hazard that is injurious to public health. The City of Fresno, Fresno County Department of Health, and the DDW may take measures to ensure that a Customer’s On-Site Recycled Water System adequately protects public health and the environment. Conditions which may lead to unacceptable public health and environmental hazards include, but are not limited, to:
(a) Cross connections with the potable system or any other water system; (b) Improper tagging, marking or signage;
(c) Unapproved uses of Recycled Water; and
(d) Recycled Water runoff to a surface water body.
1.5. Approved Uses of Recycled Water
Tertiary disinfected Recycled Water may be used for landscape and agricultural irrigation, impoundments, commercial laundries, cooling towers and other Approved Uses as identified in Title 22, Division 4, Chapter 3, Article 3 Recycled Water Criteria.
Moreover, statutes delineating permissible uses of Recycled Water at locations such as 1 Fresno Municipal Code, Chapter 6, Article 9, Section 6-908 Rules and Regulations of Recycled Water Use 4
cemeteries and car washes are identified in the Health and Safety Code, Division 8, Part 1, Chapter 4.5 and the Water Code Division 6, Part 2.12 § 10950 – § 10953, respectively.
1.6. Violation of Rules and Regulations
The City may terminate Recycled Water service to a Customer who uses, transports, or stores Recycled Water in violation of these Rules and Regulations. No Customer will create or threaten to create conditions of pollution, contamination, and nuisance or violate discharge requirements prescribed by the RWQCB. Enforcement actions may be initiated against any Customer resulting in potential termination of Recycled Water service. In addition, no person at any time shall tamper with City property except to shut off water to protect public health or prevent damage to property or the environment. Only authorized City personnel may operate City facilities.
The City shall investigate all reports of non-compliance with any provision of these Rules and Regulations and/or the User Agreement to determine the validity and seriousness of the violation. Determinations regarding the seriousness will be based upon the violation’s magnitude and duration; effect on public health, the environment, City property or assets, or the operation of the Distribution System; effect on the City’s compliance with the Rules and Regulations of the regulatory agencies with which it must in turn comply; and the history and good faith of the Customer.
1.7. Notice of Violation
.
Unless the violation is an emergency, as determined by the City, the Customer will receive a written notice of violation describing:
(a) The nature of the violation;
(b) Requirements for submittal of a corrective action plan; (c) A reasonable time limit for the satisfactory mitigation of the violation; and (d) A date for a follow-up inspection.
The Customer may file a notice of appeal within 15 calendar days after notice of violation is received, following the guidelines for filing a notice of appeal and the City shall implement duty of enforcement procedures as defined in Fresno Municipal Code, Chapter 1, Article 4.
For emergencies that result in cross connection of recycled water with potable water, refer to Part 10. Cross Connection, Section 10.3 Emergency Preparedness and Section
10.4 Emergency Cross Connection Procedures.
1.8. User Agreements
Recycled Water shall not be delivered, used, or discharged upon any property or Use Area not owned or controlled by the City unless a non-transferrable User Agreement has been executed between the City and Customer permitting the Customer to receive Recycled Water service.
The site-specific User Agreement will identify the Recycled Water’s Use Area, an estimate of the quantity (including seasonal schedule) of Recycled Water to be used, and permitted uses of Recycled Water. User Agreements delineate contractually binding terms associated with these Rules and Regulations. Once executed, the User Rules and Regulations of Recycled Water Use 5
Agreement permits use of Recycled Water in accordance with the terms of the User Agreement, these Rules and Regulations, and all applicable local, State and federal regulations, including Title 17 and 22 of the California Code of Regulations, as may be amended from time to time. If an On-Site Recycled Water System is found to be in violation of a City of Fresno Ordinance, the corresponding User Agreement and/or these Rules and Regulations, the City shall implement provisions of Section 1.7. of these Rules and Regulations.
1.8.1. User Agreement Renewal
Upon expiration of the existing User Agreement, customer shall enter into a new agreement for continuation of recycled water services. The new agreement may have additional regulatory requirements, costs, or rates not specified on the original agreement. In the case of change of property ownership and if the new owner desires to continue the recycled water service, a new Recycled Water User Agreement with the new owner will be processed reflecting changes in regulatory requirements, costs or rates not previously specified, if any.
1.9. Conditions Precluding Delivery of Recycled Water
The City has sole discretion and flexibility in scheduling, distributing and prioritizing Recycled Water deliveries, particularly under conditions of insufficient recycled water supply, maintenance of City’s treatment or distribution systems, acts of a third party, or order of a Regulatory Agency.
2. Definitions
Whenever the following terms (or pronouns are used in their place) occur in these Rules and Regulations, they will be identified with capitalized initials and their meaning shall be interpreted as follows:
“Air Gap” is a physical separation from the free-flowing discharge end of a water supply pipeline and an open or non-pressure receiving vessel. It is generally regarded as the most protective method of backflow prevention. An approved air gap must be at least twice the diameter of the water supply pipeline, measured vertically from the flood rim of the Customer’s receiving vessel to the supply pipe from the service connection. In no case shall the air-gap separation be less than one inch. “Applicant” is a potential user requesting Recycled Water services from the City. “Approved Uses” means uses defined by California Code of Regulations, Title 22, Division 4 Environmental Health, Chapter 3 Water Recycling Criteria, Article 3 Uses of Recycled Water.
“As-Built” means engineering drawings that depict completed facilities, as constructed or modified.
“Backflow” is a condition that results in the flow of water, mixtures or substances into a potable water system from a source other than an approved water supply. “City” means City of Fresno, California.
“Contamination” means an impairment of the City’s potable water quality resulting from the introduction of sewage, industrial fluids, waste liquids, compounds or other materials Rules and Regulations of Recycled Water Use 6
to a degree which creates an actual hazard to public health through poisoning or spread of disease.
“Cross Connection” is the unprotected and/or unapproved actual or potential connection between a potable and non-potable water supply. By-pass arrangements, jumper connections, removable sections, swivel or changeover devices through which backflow could occur, shall be considered to be Cross Connections. “Cross Connection Control Specialist” is an individual trained in cross-connection control, establishment of a procedure or system for testing backflow preventers, and maintenance of records of locations, tests, and repairs of backflow preventers. “Customer”, “Consumer” or “User” means a person or entity who is the contracted recipient of Recycled Water services owned and operated by the City of Fresno.
Division of Drinking Water (“DDW”) is a division of the State Water Resources Control Board, formerly California Department of Public Health (CDPH). “Dual Plumbing” means a system that utilizes separate piping systems for Recycled Water and potable water within a facility and where the Recycled Water is used for either of the following: (a) to serve plumbing outlets (excluding fire suppression systems) within buildings or (b) outdoor landscaping irrigation at individual residences. “Easement” means a recorded document in which the land owner gives the City permanent rights to construct and maintain Recycled Water mains and/or facilities across private property.
“Impoundment” is a lined structure or a body of water with a lined structure containing Recycled Water, which is used for aesthetic, recreational or irrigation purposes. “On-Site Recycled Water System” means facilities under the control of the property owner, extending from the Recycled Water service connection to the Use Area being serviced with Recycled Water. This includes any on-site distribution plumbing, irrigation systems, industrial processes, impoundments or other approved facilities. “Overspray” means the spray of Recycled Water outside the irrigation area. “Pantone” A color standard system referenced in the American Water Works Association California-Nevada Section Guidelines for Distribution of non-potable water. “Ponding” means the unauthorized retention of Recycled Water in a Use Area for a period following the cessation of approved Recycled Water use activity. “Potable Water” means water which meets the federal, state and local standards for human consumption and is approved for human consumption. “Record Drawings” are the Customer’s plans and specifications for the proposed Use Area required by the City’s application for Recycled Water Service. “Recycled Water” means non-potable tertiary disinfected water, which as a result of treatment of wastewater is suitable for a direct beneficial use or controlled use that would otherwise not occur, and is therefore considered a valuable resource.
Rules and Regulations of Recycled Water Use 7
“Recycled Water Distribution System” means Recycled Water pipelines, transmission mains, pump stations, storage reservoirs, and appurtenances acquired, constructed and owned by the City and used for the conveyance of Recycled Water between the wastewater treatment plant and the Recycled Water service connections. “Recycled Water Project Area” means those geographical areas identified in the City’s Recycled Water Master Plan where the City expects Recycled Water service to be available. Customers within the Recycled Water Project Area are eligible for Recycled Water service for approved uses when it becomes available. “Recycled Water Service Connection” means the point of connection (POC) of the Customer’s Recycled Water line with the Recycled Water service line of the City, which shall normally be the downstream end of the Recycled Water meter tailpiece. “Recycled Water Site Supervisor” or “Site Supervisor” is the Customer’s liaison with the City regarding Recycled Water matters. This person must have the authority to enforce these Rules and Regulations, be responsible for the operation and maintenance of the On-Site Recycled Water System, must prevent potential violations and submit a Use Area Monitoring Report.
“Reduced Pressure Principle Backflow Prevention Device” is a type of backflow prevention device, usually installed near a water meter, which prevents backflow by a combination of two check valves, an automatically operated differential relief valve between the two check valves and a tightly closing shut-off valve on each side of the check valve assembly.
“Regulatory Agency” refers to those public agencies legally constituted to protect public health and water quality, and whose rules govern the use of Recycled Water, such as DDW, RWQCB and the Fresno County Department of Public Health. “Rules and Regulations” means the Rules and Regulations for Recycled Water use, distribution and transport within the City of Fresno.
“Runoff” means Recycled Water that drains outside the approved Use Area. “RWQCB” means Regional Water Quality Control Board, a subdivision of the State Water Resources Control Board.
“RWRF”, Fresno-Clovis Regional Wastewater Reclamation Facility. “SWRCB”, State Water Resources Control Board
“Use Area” means an area of Recycled Water use with defined boundaries. A Use Area may contain one or more facilities.
“Water Recycling Criteria” - the State of California’s set of requirements for the implementation of Recycled Water programs as detailed in the California Code of Regulations, Title 22, Division 4, Chapter 3.
Rules and Regulations of Recycled Water Use 8
3. General City Responsibilities
The City shall be responsible for all aspects of the treatment, distribution system and quality of Recycled Water. City responsibilities shall include:
(a) Observe and permit installation, connection, and disconnection of Recycled Water service, including, piping, valves and other appurtenances required to connect the City’s Recycled Water Distribution System to an On-Site Recycled Water System. The service includes a Recycled Water Meter(s) to measure Recycled Water consumption at the Use Area.
(b) ). Ensure users follow the City of Fresno Public Works Standard Specifications, Section 33, Recycled Water Facilities Design Criteria and Section 34, Recycled Water Facilities. 2
(c) Manage and supervise remergency and non-emergency conversions from a Recycled Water supply at a Use Area back to a Potable Water system and viceversa. This can happen if delivery of recycled water is precluded for reasons beyond the reasonable control of the City including, but not limited to insufficient recycled water supply, maintenance of City’s treatment or distribution systems, acts of a third party, or an order from a Regulatory Agency.. (d) Conduct the initial and final inspections of the Use Area as part of the Customer’s process for utilizing recycled water.
(e) Monitor the Customer’s Recycled Water management practices. (f) Collect fees from Customers Recycled Water use and related services, as designated in the Master Fee Schedule, when such fees are developed. (g) Agents of the City, RWQCB, or DDW may enter and inspect the Use Area during reasonable hours, upon providing credentials and with 24 hours advance notice or such notice as required by law, for the purposes of verifying that Customer is complying with these Rules and Regulations and to protect public health and the environment.
(h) The City shall not be responsible for abatement of Cross Connections within a Customer’s premises.
4. General Customer Responsibilities
Recycled Water Customers must comply with and enforce all aspects of these Rules and Regulations upon accepting Recycled Water service and finalizing the User Agreement. Customer responsibilities include but are not limited to the following:
2 City of Fresno Public Works Standard Specifications, Addendum No. 4, Resolution No.70-36, Sections 33. Updated version approved January 2013.
Rules and Regulations of Recycled Water Use 9
(a) Understanding that all Approved Uses of Recycled Water for the permitted Use Area are exclusively for non-potable uses as identified in Title 22, Division 4, Chapter 3, Article 3. Water Recycling Criteria
(b) Obtaining all permits necessary to install, operate and maintain the On-Site Recycled Water System.
(c) Granting the City an easement for construction of the Recycled Water Service Connection if the City decides to make provisions for delivery of Recycled Water to the proposed Use Area.
(d) Paying for, furnishing, installing, operating and maintaining all facilities necessary for conveyance of Recycled Water from the point of connection (beginning at a flow control valve adjacent to, and following the water meter assembly) to the On-Site Recycled Water System, in a manner consistent with these Rules and Regulations and without harming or damaging any person or property. (e) Identifying and labeling all facilities associated with the On-Site Recycled Water System according to the type of water in each system.
(f) Paying to install, connect and/or disconnect from the Recycled Water Service Connection in a manner ensuring no Recycled Water enters the Potable Water system.
(g) Paying for, and furnishing, all necessary modifications to the On-Site Recycled Water System such as sprinkler changes, quick-coupler modifications or installations, modifications to prevent unauthorized discharges and additional requirements related to new or expanded systems (see Section 6). (h) Providing the City a written notification, in a timely manner, specifying any material change or proposed change in the character of the use of Recycled Water.
(i) Ensuring all materials used in operating and maintaining the On-Site Recycled Water System are approved/recommended for Recycled Water use. (j) Adhering to Use Area management practices as described in Section 7. (k) Submitting an Annual Self Inspection Report (Exhibit B); arranging and paying for a third party Cross Connection inspection once every four years using the Cross Connection Control Test Procedures outlined in Exhibit C. (l) Designating a Recycled Water Site Supervisor who is responsible for the On-Site Recycled Water System at each Use Area under their control (see Section 5).
5. Site Supervisor Responsibilities
The Recycled Water Site Supervisor is responsible for the On-Site Recycled Water System at each Use Area under their control. The Site Supervisor is responsible for proper installation, operation, and maintenance of the irrigation system; compliance with Rules and Regulations of Recycled Water Use 10
these Rules and Regulations, prevention of potential hazards and preservation of the Recycled Water distribution system plans in “as built” form. Specific responsibilities include but are not limited to the following:
(a) Avoiding Cross Connections when installing, operating and maintaining pipelines, equipment and appurtenances associated with On-Site Recycled Water Systems.
(b) Attending all Cross Connection tests.
(c) Knowing and understanding the provisions of Title 17 and the Water Recycling Criteria relating to the safe use of Recycled Water; understanding basic concepts of backflow and Cross Connection prevention, system testing and related emergency procedures.
(d) Maintaining a copy of these Rules and Regulations, irrigation system layout map and a Recycled Water system operations manual at the Use Area. These documents shall be available to operating personnel at all times. (e) Ensuring Recycled Water signs are fully legible and displayed at all irrigation sites, particularly areas with greater visibility and public use. (f) Training Use Area personnel on the Approved Uses of Recycled Water. (g) Providing the City with updated contact information of the supervisor and/or a designee to ensure operational and maintenance issues receive prompt attention.
(h) Conducting a required annual self-inspection of the Use Area and submitting a monitoring report to the City (see Appendix A).
(i) Coordinating a Cross Connection test by a third party every four years and ensuring the City receives documentation following the test. (j) Establishing and maintaining a record of all inspections, modifications, maintenance, employee trainings, permit documents, and communications with the City and other Regulatory Agencies.
(k) Reporting all violations and emergencies to the appropriate Regulatory Agency.
5.1. Changing the Recycled Water Site Supervisor
The Customer must immediately notify the City of any personnel changes relating to the Recycled Water Site Supervisor position. In the event of any change, the new Site Supervisor must attend a Recycled Water Site Supervisor Certification Workshop within 90 days of the position change. Failure to attend this workshop may result in termination of Recycled Water service.
5.2. Recycled Water Site Supervisor Training
The Site Supervisor must attend a Supervisor Certification Workshop as recommended by the DDW and provided by the City, within the first 120 days of receiving Recycled Rules and Regulations of Recycled Water Use 11
Water service. Failure to attend the Site Supervisor Certification Workshop may result in the termination of Recycled Water service.
6. Facility Requirements
This section specifies the Rules and Regulations governing the design, installation and inspection of new and existing Recycled Water irrigation systems. Additionally, this section also covers the required Rules and Regulations governing design requirements at the service connection and on-site requirements for piping depth, separation requirements, vertical separation at crossings, pipe class specifications and depth of cover consistent with Title 22, Division 4, Chapter 16, Article 4 § 64572.
6.1. Design Requirements at the Service Connection
Each Recycled Water Service Connection will be equipped with a valve on both sides of, and adjacent to, the meter assembly. The valve on the inlet side of the meter assembly will be owned and maintained by the City and shall be used by the City to control the water supply through the meter assembly. The valve on the outlet side of the meter assembly will be owned and maintained by the Customer and shall be used by the Customer to control the flow of Recycled Water to the Use Area. City ownership and maintenance responsibilities of the service connection include the meter assembly and terminate at, and does not include, the valve on the Customer’s side of the meter assembly.
(a) Air gap
If conveyance of Recycled Water is carried out with existing plumbing, Potable Water service will be disconnected from the On-Site Recycled Water System and an above-ground air gap will be installed. The air gap will be spaced so that a Reduced Pressure Principle Backflow Prevention Device may be installed by the City in the future.
(b) Future Connections
In the event of potential Recycled Water service interruption or failure, Customers may connect the On-Site Recycled Water System to the previous Potable Water supply provided that (a) Recycled Water supply is disconnected from the On-Site Recycled Water System and (b) a Potable Water service point is configured to allow for future connections.
6.2. Required Temporary Connection to Potable Water Service Each On-Site Recycled Water System must pass a Cross Connection test prior to receiving Recycled Water. To facilitate this, the On-Site facility must be supplied with water via a temporary supply pipe to an on-site Potable Water system up to and during the Cross Connection test. After passing the test, the temporary supply connection must be removed and the system connected to the Recycled Water meter. On-Site Recycled Water Systems with no Potable Water within the Use Area, such as some streetscapes and medians, do not need to conduct a Cross Connection test and therefore do not need a temporary Potable Water source.
6.3. Conversion of Facilities
(a) Conversion from Potable to Recycled Water Use
Rules and Regulations of Recycled Water Use 12
No existing Potable Water facility shall be converted to, or incorporated into, a Recycled Water facility without proper testing and approval by the City. With the exception of pipe identification and pipe separation, On-site Recycled Water Systems for which the existing buried piping system is converted from Potable Water to Recycled Water must meet the same requirements as new facilities.
However, any new buried piping added to existing piping at a converted Use Area must meet the identification and separation requirements for new systems.
In addition, any existing piping uncovered for any reason during construction must be marked according to new pipe identification requirements to the extent feasible. Prior to the conversion of an existing Potable Water system to Recycled Water use, the Customer shall, at a minimum, submit Record Drawings and a report outlining the measures necessary to bring the system into full compliance to the City for review and approval.
(b) Conversion from Recycled to Potable Water Use
If the City determines it is necessary to convert Recycled Water facilities to Potable Water use, it shall be the responsibility of the Customer, at the Customer’s cost and expense, to implement the following, as determined by the City:
(i) Notify DDW of the intention to return to Potable Water use. (ii) Arrange to have the City disconnect and plug the Use Area Recycled Water Service Connection in a manner approved by the City. (iii) Shock the On-site Recycled Water System to be converted with 50 ppm of chlorine for 24 hours.
(iv) Measure the chlorine residual after 24 hours. If a residual greater than 25 ppm is maintained, then continue to the next step. If the residual is below 25 ppm, then re-chlorinate by returning to the previous step until the chlorine residual can be maintained above 25 ppm.
(v) Flush the On-site Recycled Water System with Potable Water and perform a standard bacteriological test. The final test results must be acceptable to the City before supplying the former On-site Recycled Water System with Potable Water.
(vi) Install and test approved backflow prevention assemblies on all Potable Water meter connections as required by Cross Connection requirements.
(vii) Remove all Recycled Water quick-couplers.
(viii) Notify all Use Area personnel of the change.
(ix) Remove all Recycled Water warning labels/signs from the On-site Recycled Water System and the Use Area.
(x) Notify DDW both prior to and upon completion of conversion back to Potable Water.
Rules and Regulations of Recycled Water Use 13
6.4. Recycled Water Piping Requirements
Construction of Recycled Water mains, facilities and appurtenances within the Recycled Water Project Area shall comply with design requirements as identified in the City’s Standard Specifications.3 The specifications also include identification requirements for piping, valve boxes, quick couplers, sprinkler heads, signage boards and specifications for pipe sizing, depth, materials, identification tags and service assemblies. The “California Waterworks Standards” set forth minimum separation requirements for Recycled Water and water main lines. Refer to Title 22 California Code of Regulations § 64572 for specific horizontal and vertical separation distances between potable and recycled water lines.
7. On-Site Recycled Water Systems
The following requirements shall be met for new On-Site Recycled Water System facilities. Before Recycled Water is delivered to a Use Area, the site shall be assessed and retrofitted, as necessary, by the Customer in order to meet the requirements of this subsection. Customers shall furnish, install, operate, and maintain all On-site Recycled Water Systems and appurtenances necessary to convey water from the valve immediately following the meter assembly to the approved Use Area in a manner that does not harm or damage any person or property. Refer to Sections 5 and 6 for general City and Customer responsibilities regarding On-Site Recycled Water Systems. Plans, specifications and drawings of On-Site Recycled Water Systems shall be submitted to and approved by the City prior to construction.
7.1. Signage
All Use Areas that are accessible to the public shall be posted with conspicuous signs, not smaller than 4 inches by 8 inches in area and showing an international symbol for Non-Potable Water. The lettering on the signs must be a minimum of ½ inch in height and must be back or white on a purple background (See figure 1 for an acceptable symbol). The signs must read “Recycled Water—Do Not Drink” in English, Spanish (“Agua Reciclada—No Beber”) or any additional language that may be needed to reach the population or workers in the area using recycled water The User will be responsible for posting signs in all Use Areas visible to the public (such as site entrances), and at all valves, control boxes, and similar features. Use Areas that are prone to vandalism may place Recycled Water signage at higher elevations to avoid tagging, theft, and property damage.
Recycled Water signage may also be posted at any points where after-market clip-on purple rings are used for head identification of pop-up sprinklers, rotary sprinklers and shrub riser sprinklers.
7.2. Irrigation Requirements
Operation of all On-Site Recycled Water Systems shall comply with the Use Area irrigation requirements defined in Title 22 Code of Regulations, Division 4, Chapter 3, Article 4, § 60310.
3 City of Fresno Public Works Standard Specifications, Addendum No. 4, Resolution No.70-36, Sections 33 and 34. Updated version approved January 2013.
Rules and Regulations of Recycled Water Use 14
8. Department of Transportation
In cooperation with the City, the California Department of Transportation (Caltrans) shall permit the City to place transmission lines for Recycled Water in freeway rights-of-way to promote the beneficial use of Recycled Water so long as transmission does not unreasonably interfere with use of the freeway or unreasonably increase any hazard to vehicles on the freeway. Caltrans shall require the use of Recycled Water for irrigation of freeway landscaping as identified in Streets and Highways Code, Division 1, Chapter 1, Article 1, § 92.3.
9. Recycled Water Fill Stations
Residential and commercial Customers may collect bulk supply of recycled water at Citydesignated areas to offset potable water uses by agreeing to the terms and conditions of the user agreement for fill station Customers (Exhibit E). Residential Customers may collect up to 300 gallons per load and commercial users may collect 300 gallons or more per load.
10. Cross Connection
IMPORTANT: No physical connection shall be made or allowed between any Recycled Water system and any potable water system.
10.1. General City Responsibilities
(a) The City shall implement a Cross Connection control program as required by all provisions of Title 17, Division 1, Chapter 5, Group 4, Article 1, § 7584. (b) The Cross Connection control program may be implemented directly by the City or by means of a contract with the local health agency, or with another agency approved by the health agency.
(c) The Cross Connection control program shall include the provision of at least one Cross Connection Control Specialist trained in cross-connection control to carry out the cross-connection program, the establishment of a procedure or system for testing backflow preventers, and the maintenance of records of locations, tests, and repairs of backflow preventers.
(d) The City is not responsible for abatement of Cross Connections which may exist within a Customer’s Use Area.
(e) The City shall evaluate the degree of potential health hazard to the public water supply that may be created as a result of special conditions existing in a Use Area as identified in Title 17, Division 1, Chapter 5, Group 4, Article 1, § 7585.
10.2. General Customer Responsibilities
(a) The Customer must pass a Cross Connection test before connecting the OnSite Recycled Water System to the Distribution System at any Use Area that uses both recycled and potable water.
Rules and Regulations of Recycled Water Use 15
(b) The following elements are required for a Cross Connection test. See Exhibit C for specific Cross Connection Testing Procedure. (i) The Customer must notify the City at least 48 hours prior to the test so that a City representative is present.
(ii) The test must be done once every four years under the supervision of the City and performed by an AWWA-certified Cross Connection Control Specialist.
(iii) The Recycled Water Site Supervisor must be present at the test. (iv) A written report documenting test results must be submitted by the Cross Connection Control Specialist to the Recycled Water Site Supervisor and the City following test completion.
10.3. Emergency Preparedness
In case of earthquake, flood, fire, major freeze, nearby construction, or other incident that could damage the Recycled Water or Potable Water systems, the Site Supervisor must inspect all Potable Water systems and the On-site Recycled Water System for damage as soon as it is safe to do so. If either system appears damaged, both systems should be shut off at their points of connection. The Site Supervisor must immediately contact the City for further instruction.
To prevent contamination, damage, or a public health hazard, the Customer may make emergency modifications or repairs without the prior approval of the City. As soon as possible after the modification, but within 24 hours, the Customer must notify the City of the emergency modifications and file a written report within three days.
10.4. Emergency Cross Connection Procedures
In the event that a Cross Connection occurs or is identified, the following emergency Cross Connection response plan shall be implemented:
(a) The Customer must notify the City by telephone immediately. This notification must be followed by a written notice within 24 hours that includes an explanation of the nature of the Cross Connection, date and time discovered, and the contact information of the person reporting the Cross Connection if different from the Recycled Water Site Supervisor.
(b) The City will notify DDW and other Regulatory Agencies, as appropriate, of the reported Cross Connection.
(c) Customer must immediately shut down the Recycled Water supply to the Onsite Recycled Water System. (d) Customer must keep Potable Water systems pressurized and post “Contaminated Water – Do Not Drink or Apply to Food” signs at all Potable Water fixtures and outlets.
(e) Customer must provide bottled water for employees until the Potable Water system is deemed safe to drink.
Rules and Regulations of Recycled Water Use 16
(f) After DDW has provided final approval, the City will reestablish the Recycled Water service and inform the Customer to remove “Contaminated Water – Do Not Drink or Apply to Food” signage at Potable Water fixtures and outlets.
11. Backflow Prevention
Customers shall be responsible for ensuring that all Potable Water services into Use Areas are fitted with a Reduced Pressure Principal Backflow Prevention Device if one does not already exist. The backflow prevention device must be located as close as practical to the downstream side of every Potable Water meter. Backflow prevention devices must be properly maintained and tested by the User at least annually. Backflow protection is usually not necessary on Recycled Water irrigation systems as Recycled Water is non-potable. However, the City may require certain sites to install backflow prevention devices at the service connection if it is determined that a potential on-site backflow hazard exists; this protects the quality of Recycled Water in the Distribution System. Examples include:
(a) Irrigation systems that are installed with direct injection chemical fertilizer capability; and
(b) Irrigation sites where Recycled Water impoundment may cause a backflow hazard.
Refer to Title 17, Division 1, Chapter 5, Group 4, Article 2, § 7601 - § 7605 for requirements on construction and type of backflow preventers, feasible locations, and type of protection required.
12. Obtaining Recycled Water Service
12.1. Request for Service
Potential customers requesting recycled water service shall contact the Department of Public Utilities who will determine if the customer’s proposed area is in an area where Recycled Water is or will be available. If in the area where Recycled Water is or will be available, Customer will be provided an “Application for the use of Recycled Water” form (Exhibit A) which should be filled out and returned to the City for process. Prior to receiving Recycled Water service, any proposed use of Recycled Water not listed on Title 22, Uses of Recycled Water, will be required to be approved by DDW.
12.2. Proposed Site Assessment and Inspection
Upon receipt of Application and before the On-Site Recycled Water System is connected to the Distribution System, the proposed Use Area will be inspected and an assessment will be made by the City for locations of potential Ponding, Runoff, Overspray, and other concerns. The City will indicate how the On-site Recycled Water System needs be designed in order to address potential violations of these Rules and Regulations.
Rules and Regulations of Recycled Water Use 17
12.3. Design Approval
Prior to constructing or modifying On-Site Recycled Water Systems, draft Record Drawings prepared by the Customer must be approved by the City. The Customer must meet all applicable design requirements for the Use Area to comply with these Rules and Regulations. The Customer shall submit to the City plans for the On-Site Recycled Water System utilizing City Standard format. No work shall begin by the Customer until plans and necessary permits have been approved and issued by the City.
12.5. Acceptance Inspection
(a) Construction Inspection. The City will inspect Use Areas undergoing construction to incorporate On-Site Recycled Water Systems and appurtenances in conformance with the approved Record Drawings and applicable regulations. It is the responsibility of the Customer to notify the City of all planning and construction phases so that inspections can be scheduled. (b) Cross Connection Test. Any Use Area where both Recycled and Potable Water are present shall pass a Cross Connection test prior to connecting the On-Site Recycled Water System to the Distribution System. Refer to section 11 and Appendix B for all Cross Connection requirements.
(c) Final Inspection and Approval to Receive Recycled Water. The City will perform a final inspection to ensure all requirements have been met prior to establishing Recycled Water service. This inspection may be coordinated with the Cross Connection test. The inspector will check to see that the proper equipment was used and that all required tags, labels, and signs are in place. The City must grant final approval before Recycled Water may be supplied to the Use Area.
Final approval will be granted when construction has been completed in accordance with approved Record Drawings, all Cross Connection tests have been performed, a final on-site inspection has been conducted, and all requirements have been met satisfactorily. After the User Agreement is finalized by the City and all applicable fees have been paid, the City will finalize the installation of the service connection with the service meter assembly. Upon request, DDW will be provided with a copy of all test and inspection reports as well as notification that Recycled Water service has started. For the lifetime of the On-site Recycled Water System, the City will periodically inspect the Use Area to ensure compliance with all applicable Rules and Regulations.
12.6. Coverage Test
Customers are responsible for minimizing Overspray, Runoff, and Ponding from their On-site Recycled Water System. The City will conduct an inspection of the On-site Recycled Water System; the Customer must contact the City to schedule a coverage test walk-through of the system. The Recycled Water Site Supervisor must be in attendance. All modifications to the system are the responsibility of the Customer, and the Customer must pay all costs associated with such modifications.
12.7. Metering
All Recycled Water use shall be metered, and all Recycled Water used on any Use Area where a meter is installed must pass through said meter. Users shall be held responsible, and charged, for all Recycled Water passing through the meter(s), unless otherwise specified by the City.
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12.8. Record Drawings
Customers must provide Record Drawings of the On-Site Recycled Water System to the City within 90 days of receiving Recycled Water. Record Drawings must indicate any and all changes in the work involving departures from the original contract drawings, including those involving both constant pressure and intermittent-pressure lines and appurtenances. Changes must be approved by the City before the Customer implements the changes in the construction contract.
Exhibit D provides a list of required information when submitting Record Drawings12.9. Fees and Charges
The Customer shall pay all fees and charges for the use of recycled water and other related charges based upon the actual use of recycled water by the Customer, in the amount designated in the City’s Master Fee Schedule when such a fee is developed.
12.10. Disputed Recycled Water Bills
Any dispute over the accuracy of a Recycled Water bills shall be governed byFresno Municipal Code (FMC) Article 1 – Billing and Collection Procedures for Municipal Utility Services, Section 6-104 (h)
12.11. Non-Registering Recycled Water Meter
When a meter is found to be out of order, the charge for Recycled Water will be governed FMC Article 1 – Billing and Collection Procedures for Municipal Utility Services, Section 6-104 (j)
13. Service Termination
13.1. Turn-off at User’s Request
A Customer may request that service be discontinued, either temporarily or permanently, by giving at least 30 days’ advance notice to the City. The User assumes full responsibility for all meter and usage charges incurred from the effective date of service until User notifies the City to discontinue service.
13.2. Turn-off by the City
The City may discontinue a Customer’s service for any of the following reasons:
(a) Non-Payment of Bills. Service may be discontinued for nonpayment of any water charges by a User, subject to the terms of the User Agreement. (b) Non-Compliance. Service may be discontinued for non-compliance with the terms and conditions of the User Agreement or these Rules and Regulations, as specified in the User Agreement.
(c) Water Quality. Service may be discontinued if, at any point in the City’s Distribution System, the Recycled Water does not meet the quality requirements of the City or a Regulatory Agency. Service would, in such case, be restored at such time as Recycled Water again meets the quality requirements or at such time as the City supplements the Recycled Water system with water from other sources.
Rules and Regulations of Recycled Water Use 19
(d) Non-Compliance with Regulations. Service may be suspended or terminated in the manner provided herein at any time the Customer’s operations do not conform to these Rules and Regulations as determined by the City in its sole discretion. Where safety of water supply or public health is endangered, or Regulatory Agency regulations have been violated, service may be suspended immediately without notice. Otherwise, all defects noted shall be corrected within the period of time specified by the City.
(e) Waste of Water. In order to protect against serious and negligent waste or misuse of Recycled Water, the City may provide notice of such waste and suspend service if such wasteful practices are not remedied after notice to such effect has been given to the Customer.
(f) Unauthorized Use of Recycled Water. When the City has discovered an unauthorized use, the service may be suspended without notice.
13.3. Re-Establishment of Service
The City shall have the right to refuse to re-establish service following termination of service for violation of these Rules and Regulations or the terms of a User Agreement. If a Customer desires to re-establish service following the termination of Recycled Water service, the City may renew the original User Agreement, with modified terms and conditions to achieve compliance with these Rules and Regulations or terms of the User Agreement. . Any restoration of recycled water service to the Use Area that is desired by the Customer shall be the responsibility of the Customer and shall be at no cost to the City.
Rules and Regulations of Recycled Water Use 20
Exhibit A
APPLICATION FOR USE OF RECYCLED WATER
1. Customer Name:
2. Address:
3. Use Area Property Manager:
4. Property Manager Email:
5. Property Manager Telephone number:
6. Name of Recycled Water Site Supervisor:
7. Recycled Water Site Supervisor Telephone number:
8. Complete the following information for the Use Area:
Use Area APN:
Use Area Address:
Total Irrigated Area (Acres):
Estimated Recycled Water Demand:
Method of irrigation:
Type of plant material present:
Type of Recycled Water use: ܆Landscape Irrigation
܆Agricultural Irrigation
܆Impoundments
܆Other:
Public access to the Use Area is: ܆Unrestricted ܆Restricted Number of outdoor drinking fountains in the Use Area:
Number of outdoor eating areas in the Use Area:
Number of domestic wells in the Use Area:
Number of impoundments in the Use Area (if any, briefly describe):
For City of Fresno Use Only:
9. Check list of items required for obtaining Recycled Water service:
܆ The Customer and the City have determined that the Use Area is eligible to be served with Recycled Water.
Rules and Regulations of Recycled Water Use 21
܆ The Customer has submitted Exhibit A – Application for the Use of Recycled Water. Application received on:
܆ The City has reviewed the application.
܆ The City has assessed the Customer’s on-site irrigation system and provided a description of required improvements.
Assessment performed on:
܆ The City has approved the plans and retrofit/construction schedule prior to retrofit/construction.
܆ The Customer has constructed/retrofitted the On-Site Recycled Water System.
܆ The City has reimbursed the Customer for required improvements as recommended by the on-site assessment.
܆ The Customer has submitted “as-built” drawings to the City for record, including all remaining information requested by Exhibit B. ܆ The City has performed the final on-site inspection and approval, as specified in Exhibit C.
܆ The Customer has signed a Recycled Water User Agreement. ܆ The City initiates Recycled Water service. Date:
܆ The City confirms service to DDW.
܆ The City documents Recycled Water Site Supervisor training.
10. Description of on-site assessment and required improvements:
USE
Department of Public Utilities
Wastewater Management Division
5607 W. Jensen Ave
Fresno, CA 93706-9458
559-621-5100—FAX 559-498-1700
www.fresno.gov
PART 1
1. Site Name:
2. Site Address:
3. Indicate regular hours of irrigation system operation:
From: Choose an item. To
If you answer yes to any question from 4 to 11
4. Is there evidence of runoff
sketch. Fax sketch to (559) 498
܆Yes ܆No
Corrective Action:
5. Is odor of wastewater origin emanating from the irrigation site? apparent sources, characterization, and direction of travel. ܆Yes ܆No
Corrective Action:
6. Is there evidence of ponding of
breeding within the irrigation area due to ponding?
܆Yes ܆No
Corrective Action:
7. Are warning signs, tags, stickers and
to inform the public that Recycled Water
suitable for drinking?
Rules and Regulations of Recycled Water Use
Exhibit B
AREA MONITORING REPORT
Department of Public Utilities
1700
PART 1 - ANNUAL INSPECTION
hours of irrigation system operation:
To: Choose an item.
If you answer yes to any question from 4 to 11 list the corrective action in each case.
4. Is there evidence of runoff Recycled Water from the site? Show affected area(s) on a sketch. Fax sketch to (559) 498-1700, Attn: Reclamation Coordinator.
Is odor of wastewater origin emanating from the irrigation site? If present, indicate apparent sources, characterization, and direction of travel.
Is there evidence of ponding of Recycled Water, and evidence of mosquitoes breeding within the irrigation area due to ponding?
7. Are warning signs, tags, stickers and above-ground pipe markings properly posted to Recycled Water is being used for irrigation, which is not Rules and Regulations of Recycled Water Use 22
action in each case.
from the site? Show affected area(s) on a
If present, indicate
, and evidence of mosquitoes
ground pipe markings properly posted to
is being used for irrigation, which is not
Rules and Regulations of Recycled Water Use 23
܆Yes ܆No
Corrective Action:
8. Is there evidence of plugged, broken, or otherwise faulty drip irrigation system emitters, valves, or sprinklers?
܆Yes ܆No
If yes, indicate which apply:
܆Pop-up repair Date: Click here to enter a date.
܆Rotor repair Date: Click here to enter a date.
܆Nozzle replacement Date: Click here to enter a date.
܆Lateral repair Date: Click here to enter a date.
܆Main-line repair Date: Click here to enter a date.
܆Quick coupler repair Date: Click here to enter a date. ܆Other Date: Click here to enter a date.
9. Are the irrigation controls working properly?
܆Yes ܆No
Corrective Action:
10. Is there evidence of direct spraying of Recycled Water on drinking water fountains, passing vehicles, buildings, and food facilities?
܆Yes ܆No
Corrective Action:
11. Has there been any construction or have there been any modifications done on the property within the last six months? If yes, please explain. ܆Yes ܆No
Explanation:
Rules and Regulations of Recycled Water Use 24
PART II - RECYCLED WATER SITE SUPERVISOR SIGN OFF
I, _____________________, certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, and accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and/or disconnection of Recycled Water service.” ܆ By checking this box, I have read and agree to the statement above.
Name of Recycled Water Site Supervisor:
Date: Click here to enter a date.
PART III – CHANGE OF ON-SITE SUPERVISOR, OWNERSHIP OR MANAGEMENT If the on-site supervisor, property ownership or management has changed since the last inspection, fill out the following change of information:
New Owner/Management:
Address:
Street Name
City: State: Zip:
Email: Phone:
New On-Site Supervisor:
Address:
Street Name
City: State: Zip:
Email: Phone:
PART IV – SAVE, PRINT AND SUBMIT
Save, Print and Submit form:
Attn: Reclamation Coordinator
Fresno-Clovis Regional Reclamation Facility
5607 W. Jensen Ave
Fresno, CA 93706
Or fax to: (559) 498-1700, Attn: Reclamation Coordinator Rules and Regulations of Recycled Water Use 25
Rules and Regulations of Recycled Water Use 26
Exhibit C
CROSS CONNECTION TEST PROCEDURE
The following is the required methodology for conducting Cross Connection control tests in Use Areas having both Recycled Water and Potable Water service. An AWWAcertified Cross Connection Control Specialist must perform the test using equipment dedicated for use with Recycled Water. Backflow testing equipment used for Recycled Water must not be reused on Potable Water systems.
Cross Connection Control Test Part 1
The Potable Water system shall be activated and pressurized. The On-Site Recycled Water System shall be shut down at its point of connection to the Distribution System and depressurized – this is usually done by manually bleeding a control valve or quickcoupling valve located in the lowest elevation of the On-Site Recycled Water System. (a) The Cross Connection Control Specialist will specify the amount of time that the Potable Water system shall remain pressurized while the On-Site Recycled Water System is depressurized. The size and complexity of the Potable Water and On-Site Recycled Water System will determine the minimum amount of time the On-Site Recycled Water System is to remain depressurized. (b) All On-Site Recycled Water System control valves, quick-coupling valves, irrigation systems and impoundment inlets shall be tested and surveyed for flow.
If the On-Site Recycled Water System is shut down at its point of connection to the Distribution System, then continuous flow from any part of the On-Site Recycled Water System indicates a Cross Connection.
(c) All water fixtures using Potable Water (hose bibs, faucets, drinking fountains, urinals, decorative fountains) shall be tested and surveyed for flow. No flow from Potable Water outlets indicates that it may be connected to the On-Site Recycled Water System and therefore constitutes a Cross Connection to be remedied. (d) Use Areas where no Cross Connections have been identified may proceed to part 2 of this test. If any Cross Connections are discovered, they must be disconnected and the Use Area must be re-inspected by an AWWA-certified Cross Connection Specialist per these procedures, beginning with Part 1 of the Cross Connection Control Test.
Cross Connection Control Test Part 2
(a) The Potable Water system shall be shut down at its point of connection (usually the City-controlled valve immediately preceding the meter assembly) and depressurized. For multistory buildings, the Cross Connection Control Specialist will determine the amount of pressure to be reduced and monitored with a gauge installed at a low point of elevation in the Potable Water System. (b) The On-Site Recycled Water System shall then be activated and pressurized. (c) The Cross Connection Control Specialist shall specify the minimum amount of time to pressurize the On-Site Recycled Water System while the Potable Water system is depressurized (or in the case of multistory buildings remains in a state of reduced pressure). The minimum amount of time the Potable Water system is Rules and Regulations of Recycled Water Use 27
to remain depressurized shall be determined by the Cross Connection Control Specialist.
(d) All water fixtures using Potable Water (hose bibs, faucets, drinking fountains, urinals, decorative fountains) shall be tested and surveyed for flow. If the Potable Water System has been shut down at its point of connection, then continuous flow from any part of the Potable Water system indicates a Cross Connection.
Potable Water fixtures in multistory buildings may be inspected in combination with a pressure gauge, or the pressure gauge may be used instead of testing all fixtures. If the Potable Water system has truly been shut down at its point of connection, an increase in pressure viewed at the gauge over a period of time specified by the Cross Connection Control Specialist indicates a Cross Connection with the Recycled Water System.
(e) All On-Site Recycled Water System control valves, quick-coupling valves, and any other approved Use Area facilities (such as supply lines to impoundments) shall be tested and surveyed for flow. No flow from any On-Site Recycled Water System control valve, quick-coupling valve or Recycled Water fixture indicates a likely connection with the Potable Water system, and therefore constitutes a Cross Connection to be remedied.
(f) If no Cross Connections are identified, then the Potable Water system shall be re-pressurized. If any Cross Connections are discovered, the On-Site Recycled Water System must be re-inspected by a Cross Connection Control Specialist according to these procedures, beginning with part 1 of the Cross Connection Control Test.
(g) The Cross Connection Control Specialist performing the foregoing tests must report the results and return it to the Department of Public Utilities, Wastewater Management Division.
Rules and Regulations of Recycled Water Use 28
Exhibit D
REQUIRED INFORMATION FOR RECORD DRAWINGS
Customers shall submit draft Record Drawings during the process for obtaining Recycled Water service and then provide final as-built Record Drawings upon completion of all modifications to the On-Site Recycled Water System(s) and Potable Water System(s). Applicants shall submit drawings of each Use Area on 8½” x 11”, 11” x 17” or 24” x 36” sheets of paper which shall include a signature line for the Department of Public Utilities approval.
Sheet 1
܆ Location and vicinity map including surrounding land use and adjacent streets demarking the Recycled Water Use Area.
Sheet 2
܆ Specific Potable Water irrigation use areas (if applicable). ܆ Location of Potable Water main lines, ancillary lines, gate valves, controllers, drinking fountains, and supply facility.
܆ Location and size of Potable Water service connections. ܆ Location and size of existing and future Recycled Water service connections. ܆ Location of all On-Site Recycled Water System distribution lines, gate valves, master valves, pressure regulating valves, and other associated facilities.
Exception: Although it may not be possible to show the location of all water pipelines for existing irrigation systems converting to Recycled Water, all locations where future Recycled Water piping must be separated from the Potable water piping must be clearly indicated on the plans. ܆ Location of any other piping network piping, gate valves, strainers, controllers, and supply facilities, specifically all backflow prevention devices for Potable Water systems.
܆ Where applicable, indicate that the separation between Potable and Recycled Water lines meets minimum requirements. Also show sleeving and other cross-
connection prevention measures where applicable.
܆ Areas of public access on the Use Area.
܆ Location of domestic wells on or within 100 ft. of the Use Area. ܆ Location of any lakes, ponds, reservoirs, or other impoundments located within
the Use Area or within 100 feet of the Use Area, and indicate the type of water
source.
܆ Location of Recycled Water signage on the Use Area.
܆ Location of foundations, buildings, structures, and public facilities with either Recycled or Potable Water service. Public facilities include, but are not limited to
Rules and Regulations of Recycled Water Use 29
drinking fountains, outdoor eating areas, restrooms, snack bars, swimming pools,
wading pools, decorative fountains and showers. Include the pipelines feeding all
of these facilities.
܆ Any other features known or considered to be important to the on-site use of Recycled Water.
܆ Depiction of any other applicable On-Site Recycled Water System components
as required by the Rules and Regulations.
܆ Include the Standard Notes specified by the City.
Sheet 3 (if applicable)
܆ Construction details of any domestic well within 100 feet of the Use Area.
FILL STATION APPLICATION FORM
Department of Public Utilities
Wastewater Management Division
5607 W. Jensen Ave
Fresno, CA 93706-9458
559-621-5100—FAX 559-498-1700
www.fresno.gov
Recycled Water Use Application and Agreement
Customer Information:
Customer Name:
Customer Street Address:
City:
Zip Code:
Customer Phone:
Your Water Provider:
Phone:
Email:
Type of Customer: Residential (up to 300 gallons per load) Commercial (300 gallons and more per load)
Please provide the following information for all vehicles collecting
1. Vehicle A License Plate Number:
Does Vehicle A have valid insurance and registration?
What is the automobile insurance expiration date for Vehicle A
2. Vehicle B License Plate Number:
Does Vehicle B have valid insurance and registration?
What is the automobile insurance expiration date for Vehicle B?
3. Vehicle C License Plate Number:
Does Vehicle C have valid insurance and registration?
Rules and Regulations of Recycled Water Use
Exhibit E
FILL STATION APPLICATION FORM
Department of Public Utilities
1700
Water Use Application and Agreement for Fill Station Customer : Residential (up to 300 gallons per load)
Commercial (300 gallons and more per load)
Vehicle Information
Please provide the following information for all vehicles collecting recycled water:
License Plate Number:
Does Vehicle A have valid insurance and registration?
What is the automobile insurance expiration date for Vehicle A? License Plate Number:
Does Vehicle B have valid insurance and registration?
What is the automobile insurance expiration date for Vehicle B? License Plate Number:
Does Vehicle C have valid insurance and registration?
Rules and Regulations of Recycled Water Use 30
Customers
water:
Rules and Regulations of Recycled Water Use 31
What is the automobile insurance expiration date for Vehicle C? Recycled Water Use Information
From the list below, select all applicable uses of Recycled water:
Dust control
Irrigation of trees, landscaping and gardens
Vehicle Washing
Soil compaction
Washing of hard surfaces such as paths, walls, windows
Other:
Specify the street address, City and zip code where recycled water will be used:
Location A:
Location B:
Location C:
Frequently Asked Questions about Recycled Water
1. What is the Recycled Water Fill Station Program?
The “Recycled Water Fill Station” program is a pilot initiative to provide recycled water from the Fresno-Clovis Regional Wastewater Reclamation Facility (RWRF) for commercial and residential Customers to offset the use of drinking water for nondrinking uses.
2. What is recycled water and is it safe?
Recycled water is wastewater which as a result of treatment and disinfection is suitable for a beneficial use and is therefore considered a valuable resource. The ultra violet disinfection process uses high energy ultraviolet light to inactivate pathogens and other microorganisms. It must meet strict standards of the Division of Drinking Water (DDW)
3. What can I use recycled water for?
Recycled water can be used for watering trees, lawns and gardens. It can also be used for dust control, soil compaction, washing vehicles and hard surfaces such as paths, walls and windows.
4. What is recycled water NOT suitable for?
Rules and Regulations of Recycled Water Use 32
It is not suitable for drinking, cooking or use in the kitchen, bathing or showering, filling swimming pools or spas, children’s water toys and connecting it to the household domestic (drinking water) plumbing or irrigation system.
5. Do water use restrictions (conservation) apply to recycled water? No. Water use restrictions do not apply to recycled water. However, it is a valuable resource and should not be wasted.
6. How much will recycled water cost me?
The Customer shall pay all fees and charges for the use of recycled water and other related charges based upon the actual use of recycled water by the Customer in an amount to be designated in the City’s Master Fee Schedule.
7. How much recycled water can I pick up at a time?
Commercial Customers may collect 300 gallons or more per load and residential Customers may collect up to 300 gallons per load. The City of Fresno is not liable for any damages to you or your vehicle(s) due to your participation in the recycled water fill station program.
8. Where and when can I use the Recycled Water Fill Station? Designated areas for recycled water fill stations will be approved by the City’s Director of Public Utilities.
Rules and Regulations of Recycled Water Use
1. DO NOT DRINK recycled water.
2. Recycled water shall not be put into any piping or storage facility that has any connection to an on-site drinking water supply.
3. Commercial distributor’s vehicles used for bulk collection, transportation and distribution of recycled water must have containers with capabilities of 300 gallons or greater.
4. Designated vehicles must have water tight valves and fittings, must not leak, and tanks must be cleaned of contaminants prior to use.
5. Hauling vehicles may be self-propelled or towed vehicles having an attached water tank, with or without pumps, hoses and accessory equipment for filling or distribution of recycled water. Use of convertible trucks, dump trucks, or flat-bed trucks with detachable tanks is allowed if the tanks are securely attached.
6. Vehicles without a tank or detached tank are not approved for collecting recycled water.
7. A truck or tank that has contained material from a septic tank or cesspool shall not be used to convey recycled water.
Rules and Regulations of Recycled Water Use 33
8. Customers are required to label both sides of their water tanks with the words “Recycled Water/Do not drink” in letters of at least 4 inches in height. Labeling must be permanently attached to or painted on the vehicle and must be fully legible and visible at all times.
9. Recycled water shall be used and/or applied promptly. No storage of recycled water on-site at a residential property.
10. Recycled water shall not be discharged to the street gutter or storm drain system. If you have leftover recycled water and want to dispose of it, either discharge it to a landscaped area or to the sanitary sewer system via an on-site cleanout.
11. After handling recycled water, remember to apply hand sanitizer or wash hands with soap and drinking water, especially before eating or smoking.
12. The City may conduct site visits to ensure your proper use of recycled water and to ensure the health and safety of your family and the public.
Procedure to Obtain Recycled Water
1. Read and understand the conditions of this Use Application/Agreement. Download and save the form to your Desktop. Type in your responses, Save, Print, and mail a signed form to the following address:
Attn: Reclamation Coordinator
Fresno Clovis Regional Wastewater Reclamation Facility
5607 W. Jensen Ave
Fresno, CA 93706
A hard copy of the form can be mailed to you by calling (559) 621-5134.
2. Approved applicants will receive a brief one-on-one training on use requirements of recycled water. Customers will be provided a badge to access the gate into the fill station site and activate the water supply. A City representative will direct participating Customers to the fill station located inside the RWRF.
3. The badge holder is the primary party held accountable for accessing the fill station site. If the badge is misplaced or damaged, the primary badge holder shall pay $25.00 to the Wastewater Management Division for a new badge.
4. All water tanks and containers are required to be labeled with the words “Non-potable water/Do not drink”.
5. Access to the commercial and residential recycled water fill station is based on a first- come basis.
6. Haulers must ensure that tanks are sealed and secured for transport prior to leaving the facility.
Rules and Regulations of Recycled Water Use 34
Certification Statement/Signature Section
By checking this box, myself, and if applicable, my organization’s officers, owners, personnel, employees, agents, contractors, invitees or volunteers agree to hold harmless the City of Fresno from any and all claims, lawsuits, demands, liability, monetary loss, property damage and/or injury arising out of our organization’s connection with the collection, transportation and distribution of recycled water.
By checking this box, I assert that the information provided in this application is true and accurate to the best of my knowledge, and represent that I have read, understand, and agree to comply with the City’s Rules and Regulations for recycled water. Failure to comply with the conditions of this agreement may lead to termination of this agreement and the ability to obtain recycled water from the commercial/residential fill station.
Name:
Customer’s Signature
Date
Rules and Regulations of Recycled Water Use 35
Figure 1
NON-POTABLE DO NOT DRINK ACCEPTABLE FIGURE
Engineering Report for the Production,
Distribution and Use of Recycled Water
215138_rpt01.docx Blair, Church & Flynn Consulting Engineers
APPENDIX C
RECYCLED WATER USER AGREEMENT
-1-
AGREEMENT
CITY OF FRESNO, CALIFORNIA
RECYCLED WATER SERVICES
THIS AGREEMENT is made and entered into effective the [Day of the month, e.g., 1st] day of Choose an item. [Year], by and between the CITY OF FRESNO, a California municipal corporation (hereinafter referred to as “CITY”, and [Customer's Name], [Legal identity], located at [address] (hereinafter referred to as “CUSTOMER”).
RECITALS
WHEREAS, CITY produces and distributes recycled water of satisfactory quality for use in irrigating landscaped areas and impoundment areas with unrestricted public access; and
WHEREAS, CUSTOMER owns and operates certain landscaped areas and/or impoundment areas that CUSTOMER desires to irrigate/supply with recycled water distributed by CITY; and
WHEREAS, CITY and CUSTOMER will conserve potable water by using recycled water for agricultural or landscape irrigation and/or impoundment water supply; and
WHEREAS, CUSTOMER acknowledges that this Agreement is subject to the requirements of Fresno Municipal Code Section Chapter 6, Article 9, Recycled Water Ordinance; and
WHEREAS, this Agreement will be administered for CITY by its Director of Public Utilities (hereinafter referred to as “Administrator”) or his/her designee.
AGREEMENT
NOW, THEREFORE, in consideration of the foregoing and of the covenants, conditions, and premises, hereinafter contained to be kept by the respective parties, it is mutually agreed as follows:
1. Term of Agreement. This Agreement shall be effective from the date first set forth above (“Effective date”) and shall continue in full force and effect through [Day of the month, e.g., 1st] day of Choose an item., [Year], subject to any earlier termination in accordance with this Agreement.
2. Recycled Water Use Area. CUSTOMER shall use recycled water supplied by CITY on approximately [Number of acres] acres within the permitted use area. The location of the use area is described in the attached Exhibit A as submitted with the “Application for the Use of Recycled Water”. CITY understands that the CUSTOMER has the right to add or subtract from the total use area as operations plans dictate, provided that all potential use areas are disclosed in this Agreement. -2-
3. City Ordinance. CUSTOMER has read and agrees to the terms stated in CITY Ordinance 2014-32 (hereinafter, “Recycled Water Ordinance”), attached as Exhibit D and incorporated herein.
4. Rules and Regulations. CUSTOMER has read and agrees to the terms of the CITY’s Recycled Water Use Rules and Regulations governing the use, distribution and transport of recycled water (hereinafter, “CITY’s Rules and Regulations”), which are attached as Exhibit E and incorporated herein.
5. No Representation Regarding Water Service, Pressure, or Volume for any Portion of the Recycled Water Pipeline. CITY does not make any representation, warranty or guarantee of any kind or nature and hereby specifically disclaims any kind of representation, warranty or guarantee that any portion of the recycled water system described or the recycled water system as a whole will yield any specific volume of water or provide any specific water pressure to CUSTOMER under static or demand scenarios or for any use by CUSTOMER and its tenants, lessees, purchasers, successors or assigns. CUSTOMER assumes full responsibility for the adequacy of volume of water and water pressure beyond the Point of Connection (“POC”) as defined in the CITY’s Rules and Regulations.
6. Maintenance and Repair. CUSTOMER shall be responsible for operation, maintenance, repair, and replacement of all portions of the recycled water system beyond the POC. Under no circumstances shall CITY be required or accountable to maintain, repair or replace CUSTOMER’s recycled water system unless and until CITY may, at its sole discretion and option, accept dedication of the water system, or any portion thereof in increments or otherwise, at some future date. CUSTOMER's obligation to maintain, repair and replace its recycled water system shall include, without limitation, any operation and maintenance, repair, replacement or modification of the recycled water system as may be required by CITY. Should CUSTOMER fail to operate, maintain, repair and replace its portion of recycled water pipeline as needed for proper operation of the public portions of the recycled water pipeline, the CITY shall have the right, but not the obligation, to stop providing water.
7. Priorities for Delivery of Recycled Water.
(a) The CITY reserves the right to control and schedule recycled water distribution as necessary to maintain an acceptable working pressure; protect public health; construct, maintain and operate other CITY facilities; and manage availability of recycled water supply.
(b) Delivery of recycled water may at times be precluded for reasons beyond the reasonable control of the CITY including, but not limited to insufficient recycled water supply, maintenance of CITY’s treatment or distribution systems, acts of a third party, or order of a regulatory agency. -3-
(c) If recycled water supply is interrupted for any reason, including but not limited to those outlined in (b), first priority for recycled water service shall be given to potable water rate payers of the CITY to meet all anticipated municipal needs of the CITY.
(d) If recycled water delivery is interrupted for more than 48 hours, the CITY may connect the CUSTOMER’S back-up water supply. If the CUSTOMER does not have a backup supply and was originally connected to the CITY potable water system, CITY may reconnect CUSTOMER’S on-site recycled water system to the CITY potable water system subject to the terms of the Rules and Regulations. The CUSTOMER agrees to return to recycled water use as soon as the CITY is able to resume recycled water delivery. CUSTOMER shall pay for the full cost of water used from the alternate supply.
8. Receipt and Application of Recycled Water.
(a) CUSTOMER agrees to use recycled water for uses stated in Exhibit A of this Agreement, as submitted on the “Application for the Use of Recycled Water,” except for portions of the use area where application of recycled water may be prohibited by any law, statute, rule, regulations or guidelines governing the use of recycled water.
(b) CUSTOMER understands that the CITY will inspect and assess the use area before the On-Site Recycled Water System is connected to the Distribution System. The CITY will indicate how the On-site Recycled Water System needs be designed in order to minimize/eliminate potential violations of the Rules and Regulations. Furthermore, CUSTOMER understands that this Agreement shall become valid upon passing a Final On-Site Inspection by the CITY (Exhibit -C).
(c) CUSTOMER agrees that any agreement it may have with a third party for the management of the use area shall not in any way relieve CUSTOMER of the requirements, terms and conditions of this Agreement.
CUSTOMER shall be responsible to the CITY for the safe use of recycled water by CUSTOMER and any third party.
(d) The CITY shall not be liable for any damage related to CUSTOMER’s recycled water infrastructure, use, and distribution, including damage resulting from inadequate capacity, defective plumbing, broken or faulty services, or any conditions beyond the control of the CITY. Furthermore, CUSTOMER accepts such conditions of pressure, as provided by the distribution system at the location of its service connection, and holds the CITY harmless from any and all liability, damage, losses, costs, fees or expenses, arising from low pressure or high pressure conditions, or from interruptions of service. -4-
(e) CUSTOMER understands and accounts for the nutrient contribution of recycled water when irrigating crops, green spaces, freeway medians, parks, school yards and cemeteries. CUSTOMER agrees that the CITY will not be liable for damage to vegetation resulting from the application of recycled water.
9. Recycled Water Use Requirements. CUSTOMER agrees to abide by all use requirements identified in the CITY’s Rules and Regulations, the Recycled Water Ordinance, California Code of Regulations Title 17 and 22 relating to the use of recycled water, and all laws, statutes or guidelines governing recycled water use. Approved uses of recycled water for the CUSTOMER’s use area shall be limited to those described in Exhibit A of this Agreement and as specified on the “Application for the Use of Recycled Water”.
10. Recycled Water Site Supervisor. CUSTOMER shall designate an individual as its Recycled Water Site Supervisor (“Site Supervisor”), who shall be the CUSTOMER’s coordinator and direct liaison with the CITY regarding recycled water matters. CUSTOMER agrees that the Site Supervisor shall be responsible for all duties identified in CITY’s Rules and Regulations. The Site Supervisor is required to attend a certification course provided by the City on the accepted uses and regulatory restrictions for the use of Recycled Water. The Site Supervisor is also responsible for training operators or recycled water in the Use Area.
11. On-Site Recycled Water System Modifications. CUSTOMER understands and agrees that any modifications to its On-Site Recycled Water System, as defined in the Recycled Water Ordinance, must comply with the CITY’s Rules and Regulations relating to recycled water and failure to do may result in termination of recycled water service.
12. Notification of Public. CUSTOMER shall provide adequate notification, as required by the Division of Drinking Water (DDW) to employees and the general public that recycled water is being applied within the designated use area.
13. Record Drawings. Upon completion of all modifications to CUSTOMER’S on-site recycled water system and potable water system, CUSTOMER shall provide the CITY with record drawings containing specific information as identified in Exhibit B of this agreement.
14. Fees and Charges. CUSTOMER shall pay all fees and charges for the use of recycled water and other related charges based upon the actual use of recycled water by the CUSTOMER, in an amount designated in the CITY’s Master Fee Schedule when such a fee is developed. The CITY shall provide recycled water at no cost until June 30, 2019. As an incentive, CUSTOMERS may receive a one-time reimbursement of up to $5,000 at the sole discretion of the Director of Public Utilities or his or her designee for on-site improvements needed to utilize recycled water. -5-
15. Indemnification. To the furthest extent allowed by law, CUSTOMER shall indemnify, hold harmless and defend CITY and each of its officers, officials, employees, agents and volunteers from any and all loss, liability, fines, penalties, forfeitures, costs and damages (whether in contract, tort or strict liability, including but not limited to personal injury, death at any time, and property damage) incurred by CITY, CUSTOMER or any other person, and from any and all claims, demands, liabilities, damages and actions in law or equity (including attorney's fees and litigation expenses), arising or alleged to have arisen directly or indirectly out of the performance of this Agreement and the performance of any or all work to be done in and upon the street rights-of-way or within CUSTOMER’s property boundary, and premises adjacent thereto, pursuant to this Agreement, or arising or alleged to have arisen directly or indirectly in any way related to the construction, installation and operation of the recycled water supply pipeline or its appurtenances by anyone occupying any portion of CUSTOMER’s property including, without limitation, any such claims, causes of action, damages, liabilities, fees, costs, expenses, and attorney fees arising from water quality compliance, a lack of volume of water, inadequate fire flow, lack of water pressure in, from or delivered to the recycled water supply pipeline, or lack of flow capacity in the recycled water supply pipeline. CUSTOMER’s obligations under the preceding sentence shall apply regardless of whether CITY or any of its officers, officials, boards, employees, agents or volunteers are passively negligent, but shall not apply to any loss, liability, fines, penalties, forfeitures, costs or damages caused by the active or sole negligence, or the willful misconduct, of CITY or any of its officers, officials, employees, agents or volunteers.
16. General Terms.
(a) Governing Law and Venue. This Agreement shall be governed by, and construed and enforced in accordance with the laws of the State of California, and venue for purposes of filing any action regarding the enforcement or interpretation of this Agreement shall be Fresno County, California. (b) Severability. The provisions of this Agreement are severable. The invalidity or unenforceability of any one provision in this Agreement shall not affect the other provisions.
(c) Binding. Once this Agreement is signed by all parties, it shall be binding upon all parties and each parties’ respective heirs, successors, lessees, sub lessees, assigns, transferees, agents, servants, employees and representatives.
(d) No Third Party Beneficiaries. The rights, interests, duties and obligations defined within this Agreement are intended for the specific parties hereto as identified in the preamble of this Agreement. Notwithstanding anything stated to the contrary in this Agreement, it is not intended that any rights or interests in this Agreement benefit or flow to the interest of any third parties.
(e) Extent of Agreement. Each party acknowledges that they have -6-
read and fully understand the contents of this Agreement. This Agreement represents the entire and integrated agreement between the parties with respect to the subject matter hereof and supersedes all prior negotiations, representations or agreements, either written or oral.
17. Monitoring and Reporting. CUSTOMER agrees to comply with the monitoring and reporting requirements as identified in the CITY’s Rules and Regulations.
18. Headings. The section headings in the Agreement are for convenience and reference only and shall not be construed or held in any way to explain, modify or add to the interpretation or meaning of the provisions of this Agreement.
19. Exhibits. Each exhibit and attachment referenced in this Agreement is, by the reference, incorporated into and made part of this Agreement.
20. Notices. Any notice required or intended to be given to either party under the terms of this Agreement shall be in writing and shall be deemed to be duly given if delivered personally, transmitted by facsimile followed by phone confirmation of receipt, or sent by United States registered or certified mail, with postage prepaid, return receipt requested, addressed to the party to which notice is to be given at the party’s address set forth on the signature page of this Agreement.
21. Attorney’s Fees. If a party is required to commence any proceeding or legal action to enforce or interpret any term, covenant or condition of this MOU, the prevailing party in such proceeding or action shall be entitled to recover from the other party its/their reasonable attorney's fees and legal expenses.
22. Termination. Upon any breach of this Agreement by CUSTOMER, CITY may (a) exercise any right, remedy (in contract, law or equity), or privilege which may be available to it under applicable laws of the State of California or any other applicable law; (b) proceed by appropriate court action to enforce the terms of the Agreement and/or recover all direct, indirect, consequential, economic, and incidental damages for the breach of the Agreement.
The CITY may terminate this Agreement immediately following any of the reasons listed in Section 13.2 of the CITY’s Rules and Regulations for recycled water use. -7-
IN WITNESS WHEREOF, the parties have executed this Agreement at Fresno, California, the day and year first above written.
Attachments:
1. Exhibit A – Application for the Use of Recycled Water
2. Exhibit B – Required Information for Record Drawings
3. Exhibit C – Final On-Site Inspection and Approval
4. Exhibit D – Recycled Water Ordinance
5. Exhibit E – CITY’s Recycled Water Use Rules and Regulations [Name of Company]
[legal entity]
By:
Name:
(Type or print written
signature.)
Addresses:
CUSTOMER:
[Company Name]
Attention:
[Title]
[Street Address]
[City, State, Zip Code]
Phone:
Fax:
CITY OF FRESNO,
a California municipal corporation
By: ______
Thomas C. Esqueda, Director
Department of Public Utilities
Dated:
CITY:
City of Fresno
Attention: Conrad Braganza
Wastewater Reclamation Coordinator
5607 W. Jensen Ave.
Fresno, CA 93706
Phone: (559) 621-5134
Fax: (559) 498-1700
-8-
Exhibit A
APPLICATION FOR THE USE OF RECYCLED WATER
1. Customer Name:
2. Address:
3. Use Area Property Manager:
4. Property Manager Email:
5. Property Manager Telephone number:
6. Name of Recycled Water Site Supervisor:
7. Recycled Water Site Supervisor Telephone number:
8. Complete the following information for the Use Area:
Use Area APN:
Use Area Address:
Total Irrigated Area (Acres):
Estimated Recycled Water Demand:
Method of irrigation:
Type of plant material present:
Type of Recycled Water use: ܆Landscape Irrigation
܆Agricultural Irrigation
܆Impoundments
܆Other:
Public access to the Use Area is: ܆Unrestricted ܆Restricted Number of outdoor drinking fountains in the Use Area:
Number of outdoor eating areas in the Use Area:
Number of domestic wells in the Use Area:
Number of impoundments in the Use Area (if any, briefly describe):
For City of Fresno Use Only:
9. Check list of items required for obtaining Recycled Water service:
܆ The Customer and the City have determined that the Use Area is eligible to be served with Recycled Water.
܆ The Customer has submitted Exhibit A – Application for the Use of Recycled Water. Application received on:
܆ The City has reviewed the application.
-9-
܆ The City has assessed the Customer’s on-site irrigation system and provided a description of required improvements.
Assessment performed on:
܆ The City has approved the plans and retrofit/construction schedule prior to retrofit/construction.
܆ The Customer has constructed/retrofitted the On-Site Recycled Water System.
܆ The City has reimbursed the Customer for required improvements as recommended by the on-site assessment.
܆ The Customer has submitted “as-built” drawings to the City for record, including all remaining information requested by Exhibit B. ܆ The City has performed the final on-site inspection and approval, as specified in Exhibit C.
܆ The Customer has signed a Recycled Water User Agreement. ܆ The City initiates Recycled Water service. Date:
܆ The City confirms service to DDW.
܆ The City documents Recycled Water Site Supervisor training.
10. Description of on-site assessment and required improvements:
-10-
Exhibit B
REQUIRED INFORMATION FOR RECORD DRAWING
Customers shall submit draft Record Drawings during the process for obtaining Recycled Water service and then provide final as-built Record Drawings upon completion of all modifications to the On-Site Recycled Water System(s) and Potable Water System(s). Applicants shall submit drawings of each Use Area on 8½” x 11”, 11” x 17” or 24” x 36” sheets of paper which shall include a signature line for the Department of Public Utilities approval.
Sheet 1
܆ Location and vicinity map including surrounding land use and adjacent streets demarking the Recycled Water Use Area.
Sheet 2
܆ Specific Potable Water irrigation use areas (if applicable). ܆ Location of Potable Water main lines, ancillary lines, gate valves, controllers, drinking fountains, and supply facility.
܆ Location and size of Potable Water service connections. ܆ Location and size of existing and future Recycled Water service connections. ܆ Location of all On-Site Recycled Water System distribution lines, gate valves, master valves, pressure regulating valves, and other associated facilities.
Exception: Although it may not be possible to show the location of all water pipelines for existing irrigation systems converting to Recycled Water, all locations where future Recycled Water piping must be separated from the Potable water piping must be clearly indicated on the plans. ܆ Location of any other piping network piping, gate valves, strainers, controllers, and supply facilities, specifically all backflow prevention devices for Potable Water systems.
܆ Where applicable, indicate that the separation between Potable and Recycled Water lines meets minimum requirements. Also show sleeving and other crossconnection prevention measures where applicable. ܆ Areas of public access on the Use Area.
܆ Location of domestic wells on or within 100 ft. of the Use Area. ܆ Location of any lakes, ponds, reservoirs, or other impoundments located within the Use Area or within 100 feet of the Use Area, and indicate the type of water source.
܆ Location of Recycled Water signage on the Use Area.
܆ Location of foundations, buildings, structures, and public facilities with either Recycled or Potable Water service. Public facilities include, but are not limited to drinking fountains, outdoor eating areas, restrooms, snack bars, swimming pools, wading pools, decorative fountains and showers. Include the pipelines feeding all -11-
of these facilities.
܆ Any other features known or considered to be important to the on-site use of Recycled Water.
܆ Depiction of any other applicable On-Site Recycled Water System components as required by the Rules and Regulations.
܆ Include the Standard Notes specified by the City.
Sheet 3 (if applicable)
܆ Construction details of any domestic well within 100 feet of the Use Area. -12-
Exhibit C
FINAL ON-SITE INSPECTION AND APPROVAL
1. Customer Name:
2. Complete the following information for the Use Area:
Use Area APN:
Use Area Address:
Requested date of service:
Recycled Water service initiated on (TBD):
Number of service connections:
Specify the back-up water supply source:
Has the Cross Connection Test been waived?1 ܆Yes ܆No
Date of Cross Connection Test:
Briefly describe any upgrades to the Use Area:
How many domestic wells are present within 50 ft. of the Use Area or within 100 ft. of any impoundment?
Describe the level and method of backflow protection at the Use Area:
Is Recycled Water signage displayed in visible and public areas? ܆Yes ܆No Special requirements and conditions:
3. Final Inspection by the City:
I have inspected the On-Site Recycled Water System(s) governed by this User Agreement and attest that the construction and operation of this system are in accordance with the City’s Rules and Regulations governing recycled water use.
Inspector Name:
Inspector Signature: _________________________________
Date:
1 Customers may request a waiver of the Cross Connection test if no potable water piping is present in the Use Area.
-13-
Exhibit D
RECYCLED WATER ORDINANCE
-14-
Exhibit E
RECYCLED WATER RULES AND REGULATIONS
Engineering Report for the Production,
Distribution and Use of Recycled Water
215138_rpt01.docx Blair, Church & Flynn Consulting Engineers
APPENDIX D
TTDF DESIGN REPORT
December, 2010
Technical Memorandum—DRAFT
(Part One—Schematic Design Phase)
City of Fresno
Tertiary Treatment and Disinfection Facility
Fresno-Clovis Regional Wastewater Reclamation Facility
August 2011
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
TABLE OF CONTENTS
TABLE OF CONTENTS
TECHNICAL MEMORANDUM (PART ONE – SCHEMATIC DESIGN PHASE) Executive Summary
Section1 Introduction and Objective
Section 2 Existing Relevant Treatment Facilities
Section 3 Planned Tertiary Treatment and Disinfection Facility (TTDF) Section 4 Filtration System Alternatives Analysis
Section 5 Disinfection System Alternatives Analysis
Section 6 Storage System Alternatives Analysis
Section 7 Membrane Bio Reactor (MBR) Option
Section 8 Summary of Workshop No.1
Section 9 Plan A: MBR, UV Disinfection and Storage Scheme (12 mgd Capacity) Section 10 Plans B and C: Nova Filtration, UV Disinfection and Storage Schemes Section 11 Comparison of MBR System with Nova Filtration System (Plan A vs. Plan C) Section 12 Evaluation of Power Supply Options for Planned TTDF Section 13 Integration of TTDF Controls with Existing SCADA System Section 14 Summary of Workshop No.2 and New Project Direction Section 15 Selected MBR Alternatives Analysis
Section 16 Recommended Project Description
Appendix A Preliminary Construction and O&M Cost Estimates Appendix B Reference Drawings
Appendix C Reference Documents
Pre-Workshop No.1
Analysis
Post Workshop No.2
Analysis
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
LIST OF TABLES
LIST OF TABLES
Table 2-1: Existing Relevant Facilities - Major Design Information Table 4-1: Secondary Effluent Permitted Quality and Currently Achieved Quality Table 4-2: Tertiary Effluent (Title 22) Criteria
Table 4-3: Dual Media Filter Advantages and Disadvantages Table 4-4: Dual Media Filter Design Criteria
Table 4-5: Dual Media Filter Cost Summary (5 mgd Constant Flow) Table 4-6: Deep Bed Monomedia Filter Advantages and Disadvantages Table 4-7: Deep Bed Monomedia Filter Design Criteria
Table 4-8: Deep Bed Monomedia Filter Cost Summary (5 mgd Constant Flow) Table 4-9: Continuous Backwash Filter Advantages and Disadvantages Table 4-10: Continuous Backwash Filter Design Criteria
Table 4-11: Continuous Backwash Filter Cost Summary (5 mgd Constant Flow) Table 4-12: Traveling Bridge Filter Advantages and Disadvantages Table 4-13: Traveling Bridge Filter Design Criteria
Table 4-14: Traveling Bridge Filter Cost Summary (5 mgd Constant Flow) Table 4-15: Fuzzy Filter Advantages and Disadvantages
Table 4-16: Fuzzy Filter Design Criteria
Table 4-17: Fuzzy Filter Cost Summary (5 mgd Constant Flow) Table 4-18: Cloth Media Filter Advantages and Disadvantages Table 4-19: Cloth Media Filter Design Criteria
Table 4-20: Cloth Media Filter Cost Summary (5 mgd Constant Flow) Table 4-21: Nova Ultrascreen Advantages and Disadvantages Table 4-22: Nova Ultrascreen Filter Design Criteria
Table 4-23: Nova Ultrascreen Filter Cost Summary (5 mgd Constant Flow) Table 4-24: Microfilter Advantages and Disadvantages
Table 4-25: Microfilter Design Criteria
Table 4-26: Microfilter Cost Summary (5 mgd Constant Flow) Table 4-27: Summary of Costs of Each 5 mgd Constant Flow Filtration Alternative Table 5-1: UV Disinfection Design Criteria
Table 5-2: UV Disinfection Advantages and Disadvantages Table 5-3: Design Characteristics of Open Channel UV System for Design Flow of 5 MGD Table 5-4: Open Channel UV System Following Media Filtration Cost Summary (5 mgd Constant Flow)
Table 5-5: In-pipe UV Disinfection System Advantages and Disadvantages Table 5-6: Design Characteristics of In-pipe UV System for Design Flow of 5 MGD Table 5-7: In-pipe UV Disinfection System following Media Filtration Cost Summary (5 mgd Constant Flow)
Table 5-8: Ozone Disinfection System Advantages and Disadvantages Table 5-9: Design Characteristics of Ozone Disinfection System for Design Flow of 5 MGD Table 5-10: Ozone Disinfection System Cost Summary (5 mgd Constant Flow) Table 5-11: Summary of Costs for Disinfection System Alternatives (5 mgd Constant Flow) CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
LIST OF TABLES
LIST OF TABLES (CONTD…)
Table 6-1: Earthen Basins Advantages and Disadvantages
Table 6-2: Earthen Basins Design Criteria
Table 6-3: Earthen Basins Cost Summary
Table 6-4: Steel Tank Advantages and Disadvantages
Table 6-5: Steel Tank Design Criteria
Table 6-6: Steel Tank Cost Summary
Table 6-7: Prestressed Concrete Tank Advantages and Disadvantages Table 6-8: Prestressed Concrete Tank Design Criteria
Table 6-9: Prestressed Concrete Tank Cost Summary
Table 6-10: Conversion of Train A Aeration Basin Advantages and Disadvantages Table 6-11: Conversion of Train A Aeration Basin Design Criteria Table 6-12: Conversion of Train A Aeration Basin Cost Summary Table 6-13: Summary of Cost for Each Storage Alternative Table 7-1: MBR Capital Cost – Train A
Table 7-2: MBR Capital Cost – Train B
Table 8-1: Revised Cost Summary for Cloth Media and Nova Ultrascreen Filters Table 8-2: Revised Cost Summary for In-pipe UV Disinfection Following Media Filtration Table 9-1: Design Criteria for Capacity Analysis of MBR Aeration Basin to Achieve NDN Table 9-2: Primary Effluent Pumps Design Characteristics Table 9-3: Design Characteristics of Fine Screens and Washer/Compactors Table 9-4: Bioreactors Design Characteristics
Table 9-5: Aeration System Design Characteristics
Table 9-6: Sludge Pumping Systems Design Characteristics Table 9-7: MBR Membrane System Design Characteristics
Table 9-8: In-pipe UV Disinfection Design Characteristics Table 9-9: “Plan A” Capital Cost
Table 9-10: “Plan A” O&M Cost
Table 9-11: “Plan A” Life-Cycle Cost
Table 10-1: Plan B Design Criteria
Table 10-2: Plan B Cost Summary
Table 10-3: Plan C Design Criteria
Table 10-4: Plan C Cost Summary
Table 11-1: Comparison of Plan “A” and Plan “C” Capital, O&M, and Life-Cycle Costs Table 11-2: Comparison of Plan A and Plan C Non-Economic Features Table 12-1: Proposed TTDF (MBR) Electrical Loads (30 mgd) Table 12-2: Proposed TTDF (MBR) Electrical Loads (12 mgd) Table 12-3: Proposed TTDF (Tertiary Filtration) Electrical Loads (30 mgd) Table 12-4: Proposed TTDF (Tertiary Filtration) Electrical Loads (12 mgd) CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
LIST OF TABLES
Table 15-1: Design Criteria for Capacity Analysis of MBR Aeration Basin to Achieve NDN Table 15-2: Design Characteristics of Fine Screens and Washer/Compactors Table 15-3: Bioreactors Design Characteristics
Table 15-4: Aeration System Design Characteristics
Table 15-5: Sludge Pumping Systems Design Characteristics Table 15-6: MBR Membrane System Design Characteristics
Table 15-7: In-pipe UV Disinfection Design Characteristics Table 15-8: MBR Alternatives Capital Cost (5 mgd)
Table 15-9: MBR Alternatives O&M Cost (5 mgd)
Table 15-10: MBR Alternatives Life-Cycle Cost (5 mgd)
Table 16-1: Design Criteria for TTDF
Table 16-2: List of Major Process Equipment
Table 16-3: MBR System Life-Cycle Cost (5 mgd)
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
LIST OF FIGURES
LIST OF FIGURES
Figure 2-1: Relevant Facilities
Figure 2-2: Existing Relevant Facilities - Current Operation Figure 3-1: Planned TTDF
Figure 3-2: Simplified Schematic of the TTDF
Figure 4-1: Simplified Schematic of a Granular Media Depth Filter Figure 4-2: Preliminary Layout of 5 mgd Dual Media Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-3: Preliminary Layout of 5 mgd Deep Bed Monomedia Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-4: Continuous Backwash Filter (Figure from DynaSand®) Figure 4-5: Preliminary Layout of 5 mgd Continuous Backwash Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-6: Traveling Bridge Filter (Figure from ABW®)
Figure 4-7: Preliminary Layout of 5 mgd Traveling Bridge Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-8: Fuzzy Filter (Figure from Schreiber, LLC)
Figure 4-9: Preliminary Layout of 5 mgd Fuzzy Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-10: Cloth Media Filter (Figure from Aqua-Aerobic) Figure 4-11: Preliminary Layout of 5 mgd Cloth Media Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-12: Nova Ultrascreen Filter (Figure from Nova Water Technologies) Figure 4-13: Preliminary Layout of 5 mgd Nova Ultrascreen Filter, with Future Footprint for Phased Expansion to 30 mgd
Figure 4-14: Microfilter Cross Section
Figure 4-15: Preliminary Layout of 5 mgd Microfiltration System, with Future Footprint for Phased Expansion to 30 mgd
Figure 5-1: Simplified Schematic of a UV-Open Channel System Figure 5-2: Preliminary Layout of 5 mgd UV Open Channel Disinfection System, with Future Footprint for Phased Expansion to 30 mgd
Figure 5-3: Simplified Schematic of a In-pipe UV Disinfection System Figure 5-4: In-pipe UV Disinfection System
Figure 5-5: Schematic of Ozone Generation
Figure 5-6: Ozone Disinfection System
Figure 6-1: Preliminary Layout of 5 MG Earthen Basins
Figure 6-2: Preliminary Layout of 5 MG Steel Tank
Figure 6-3: Preliminary Layout of 5 MG Prestressed Concrete Tank Figure 6-4: Train A Aeration Basin Converted to Storage Basin CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
LIST OF FIGURES
LIST OF FIGURES (CONTD…)
Figure 7-1: Membrane Bioreactor (MBR) Consisting of Activated Sludge Bioreactor and Membrane Filtration
Figure 7-2: 5 MGD MBR - Train A
Figure 7-3: 10 MGD MBR - Train A
Figure 7-4: 5 MGD MBR - Train B
Figure 7-5: 10 MGD MBR - Train B
Figure 9-1: 12 mgd MBR - Membranes inside Secondary Clarifier No. 5 Figure 9-2: 12 mgd MBR - Membranes inside New Structure Figure 9-3: In-pipe UV Disinfection System Preliminary Layout Figure 10-1: Selected Filtration, Disinfection, and Storage Scheme Figure 10-2: Plan B Nova Ultrascreen Filter Preliminary Layout Figure 10-3: Plan B UV Disinfection System Preliminary Layout Figure 10-4: Plan C Nova Ultrascreen Filter Preliminary Layout Figure 10-5: Plan C UV Disinfection System Preliminary Layout Figure 11-1: Plan “A” Preliminary Layout
Figure 11-2: Plan “C” Preliminary Layout
Figure 15-1: 5 mgd – Retrofit MBR Layout
Figure 15-2: 5 mgd – New MBR Layout
Figure 16-1: Simplified Schematic of Recommended Project for TTDF Figure 16-2: Recommended MBR System on “Green Field”
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 1
EXECUTIVE SUMMARY
BACKGROUND
New Water Source – Recycled Water
The City of Fresno (City) has embarked on development of a new water source – recycled water, to offset potable water use and improve ground water quality. The City prepared a Recycled Water Master Plan (July 2010) to assess potential uses and demand for recycled water.
The City’s ultimate goal is to recycle 25,000 acre feet/year or more of recycled water by 2025.
The recycled water goal includes direct non-potable use of State of California Title 22 quality recycled water for landscape irrigation as well as for groundwater recharge. The City anticipated that the project would be developed in three logical phases and decided to construct a 5 to 10 mgd first phase Tertiary Treatment and Disinfection Facility (TTDF) at their Fresno-Clovis Regional Water Reclamation Facility (RWRF).
During the master planning efforts, although the City had decided on the approximate capacity of the TTDF, the tertiary treatment technology, system layout and location of the facilities were not finalized. These tasks have been performed as part of the pre-design and are summarized in this technical memorandum (TM). Therefore, this pre-design TM, in addition to developing the design basis, focuses on evaluation and selection of a filtration technology out of eight (8) proven California Department of Public Health (CDPH) approved technologies, a disinfection technology between UV irradiation and ozonation, and a recycled water storage system from several options.
Nitrogen Removal and Effluent Electrical Conductivity (EC) The RWRF’s discharge currently has a limit for electrical conductivity (EC) of 500 micro mhos/cm + EC of the source water. Meeting this limit is a challenge and may require various measures including source water treatment or replacement, expensive systems to remove salts in wastewater, industrial source control and/or public education on waste minimization. The various alternatives presented, including Membrane Bio Reactor (MBR), may not be effective removing all salts from the final effluent. However, MBR technology could help reduce EC levels through its reliable nitrification/denitrification (NDN) capability. Parsons estimates that effluent EC can be reduced by about 150 micro mhos/cm through NDN in the MBR permeate, as ammonia is converted to nitrogen gas and escapes into the atmosphere.
During the past few years, the RWRF has experienced a reduction of the effluent EC through an incidental NDN process that reduced ammonia to nitrogen gas. The reduction in the effluent was estimated between 8% to 9.5% of the total EC influent, enough to maintain compliance with the Waste Discharge Requirements (WDR) discharge limit.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 2
North Fresno Wastewater Reclamation Facility, operated by the City, was issued a WDR/NPDES permit on December 10, 2009 by the Central Valley Regional Water Quality Control Board (RWQCB) with a Total Nitrogen (TN) limit of 10 mg/L for the recycled water used for golf course irrigation. It is expected that the proposed TTDF at the RWRF will also have a similar TN limit for irrigation water. This means that it will be short sighted to design the TTDF with no consideration for nitrogen removal.
Aging Train A Infrastructure
Train A facilities, reportedly, are old, of obsolete design and are difficult to operate and maintain. Further, nitrogen removal cannot be achieved reliably with the current configuration of the aeration basins in Train A. Discussions with the City’s operations staff indicated that the ceramic disc diffusers installed in the aerations basins need replacement/cleaning and it may not be possible to restore them to their original state due to their age. Further, the aeration pipe grids that connect the diffusers are old and unique to the type of diffusers currently installed. The secondary clarifiers in Train A are in need of central column and scraper mechanism replacement. Based on the above extensive repair/replacement needs related to Train A infrastructure coupled with the long age of the equipment, it appears that replacement of Train A facilities in the near future would be a prudent measure, if the intention is to continue to use Train A for the long term.
MBR - A CLEAR CHOICE FOR HOLISTIC SOLUTION
Considering the regulatory requirements discussed earlier and long age of Train A facilities, a decision was made to consider the MBR process as a potential alternative to conventional tertiary filtration technologies. The MBR system followed by ultraviolet disinfection offers a multi faceted solution and provides the following four key benefits. • Excellent Filtration – Produces the highest quality recycled water with effluent turbidity consistently less than 0.2 NTU. The MBR permeate is superior in quality compared to effluent from any conventional tertiary filtration process and exceeds Title 22 standards for recycled water.
• Simultaneous Nitrification and Denitrification (NDN) – Provides effluent that meets the expected permit limits, specifically Total Nitrogen (TN) of less than 10 mg/L, without significant infrastructure addition.
• Reduction in EC – Due to its NDN capability, a measurable reduction in EC can be achieved by using MBR process.
• Future Capacity Replacement – Provides a means for reliable, phased capacity replacement of aging infrastructure at Train A, with one of the most advanced and state-of-the-art membrane filtration technologies that will consistently and reliably meet current and future discharge regulations. This would avoid substantial costs associated with replacing and/or upgrading of Train A facilities in the near future, if tertiary filters were used in lieu of an MBR system.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 3
Based on the above considerations, MBR will be more cost effective compared to conventional filtration systems, when considering its ability to produce high quality effluent with nitrogen removal and avoided cost of future upgrades/replacement of Train A facilities for nitrogen removal.
The scope of this TM evolved around the City’s recycled water goals and associated electrical power supply options. Although a major part of this TM focuses on evaluation and selection of a conventional filtration technology, Sections following Workshop No.1 (Sections 8 through 13) compare conventional tertiary filtration systems with MBR system.
During Workshop No. 2 (Section 14), the decision was made in favor of MBR process due to the key benefits discussed above. Therefore, the last Section (Section 15) of this TM, which serves as a standalone section with MBR as the system of choice, has been printed on color paper to differentiate it from the rest of the report.
The proposed TTDF needs to become an integral part of the RWRF for its operation, reliability and compliance with the near term and future regulatory requirements. Further, the SCADA system of the proposed TTDF should fully integrate with the existing RWRF SCADA system for smooth and reliable operation.
COMMUNICATION AND DECISION WORKSHOPS
Since the inception of this project, Parsons maintained regular interaction and discussions with the City’s staff throughout the development of this TM. The feedback received from the City’s staff helped Parsons immensely to understand the plant’s operational and maintenance constraints as well as City’s preferences and to incorporate them into the TM. Two full-day technical Workshops were conducted at the RWRF to review and discuss the progress of this TM development. The first Workshop was held on 11/4/2010 while the second one was conducted on 2/3/2011.
Sections 3 through 7 present the work completed prior to Workshop No.1. This includes a comparison of eight conventional filtration system alternatives, three disinfection system alternatives/variations, and three storage alternatives. Features of operation, pros and cons, reliability, expandability to 30 mgd, capital, O&M and life cycle costs were compared and discussed. Section 8 summarizes the discussions and decisions made during Workshop No.1.
The following are the key collective decisions made during Workshop No.1.
1. Nova filtration system will be the preferred conventional filtration technology, if filtration is considered over MBR process.
2. In-pipe UV disinfection will be used for all alternatives
3. Depending on the physical configuration of the alternative, either pre-stressed concrete tanks or converted Train A aeration basins will be used as storage tanks for recycled water.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 4
4. Due to aging infrastructure at Train A, only Train A will be considered for retrofitting into MBR system.
Moving forward, three Plans were identified for further development. Plan A – Conversion of Train A facilities into a 12 mgd MBR with 1.23 peaking factor. This plan includes conversion of one secondary clarifier into aeration basin for MBR; building new tank(s) to house membranes; constructing new housing for in-pipe UV reactors and conversion of one aeration basin into recycled water storage Plan B – 5 mgd constant flow conventional filtration (Nova disc filter) system for Train B.
This plan includes feed from Canal B at a constant flow rate, Nova disk filters for filtration, construction of new housing for in-pipe UV reactors, and building new prestressed concrete tank (5 MG) for recycled water storage Plan C – 12 mgd constant flow conventional filtration (Nova disk filter) system for Train B.
These Plans are discussed in detail in Sections 9, 10 and 11. Section 11 presents a comparison of Plan A with Plan C. Section 12 describes the power source options for TTDF with both conventional filtration and MBR system for a 12 mgd facility expandable to an ultimate capacity of 30 mgd. The Section includes a duct bank and cable routing plan for the two alternative systems. These routing plans were developed after a thorough review of the Plant’s record drawings and in close coordination with City’s electrical engineers. Utilization of existing conduits was maximized to the extent possible in both the alternatives.
During Workshop No. 2, in addition to the option of converting Train A facilities into MBR, the City expressed their interest to explore the option of having MBR designed and built as a separate stand-alone system with all new structures.
As a result of the discussion during Workshop No.2, the following two MBR alternatives are selected over the conventional tertiary filtration alternatives for further development and City’s review and final decision.
1. Converting Train A into MBR – (5 mgd constant flow; no peaking factor) – This is similar to Plan A as discussed in Section 9 of this report, except that the capacity will be 5 mgd constant flow instead of 12 mgd with peaking factor.
2. Constructing a separate standalone MBR system with all new tanks – (5 mgd constant flow; no peaking factor)
Sections 14 and 15 summarize the latest developments, subsequent to Workshop No.2. Section 14 sets the stage for a new project direction provided by the City during Workshop No.2. and steers the discussion into Section 15, which compares the two MBR alternatives noted above.
Figures 15-1 and 15-2 present the preliminary layouts for the two alternatives.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 5
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 6
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 7
IN-PIPE UV FOR DISINFECTION
During Workshop No.1, the City chose in-pipe UV disinfection as opposed to an open channel UV system. One of the major drivers was the positive feedback received from the staff at neighboring Clovis Water Reuse Facility in operating and maintaining their in-pipe UV system.
Therefore, for the purpose of this TM, 1-mgd capacity in-pipe UV reactors were considered.
The 1 MGD rating for each reactor is based upon high quality membrane permeate feed such as from the MBR system. Four reactor trains (3 operating + one standby) will be required to disinfect 5 mgd of flow and each train will accommodate two reactors. There are several larger in-pipe reactors currently available from other manufacturers that may be more economical for the present project and will be evaluated during detailed design.
CONVERSION OF AERATION BASIN (TRAIN A) FOR RECYCLED WATER STORAGE It was determined that the aeration basins at Train A, with sloping walls could be retrofitted into recycled water storage tanks. According to the City’s staff, at least one of the units in Train A is typically out of service and hence conversion of one aeration basin into recycled water storage tank will not negatively impact the current plant operations. Further, due to the proximity of the proposed MBR facilities to Train A, conversion of one of the aeration basins into a storage tank would be a prudent choice.
PRELIMINARY COSTS
Preliminary costs were developed for two alternatives described earlier - retrofitting the existing facilities in Train A for aeration basins of MBR system or using completely new structures for this purpose. The costs estimated are according to Class 4 level per AACE (Association for the Advancement of Cost Engineering) guidelines. At this point in the design process, these costs are preliminary and should be used only for comparative purposes. The costs were estimated using several resources. Quotes from the manufacturers, information available from similar projects performed by Parsons, including construction in the Central Valley, were used to determine these costs.
Avoided Cost of Future Upgrades/Replacement of Train A
As disused earlier, a credit could be given to compensate for the cost of replacing and upgrading Train A in the near future, which would occur under conventional filtration alternatives but not under MBR alternatives. To estimate this credit, $3-$4 per gal of wastewater treated was used as the cost basis, which would translate into $15-$20 million of avoided future capital investment for a 5 mgd system. For the purposes of cost comparison, $18 million is considered as avoided capital replacement cost. Note that the estimated avoided cost is based on constructing new basins to remove nitrogen but without new aeration blowers.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
EXECUTIVE SUMMARY 8
Table ES-1: MBR Alternatives Capital Cost (5 mgd) a
Parameter
Capital Cost ($ Million)
Retrofit MBR New MBR
MBR Equipment and Structures Cost 8.4 8.7
MBR Total Capital Cost 24.5 b 24.4
UV Disinfection Total Capital Cost 5.3 b 5.3
Storage (Aeration Basin No. 3 or 4) Total Capital Cost 3.1 b 3.1 Total Capital Cost 32.9 32.8
a For detailed cost analysis see Appendix A. b Including installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012-2013) c Near future replacement cost of Train A facilities equivalent to 5 mgd capacity
DISCUSSION AND CONCLUSION
It is evident from the data presented in Table ES-1 above that the two MBR alternatives compared are very close to each other from a cost standpoint. The capital cost difference between the two alternatives is insignificant and is within the margin of error of our estimates.
The concrete savings realized by retrofitting existing structures is balanced by less extensive piping required by using new structures.
However, using all new structures offers a more flexible and compact design. By properly planning the new facilities, they can be built in a monolithic construction with common walls, which would make it easier to build and more efficient to operate. The future expansion of tertiary facilities would follow the same compact pattern. Also, the design would not need to be tailored based on the constraints of existing facilities, but based on the best design practices. For example, deeper new aeration basins compared to the retrofitted basins would allow for a more efficient aeration system.
Further, a separate standalone MBR system will be easier to construct and will also provide some redundant treatment facilities associated with that particular train in the interim and for several years until the City decides to totally decommission that train due to its obsolescence.
Based on the above discussion, Parsons recommends using all new structures for constructing the MBR system, as it would be a more prudent and reliable approach to achieve filtration, nitrogen removal and future capacity replacement for Train A.
Train A Capacity Replacement (Avoided Cost) (18) c (18) Net Effective Capital Cost 14.9 14.8
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 1 - INTRODUCTION AND OBJECTIVE 1-1
SECTION 1 - INTRODUCTION AND OBJECTIVE
1.1 BACKGROUND
The City of Fresno (City) mainly relies on groundwater as the primary drinking water resource where the groundwater level is approximately 300 feet below ground surface. To conserve valuable drinking water resources, the City plans to use tertiary treated recycled water for landscape irrigation as well as for commercial and industrial uses. Also the City plans to maximize the recharge of groundwater with high quality recycled water. The City’s goal is to recycle 25,000 acre feet/year or more of recycled water by 2025. Therefore, the City is embarking upon new projects to design and construct a tertiary treatment and disinfection facility (TTDF) at the City of Fresno-Clovis Regional Water Reclamation Facility (RWRF) and new recycled water distribution system including pipelines, pump stations and storage reservoirs.
The new recycled water distribution system will deliver disinfected tertiary recycled water to potential recycled water use sites according to the City’s Recycled Water Master Plan that is currently being prepared.
The size of the new TTDF will have an initial capacity of 5 to 10 million gallons a day (mgd) in response to the immediate recycled water demand identified in the Recycled Water Master Plan; however it will ultimately expand to 30 mgd over the years to accommodate more users.
The City’s initial plan was to expand the TTDF in phases: the first phase (Phase I) would have a capacity of 5 mgd, the second phase (Phase II) would have a capacity of 10 mgd for a total of 15 mgd, and the third phase (Phase III) would have a capacity of 15 mgd for a total of 30 mgd. The City is now considering a Phase I capacity of 5 to 10 mgd, depending on the system selection and associated economics. If the Phase I is constructed for a capacity greater than 5 mgd, the capacity of subsequent phases will be adjusted accordingly. A phased expansion approach is prudent for several reasons:
• Recycled water demand will be low initially, but will increase over the years. • It will minimize initial capital outlay.
• This approach takes advantage of emerging technologies in the area of recycled water production as new technologies emerge and are developed and optimized over the years, e.g., ultraviolet (UV) disinfection, ozonation, membrane filtration and so forth. • Public acceptance of recycled water and hence the demand for that water will increase over the years.
The proposed TTDF needs to become an integral part of the RWRF for its operation, reliability and compliance with the near term and future regulatory requirements. Train A, the oldest treatment train at RWRF, is dated and has operational issues and therefore is a candidate for replacement in the near future with a more reliable and state-of-the-art treatment system.
Furhter, the SCADA system of the proposed TTDF should fully integrate with the existing RWRF SCADA system for smooth and reliable operation.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 1 - INTRODUCTION AND OBJECTIVE 1-2
1.2 SCOPE AND OBJECTIVES
Key objectives of this project include:
• Design and construct the first phase of the TTDF to match the demand of 5 to 10 mgd. • Consider proven, cost effective and state-of-the-art technologies for upgradability and expandability in the future to a capacity of 30 mgd.
• Develop phased site master plan for ultimate 30 mgd capacity. • Design treatment facilities that meet Title 22 irrigation and groundwater recharge requirements and could be retrofitted in the future to meet more stringent effluent quality requirements, if needed, in a cost effective manner, such as nitrogen removal. • Consider facilities that present desired flexibility and redundancy as required for California Department of Public Health (CDPH) Title 22 criteria. • Design facilities which are easier to operate.
• Consider full integration of TTDF control system (SCADA, etc.,) with the existing facilities at RWRF’s control system.
More specifically, the following eight types of commonly used filters will be evaluated for tertiary filtration:
• Dual media gravity filters
• Deep bed mono-media gravity filters
• Continuous backwash filters
• Traveling bridge filters
• Fuzzy FiltersTM
• Cloth media disk filters
• Nova Ultrascreen® filters
• Microfilters
In addition to the alternatives above, membrane bioreactors (MBR), which replace secondary clarifiers and provide filtration at the same time, will also be evaluated.
The filtered effluent in all cases will be disinfected to meet the State of California Title 22 requirements for unrestricted reuse. Both UV disinfection and ozone will be evaluated for this purpose. Disinfection by gaseous or liquid chlorine (NaOCl) was not considered at the suggestion of the City, due to extensive operation and maintenance requirements associated with chlorine storage, handling and pumping and due to its potential to form toxic disinfection by products (DBP). A storage tank, 5 million gallons (MG) capacity, will be provided for storage of the final effluent/recycled water before it can be pumped though the recycled water distribution system.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 2 - EXISTING RELEVANT TREATMENT FACILITIES 2-1
SECTION 2 - EXISITNG RELEVANT TREATMENT FACILITIES
2.1 EXISTING FACILITIES AT THE CITY OF FRESNO CLOVIS REGIONAL WATER
RECLAMATION FACILITY (RWRF)
The existing RWRF located at 5607 W. Jenson Avenue in Fresno, is designed for a capacity of 80 mgd average annual flow while the current plant flow is about 64 mgd. The wastewater entering the plant is received at the headworks, which includes an influent pump station, bar screens, grit removal tanks, and grit processing equipment. After the preliminary treatment at the headworks, the wastewater is provided with primary treatment by six clarifiers. The primary effluent from these clarifiers is distributed to three trains of secondary treatment facilities (Trains A, B and C). See Figure 2-1 below.
Figure 2-1: Relevant Facilities
Train A is the oldest one. It consists of four square aeration basins and four square secondary clarifiers. Train A has several operational and maintenance issues as summarized in Section 14 of this TM. Train B is the next oldest one. It consists of four rectangular aeration basins and eight rectangular secondary clarifiers. This train is located between trains A and C. Train C is the newest train. It consists of two rectangular aeration basins and four rectangular secondary clarifiers. The effluent from the plant flows into two canals on the site and finally from there to percolation ponds. The RWRF is in compliance with all the current regulatory requirements, except for Electrical Conductivity (EC) and occasionally other constituents such as chlorides, manganese and arsenic. Relevant design information for the three trains is provided in Table 2- 1 with a brief schematic shown in Figure 2-2.
Train A
Train B
Train C
RAS/WAS Pump
Station
Blower
Buildings
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 2 - EXISTING RELEVANT TREATMENT FACILITIES 2-2
Table 2-1: Existing Relevant Facilities - Major Design Information1 Parameter Units Train A Train B Train C Total
Rated Average Flow 2 mgd - - - 80
Rated Max Month Flow 2 mgd - - - 88
Aeration Basins, Blowers, and Air Supply System
Number - 4 4 2 10
Volume, Each MG 2.7 2.6 2.7 26.6
Side Water Depth (SWD) ft 16 17 17 -
Mixed Liquor Suspended
Solids (MLSS)
mg/L 2,500 -
3,000
2,500 -
3,000
2,500 -
3,000
-
Solids Retention Time (SRT) days 4 - 5 4 - 5 4 - 5 -
Blower Type - Single-stage centrifugal (Turblex) -
Blower No. - 6 (Located in Two Buildings) -
Bower Capacity, Each scfm 27,000 162,000
Diffuser Type - Ceramic
Dome
Ceramic
Plate
Membrane -
Secondary Clarifiers
Number - 4[3] 8 4 163
Volume, Each MG 2.36 0.93 0.93 20.6
SWD ft 14 13 13 -
1 Values obtained from 2006 conformed drawings. SRT was obtained from Water Environment & Technology (WE&T) paper, June 2009
2 Per Waste Discharge Report (WDR) Order No. 5-01-254 - See Appendix C) 3 Train A circular secondary clarifier (clarifier no.5) is not included.
Even though the current discharge permit only requires Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) removal (40 mg/L BOD and 40 mg/L TSS in the effluent), the operations staff has been able to achieve some nitrification and denitrification by dissolved oxygen (DO) control at strategic locations and maintaining a higher (4-5 days) SRT in the aeration basins.1
1 “How Low is Too Low?” Schuyler, Ronald G et.al., WE&T Journal, June 2009 CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 2 - EXISTING RELEVANT TREATMENT FACILITIES 2-3
Figure 2-2: Existing Relevant Facilities - Current Operation Train A, as pointed out above, is the oldest and is of obsolete design. The aeration basins are square shaped with sloping side walls. The mixed liquor is difficult to mix and aerate, the design is inefficient and does not allow plug flow regime (nearly essential to achieve high efficiency in a biological reactor), and operation and maintenance is less than optimum with sloping “gunited” walls. Further, based on Parsons’ discussions with City’s operations staff, Train A has immediate need for significant repairs/replacements (See Section 14 for details).
Trains B and C, however, are of newer construction and are well designed and operated. They have concrete walls and employ plug flow in reactors. The associated secondary clarifiers are also of proper design in terms of detention time, surface settling rates and other important criteria.
Therefore, the City believes and Parsons concurs, that in the current TTDF project, if any existing facilities should be upgraded and/or modified for reuse, they should be of Train A.
Train A
Train B
Train C
Flow 65 - 70 mgd
BOD 200- 220 mg/L
TSS 100 - 120 mg/L
NH3-N 28 – 32 mg/L
Primary Effluent
Secondary Effluent
BOD 10 - 20 mg/L
TSS 5- 10 mg/L
NH3-N 10– 20 mg/L
Canal A
Canal B
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 2 - EXISTING RELEVANT TREATMENT FACILITIES 2-4
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CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
PRE-WORKSHOP ANALYSIS
PRE-WORKSHOP NO.1 ANALYSIS (SECTION 3 - SECTION 7)
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 3 - PLANNED TERTIARY TREATMENT AND DISINFECTION FACILITY (TTDF) 3-1 SECTION 3 - PLANNED TERTIARY TREATMENT AND DISINFECTION
FACILITY (TTDF)
3.1 GENERAL
As described in the previous Sections of this Technical Memorandum (TM), the City plans to construct a 5 to 10 mgd TTDF at the RWRF under first phase. This facility will consist of a 5 to 10 mgd filter feed pump station, a new conventional filtration system, a disinfection system, and a 5 million gallon (MG) storage tank along with post-chlorination and recycled water distribution pump station. The recycled water treated at the TTDF will be used for unrestricted landscape irrigation. The City, in the future, may also use the recycled water for ground water recharge, which requires removal of nitrogen to comply with the CDPH guidelines for recycled water recharge. The TTDF will be located in an open area north of Canal “B.” During the Schematic Design Phase, a preliminary layout of 5 to 10 mgd TTDF expandable to ultimate capacity of 30 mgd will be prepared. Figure 3-1 below shows the planned TTDF in the overall RWRF treatment scheme. A simplified schematic of the TTDF and its unit processes is shown in Figure 3-2.
Figure 3-1: Planned TTDF
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 3 - PLANNED TERTIARY TREATMENT AND DISINFECTION FACILITY (TTDF) 3-2 Figure 3-2: Simplified Schematic of the TTDF
A detailed analysis of the alternative technologies considered for evaluation for filtration, disinfection and storage systems is presented in Sections 4, 5 and 6, respectively, of this TM.
3.2 FILTER FEED PUMP STATION
A new filter feed pump station will be located adjacent to the existing effluent junction box to feed the secondary effluent to the proposed filters. The pump station will be sized to accommodate a total of four (4) vertical turbine pumps: two (one duty and one standby) will be installed for 5 mgd capacity and two more will be installed for next 10 mgd expansion of the TTDF. Space will be left for expansion of the pump station to 30 mgd.
3.3 FILTRATION
The following eight CDPH approved conventional filtration technologies will be evaluated to select the preferred filtration technology:
• Dual Media Gravity Filters
• Deep Bed Monomedia Filters
• Continuous Backwash Filters
• Traveling Bridge Filters
• Fuzzy Filters
• Disk (Cloth Media) Filters
• NOVA Ultrascreen Filters
• Microfiltration
In addition to the alternatives above, MBR, which replaces secondary clarifiers and provides filtration at the same time, will also be evaluated as an alternative to conventional filtration.
3.4 DISINFECTION
To select the most viable technology for the TTDF, proven disinfection technologies including CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 3 - PLANNED TERTIARY TREATMENT AND DISINFECTION FACILITY (TTDF) 3-3 UV radiation (open channel and in-pipe) and ozonation will be evaluated. Only low-pressure high-intensity UV lamps will be considered for both open channel and in-pipe UV disinfection.
Ozonation alternative will only consider the use of liquid oxygen for ozone generation. Section 5 of this TM provides a detailed analysis of disinfection system alternatives.
3.5 STORAGE
The proposed TTDF will include a 5 MG recycled water storage tank. The storage tank will have a recycled water distribution pump station. The following four alternatives for the storage tank construction will be evaluated to select the most viable alternative:
• Earthen Basins (lined and covered)
• Steel Tank
• Concrete Tank
• Conversion of an existing aeration basin from train A (capacity will be limited to 2.7 MG) – only for MBR option
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
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CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-1 SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS
4.1 BACKGROUND
As noted in Section 1, the City’s goal is to produce 25,000 acre-ft/year of recycled water by 2025. This Section of the TM presents the eight filtration alternatives that were evaluated for the TTDF.
As described earlier, the existing facilities at the RWRF are designed to treat an average wastewater flow of 80 mgd. The existing RWRF produces secondary effluent that is well within the permitted BOD and TSS limits, as indicated in Table 4-1 below.
Table 4-1: Secondary Effluent Permitted Quality and Currently Achieved Quality Parameter Units WDR Permit Limit1
(Monthly Average) Currently Achieving
BOD5 mg/L 40 10 - 20
TSS mg/L 40 5 - 10
1 WDR Order No. 5-01-254 (See Appendix C)
To comply with CDPH standards for unrestricted reuse (Title 22) of wastewater effluent, the secondary effluent must be coagulated (although this requirement can be waived - see below), filtered, and disinfected. By removing a majority of the suspended solids and turbidity, filtration enhances the effectiveness of the downstream disinfection process.
Per Title 22 standards, when media filtration is used, the filtered effluent turbidity must not exceed a daily average of 2 Nephelometric Turbidity Units (NTU), 5 NTU more than 5% of the time within a 24 hour period, and 10 NTU at any time. These turbidity maxima were developed based on the Pomona Virus Study conducted by the County Sanitation Districts of Los Angeles County (CSDLAC, 1977), which correlated the turbidity values with successful disinfection as measured by total coliforms (less than 2.2 per 100 ml for Title 22 tertiary effluent) and viruses.
When membrane filtration is used, the filtered effluent turbidity must not exceed 0.2 NTU more than 5% of the time within a 24 hour period, and 0.5 NTU at any time. Table 4-2 below summarizes Title 22 tertiary effluent criteria.
Table 4-2: Tertiary Effluent (Title 22) Criteria
Parameter Units Value
Turbidity for Media Filtration NTU ≤2 Daily Average, ≤5 95% of the time within a 24 hour period, ≤10 at all times
Turbidity for Membrane
Filtration
NTU ≤0.2 NTU 95% of the time within a 24 hour period, ≤0.5 NTU at all times
Filter Loading Rate gpm/ft2 2 – 30
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-2 Title 22 standards state that coagulation may be waived if the filter effluent does not exceed 2 NTU, the filter influent is continuously measured, the filter influent turbidity does not exceed 5 NTU, and automatically activated chemical addition or diversion facilities are provided in the event filter influent turbidity exceeds 5 NTU. The current secondary effluent quality data suggests that the RWRF meets the filter influent criteria for waiving the coagulation requirement. To enhance reliability and provide a prudent design, automatically actuated coagulation will be provided in the event filter influent turbidity exceeds 5 NTU.
There are several CDPH approved filtration technologies which generally fall into the following eight categories:
• Dual media gravity filters
• Deep bed monomedia filters
• Continuous backwash filters
• Traveling bridge filters
• Fuzzy filters
• Cloth media filters
• Nova Ultrascreen filters
• Microfilters
Each of these categories of filters has a specific maximum allowable filtration rate approved by the CDPH. The approved rates are based on pilot tests conducted (typically by an independent testing agency) on these filters using secondary effluent from an actual wastewater treatment plant and measurement and verification of performance in these tests.
Operational reliability is an important criterion for recycled water systems and there are several options for meeting Title 22 reliability requirements, including (reproduced from California Code of Regulations, Title 22, Chapter 3, Article 10, Section 60351) :
• Alarm and multiple filter units capable of treating the entire flow with one unit not in operation.
• Alarm, short-term retention or disposal provisions and standby replacement equipment. • Alarm and long-term storage or disposal provisions.
• Automatically actuated long-term storage or disposal provisions. • Alarm and standby filtration unit process.
For the purposes of filtration system alternative analysis in this TM, multiple filter units capable of treating the entire flow with one unit not in operation were considered. However, it should be noted that the RWRF does currently have long term disposal provisions under its existing WDR Order No. 5-01-254.
This TM presents the features of operation, advantages and disadvantages, design criteria, preliminary layout drawings, and preliminary construction, O&M, and 20 year life-cycle cost estimates for each of the eight filtration technologies. The evaluations consider a filtration capacity of 5 mgd constant flow (enough to satisfy near-term recycled water demand identified in the City’s Recycled Water Master Plan).
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-3
4.2 FILTRATION SYSTEM ALTERNATIVES
4.2.1 Dual Media Gravity Filters
Features of Operation
Dual media filters are custom designed filters employing anthracite (typically 18-inches depth) and sand (typically 12-inches depth) media. The anthracite medium layer is above the sand medium layer. The sand medium is supported by a layer of gravel (in order to prevent plugging of underdrain nozzles/orifices and to distribute the backwash water evenly across the filter) which, in turn, is supported by the filter underdrain system. Many underdrain systems, however, are now capable of supporting the media directly, without the need of a gravel layer.
Solids are removed by a variety of mechanisms including straining, sedimentation, impaction, interception, and adhesion (removal mechanisms that are common to all granular media depth filters). Figure 4-1 below presents a simplified schematic of a granular media depth filter.
Figure 4-1: Simplified Schematic of a Granular Media Depth Filter Over time, the solids accumulate within the voids of the filter bed, increasing the headloss across the filter. After the headloss exceeds a certain allowable level or after the filtered turbidity exceeds the allowable level, the filter must be backwashed in order to remove the accumulated solids. In the majority of operating filtration systems, headloss is used as the criteria for backwashing. The backwashing sequence in these filters is automatic and programmable so that backwashing occurs first with air only (approximately 3 minutes, but to be preselected), then air and water (approximately 5 minutes, but to be preselected), and then water only (approximately 10 minutes, but to be preselected). Two backwash pumps (one duty and one standby) and two air scour blowers (one duty and one standby), sized for backwashing one filter cell at a time, are provided. The backwash velocity is enough to fluidize the bed while avoiding media loss. In other words, the backwash velocity is controlled such that height of the fluidized bed does not exceed the level of the wash trough. The backwash waste is collected in the wash trough and is sent to a backwash waste storage tank. From the backwash waste CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-4 storage tank, the backwash waste is pumped at a controlled rate back to the headworks via return pumps. The length of a filter run (i.e. the time between filter cell backwashes) is conservatively 24 hours; however, the length of a filter run will depend upon the filter influent quality. Influent with higher turbidity would require more frequent backwashes and vice versa.
The typical headloss through the filter is 2 (clean bed) - 10 (dirty bed) feet. The backwash waste production rate varies depending upon the filter influent quality, typically ranging between 5 - 15% of the filter influent flow rate.
Advantages and disadvantages of dual media gravity filters are summarized in Table 4-3 and the design criteria are summarized in Table 4-4. A preliminary layout for the dual media gravity filters at the TTDF is presented in Figure 4-2. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented. Note that one redundant filter cell is planned for the 5 mgd and 15 mgd systems and two redundant filter cells are planned for the 30 mgd system. Preliminary construction, O&M, and 20 year life-cycle cost estimates for dual media filters are presented in Table 4-5.
Advantages and Disadvantages
Table 4-3: Dual Media Filter Advantages and Disadvantages Advantages Disadvantages
Dual media filters are proven, with many long-operating installations.
Backwashes produce a large, instantaneous flow of
backwash waste - which requires storage. The
backwash waste storage tank is large (sized for two
backwashes), adding to capital costs.
Dual media filters are, by virtue of their ample storage capacity, less susceptible to upsets and breakthrough
than other filtration technologies that do not employ
depth filtration.
Backwashing requires that a filter cell be taken off-line.
Dual media filters are non-proprietary (both in terms of design and materials e.g. media) and can be
competitively bid.
Concrete and piping requirements are high.
Expansion of the filter requires the construction of
additional filter cells.
Operating issues, such as loss of media and
destratification of media, will occur over time.
Chlorine dosing is recommended for algae control.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-5 Design Criteria
Table 4-4: Dual Media Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 5
Number of Filter Cells 4
Dimensions of Each Cell,
Length (ft) x Width (ft) x Depth (ft)
16 x 16 x 15.5
Total Filtration Area, ft2 1,024
Filtration Rate with One Filter Backwashing, gpm/ft2 4.5 Backwash
Type Air-water (Air, Air & Water, Water)
Rate, Air and Water Cycle
Air, scfm/ft2 3 to 5
Water, gpm/ft2 8 to 9
Rate, Water Cycle Only, gpm/ft2 16 to 18
Underdrain Type False Bottom with Nozzles or Underdrain Blocks Backwash Waste Storage Tank Capacity 2 Backwashes
Headloss Through Filter, ft (Operating) 10
Preliminary Layout
Figure 4-2: Preliminary Layout of 5 mgd Dual Media Filter, with Future Footprint for Phased Expansion to 30 mgd
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-6 Cost Summary
Table 4-5: Dual Media Filter Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 1,600,000
Total Capital Costa 4,300,000
Total Annual O&M Costb 90,000
20-Year Life Cycle Cost c 5,900,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
4.2.2 Deep Bed Monomedia Filters
Features of Operation
The features of operation for deep bed monomedia filters are essentially identical to dual media gravity filters, with the only major difference being the media - deep bed monomedia filters employ a single medium (typically anthracite with a depth of 48-inches). The length of a filter run, the operating headloss across the filter bed, and the backwash waste production rate for deep bed monomedia filters are essentially the same as for dual media gravity filters (refer to Section 4.2.1).
Advantages and disadvantages of deep bed monomedia filters are summarized in Table 4-6 and the design criteria are summarized in Table 4-7. A preliminary layout for the deep bed monomedia filters at the TTDF is presented in Figure 4-3. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented. Note that one redundant filter cell is planned for the 5 mgd and 15 mgd systems and two redundant filter cells are planned for the 30 mgd system. Preliminary construction, O&M, and 20 year life-cycle cost estimates for deep bed monomedia filters are presented in Table 4-8 below.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-7 Advantages and Disadvantages
Table 4-6: Deep Bed Monomedia Filter Advantages and Disadvantages Advantages Disadvantages
Deep bed monomedia filters are proven, with many
long-operating installations.
Backwashes produce a large, instantaneous flow of
backwash waste - which requires storage. The backwash
waste storage tank is large (sized for two backwashes), adding to capital costs.
Deep bed monomedia filters are, by virtue of their
ample storage capacity, less susceptible to upsets and
breakthrough than other filtration technologies,
including dual media gravity filters.
Backwashing requires that a filter cell be taken off-line.
Deep bed monomedia filters are non-proprietary (both
in terms of design and materials e.g. media) and can be competitively bid.
Concrete and piping requirements are high.
Deep bed monomedia filters use a single medium,
avoiding the problems with destratification of media
experienced with multimedia filters.
Expansion of the filter requires the construction of
additional filter cells.
Operating issues, such as loss of media, occur over time.
Chlorine dosing is recommended for algae control.
Design Criteria
Table 4-7: Deep Bed Monomedia Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 5
Number of Filter Cells 4
Dimensions of Each Cell,
Length (ft) x Width (ft) x Depth (ft)
16 x 16 x 17
Total Filtration Area, ft2 1,024
Filtration Rate with One Filter Backwashing, gpm/ft2 4.5 Backwash
Type Air-water (Air, Air & Water, Water)
Rate, Air and Water Cycle
Air, scfm/ft2 3 to 5
Water, gpm/ft2 8 to 9
Rate, Water Cycle Only, gpm/ft2 16 to 18
Underdrain Type False Bottom with Nozzles or Underdrain Blocks Backwash Waste Storage Tank Capacity 2 Backwashes
Headloss Through Filter, ft (Operating) 10
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-8 Preliminary Layout
Figure 4-3: Preliminary Layout of 5 mgd Deep Bed Monomedia Filter, with Future Footprint for Phased Expansion to 30 mgd
Cost Summary
Table 4-8: Deep Bed Monomedia Filter Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 1,600,000
Total Capital Costa 4,400,000
Total Annual O&M Costb 90,000
20-Year Life Cycle Cost c 6,000,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-9
4.2.3 Continuous Backwash Filters
Features of Operation
Continuous backwash filters, marketed under various names such as DynaSand, SuperSand, and TechnaSand, are deep bed granular media filters that are similar to the granular media filters discussed above in that solids are removed by straining, sedimentation, impaction, interception, and adhesion. However, there are a several major differences: the filter bed is continuously backwashed via an airlift pump and the filter operates as an up-flow filter rather than a down-flow filter. The filters are supplied in modules, either as packaged units (for low flow applications) or for installation in concrete basins (for high flow applications). Due to the continuous filter bed cleaning system, this type of filter requires a low operating head (about 3 feet). It also produces a continuous low rate of waste backwash flow to eliminate the need for flow equalization of the waste backwash before return to the main treatment plant. The backwash waste production rate is approximately 5% of the filter influent flow rate.
Figure 4-4: Continuous Backwash Filter (Figure from DynaSand®) As shown in Figure 4-4 above, sand containing captured solids is drawn though an airlift pipe and into a reject compartment. The sand is scoured within the airlift pipe, cleaning the sand before it is collected in the reject compartment. The scoured solids, which are less dense than the sand media, flow over the reject weir and into the reject pipe. The clean sand then returns to the filter bed though a sand washer, in which any remaining solids are removed and carried back into the reject compartment by a small amount of filtrate. Figure 4-4 above shows filter cells arranged in 2 x 2 configuration. For the TTDF, a 4 x 1 module configuration is planned.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-10 Advantages and disadvantages of continuous backwash filters are summarized in Table 4-9 and the design criteria are summarized in the Table 4-10. A preliminary layout for the continuous backwash filters at the TTDF is presented in Figure 4-5. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented. Note that one redundant filter cell is planned for the 5 mgd and 15 mgd systems and two redundant filter cells are planned for the 30 mgd system. Preliminary construction, O&M, and 20 year life-cycle cost estimates are presented in Table 4-11.
Advantages and Disadvantages
Table 4-9: Continuous Backwash Filter Advantages and Disadvantages Advantages Disadvantages
Continuous backwash filters are proven, with many
long-operating installations.
The design of continuous backwash filters is
proprietary.
Continuous backwash filters are, by virtue of their
ample storage capacity, less susceptible to upsets and
breakthrough than other filtration technologies that do not employ depth filtration.
Expansion of the filter requires the construction of
additional filter cells.
Continuous backwash filters have no moving parts. The
only mechanical component of this type of filter is an
air compressor to produce the air needed for the airlift pumps.
Air flow must be precisely controlled in order to prevent the loss of media.
Continuous backwashing eliminates the need for taking
a filter off-line for cleaning, storing backwash water and filtered water, and backwash waste return pumps.
Internal parts of the filter cannot be accessed for
maintenance without taking the filter offline and
removing the media.
Design Criteria
Table 4-10: Continuous Backwash Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 5
Number of Filter Cells 5
Dimensions of Each Cell,
Length (ft) x Width (ft) x Depth (ft)
28.3 x 7.1 x 16.2
Total Filtration Area, ft2 1,000
Filtration Rate with One Filter Backwashing, gpm/ft2 4.3 Backwash
Type Air
Rate, Air
Air, scfm per module (scfm per ft2) 2 - 3 (>150)
Headloss Through Filter, ft (Operating) 3
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-11 Preliminary Layout
Figure 4-5: Preliminary Layout of 5 mgd Continuous Backwash Filter, with Future Footprint for Phased Expansion to 30 mgd
Cost Summary
Table 4-11: Continuous Backwash Filter Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 1,300,000
Total Capital Costa 3,800,000
Total Annual O&M Costb 105,000
20-Year Life Cycle Cost c 5,600,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-12
4.2.4 Traveling Bridge Filters
Features of Operation
Traveling bridge filters, marketed under various names such as ABW, AquaABF, and Gravisand, are shallow bed (typically 11-inches) granular media filters that are installed in a segmented bed arrangement. The backwash system is suspended from a bridge that moves across the bed.
A pump takes filtered water from the effluent channel and directs it back into a segment of the filter bed, forcing the water back up through the filter bed, dislodging the particles removed from the wastewater. A second pump, attached to a hood that covers the segment being backwashed, draws the waste backwash water into the hood and discharges it into a trough for return to the head of the treatment plant.
Figure 4-6: Traveling Bridge Filter (Figure from ABW®)
As with other filtration technologies, the backwash frequency and backwash waste production rate vary depending upon the filter influent quality; however, typically each filter is backwashed three times per day and the backwash waste production rate is typically 1 - 2% of the filter influent flow rate. The operating headloss across the filer is low, typically 2 - 12 inches of water. Typically, backwashing is initiated when a predetermined headloss across the filter bed is exceeded although the operator can choose to initiate backwashing after the filter effluent turbidity exceeds a predetermined set point.
Advantages and disadvantages of traveling bridge filters are summarized in Table 4-12 and design criteria are summarized in the Table 4-13. A preliminary layout for the traveling bridge filters at the TTDF is presented in Figure 4-7. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented. Note that one redundant filter cell is planned for the 5 mgd, 15 mgd, and CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-13 30 mgd systems. Preliminary construction, O&M, and 20 year life-cycle cost estimates for traveling bridge filters are presented in Table 4-14.
Advantages and Disadvantages
Table 4-12: Traveling Bridge Filter Advantages and Disadvantages Advantages Disadvantages
Traveling bridge filters are proven, with many longoperating installations.The design of traveling bridge filters is proprietary.
The backwashing arrangement eliminates the need for
taking a filter out-of-service for cleaning.
The CDPH approved filtration rate is low (≤2 gpm/ft2),
resulting in a large footprint.
Filter feed pump pressure requirements are lower due
to the shallow filter bed depth.
Expansion of the filter requires the construction of
additional filter cells.
The backwash system bridge has many moving parts.
The depth of the filter bed is shallow and the filter is more susceptible to upsets and breakthrough than deep
bed filters.
Design Criteria
Table 4-13: Traveling Bridge Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 2
Number of Filter Cells 2
Dimensions of Each Cell,
Length (ft) x Width (ft) x Depth (ft)
110 x 16 x 6.25
Total Filtration Area, ft2 3,520
Filtration Rate with One Filter Offline, gpm/ft2 1.97
Headloss Through Filter, ft (Operating) 1
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-14 Preliminary Layout
Figure 4-7: Preliminary Layout of 5 mgd Traveling Bridge Filter, with Future Footprint for Phased Expansion to 30 mgd
Cost Summary
Table 4-14: Traveling Bridge Filter Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 1,800,000
Total Capital Costa 4,800,000
Total Annual O&M Costb 80,000
20-Year Life Cycle Cost c 6,200,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-15
4.2.5 Fuzzy Filters
Features of Operation
Fuzzy filter is a proprietary filtration technology from Schreiber, LLC utilizing media consisting of highly porous (~90%) 1.25-inch diameter synthetic fiber spheres. The media is compressible, which allows the properties of the filter bed (including bed depth and porosity) to be controlled by the operator in response to changes in filter influent quality, amount of solids accumulated in the filter bed, and desired effluent quality. The high porosity allows the filter to be operated at a filtration rate well in excess of conventional incompressible granular media filters (30 gpm/ft2 as opposed to 5 gpm/ft2), which translates to a very compact footprint. The filters are supplied as modular, packaged units.
Figure 4-8: Fuzzy Filter (Figure from Schreiber, LLC)
The media is retained between two perforated plates as shown in Figure 4-8, of which the top plate is adjustable. During the “Filtration Cycle”, the influent is filtered in an up-flow configuration - it is introduced at the bottom of the filter and withdrawn at the top of the filter.
When the headloss across the filter reaches a predetermined set point or when the effluent turbidity exceeds a predetermined set point, the filter enters into the “Wash Cycle.” Typically, backwashing is initiated every 24 hours or after the headloss across the filter exceeds a predetermined set point, whichever occurs sooner. In the “Wash Cycle,” the adjustable plate automatically rises and the filter media is expanded using the flow velocity of filter influent water. “Washing air” is then introduced to scour the media and remove the captured solids.
The dirty wash water is withdrawn from the top of the filter and returned to the plant. Before the filter is brought back into service, the adjustable plate comes back to its original position and the filter is flushed to waste (“Flush Cycle”) for approximately one minute. The entire backwash cycle takes about 30 minutes. The backwash waste production rate is approximately 1 - 5% of the influent filter flow rate, depending upon the filter influent quality.
Advantages and disadvantages of fuzzy filters are summarized in Table 4-15 and the design criteria are summarized in the Table 4-16. A preliminary layout for the fuzzy filters at the TTDF is presented in Figure 4-9. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented.
Note that one redundant filter unit is planned for the 5 mgd, 15 mgd, and 30 mgd systems.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-16 Preliminary construction, O&M, and 20 year life-cycle cost estimates for fuzzy filters are presented in Table 4-17 below.
Advantages and Disadvantages
Table 4-15: Fuzzy Filter Advantages and Disadvantages
Advantages Disadvantages
The CDPH approved filtration rate for Fuzzy Filters is
high (≤30 gpm/ft2), resulting in a compact footprint.
Fuzzy filters are proprietary and would need to be sole sourced from Schreiber, LLC.
The properties of the bed (porosity, depth, etc.) are
adjustable and, thus, the filter is able to handle
variations in influent quality.
The media is proprietary and media replacement is
expensive.
Filters are supplied as easy to install skid mounted,
packaged units.
There are only small (less than 1 mgd filtration capacity) installations in California.
The history and number of Title 22 installations is
limited.
Backwashing requires the shutdown of the entire filter
unit.
Design Criteria
Table 4-16: Fuzzy Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 30
Number of Filter Units 3
Dimensions of Each Filter Bed,
Length (ft) x Width (ft)
7 x 7
Total Filtration Area, ft2 147
Filtration Rate with One Filter Backwashing,
gpm/ft2
35.4 Headloss Through Filter, ft (Operating) 4
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-17 Preliminary Layout
Figure 4-9: Preliminary Layout of 5 mgd Fuzzy Filter, with Future Footprint for Phased Expansion to 30 mgd
Cost Summary
Table 4-17: Fuzzy Filter Cost Summary(5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 1,350,000
Total Capital Costa 4,100,000
Total Annual O&M Costb 110,000
20-Year Life Cycle Cost c 6,000,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-18
4.2.6 Cloth Media Filters
Features of Operation
Cloth media filters are type of filters consisting of segmented disks of synthetic media. Unlike in deep bed granular media filtration, cloth media filters remove solids primarily by straining and, while the media does have depth, the “filter bed” is essentially two-dimensional. There are many proprietary products that fall into this category, including: AquaDisk from Aqua Aerobics, Hydrotech from Veolia, and Forty X from Siemens. Aqua Aerobics also supplies AquaDiamond, which operates on the same principles as AquaDisk; however, it is primarily used as a retrofit to traveling bridge filters.
Figure 4-10: Cloth Media Filter (Figure from Aqua-Aerobic) Depending upon the specific manufacturer, cloth media filters operate in both “inside-out” (filter influent is introduced within the center shaft of the disks, flows through the disk media, and filtered water is collected in the basin) and “outside-in” (filter influent is introduced in the basin, flows through the disk media, and filtered water is collected in the center shaft of the disks as shown in Figure 4-10) configurations. The description that follows describes a cloth media filter with an “out-to-in” configuration, such as AquaDisk. Inlet wastewater enters the basin, completely submerging the cloth media. Liquid passes through the cloth media. The filtered liquid enters the internal portion of the disk and is discharged through the center shaft.
As the filter cloth collects solids on the outer surface, headloss across the media gradually increases and water level inside the tank rises to a set point elevation. At this point, the backwash cleaning system initiates backwash operation and cleans a set of two discs while the other discs in the tank continue filtration. During backwash, the disks undergoing backwash are rotated and a vacuum pump cleans the disk media. Influent will continue to be processed CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-19 during the backwash cleaning cycle, allowing for continuous filtration. Heavier solids are allowed to settle to the bottom portion of the filter tank. These solids are then pumped on an intermittent basis. All components of the system are constructed from corrosion resistant materials designed for continuous operation.
The backwash waste production rate varies depending upon filter influent quality, but typically ranges from 5 - 10% of the filter influent flow rate. The number of backwashes per day also varies widely depending upon influent water quality. Typically, disks are backwashed every 30 to 40 minutes and the backwash duration for one 12 disk unit is 12 minutes.
Advantages and disadvantages of cloth media filters are summarized in Table 4-18 and the design criteria are summarized in the Table 4-19. A preliminary layout for the cloth media filters at the TTDF is presented in Figure 4-11. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented. Note that one redundant filter unit is planned for the 5 mgd, 15 mgd, and 30 mgd systems and that the structure that is planned for the 5 mgd system is sufficient for housing disks with a filtration capacity of up to 9 mgd. Preliminary construction, O&M, and 20 year lifecycle cost estimates for cloth media filters are presented in Table 4-20.
Advantages and Disadvantages
Table 4-18: Cloth Media Filter Advantages and Disadvantages Advantages Disadvantages
Filtration capacity can be increased without adding
tanks. The cloth media filter considered for the TTDF is expandable to 9 mgd with just the addition of disks.
The design of cloth media filters is proprietary.
There are no moving parts during filtration. The media for cloth media filters is proprietary and relatively expensive.
There is no downtime during backwashing (only a set of
two disks are backwashed at a time).
There are pronounced spikes in effluent turbidity for ~5 minutes following backwash - more so than in
conventional deep bed granular media filters.
Backwash volume requirements are low.
The footprint is relatively small (since the disks allow for a high filter surface area per ft2 of physical footprint).
There is a good customer base in California with many
Title 22 installations.
The headloss across the filter is low.
Media replacement is simple.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-20 Design Criteria
Table 4-19: Cloth Media Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 6
Number of Filter Units 3
Number of Disks per Unit 8
Total Filtration Area, ft2 1291
Filtration Rate with One Filter Offline, gpm/ft2 4.0
Headloss Through Filter, ft (Operating) 3
Preliminary Layout
Figure 4-11: Preliminary Layout of 5 mgd Cloth Media Filter, with Future Footprint for Phased Expansion to 30 mgd
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-21 Cost Summary
Table 4-20: Cloth Media Filter Cost Summary (5 mgd Constant Flowd) Parameter Cost ($)
Equipment and Structures Cost 1,400,000
Total Capital Cost a 4,100,000
Total Annual O&M Cost b 90,000
20-Year Life Cycle Cost c 5,700,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
d
Concrete structure is capable of housing additional disks with a filtration capacity of 4 mgd i.e. the concrete structure is designed for a total filtration capacity of 9 mgd.
4.2.7 Nova Ultrascreen Filters
Features of Operation
The Nova Ultrascreen® filter is a proprietary filter from Nova Water Technologies that, like cloth media filters, utilizes segmented disks for filtration. The key difference between Nova Ultrascreen filters and cloth media filters is the filtration media - Nova Ultrascreen filters use precision woven stainless steel micronic screen mesh with precise perforation sizes depending upon the application. The media has no depth and the mechanism of solids removal is exclusively straining (i.e. operates as a surface filter). The filter operates in an “inside-out” configuration - the filter influent is directed to the inside of the disks, flows through the stainless steel mesh, and is collected in a clear well (see Figure 4-12 below). Nova Ultrascreen filters are supplied as modular, fully enclosed, packaged units constructed in full stainless steel.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-22 Figure 4-12: Nova Ultrascreen Filter (Figure from Nova Water Technologies) The other major difference when compared to cloth media disc filters is that here the disks rotate continually during filtration in order to achieve “dynamic tangential filtration,” a phenomenon that the supplier claims increases solids rejection and limits the build-up of solids on the screen. By continuously rotating the disks during filtration, the angle of approach taken by a particle will be less than 90o
, making the projected area of perforations in the media smaller than their rated size. Per the manufacturer, these filters are able to remove a target particle size of 10 microns with a mesh opening size of 20 microns due to “dynamic tangential filtration”.
Nova Ultrascreen discs are partially submerged as shown in Figure 12. The backwash is initiated in a manner similar to cloth media disc filters upon the water level in the basin reaching a preset elevation. However, unlike the cloth media filters, the backwash is carried out via a set of backwash arms installed on both sides of the discs and fitted with nozzles. Per the manufacturer, the disks undergo “pulsed backwashing”, which is a short burst of backwashes lasting 10-15 sec and occur quite frequently throughout the day. The number of backwashes per day varies widely depending on the quality of the influent. The filtration cycle continues during the backwash as the discs continually rotate. Upper half of the discs that are above the water level are backwashed while the lower half of the discs continue filtration. The backwash waste production rate also varies depending upon filter influent quality, but is typically less than 1% of the filter influent flow rate.
Advantages and disadvantages of Nova Ultrascreen filters are summarized in Table 4-21 and the design criteria are summarized in the Table 4-22. A preliminary layout for the Nova Ultrascreen filters at the TTDF is presented in Figure 4-13. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented. Note that one redundant filter unit is planned for the 5 mgd, 15 mgd, and 30 mgd systems. Preliminary construction, O&M, and 20 year life-cycle cost estimates for Nova Ultrascreen filters are presented in Table 4-23.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-23 Advantages and Disadvantages
Table 4-21: Nova Ultrascreen Advantages and Disadvantages Advantages Disadvantages
The CDPH approved filtration rate for the Nova
Ultrascreen filter is 16 gpm/ft2, provided that the filter is coupled with a disinfection process that achieves a 5- log polio virus removal.
Nova Ultrascreen filters are proprietary and would need to be sole sourced from Nova Water Technologies.
Supplied as modular, packaged units that are easy to
install.
The disks are continuously rotating, which could
present reliability issues.
The filter occupies a small footprint. Limited history of installations in operation (less than one year).
The media replacement is less frequent than for other
non-granular media filters.
There are no operating municipal installations in
California. All municipal installations are on the East Coast (total of eight installations, of which four are in Florida).
The disk rotation speed is variable, allowing the
operator to adjust the speed based on the filter influent quality or the desired filtered water quality.
The headloss across the filter is low.
Effluent turbidity is relatively constant, even after a backwash.
Design Criteria
Table 4-22: Nova Ultrascreen Filter Design Criteria
Parameter Criteria
Design Flow, mgd 5
CDPH Approved Filtration Rate, gpm/ft2 16
Number of Filter Units 2
Number of Disks per Unit 10
Total Filtration Area, ft2 444
Filtration Rate with One Filter Offline, gpm/ft2 15.6
Headloss Through Filter, ft (Operating) 2.5
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-24 Preliminary Layout
Figure 4-13: Preliminary Layout of 5 mgd Nova Ultrascreen Filter, with Future Footprint for Phased Expansion to 30 mgd
Cost Summary
Table 4-23: Nova Ultrascreen Filter Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 1,200,000
Total Capital Costa 3,500,000
Total Annual O&M Costb 100,000
20-Year Life Cycle Cost c 5,300,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-25
4.2.8 Microfilters
Features of Operation
Microfilters use membrane filtration to separate micron-sized particles from the filter influent water. Like the Nova Ultrascreen, the solids removal mechanism used is straining - however, the membrane pore sizes are much smaller, typically close to 0.1 microns. The membrane material varies depending upon the supplier, but is usually natural or synthetic polymers. For example, Pall’s Microza LGV microfilters are made of PVDF (polyvinylidene fluoride) membranes.
Microfilters can be arranged in horizontal or vertical configuration, depending on the influent quality and manufacturer. Microfilter modules are arranged in racks and are pre-engineered to suit various flow rates.
Figure 4-14: Microfilter Cross Section
Due to the small membrane pore sizes, the majority of solids and even some viruses are rejected and the quality of permeate produced is much higher than the quality of filtered water produced with media filtration technologies discussed earlier. Due to the high solids removal efficiency, the downstream disinfection efficiency is enhanced. If UV disinfection is used, the NWRI guidelines allow for a smaller UV system resulting in significant capital and operating cost savings when operating on microfilter permeate.
Advantages and disadvantages of microfilters are summarized in Table 4-24 and the design criteria are summarized in the Table 4-25. A preliminary layout for microfilters at the TTDF is presented in Figure 4-15. The footprint for 5 mgd, 15 mgd, and 30 mgd capacity is presented.
Peliminary construction, O&M, and 20 year life-cycle cost estimates for microfilters are presented in Table 4-26.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-26 Advantages and Disadvantages
Table 4-24: Microfilter Advantages and Disadvantages
Advantages Disadvantages
Microfilters produce recycled water exceeding Title 22
requirements.
Microfilters have a higher capital cost when compared
to media filters.
Microfilters remove most viruses, giardia, and crypto. The influent pumping requirements increase the O&M costs when compared to media filters.
Available in modular, skid mounted units - lowering
installation costs.
Membrane replacement is relatively expensive.
When coupled with a downstream UV disinfection
system, substantial cost savings can be realized when
compared to media filtration coupled with UV
disinfection.
Microfilters are more O&M intensive than conventional
media filters.
Design Criteria
Table 4-25: Microfilter Design Criteria
Parameter Criteria
Design Flow, mgd 5
Flux Rate, gpd/ft2 Not regulated1
Feed pressure, psi 20-30
1 Flux rates are not regulated for Title 22 recycled water applications. The microfilter membranes used for Title 22 applications are similar to the ones approved for drinking water filtration applications, where the approved flux rates range from 75 – 120 gpd/sq.ft, depending on the manufacturer. However, based on current installations for Title 22 applications, the operating flux rates range from 30-50 gpd/sq.ft.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-27 Preliminary Layout
Figure 4-15: Preliminary Layout of 5 mgd Microfiltration System, with Future Footprint for Phased Expansion to 30 mgd
Cost Summary
Table 4-26: Microfilter Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 3,500,000
Total Capital Costa 10,700,000
Capital Cost Credit for UV Disinfection
b (2,000,000)
Net Total Capital Cost 8,700,000
Total Annual O&M Costc 400,000
Annual O&M Cost Credit for UV Disinfection (100,000)
Net Total Annual O&M Cost 300,000
20-Year Life Cycle Cost d 14,200,000
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 4 - FILTRATION SYSTEM ALTERNATIVES ANALYSIS 4-28 a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Credit due to higher UVT and lower UV dosage for microfilter permeate. c Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
d
At a 5% discount rate and a 4% escalation rate.
4.3 SUMMARY OF COSTS
Table 4-27 presents a summary of the construction, O&M, and 20-year life-cycle cost estimates for each of the eight filtration technologies evaluated. As can be seen below, Nova Ultrascreen filters are the lowest both in terms of capital cost (~$300,000 less than continuous backwash filters, the next lowest cost alternative) and 20-year life-cycle cost (~$400,000 less than cloth media filters, the next lowest cost alternative). See Appendix A for preliminary cost estimates.
Table 4-27: Summary of Costs of Each 5 mgd Constant Flow Filtration Alternative Technology Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20-Year Life Cycle Cost
($ Millions)
Dual Media Gravity Filters 4.3 90 5.9
Deep Bed Monomedia Filters 4.4 90 6.0
Continuous Backwash Filters 3.8 105 5.6
Travelling Bridge Filters 4.8 80 6.2
Fuzzy Filters 4.1 110 6.0
Cloth Media Filters1 4.1 90 5.7
Nova Ultrascreen Filters 3.5 100 5.3
Microfilters2 8.7 300 14.2
1 Concrete structure is designed for a filtration capacity of up to 9 mgd. 2 Includes UV system credit.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-1 SECTION 5 - DISINFECTION SYSTEM ALTERNATIVES ANALYSIS
5.1 BACKGROUND
Currently the RWRF does not disinfect the secondary treated effluent. The secondary effluent is discharged to percolation ponds through effluent canals A and B. As described earlier in this TM, in order to upgrade the discharge to California Title 22 standards for unrestricted reuse, the City has decided to construct a TTDF, which consists of filtration, disinfection and storage.
This Section of the TM evaluates three alternatives for disinfection at the TTDF.
The two disinfection technologies evaluated are:
1. Ultraviolet (UV) Disinfection
a. Open Channel UV Disinfection
b. In-pipe UV Disinfection
2. Ozone Disinfection
The UV disinfection system considers low pressure, high intensity lamps, which are the result of progressive research and energy conservation measures over the years. The use of low pressure high intensity lamps results in a compact and more efficient UV disinfection system. Ozone disinfection, which is still considered an emerging technology for wastewater disinfection, considers generation of ozone from liquid oxygen. Ozone can also be generated from air, which however, may be cost prohibitive for a large plant such as TTDF.
5.2 UV DISINFECTION
UV disinfection utilizes ultra-violet portion of the light spectrum to render disease causing pathogens inactive. The UV lamps can be placed in several banks, in series, in an open channel system or may be placed inside a vessel (pipe) for an inline UV system. The design of UV system highly depends on the quality of water being disinfected. The UV system design criteria for tertiary-filter (media based) treated recycled water are more stringent than membrane treated recycled water, primarily due to the fact that the higher turbidity of former creates a shielding effect on pathogens thus reducing the effectiveness of UV light. According to National Water Research Institute (NWRI), May 2003 guidelines, the minimum UV transmittance for media filter effluent and membrane effluent shall be 55% and 65% at 254 nm, respectively. The minimum UV dose required for media filter effluent and membrane effluent are 100 mJ/cm2 and 80 mJ/cm2, respectively, under maximum flow. Besides the above criteria, end of lamp life and fouling factors are used in the design of UV system. The former addresses the loss in the output of UV lamps as they age and the latter compensates for the fouling of lamp sleeve. The values of these factors differ from manufacturer to manufacturer as approved by CDPH. To comply with CDPH standards for unrestricted reuse (Title 22) of wastewater effluent, the City will need to provide tertiary treatment (filtration) to reduce the effluent suspended solids to a CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-2 turbidity level less than 2 NTU in case of media filtration and less than 0.2 NTU for membrane filtration prior to final disinfection. By removing a majority of the solids, the effectiveness of the downstream disinfection process is enhanced.
5.2.1 UV Design Criteria
According to NWRI guidelines, the UV disinfection system for TTDF should include the following two parameters and should be designed according to Table 5-1:
1. The UV system should be capable of 5 – log polio virus inactivation and total coliform not to exceed 2.2 MPN/ 100 ML
2. The UV system should include one standby bank per train or a separate standby train must be provided.
Table 5-1: UV Disinfection Design Criteria
Parameter Units Media Filtration Membrane Filtration
Capacity mgd 5 5
UV Transmittance UVT 55% 65%
Design Dose
(Maximum daily design
flow of 5 mgd)
mJ/cm2 100 80
5.3 UV OPEN CHANNEL EQUIPMENT AND STRUCTURE
Features of Operation
In an open channel disinfection system, the UV lamps are placed in modules and several modules make up for a bank. These banks may be placed in series in a channel to provide required disinfection (refer to Figure 5-1). For the TTDF, two identical parallel channels will be constructed to house UV banks; the channels will be located north of the effluent canal B. The channels will initially house 3 banks each to accommodate 5 mgd filtered water flow through the facility. The channels will be designed to have extra room for adding more banks in the future to disinfect up to a total of 10 mgd flow in the same structure as shown in Figure 5-2.
The design characteristics of the UV channels are shown in Table 3. Each UV channel will have a level control gate / weir at the discharge end to ensure the UV lamps are submerged consistently. The disinfected water will be either conveyed by gravity or pumped into storage for distribution.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-3 Figure 5-1: Simplified Schematic of a UV-Open Channel System Advantages and Disadvantages
Advantages and Disadvantages are included in Table 5-2
Table 5-2: UV Disinfection Advantages and Disadvantages Advantages Disadvantages
Modular design - UV banks may be added to the same
channel to increase capacity
Canopy/building may be required to protect the
electronic ballasts from direct sunlight
Lamps are arranged in modules - each module can be
taken out for maintenance without taking the bank
offline.
Mechanical components like mechanical wiping system
require more maintenance
Low head loss Future compliance with EDC’s and NDMA is expensive as it requires increasing the UV dose to 6-7 times by
upgrading the facility by employing reverse osmosis and or increasing the number of UV banks.
Less process instrumentation and controls required
when compared to other technologies considered for
the project
Extensive experience in wastewater disinfection
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-4 Open Channel UV Design Characteristics
Key design criteria for open channel UV system are listed in Table 5-3 below.
Table 5-3: Design Characteristics of Open Channel UV System for Design Flow of 5 mgd Parameter Units Design Value
Type of UV system - Low Pressure, High Intensity
Number of Channels - 2
Length of channel ft 62
Width of Channel ft 4
Depth of Channel ft 5.2
Total Number of Banks - 6 (4 Duty, 2 Redundant)
Total Number UV lamps - 528 (including redundancy)
Disinfection Capacity per Bank mgd 1.25
Preliminary Layout
Figure 5-2: Preliminary Layout of 5 mgd UV Open Channel Disinfection System, with Future Footprint for Phased Expansion to 30 mgd
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-5
5.3.1 Expandability
The UV system layout is presented in Figure 5-2 above planned for 5 mgd, expandable to 15 mgd and ultimately to 30 mgd capacity. The initial expansion to 15 mgd shall be accomplished by providing additional banks (two banks each) in the existing two channels and constructing an additional identical channel with same number of banks. The ultimate 30 mgd expansion will require construction of three additional identical channels and populating them with equal number of banks.
5.3.2 Capital, O&M and Life Cycle Costs
The capital cost includes cost for 5 mgd UV equipment, concrete structure, canopy, distribution pipes and a building required to house the ballasts. Table 5-4 below presents preliminary capital, O&M and 20 year life cycle costs.
Table 5-4: Open Channel UV System Following Media Filtration Cost Summary (5 mgd Constant Flowd)
Parameter Cost ($)
Equipment and Structures Cost 1,450,000
Total Capital Cost a 4,500,000
Total Annual O&M Cost b 230,000
20-Year Life Cycle Cost c 8,700,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to mid point of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
d
Concrete structure designed to house additional banks with a disinfection capacity of 5 mgd for a total disinfection capacity of 10 mgd.
5.4 UV IN-PIPE EQUIPMENT AND STRUCTURE
Features of Operation
UV in-pipe system consists of UV lamps that are housed in a stainless steel reactor. Each reactor has an inlet and an outlet and the flow can be controlled via a flow meter and a control valve.
This system requires more instrumentation and control than the open channel UV systems. The capacity of each reactor considered (for workshop no. 1) is approximately 2.30 mgd for filtered water. For 5 mgd system four reactors (3 Duty + 1 Standby) would be necessary to reliably disinfect the required flow as shown in Figure 4. The reactors can be arranged in series or CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-6 parallel depending on the manufacturer, site constraints and capacity of the facility. Several trains can be installed parallel to each other to provide require disinfection capacity.
Based upon Parsons’ discussions with the in-pipe UV disinfection system manufacturers and CDPH, we understand that in-pipe UV disinfection systems are validated but are not approved for Title 22 unrestricted water reuse. It is our understanding that CDPH approves in-pipe UV disinfection systems on a case-by-case basis, only after a wastewater facility has installed the particular system under consideration.
Figure 5-3: Simplified Schematic of an In-pipe UV Disinfection System Advantages and Disadvantages
Table 5-5 below shows advantages and disadvantages for In-pipe UV disinfection system.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-7 Table 5-5: In-pipe UV Disinfection System Advantages and Disadvantages Advantages Disadvantages
Modular design – UV inline system reactors are modular
and can be places parallel or in series depending on
design capacity
Lamps are enclosed in the reactor and it needs to be
taken off line for servicing
Ease of expandability More modulating valves required to control flow Less civil and site work is required compared to other
disinfection technologies considered in the project.
More process instrumentation and control required
Little to no site excavation required CDPH approves the system on a case by case basis; CDPH has not given any blanket approved for inline
systems.
Lamps are serviceable from the reactor end
In-pipe UV Design Characteristics
Key design criteria for in-pipe UV system are listed in Table 5-6 below.
Table 5-6: Design Characteristics of In-pipe UV System for Design Flow of 5 mgd Parameter Units Design Value
Type of UV system - Low Pressure, High Intensity
Number of Reactors - 4
Length of Reactor ft 13
Total number of lamps in each
Reactor
- 144
Total Number UV lamps - 576 (including redundancy)
Disinfection Capacity per
Reactor
mgd 2.3
Preliminary Layout
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-8 Figure 5-4: In-pipe UV Disinfection System
5.4.1 Expandability
The initial 5 to 15 mgd expansion of the facility will be accomplished by adding 4 additional reactors of the same capacity. Similarly expansion to 30 mgd will be accomplished by adding 7 additional reactors. However several automatic actuated control valves and flow meters will be required to ensure proper flow distribution and control to each reactor. This will lead to higher instrumentation and control costs and operational complexity compared to open channel UV system.
5.4.2 Capital, O&M and Life Cycle Costs
The capital cost includes cost for 5 mgd inline UV equipment, concrete pad, canopy, distribution pipes and a building required to house the ballasts. Table 5-7 below presents preliminary capital, O&M and 20 year life cycle costs.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-9 Table 5-7: In-pipe UV Disinfection System following Media Filtration Cost Summary (5 mgd Constant Flow)
Parameter Cost ($)
Equipment and Structures Cost 1,460,000
Total Capital Cost a 4,800,000
Total Annual O&M Cost b 230,000
20-Year Life Cycle Cost c 8,900,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
5.5 OZONE DISINFECTION
Features of Operation
Ozone is a much stronger disinfectant than chlorine, UV and other common disinfectants.
Unlike chlorine (or sodium hypochlorite) which diffuses through the cell wall of the microorganisms and disinfects, ozone oxidizes the cell wall causing the microbes to disintegrate. Ozone is a very strong oxidizing agent with 1.5 times the oxidizing potential of chlorine.
Ozone is produced from either air or oxygen. Typically, the concentration of ozone is about 3 % (maximum) when produced by air versus 10% when produced using oxygen. Therefore ozone generation using air could be cost prohibitory for smaller installations. For purposes of this evaluation, ozone generation system using liquid oxygen is considered. The system is designed for a dose of 10mg/L with a contact time of 15 minutes to be conservative and to keep a factor of safety for the system. Pilot testing is highly recommended to establish a design dose and contact time for ozone disinfection of recycled water specific to TTDF, which is an additional cost to the project.
Ozone Disinfection Equipments and Structure
Ozone disinfection system comprises a liquid oxygen tank that provides liquid oxygen to ozone generators via ambient vaporizers (used to eliminate moisture). Nitrogen gas is introduced in the ozone generators as a catalyst. The ozone is produced by several dielectrics in the generators and is introduced into the filtered water via coarse bubble diffusers in a contact basin. Excess ozone is collected and destroyed in the ozone destruct system as shown in CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-10 schematic Figure 5-5. A preliminary layout for ozone disinfection system is included as Figure 5-
6. Figure 5-5: Schematic of Ozone Generation
Advantages and Disadvantages
Table 5-8 includes advantages and disadvantages for Ozone disinfection system.
Table 5-8: Ozone Disinfection System Advantages and Disadvantages Advantages Disadvantages
Skid mounted system Dose and contact time are critical and must be decided carefully
Less civil and site work required for the equipment Regular liquid oxygen supply is required Compact design Second and third phase expansion will require larger units than the one proposed for initial installation
More economical for future removal of Endocrine
Disruptive Chemicals and NDMA etc.
More process instrumentation and controls required
Extensive mechanical equipment required for the
system
High power consumption
Limited experience in wastewater disinfection
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-11 Ozone Disinfection Equipments and Structure
The ozone disinfection system design criteria are summarized in the Table 5-9 below.
Table 5-9: Design Characteristics of Ozone Disinfection System for Design Flow of 5 mgd Parameter Units Design Value
Ozone Dose mg/L 10
Contact Time Minutes 15
Preliminary Layout
Figure 5-6: Ozone Disinfection System
5.5.1 Expandability
The Ozone system is skid mounted but may not be expandable as easily as UV disinfection systems. Increasing the capacity of the system may be accomplished by including more reactors of the same size or larger Ozone reactors and larger contact basins which need to be carefully designed. Alternatively, the larger Ozone Generators may be installed initially and similar Ozone generators may be added depending on the capacity of expansion.
5.5.2 Capital, O&M and Life Cycle Costs
The capital cost for the ozone disinfection system includes 5 mgd ozone equipment, concrete pad, distribution pipes and building required to house ozone reactors. Table 5-10 below presents preliminary capital, O&M and 20 year life cycle costs.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 5 – DISINFECTION SYSTEM ALTERNATIVES ANALYSIS 5-12 Table 5-10: Ozone Disinfection System Cost Summary (5 mgd Constant Flow) Parameter Cost ($)
Equipment and Structures Cost 2,200,000
Total Capital Cost a 6,600,000
Total Annual O&M Cost b 450,000
20-Year Life Cycle Cost c 14,800,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
5.6 SUMMARY OF COSTS
Table 5-11: Summary of Costs for Disinfection System Alternatives (5 mgd Constant Flow) Technology Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20-Year Life Cycle Cost
($ Millions)
UV – Open Channel1 4.5 230 8.7
UV – In-pipe 4.8 230 8.9
Ozone 6.6 450 14.8
1 Concrete structure designed to house banks with a total disinfection capacity of 10 mgd.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-1
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS
6.1 BACKGROUND
As pointed out in Section 1, the City’s goal is to produce 25,000 acre-ft/year of recycled water by 2025. This TM will present the four storage alternatives that were evaluated for the TTDF.
The following four storage alternatives were considered:
• Earthen basins, lined and covered
• Steel tank
• Pre-stressed concrete tank
• Conversion of Train A aeration basin into a storage reservoir The last option (the conversion of a Train A aeration basin into a storage tank) is only an option if the City decides to select MBR alternative. A detailed discussion of the MBR option is presented in Section 7.
6.2 STORAGE ALTERNATIVES
6.2.1 Earthen Basins, Lined and Covered
Description
Earthen basins are constructed by excavating and forming earthen berms with the excavated soil, resulting in basins that are partially above grade and partially below grade. In order to function as a storage reservoir, the basins must be lined (to prevent loss of recycled water via percolation) and covered (to prevent the loss of recycled water via evaporation and the contamination of recycled water). While there are many options for lining and covering earthen basins, the use of gunite lining and a hypalon membrane cover have been considered in the evaluation of this alternative. Gunite lining is proven, cost effective, easy to install, and has been used by the City in the past. Hypalon membrane covers, while more expensive than polypropylene or high density polyethylene (HDPE) membrane covers, are of a superior quality, and come with a standard 30-year material warranty.
Advantages and disadvantages of earthen basins are summarized in Table 6-1 and the design criteria are summarized in Table 6-2. A preliminary layout for the earthen basins at the TTDF is presented in Figure 6-1. Preliminary construction, O&M, and 20 year life-cycle cost estimates for the planned earthen storage basins at the TTDF are presented in Table 6-3. The typical life of storage structures is at least 50 years; however, a 20 year life-cycle cost analysis is presented for consistency.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-2
Advantages and Disadvantages
Table 6-1: Earthen Basins Advantages and Disadvantages
Advantages Disadvantages
Lined and covered earthen basins are typically less
expensive than steel tanks or concrete tanks.
Periodic maintenance and replacement of floating
membrane covers are required.
Earthen basins are easily constructed. Membrane covers need to be removed to access the basin internals for maintenance.
Permits recycled water from the treatment system to
flow by gravity into the storage
Leak detection is difficult.
Partitions within the basin allow for taking one cell
offline for maintenance while keeping the others in
operation.
Floating covers are prone to vandalism.
Less conducive to water circulation, which may impact
water quality.
Design Criteria
Table 6-2: Earthen Basins Design Criteria
Parameter Criteria
Design Capacity, MG 5
Number of Basins 2
Dimensions of Each Basin,
Length (ft) x Width (ft) x Depth (ft) (Free Board
(ft))
255 x 180 x 10 (3)
Side Wall Slope (H:V) 3:1
Number of Distribution Pumps 2 (1 duty + 1 standby)
Distribution Pump Capacity, Each 3,500 gpm
Distribution Pump Discharge Head 230 feet
Distribution Pump Motor hp, Each 300 hp
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-3
Preliminary Layout
Figure 6-1: Preliminary Layout of 5 MG Earthen Basins
Cost Summary
Table 6-3: Earthen Basins and Recycled Water Pump Station Cost Summary Parameter Cost ($)
Total Capital Costa 4,000,000
Total Annual O&M Costb 310,000
20 Year Life-Cycle-Costc 9,600,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power for distribution pumps and general maintenance. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-4
6.2.2 Steel Tank
Description
A single welded steel storage tank with a welded steel roof and a concrete ring wall foundation has been considered in the evaluation of this alternative. Advantages and disadvantages of steel tanks are summarized in Table 6-4 and the design criteria are summarized in Table 6-5. A preliminary layout for the steel tank at the TTDF is presented in Figure 6-2. Preliminary construction, O&M, and 50 year life-cycle cost estimates for the planned steel storage tank at the TTDF are presented in Table 6-6.
Advantages and Disadvantages
Table 6-4: Steel Tank Advantages and Disadvantages
Advantages Disadvantages
Steel storage tanks are typically less expensive than
concrete storage tanks.
Since steel storage tanks are installed above grade,
pumping to the steel storage tank will be required -
adding to O&M costs.
Circular shape promotes water circulation, improving
water quality.
Steel storage tanks require maintenance (e.g. painting
of the interior surface) and typically have lower
lifetimes when compared to concrete tanks.
Leakage can be readily detected. Cathodic protection is required to prevent corrosion.
When maintenance is required, entire tank needs to be
taken out of service.
Design Criteria
Table 6-5: Steel Tank Design Criteria
Parameter Criteria
Design Capacity, MG 5
Number of Tanks 1
Dimensions of Tank,
Diameter (ft) x Depth (ft) (Free Board (ft))
210 x 24 (4)
Number of Feed Pumps 2 (1 duty + 1 standby)
Feed Pump Capacity, Each 3,500 gpm
Feed Pump Discharge Head 20 feet
Feed Pump Motor hp, Each 30 hp
Number of Distribution Pumps 2 (1 duty + 1 standby)
Distribution Pump Capacity, Each 3,500 gpm
Distribution Pump Discharge Head 230 feet
Distribution Pump Motor hp, Each 300 hp
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-5
Preliminary Layout
Figure 6-2: Preliminary Layout of 5 MG Steel Tank
Cost Summary
Table 6-6: Steel Tank and Recycled Water Pump Station Cost Summary Parameter Cost ($)
Total Capital Costa 6,400,000
Total Annual O&M Costb 370,000
20 Year Life-Cycle-Costc 13,100,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power for feed and distribution pumps and general maintenance. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
6.2.3 Prestressed Concrete Tank
Description
A single partially buried, strand-wrapped circular prestressed concrete storage tank has been considered in the evaluation of this alternative. Advantages and disadvantages of prestressed concrete tanks are summarized in Table 6-7 and the design criteria are summarized in Table 6-
8. A preliminary layout for the prestressed concrete tank at the TTDF is presented in Figure 6-3.
Preliminary construction, O&M, and 50 year life-cycle cost estimates for the planned prestressed concrete storage tank are presented in Table 6-9.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-6
Advantages and Disadvantages
Table 6-7: Prestressed Concrete Tank Advantages and Disadvantages Advantages Disadvantages
Prestressed concrete storage tanks are lower
maintenance than both steel tanks or lined and covered
earthen basins.
Prestressed concrete storage tanks are typically more
expensive than both steel tanks and lined and covered
earthen basins.
Prestressed concrete storage tanks have a longer life
than steel tanks or lined and covered earthen basins.
Leak detection for partially buried tank is difficult - an observation vault is required for leak detection.
Circular shape promotes water circulation, improving
water quality.
Piping and tank repairs are more costly due to buried
depth.
Design Criteria
Table 6-8: Prestressed Concrete Tank Design Criteria
Parameter Criteria
Design Capacity, MG 5
Number of Tanks 1
Dimensions of Tank,
Diameter (ft) x Depth (ft) (Free Board (ft))
178 x 30 (2)
Number of Distribution Pumps 2 (1 duty + 1 standby)
Distribution Pump Capacity, Each 3,500 gpm
Distribution Pump Discharge Head 230 feet
Distribution Pump Motor hp, Each 300 hp
Preliminary Layout
Figure 6-3: Preliminary Layout of 5 MG Prestressed Concrete Tank CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-7
Cost Summary
Table 6-9: Prestressed Concrete Tank and Recycled Water Pump Station Cost Summary Parameter Cost ($)
Total Capital Costa 7,500,000
Total Annual O&M Costb 290,000
20 Year Life-Cycle-Costc 12,700,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power for distribution pumps and general maintenance. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
6.2.3 Conversion of Train A Aeration Basin
Description
The conversion of a Train A aeration basin into a storage tank requires the removal of all mechanical internals including aeration piping (with diffusers) and the old mechanical aerators (with the associated supports and platforms). In addition, the converted aeration basin requires modifications to support a cover, including a supporting curb around the perimeter of the basins and support columns within the basin. Due to the long life and minimal maintenance associated with aluminum covers, a flat aluminum cover has been considered in the evaluation of this alternative.
Advantages and disadvantages of using a converted Train A aeration basin as a recycled water storage tank are summarized in Table 6-10. The design criteria for this alternative are summarized in Table 6-11. A preliminary layout of the converted Train A aeration basin is presented in Figure 6-4. Preliminary construction, O&M, and 50 year life-cycle cost estimates for the conversion of a Train A aeration basin are presented in Table 6-6.
Advantages and Disadvantages
Table 6-10: Conversion of Train A Aeration Basin Advantages and Disadvantages Advantages Disadvantages
This alternative uses an existing structure, reducing
costs and minimizing footprint.
The conversion of a Train A aeration basin is only
feasible if a MBR is used.
Due to conversion of existing aeration basin, the
storage capacity is limited to about 2.7 MG.
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SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-8
Design Criteria
Table 6-11: Conversion of Train A Aeration Basin Design Criteria Parameter Criteria
Design Capacity, MG 2.7
Number of Tanks 1
Dimensions of Tank,
Length (ft) x Width (ft) x Side Water Depth (ft)
170 x 170 x 16
Number of Distribution Pumps 2 (1 duty + 1 standby)
Distribution Pump Capacity, Each 3,500 gpm
Distribution Pump Discharge Head 230 feet
Distribution Pump Motor hp, Each 300 hp
Preliminary Layout
Figure 6-4: Train A Aeration Basin Converted to Storage Basin CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 6 - STORAGE SYSTEM ALTERNATIVES ANALYSIS 6-9
Cost Summary
Table 6-12: Conversion of Train A Aeration Basin and Recycled Water Pump Station Cost Summary (2.7 MG Storage Capcity)
Parameter Cost ($)
Total Capital Costa 2,900,000
Total Annual O&M Costb 290,000
20 Year Life-Cycle-Costc 8,100,000
a
Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b
Including power for distribution pumps and general maintenance. Unit power cost is considered as $ 0.14/kWh.
c
At a 5% discount rate and a 4% escalation rate.
6.3 SUMMARY OF COSTS
Table 6-13 presents a summary of the construction, O&M, and 20 year life-cycle cost estimates for each of the four storage alternatives evaluated. As shown in the Table, excluding the option of converting a Train A aeration basin into a storage tank (only an option if MBR option is selected), earthen basins are the lowest cost both in terms of capital cost (~$2,400,000 less than a steel tank, the next lowest cost alternative) and 20 year life-cycle cost (~$3,100,000 less than a prestressed concrete tank, the next lowest cost alternative).
Table 6-13: Summary of Cost for Each Storage and Distribution Pump Station Alternative Alternative Storage
Capacity (MG)
Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20 Year Life
Cycle Cost
($ Millions)
Earthen Basins, Lined and
Covered
5.0 4.0 310 9.6
Steel Tank 5.0 6.4 370 13.1
Prestressed Concrete Tank 5.0 7.5 290 12.7
Train A Aeration Basin
Conversion
2.7 2.9 290 8.1
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SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-1
SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION
7.1 BACKGROUND
As an alternative to tertiary filters, which were discussed in Section 4, MBR system can be used to produce Title 22 recycled water. This section first describes the MBR technical concept and how its different components are tied together and later briefly discusses the MBR alternatives considered prior to Workshop No. 1. A detailed analysis of the selected alternative will be presented in Section 9. Refer to Section 9 for information regarding the design criteria and specifications of equipment.
7.2 TECHNICAL CONCEPT
The MBR is a multi-purpose process providing secondary treatment for organic and nitrogen removal, and using membrane filters to separate the mixed liquor solids from the wastewater.
The membranes take the place of the clarifiers and tertiary filters of the conventional treatment plant. By removing the secondary clarifiers from the mainstream through the plant, problems controlling the settling characteristics of the solids, as measured by Sludge Volume Index (SVI) are eliminated. This allows the aeration basin (bioreactor) mixed liquor to be increased in concentration by almost three times the usual levels, i.e. from 3,500 mg/L to 10,000 mg/L, reducing the volume of aeration basin required to less than one-half that of the conventional treatment process.
The MBR process dates back 50 years. In the last ten years, the process has been applied in numerous installations of increasing size. Several plants today have design capacities in excess of 10 mgd, with larger facilities in design and construction. The worldwide application of the process over the last ten years has taken it from an emerging technology to one that is regarded as proven based on its long term consistent performance at numerous plants.
The general concept of the MBR is similar to that of conventional treatment, except it takes advantage of the latest in membrane technology to minimize the footprint of the secondary and tertiary treatment facilities and to enhance the performance of the plant to produce an effluent of exceptional quality.
To consistently achieve NDN, i.e. to meet a Total Inorganic Nitrogen (TIN) level of 10 mg/L in the effluent, a treatment plant should be designed to reliably produce an effluent TIN level in the range of 5 to 8 mg/L. This can be accomplished by upgrading the treatment to provide biological nutrient removal (BNR). Further, addition of membranes will result in an effluent containing low levels of organics (BOD), solids (TSS) and nitrogen allowing for effective disinfection so that the final effluent complies with water quality standards for unrestricted reuse.
The current plant uses conventional activated sludge consisting of aeration basins followed by clarification to significantly reduce the level of BOD and TSS in the effluent and to achieve partial NDN. The City has a significant investment in the process and with some modifications it CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-2
can be converted into a BNR facility to provide full secondary treatment.
Figure 7-1 shows a schematic of the overall liquid treatment train. This section of the TM will focus on the technical concepts of the fine screening, bioreactor and membrane portions of the plant.
Figure 7-1: Membrane Bioreactor (MBR) Consisting of Activated Sludge Bioreactor and Membrane Filtration
7.2.1 Fine Screening
Hair, stringy material and other deleterious matter passing through the preliminary treatment (coarse bar racks and grit tanks) and primary settling tanks can damage the MBR membranes.
To protect the membranes, ultra-fine screens are installed ahead of the MBR system on the primary effluent flow stream. Openings through the screens are in the range of 1 to 3-mm in size. The screens are of the band or drum type comprised of a series of perforated plates. The screen cleaning operation is automatically controlled based on differential level or time. These types of screens have been found to be the most efficient for removal of fine material. The screens are equipped with washing systems to clean odorous organic material from the screenings and return it back to the flow stream for treatment. The washed screenings are compacted to reduce the water content and volume prior to hauling off-site for disposal.
7.2.2 Secondary Treatment – Bioreactor (Aeration Basin) The bioreactor portion of the MBR process is very similar to that in the conventional activated sludge system. The aeration basin will be divided into anoxic and oxic zones for denitrification, organic removal and nitrification. Primary effluent will enter the anoxic zones where it will be mixed with mixed liquor recirculated from the oxic zones. However, because of the high level of dissolved oxygen in the sludge return from the membrane chambers, this recycled sludge will be returned to the start of the oxic zones.
The anoxic zones are equipped with mixers to maintain the mixed liquor biomass in suspension without introducing ambient air (oxygen). This promotes the scavenging of oxygen from the Screens Grit
Tanks
Primary
Clarifiers
Disinfection
WW Reuse
Water
Mixed Liquor Recirculation
Sludge Recirculation
Membrane
Fine
Tanks
Screens
Oxic Tanks
Anoxic
Tanks
MEMBRANE BIOREACTOR (MBR)
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SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-3
nitrates present in the recirculated sludge and exhausting of the resultant nitrogen gas, which reduces the nitrogen content in the wastewater. The oxic zones are equipped with fine bubble diffusers to create an oxygen rich environment for the biomass.
The most significant difference between conventional activated sludge and the bioreactor portion of an MBR system is the ability to raise the mixed liquor concentration in the bioreactor from a conventional 3,500 mg/L to 10,000 mg/L, resulting in a reduction in the tankage volume required to provide an equal level of secondary treatment.
A consequence of the higher mixed liquor concentration is that the oxygen transfer efficiency is slightly lower (i.e. lower alpha), reducing the overall efficiency of the aeration system and increasing the aeration energy. This difference may add 10 to 15% to the amount of air required in the oxic zones of an MBR system. However, the oxygen contained in the membrane chamber’s recycled sludge will typically balance the extra air/oxygen required in the aeration basins.
7.2.3 Tertiary Treatment - Membrane Filtration
Membrane technology started in the water treatment field, and has been successfully used in water treatment plants for more than 20 years. Membrane filtration can consistently reduce the level of solids and contaminants in the effluent to below detection limits. Though membranes are an effective physical barrier, straining out many contaminants, further treatment through a disinfection process is necessary to remove the remaining contaminants. This provides a “dual-barrier” to enhance the safety of the final effluent, complying with CDPH requirements for unrestricted reuse of the plant effluent.
Operating experience of several membrane manufacturers have shown that the membranes are consistently capable of producing an effluent essentially approaching non-detectable levels of organics, solids and pathogens. The clarity of the membrane effluent is significantly superior to that produced by traditional filtration processes. The high quality effluent is ideal for reuse applications and public acceptance.
In the MBR process, the membranes can be located externally from the mixed liquor tanks in tubes, but typically are submerged in tanks in direct contact with the mixed liquor and function as the clarification and filtration steps. Externally installed membranes are configured in pressure vessels with pumps transferring flow from the bioreactors to the vessels. In submerged membrane applications, pressure differential across the membranes in the form of a vacuum is provided using either the hydraulic grade (gravity) or a filtrate pump suction to siphon liquid (permeate) through the membrane material. In all cases, permeate or membrane effluent, passes through the membrane material leaving the solids behind for recirculation back to the bioreactors.
Unlike a media type tertiary filter, in an MBR system, the membranes are not backwashed, but rather, the solids are air scoured from the membrane surface and recycled back to the CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-4
activated sludge bioreactor. The main waste from an MBR system is the waste activated sludge (WAS), similar to the WAS currently pulled from the secondary clarifiers.
Chemical cleanings of the membranes, performed using a clean-in-place (CIP) system, is dependent on the feed water quality and membrane manufacturer; thus, the frequency of cleaning can range from once or twice a week to three or four times a year. Extensive cleaning of the membranes beyond this routine cleaning is required approximately once or twice per year.
There are two types of membranes commonly used in an MBR system; hollow-fiber and flat-sheet. Both membrane types are able to reliably produce high quality water and therefore, the choice of membranes will be mostly a matter of capital and operational costs evaluated on a life cycle cost basis. Hollow-fiber membranes can be installed in a smaller footprint. Flat-sheet membranes require more area, but a lower operating differential pressure across the
membranes (transmembrane pressure, TMP),
and reportedly (per manufacturers) have a
higher maximum flow capacity (flux rate).
Because both membrane types are a viable alternative for application at the Fresno TTDF, it is recommended that pre-selection be undertaken during the early stages of detailed design to select a membrane manufacturer and facilitate the design of the MBR system specific to that manufacturer.
7.3 LOCATION AND CAPACITY OF MBR
Two locations were considered for MBR system: Train A and Train B (Figures 7-2 through 7-5):
• Train A:
o Convert one of the secondary clarifiers to aeration basin of MBR (due to age of structure and sloping walls of the existing aeration basins in Train A, it was decided not to use them for this purpose)
o Construct the membrane tanks in vicinity of secondary clarifiers • Train B:
o Use aeration basin No. 5 as the aeration basin of MBR o Modify secondary clarifier No. 6 to accommodate membrane tanks Two flow rates were considered for analysis: 5 and 10 mgd. Primary effluent will be pumped to fine screens and then will flow by gravity to aeration basin and then membrane tanks. The flow for 5 mgd scenario is constant, while the flow for 10 mgd scenario includes a peaking factor of
1.23. For both flows, nitrogen removal (NDN) is included in the design.
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SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-6
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SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-7
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SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-8
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SECTION 7 – MEMBRANE BIOREACTOR (MBR) OPTION 7-9
7.4 COSTS
The capital costs for Train A and Train B (5 and 10 mgd) are shown in Tables 7-1 and 7-2, respectively. A credit for conventional NDN is included. This is the investment the City would need to make on secondary treatment system, if the plant had to be upgraded to NDN process using conventional tertiary filters rather than MBR. As can be seen, using Train A for MBR would result in higher cost. This is due to the extensive modifications needed in Train A.
Table 7-1: MBR Capital Cost – Train A
Parameter
a
Capital Cost ($ Million)
Flow 5 mgd 10 mgd
Equipment and Structures Cost 7.0 12.1
Total Capital Cost 20.2 b 34.9
Credit for Conventional NDN (0) b,c (8.2)
Total Capital Cost Including NDN Credit 20.2 26.7 a UV credit not included. b Including installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012-2013) c NDN credit based on constructing additional facilities (one aeration basin and installing new equipment such as mixed liquor recycle pumps) if the City were to choose conventional filters instead of MBR and were required to achieve NDN in the conventional secondary treatment process.
Table 7-2: MBR Capital Cost – Train B
Parameter
a
Capital Cost ($ Million)
Flow 5 mgd 10 mgd
Equipment and Structures Cost 5.9 10.9
Total Capital Cost 17.0 b 31.5
Credit for Conventional NDN (0) b,c (8.2)
Total Capital Cost Including NDN Credit 17.0 23.3 a UV credit not included. b Including installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012-2013) c NDN credit based on constructing additional facilities (one aeration basin and installing new equipment such as mixed liquor recycle pumps) if the City were to choose conventional filters instead of MBR and were required to achieve NDN in the conventional secondary treatment process.
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SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-1
SECTION 8 – SUMMARY OF WORKSHOP NO.1
8.1 BACKGROUND
A Workshop was conducted with the City on November 4, 2010 to present and discuss various system alternatives for filtration, disinfection and storage systems for the proposed TTDF.
These alternatives are discussed in detail in Sections 4, 5 and 6, respectively, of this TM. This Section of the TM summarizes the discussion carried out at the Workshop and highlights the important decisions made for subsequent work.
8.2 FILTRATION SYSTEM ALTERNATIVES ANALYSIS
Eight filtration technologies were analyzed and summarized during the Workshop. The technologies discussed were:
1. Dual media gravity filters
2. Deep bed mono media filters
3. Continuous backwash filters
4. Traveling bridge filters
5. Fuzzy filters
6. Cloth media filters
7. Nova Ultrascreen filter
8. Microfilters
The Workshop presentations & discussions included the following:
1. Introduction and filter history
2. Photos and cross-sections
3. Features of operation
4. Pros and Cons
5. Title 22 design criteria including reliability
6. Preliminary layout for 5 mgd expandable to 15 mgd and ultimately to 30 mgd.
7. Capital, O&M and life cycle cost analysis
Based on the discussions, the City indicated their preference for cloth media filters and Nova Ultrascreen filters. The City expressed their concern about possibility of air-borne dust contaminating the recycled water and directed that all filtration units be covered. City requested that revised cost estimates be prepared for the two preferred filtration technologies including a building to house cloth media filters and a canopy for Nova Ultrascreen filters. Subsequently, the City asked Parsons to consider a building for Nova filters as well. The City also asked Parsons to inquire Nova about potential effluent turbidity spikes following backwash with Nova filters.
Parsons will revise the cost estimates and will contact Nova to inquire about the potential effluent spike problems immediately following the backwash.
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SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-2
8.2.1 Subsequent Developments
Following the Workshop, Parsons submitted revised cost estimates to the City for cloth media filters and Nova Ultrascreen filters. Table 8-1 presents a summary of revised costs for the two systems (including CMU buildings to house each type of filters) for 5 mgd constant flow rate.
Table 8-1: Revised Cost Summary for Cloth Media and Nova Ultrascreen Filters (5 mgd Constant Flow)
Parameter Cloth Media Filterse
($)
Nova Ultrascreen Filters
($)
Equipment and Structures Costa 1,870,000 1,325,000
Total Capital Cost
b 5,000,000 3,800,000
Total Annual O&M Costc 90,000 100,000
20 Year Life Cycle Cost
d 6,700,000 5,650,000
a Includes CMU building to house the filters. b Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
c Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
d At a 5% discount rate and a 4% escalation rate.
e Concrete structure designed for a total filtration capacity of 9 mgd.
Per City’s request, Parsons contacted Nova to inquire about possible effluent turbidity spikes immediately following backwash operation. Staff at Nova clarified that Nova filters do not experience the effluent turbidity spikes, unlike cloth media filters, immediately following backwash. They attribute this to what they call “pulse backwashing”. Nova filter discs go through much frequent backwash cycles; one backwash every 6-10 minutes each lasting for about 10-15 sec. This “pulse backwashing” not only eliminates effluent turbidity spikes but the volume of backwash is significantly less (less than 1% of feed water volume) when compared to cloth media filters. Nova also claims that due to the fact that Nova filter discs use a filter medium (precision woven SS mesh) which provides fine pore size control, their filtration system does not depend on cake filtration as is the case with cloth media filters. To substantiate their claim against effluent turbidity spikes following backwash, Nova supplied an evaluation report for Orange County South Regional Water Reclamation Facility – Sand Lake Road in Florida, where cloth media filters and Nova filters were tested side-by-side. The report supports Nova’s claim that their filters do not experience effluent turbidity spikes as in the case of cloth media filters. This report is attached in Appendix C. The graphs presented in pages 5 and 6 of the report clearly document relatively constant effluent turbidity from Nova filters when compared to distinct spikes in effluent turbidity after every backwash in case of cloth media filters.
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SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-3
Based on the above analysis and fact finding, City selected Nova Ultrascreen filters as their system of choice for filtration for comparison against MBR system. Parsons would like to highlight the Nova’s lack of experience in meeting Title 22 regulations in California. Nova Ultrascreen® filters have a long history (~10 years) of use in overseas installations; however, the history of use in the US on municipal wastewater is limited. There are currently no installations in California and the longest operating municipal wastewater installation in the US has been in operation for less than one year (in Orange Park, FL) and has a rated capacity of 3.0 mgd. If the City should consider this filtration system, Parsons strongly recommends a minimum of two (2) site visits to operating installations by Parsons and City staff to gain first-hand knowledge of the performance and operation of Nova filters before finalizing this choice.
In addition, disc filters in general, require the upstream biological treatment system to have a minimum SRT of 5 days prior to filtration (including Nova Ultrascreen filters) for consistent effluent quality. Without such a high SRT, the extra cellular enzymes secreted by the microorganisms will potentially plug the fine pores on the disk media. If the existing biological system does not provide an SRT of at least 5 days, modifications to the pertinent secondary treatment facilities’ operations will be required.
8.3 DISINFECTION SYSTEM ALTERNATIVES ANALYSIS
Three disinfection technologies were analyzed and summarized during the Workshop. The technologies discussed were:
1. Open channel UV Disinfection
2. In-pipe UV Disinfection
3. Ozone Disinfection
Each disinfection technology was discussed in detail and consisted of the following:
1. Introduction
2. Photos and cross-sections
3. Features of operation
4. Pros and Cons
5. Title 22 design criteria including reliability
6. Preliminary layout for 5 mgd expandable to 15 mgd and ultimately to 30 mgd.
7. Capital, O&M and life cycle cost analysis
Based on the discussions, the City expressed their preference for in-pipe UV disinfection system similar to neighbouring Clovis Water Reuse Facility. At the Clovis facility, the City noted the operator’s positive experience with operating and maintaining the in-pipe UV system. The City asked Parsons to revise the cost estimates to include 1.0 mgd capacity UV reactors instead of
2.3 mgd capacity reactors considered earlier by Parsons. City also wanted the cost estimate to include a canopy for in-pipe UV reactors. Table 8-2 presents a summary of the revised cost estimates for the 1 mgd in-pipe UV system compared to the 2.3 mgd in-pipe UV system. Final CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-4
selection of the UV system will be made during detailed design and will be based on competitive bidding between 1 mgd reactors and lager size reactors (2.3 mgd and others, as applicable).
Table 8-2: Revised Cost Summary for In-pipe UV Disinfection Following Meida Filtration (5 mgd Constant Flow)
Parameter 2.3 mgd Reactors
($)
1 mgd Reactors
($)
Equipment and Structures Cost 1,460,000 2,000,000
Total Capital Costa 4,800,000 6,500,000
Total Annual O&M Cost
b 230,000 230,000
20 Year Life Cycle Costc 8,900,000 10,600,000
a Including typical installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012- 2013).
b Including power, media replacement, general maintenance, and labor. Unit power cost is considered as $ 0.14/kWh.
c At a 5% discount rate and a 4% escalation rate.
8.4 STORAGE AND PUMPING SYSTEM ALTERNATIVES ANALYSIS
Three storage alternatives were analyzed and summarized during the Workshop. The alternatives discussed were:
1. Earthen basins (lined and covered)
2. Steel tanks
3. Pre-stressed concrete tanks
4. Converted Train A Aeration Basin
The pros and cons of each alternative along with capital, O&M and life cycle costs were discussed during the Workshop.
If modifications to Train A are required as part of the proposed treatment system (as in case of MBR alternative), then converting an aeration basin (Train A) into storage will be the preferred choice for the City. On the other hand, if a new storage tank needs to be constructed (for conventional filtration alternative), the City prefers pre-stressed concrete tanks due to their low maintenance cost, avoided costs for pumping the recycled water to the storage tanks (as in case of a steel tank) and aesthetics.
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SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-5
8.5 MEMBRANE BIO-REACTOR (MBR) OPTION
Parsons presented MBR system as an alternative to conventional filtration. The advantages with MBR include the ability to remove nitrogen, producing higher quality effluent exceeding Title 22 standards, utilizing existing basins, and enhancing the existing treatment capacity without addition of tanks and lowering the cost of downstream UV system.
The presentation included analysis of MBR system in Train A versus Train B. City likes the idea of utilizing Train A infrastructure (aeration basins and clarifiers), which reportedly are at the end of their useful life. In contrast, Train B is a newer and well operated system, which the City prefers not to make any modification to at this time. City directed Parsons to use exclusively Train A for MBR system analysis.
Parsons presented an MBR system that made the best use of existing infrastructure at Train A.
Pre-aeration for MBR comes from modifying one of the four existing square secondary clarifiers.
The City suggested Parsons to utilize the currently decommissioned secondary clarifier no. 5 to install membrane cassettes. In-pipe UV reactor system will be used for disinfection as in case of filtration alternatives. Parsons proposed the idea of converting one of the existing four square aeration basins (app. 2.7 MG each) into a recycled water storage tank; the City concurred with this recommendation.
City requested Parsons to evaluate the option of using a portion of the air from the existing aeration blowers for membrane air scouring. Parsons has addressed this issue in Section 9 of this TM.
8.6 THREE PLANS (PLANS A, B AND C)
At the end of the Workshop, City decided to have three Plans to be developed in further detail and to be included as part of this TM. The three Plans are called A, B and C, which are described below.
PLAN A (12 mgd MBR)
1. This MBR alternative will be based on Train A with 12 mgd average dry weather flow (maximum capacity of each basin to provide nitrification & denitrification) and 14.76 mgd peak dry weather flow (12 mgd times 1.23 peaking factor). The MBR alternative with 5 mgd average constant flow will only be discussed but not evaluated, since it involves de-rating of Train A (also Train B) capacity significantly.
2. This plan will include conversion of a Train A clarifier (one only) into pre-aeration basins preceding the membrane tanks.
3. This plan will evaluate conversion of clarifier no. 5 (circular) into membrane tanks versus construction of separate membrane tanks.
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4. In-pipe ultraviolet (UV) is the preferred process for disinfection and will be designed and used as the basis for cost estimates for the same flows as above. Based on discussion at the Workshop, 1-mgd UV reactors will be used as the basis for the construction cost estimate. A canopy to cover the UV reactors will also be considered.
5. One aeration basin at Train A will be converted into a recycled water storage facility (about 2.7 MG).
PLAN B (5 mgd Filtration)
1. Plan B will incorporate a 5 mgd constant flow filtration system. Both Nova and Disk filter systems will be evaluated. Revised cost estimates including a canopy for the Nova filters and a building for the Disk filters will be submitted to the City. Furthermore, Parsons will contact Nova to investigate the issue of potential turbidity spikes in filtrate immediately after backwash. The cloth media disk filter system has reflected this phenomenon, although it is not of much concern since the effluent quality is mandated based on averages. Nova is preferred subject to resolution of this issue.
2. This plan will take 5 mgd of constant flow from the effluent junction box downstream of Train B for filtration and disinfection. There is no nitrification-denitrification (NDN) requirement right now for this flow. However, it may be required in the future, so leave space for any future facilities needed for this to be accomplished.
3. In-pipe UV is the preferred process for disinfection (a system using 1-mgd reactors with canopy).
4. Storage will be accomplished with a partially buried 5 MG pre-stressed concrete tank.
PLAN C (12 mgd Filtration)
1. Plan C will incorporate a 12-mgd constant flow filtration system. Here again, the flow will be taken from the effluent junction box downstream of Train B. There is no nitrification-denitrification (NDN) requirement right now for this flow. However, it may be required in the future, so leave space for any future facilities needed for this to be accomplished.
2. Nova and Disk filters will be evaluated as for Plan B. Nova is preferred subject to the resolution of the effluent quality issue as in Plan B.
3. In-pipe UV as for Plans A and B is the preferred process for disinfection (a system using 1-mgd reactors with canopy).
4. Storage will be accomplished with a partially buried 5 MG pre-stressed concrete tank.
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SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-7
8.7 POWER SUPPLY OPTIONS FOR TTDF
Per the scope of work, Parsons was to evaluate the feasibility of feeding the proposed TTDF facilities from an existing switchgear at RAS/WAS pump station located adjacent to the secondary clarifiers in train B. However, during the Workshop the City indicated that, for MBR system, it may be better to take the power feed from either four existing transformers or a 12kV switchgear located east of secondary clarifier no.1 in Train A. Parsons’ evaluation of various options of power supply for TTDF are presented under Section 12 of this TM.
8.8 EFFLUENT ELECTRICAL CONDUCTIVITY (EC)
The City staff brought up an important issue that needs to be considered for design of the TTDF. The RWRF’s discharge currently has a limit for electrical conductivity (EC) of 500 micro mhos/cm + EC of the source water. Meeting this limit is a challenge and may require various measures including source water treatment or replacement, expensive systems to remove salts in wastewater, industrial source control and/or public education on waste minimization. The various alternatives presented, including MBR, may not be effective removing all salts from the final effluent. However, MBR technology could help reduce EC levels through its nitrification/denitrification (NDN) abilities. Parsons estimates that effluent EC can be reduced by about 150 micro mhos/cm through NDN, as ammonia is converted to nitrogen gas and escapes into the atmosphere.
During the past few years, the RWRF has experienced a reduction of the effluent EC through an incidental NDN process that reduced ammonia to nitrogen gas. The reduction in the effluent was estimated between 8% to 9.5% of the total EC influent, enough to maintain compliance with the Waste Discharge Requirements (WDR) discharge limit.
8.9 OTHER KEY DECISIONS MADE
Aside from the discussion above, the following are the other key decisions made during the Workshop.
1. Site preparation (filling and compacting the percolation basins to grade) will be performed by the City.
2. All facilities (for Plans A, B and C) will be located north of Canal B.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 8 – SUMMARY OF WORKSHOP NO.1 8-8
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CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-1 SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY)
9.1 BACKGROUND
Per Workshop No. 1 (Section 8 of this TM), Plan A which incorporates an MBR system, disinfection, and storage is discussed under this Section. The technical concept of MBR system was discussed in Section 7. During Workshop No.1, several key decisions were made regarding the analysis of Plan A, as mentioned briefly below:
• Design the system to achieve organics as well as nitrogen removal (NDN). This is to maximize the benefits which can be obtained from MBR considering the possible future effluent nitrogen requirements.
• Use the existing facilities of Train A – and not of Train B – to build Plan A scheme. Train A is the oldest amongst the three existing Trains, is obsolete in design, and is the best candidate for modifications and conversion to MBR.
• Due to age and sloping walls of the aeration basins in Train A, do not consider conversion of any of these basins to MBR bioreactor. This will be very expensive for retrofitting and/or very inefficient. Instead, use one of the secondary clarifiers in this Train for such purpose.
• In Train A, the rated capacity of each existing aeration basin and associated clarifiers is 8 mgd. Therefore, do not consider 5 mgd design flow as the basis for analysis because this would result in significantly de-rating the exiting train. Instead, use the maximum capacity that each aeration basin (in this case converted secondary clarifier) can handle to achieve NDN.
• UV Inline System (1 mgd capacity) will be used for disinfection of MBR permeate. Final selection of the UV system will be made during detailed design and will be based on competitive bidding between 1 mgd reactors and lager size reactors (2.3 mgd and others, as applicable).
• One of the aeration basins in Train A will be used to store the recycled water (approximate capacity of 2.7 MG).
Based on the above items, MBR system as discussed later in the section will be located in Train A and designed for maximum capacity that one converted secondary clarifier can handle.
9.2 DESIGN DEVELOPMENT
This Section of the TM takes the technical concepts discussed above and develops the mainstream treatment system: i.e. membrane bioreactor (MBR), to upgrade a portion of the RWRF from a carbonaceous BOD removal facility to a simultaneous nitrification and denitrification (nitrogen removal) Title 22 water reclamation facility capable of producing a high CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-2 quality, low nitrogen effluent. Primary effluent is treated through an MBR system, providing oxidation, nitrification-denitrification and solids separation in a single process.
Primary effluent will be first pumped through fine screens and will then flow into the bioreactor (aeration basin) and then into the membrane tanks. The membrane permeate will be pumped to the UV system for disinfection prior to transfer into the storage basin. Two alternative locations are considered for membrane tanks – 1) conversion of secondary clarifier 5 2) a separate membrane tank. Figures 9-1 and 9-2 show the overall layouts for the MBR system for these two options. Detailed analysis of each option is presented later on in this document.
9.2.1 Capacity Analysis
As mentioned above and agreed upon during Workshop No.1, one of the secondary clarifiers in train A will be converted to the aeration basin associated with MBR. The capacity of the MBR system will be determined based on the amount of flow that the converted secondary clarifier can handle to achieve NDN. The basin will be compartmentalized to incorporate anoxic and oxic zones. The design criteria in Table 9-1 were developed as the basis for capacity analysis.
Table 9-1: Design Criteria for Capacity Analysis of MBR Aeration Basin to Achieve NDN Item Units Design
Value Remarks
Flow Peaking Factor - 1.23 Peak:Average ratio
Primary Effluent - - Max month values
BOD mg/L 224 70% of raw wastewater
TSS mg/L 120 40% of raw wastewater
TKN mg/L 30 65% of raw wastewater
MLSS mg/L 10,000
SRT (Minimum) days 6 Oxic zone
Anoxic:Oxic Zone Ratio
(Minimum) - 0.3
Total Volume of Basin MG 2.3 One secondary clarifier
Maximum Oxygen Uptake Rate mg/L-hr 135 For peak flow
Based on the above design criteria, the average flow that a converted secondary clarifier in Train A can handle was determined to be 12 mgd, corresponding to a peak flow of 14.76 mgd.
These values were used to size the other equipment and structures associated with the MBR system.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-3
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-4
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-5
9.2.2 Primary Effluent Pumps
The existing aeration basin distribution structure located on the east side of Train B will be modified to house the primary effluent pumps. These pumps will pump the desired flow from the distribution structure to fine screens. Table 9-2 shows the design characteristics for the pumps.
Table 9-2: Primary Effluent Pumps Design Characteristics Item Units Design
Value Remarks
Type Vertical propeller
Number - 2 (1+1)
Capacity, Each gpm 10,300 Wet weather peak will not be
handled in MBR
TDH ft 20
Horsepower hp 100
Drive Variable speed
9.2.3 Fine Screens
There are different types of fine screens which could be used in an MBR facility; in-channel rotary drum screen, internally-fed rotary drum screen, and band screen. The first type, i.e. inchannel rotary drum, consists of an inclined screen basket, placed within a channel, and is equipped with an integrated auger for dewatering/compaction of collected screenings. The second type, i.e. internally-fed rotary drum, is a skid-mounted unit. The screen basket is installed in a horizontal configuration. Wastewater is fed into the unit, flows over the weirs and free falls into the screen basket. The screenings need to be handled by a separate dewatering unit. This type of screen requires more available head due to the free-fall condition. The third type, i.e. band screen, consists of several perforated plates joined together similar to a conveyor belt. The unit is installed vertically in a channel. Wastewater is fed into the center of the unit and flows across the plates out of the unit. There have been performance issues associated with this type of screen in the past during operation. The product, however, has reportedly been improved over the past few years.
The in-channel rotary drum screen was selected for consideration in this technical memorandum due to its apparent simplicity. By way of illustration, collection and dewatering of screenings are accomplished in a single unit as noted above. A dispenser holding a roll of plastic tubes is mounted at the discharge of the screenings dewatering auger such that the plant operator can pull down a portion of the plastic tube to form a bag to receive the screenings, thus containing the odor of the screenings in the bag and avoiding nuisances like flies or other insects. Nonetheless, it is Parsons’ intent that if the MBR alternative is selected, all three types of fine screens will be evaluated for their reliability and cost-effectiveness, as well as odor control requirements and ease of screenings removal during the detail design. The best screens will be provided accordingly.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-6 As shown on Figures 9-2 and 9-3, the fine screens will be located southwest of secondary clarifier No. 4 of Train A. Two fine screens would be installed with one of the units as standby.
Each screen would be capable of handling the peak flow of 14.76 mgd. The units would be installed in concrete channels equipped with isolation gates to allow for maintenance without interfering with the plant’s operation. Each fine screen would be equipped with an integrated washer/compactor for cleaning and concentrating the screenings prior to disposal off site.
The design characteristics for the fine screens and washer/compactors are shown in Table 9-3.
Table 9-3: Design Characteristics of Fine Screens and Washer/Compactors Item Units Design
Value Remarks
Screens
Type - - In-channel perforated-plate drum
Number - 2 (1+1)
Capacity, Each mgd 14.9
Effective Opening Size mm 2
Channel Width ft 8.5 Width at screen
Screenings Handling
Type - - Washer, dewatering, compactor
unit
Number - 2 (1+1) Integrated with screens
Motor Power, Each hp 3 Also powers screen basket
9.2.4 Bioreactors and Associated Equipment
This subsection describes the structures and equipment located downstream of fine screens and upstream of membrane tanks.
Bioreactor (Aeration Basin):
As mentioned above, one of the secondary clarifiers of Train A (clarifier No. 4) will be converted to aeration basin. To provide redundancy, the clarifier will be retrofitted to accommodate two bioreactors, each divided into anoxic and oxic zones, with the first quarter of each bioreactor dedicated to the anoxic zone. Baffles would be placed in the bioreactors to separate the anoxic and oxic zones to minimize back-mixing as the flow passes through in a plug flow regime.
Additional baffling would be used to divide each anoxic and oxic zone into 3 compartments, again to minimize back-mixing. The plug flow conditions increase the efficiency of biological treatment, optimizing carbonaceous matter removal, nitrification and denitrification.
Submersible mixers would be used to provide mixing in the anoxic zones. Table 9-4 provides the design characteristics of the bioreactors.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-7 Table 9-4: Bioreactors Design Characteristics
Item Units Design Value Remarks
Bioreactors
Number (In Parallel) - 2 Converted secondary clarifier No. 4 Volume, Each MG 1.15
Anoxic Zone
Number per Bioreactor - 1
Dimensions of Zone
(L x W x SWD), Each ft x ft x ft 75 x 37 x 14
Number of
Compartments per Zone - 3 Equal volume (in series)
Oxic Zone
Number per Basin - 1
Dimensions of Zone
(L x W x SWD), Each ft x ft x ft 225 x 37 x 14
Number of
Compartments per Zone - 3 Equal volume (in series)
Anoxic Zone Mixers
Type Submersible
Number per Compartment - 1
Total Number - 7 (6+1) One shelf spare
Horsepower, Each hp 4
Aeration System:
The air will be transferred to the oxic zones in the bioreactors through fine bubble diffusers.
Either EPDM Membrane disks or more efficient aerator strips (e.g. AEROSTRIPTM), would be used to provide aeration. The aeration would be tapered so that approximately 70% of the oxygen is provided in the first half of the oxic zone to satisfy the high oxygen demand as the substrate enters the oxic zone.
The required air will be supplied to the oxic zones by the existing blowers. These blowers are of single-stage centrifugal type and have enough capacity to serve the biological needs of the MBR process as well as the remaining plant. The existing 24 inch air pipeline of aeration basin No. 3 will be used and extended to supply the air to the bioreactors. As discussed in Section 6, aeration basin No. 3 will no longer be in service and will be used as recycled water storage in the future.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-8 The design characteristics for the aeration system are presented in Table 9-5.
Table 9-5: Aeration System Design Characteristics
Item Units Design Value Remarks
Diffusers
Type Fine bubble, membrane
(EPDM) disk or strip type
Aeration Pattern Tapered along bioreactor
length
Process Air Blowers
Type Single-stage centrifugal
Number - 6 (5+1) Existing blowers
Capacity, Each scfm 27,000
Discharge Pressure psig 7.8 or 8.5 4 units at 7.8 and 2 units at
8.5 Horsepower hp 1,500
Mixed Liquor Return and Sludge Recirculation Pumps:
Two recirculation lines are provided in the MBR system; mixed liquor return and sludge recirculation. The mixed liquor return system transfers mixed liquor from the tail end of the oxic zone back to the head of the anoxic zone at a rate up to four times the average flow. This system transfers nitrates resulting from nitrification back to the anoxic zone for denitrification as the oxygen molecules associated with nitrates are used by the biomass.
The sludge recirculation system transfers sludge from the membrane tanks to the head of the oxic zone at a rate also up to four times the average flow. The recirculation system prevents the solids concentration in the membrane tanks from increasing excessively as permeate is removed from the mixed liquor. This sludge is highly oxygenated and provides a portion of the process oxygen needed for BOD removal and nitrification.
Sludge will be wasted from the MBR system from the membrane tanks. New pumps will be installed for this purpose.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-9 The design characteristics for the recirculation and waste pumps are presented in Table 9-6.
Table 9-6: Sludge Pumping Systems Design Characteristics Item Units Design Value Remarks
Mixed Liquor Return
Pumps
Returning flow from oxic zone to
anoxic zone
Type Axial propeller
Number - 3 (2+1) One shelf spare
Capacity, Each gpm 16,700
TDH ft 3
Horsepower hp 30
Drive Variable speed
Sludge Recirculation
Pumps
Returning flow from membrane
tanks to oxic zone
Type Vertical propeller
Number - 3 (2+1)
Capacity, Each gpm 16,700
TDH ft 20
Horsepower hp 150
Drive Variable speed
WAS Pumps
Type Centrifugal
Number - 2 (1+1)
Capacity, Each gpm 1,000
TDH ft 20
Horsepower hp 7.5
Drive Variable speed
9.2.5 Membranes
The membranes will be installed in 8 independent tanks. Two options were considered for the location of membranes; inside secondary clarifier No. 5 (Figure 9-2) and in a completely new structure (Figure 9-3). In the first option, the existing secondary clarifier No. 5 would be modified by removing the mechanisms and raising the bottom to house the membrane tanks.
In the second option, the membrane tanks will be constructed east of secondary clarifier No. 5.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-10 For the purpose of this Section, hollow-fiber membranes were considered. The following design criteria were developed as the basis for sizing the membranes:
• Minimum wastewater temperature of 16oC.
• Maximum flux rate of 14 gfd at average flow (all membrane tanks in service). • Maximum flux rate of 20 gfd at peak flow (one membrane tank out of service).
Eight membrane tanks, each housing 6 membrane cassettes plus space for a future cassette, would have enough capacity to handle 12 mgd of flow. The tankage would be configured to allow isolation of a tank for maintenance and cleaning.
Permeate pumps will draw the MBR effluent through the membranes, directing it to the disinfection system. A building would house new air scouring blowers and membrane control and electrical system. The building would be located adjacent to the membrane structure.
As an alternative to installing new air scouring blowers, the existing single-stage blowers could be used for membrane scouring and also to provide the process air with proper piping and valves to address the different pressure requirements at membrane tanks and bioreactors.
Although this approach is technically feasible, based on Parsons’ experience, this would complicate the operation of the plant and result in inefficient long term operation. Dedicating one or two of the single-stage blowers to air scouring is not recommended as the maximum required scour air for the 12-mgd plant is only about half of the capacity of each blower. Using these blowers would require them to operate at half the full rated capacity and will result in an inefficient operation of the blowers. Therefore, separate air scour blowers are recommended.
Table 9-7 summarizes the design characteristics of the MBR membrane system.
Table 9-7: MBR Membrane System Design Characteristics
Item Units Design Value Remarks
Tanks
Number - 8
Cassettes per Tank
Number of Installed - 6
Space for Future - 1
Total Membrane Surface Area ft2 852,480
Air Scouring Blowers
Type High-speed turbo
Number - 3 (2+1)
Capacity, Each scfm 7,900
Discharge Pressure psi 5
Horsepower, Each hp 250
Drive Variable speed
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-11 Item Units Design Value Remarks
Permeate Pumps
Type Horizontal end suction
Number - 9 (8+1) One shelf spare
Capacity, Each gpm 1,700
TDH ft 25
Horsepower, Each hp 20
Drive Variable speed
Backpulse Pumps
Type Horizontal end suction
Number - 2 (1+1)
Capacity, Each gpm 1,480
TDH ft 25
Horsepower, Each hp 30
Drive Variable speed
Instrument Air Compressors If Plant air not available
Number - 2 (1+1)
Horsepower, Each hp 15
Chemical Cleaning
Sodium Hypochlorite 12.5% Solution
Frequency
Recovery Yearly 2 Per tank
Maintenance Weekly 1 Per tank
Annual Consumption gal 7,900
Citric Acid 50% Solution
Frequency Yearly 1-2 Part of Recovery Clean
Annual Consumption gal 1,500
9.3 DISINFECTION
During Workshop No.1, as is the case with Plans B and C, the City directed Parsons to consider in-pipe UV disinfection for Plan A. It was also decided during the workshop that smaller (1 MGD capacity) reactors be considered for preliminary design and cost estimates. The 1 MGD rating for each reactor is based upon high quality membrane permeate feed such as from the MBR system. Nine reactor trains (8 operating + one standby) will be required to disinfect 12 mgd average flow (12 x 1.23 = 14.7 peak flow) and each train will accommodate two reactors. Table 9-8 presents the design criteria for the in-pipe UV disinfection system. There are several larger in-pipe reactors currently available from other manufacturers that may be more economical for CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-12 the present project and may be considered later during detailed design.
Table 9-8: In-pipe UV Disinfection Design Characteristics Parameter Criteria
Design Flow (Average), mgd 12
Peaking Factor 1.23
Type of UV System In-pipe, Low Pressure, High Intensity Number of Reactors 18 (8 trains + 1 standby) each train has 2 reactors Flow Capacity per Reactor, mgd 1.0
Length of Reactor (ft) 8
Number of Lamps per Reactor 40
Total Number of Lamps Provided 720
Figure 9-3: In-pipe UV Disinfection System Preliminary Layout
9.4 CONSTRUCTABILITY AND EXPANSION
It is critical that the treatment plant operation not be impacted by the construction activities.
The plant must, at all times, be capable of performing at the level required to achieve the water quality standards set by its permit.
The major new construction associated with the MBR system will be the fine screens, bioreactors, membrane structure, and blower building. In case of fine screens, membrane structure, and blower building, construction will be performed in areas that are not associated with the present operation of the plant. This would allow the construction of these facilities to take place independent of the current operation. In case of bioreactors, modifications of one of the secondary clarifiers should not impact the plant operation as one of the square clarifiers is currently not being used. Minor construction activities, as necessary, can be performed CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-13 during periods of low flow to avoid negative impacts on the plant performance. Finally, sequencing of construction will be necessary when making connections to existing piping and the plant electrical and control systems; these constraints will be carefully developed and specified in the contract documents.
The ultimate capacity of the Fresno TTDF is planned to reach an average flow of 30 mgd.
Additional fine screens, bioreactors, membrane tanks, and blowers will be needed to handle the ultimate capacity. As shown in Figures 9-2 and 9-3, space has been provided for the above equipment/structures, adjacent to the proposed facilities, to accommodate the future expansion.
9.5 PRELIMINARY COSTS
Preliminary costs are developed for two scenarios. The only difference between two scenarios is the location of the membranes; inside the secondary clarifier No. 5 and outside the clarifier in a completely new structure. At this point in the design process, these costs are preliminary and should be used only for comparative purposes.
The costs are estimated using several resources. The quotes from the manufacturers, information available from the similar projects performed by Parsons, and also our own experience, including construction in the Central Valley, were used to determine the costs.
The capital costs for the two scenarios are shown in Table 9-9. For both scenarios, a credit for conventional NDN is included. This is the investment the City would need to make on secondary treatment system, if the plant had to be upgraded to NDN process using conventional tertiary filters rather than MBR. As can be seen, locating the membranes inside the secondary clarifier No. 5 would result in $0.5 million additional cost to the City. This is mainly due to the substantial modifications required to the clarifier before it can accommodate the membranes.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-14 Table 9-9: Plan A Capital Cost (12 mgd) a
Parameter
Capital Cost ($ Million)
Membranes Inside
Secondary Clarifier No. 5
Membranes in New
Structure
MBR Equipment and Structures Cost 15.5 15.1
MBR Total Capital Cost 44.2 b 43.7
Credit for Conventional NDN (8.9) b,c (8.9)
MBR Total Capital Cost Including NDN Credit 35.3 34.8
UV Disinfection Total Capital Cost 12.9 b 12.9
Storage (Aeration Basin No.3) Total Capital
Cost b 3.1 3.1
Plan A Total Capital Cost 51.3 50.8 a For detailed cost analysis see Appendix A. b Including installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012-2013) c NDN credit based on constructing additional facilities (one aeration basin and installing new equipment such as mixed liquor recycle pumps) if the City were to choose conventional filters instead of MBR and were required to achieve NDN in the conventional secondary treatment process.
An evaluation of the operation and maintenance (O&M) cost was also performed (Table 9-10).
As was the case for capital cost, credit is given for operation of secondary treatment of a conventional NDN plant. The O&M cost for both scenarios is the same.
Table 9-10: Plan A O&M Cost (12 mgd)
Parameter
a
O&M Cost ($)
MBR Total Annual O&M Cost 1,834,000 b,c
Credit for Conventional NDN (670,000) b,c
MBR Total Annual O&M Cost Including NDN
Credit 1,164,000
UV Disinfection Total Annual O&M Cost 271,000 c
Recycled Water Storage and Distribution
Pumping Annual O&M Cost 680,000
Plan A Total Annual O&M Cost 2,115,000 a For detailed cost analysis see Appendix A. b Including power and chemicals consumption, membrane/diffusers replacement, general maintenance, and labor.
c Assuming power usage rate of 14¢ per kWh.
Using the estimated capital and O&M costs, a 20-year life cycle cost analysis was performed.
The results are shown in Table 9-11. The option of housing the membranes in new structure is presented in Table 9-11 as the Plan A Life-Cycle Cost.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-15 Table 9-11: Plan A Life-Cycle Cost (12 mgd)
Parameter Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20-Year Life
Cycle Cost
($ Millions)
MBR System 34.81 1,1651 55.9
Disinfection (In-pipe
UV)
12.9 270 17.8
Storage (Aeration
Basin No.3) and
Distribution Pumping
3.1 680 15.42
TOTAL 50.8 2,115 89.1 1
Includes credit for conventional NDN
2 Although the life of the storage structure is 50 years, a 20 year life cycle cost is presented for consistency.
9.6 ADVANTAGES AND DISADVANTAGES OF PLAN A VERSUS PLANS C Section 11 of this TM summarizes the advantages and disadvantages of Plan A versus Plan C.
Both Plans A and C are of 12 mgd capacity, while Plan B is 5 mgd in capacity and therefore will not be used to compare against Plan A.
Subsequent to Workshop No.2 (Section 14), The City further refined the MBR alternative(s), which are discussed in detail in Section 15 of this TM.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 9 – PLAN A: MBR, UV DISINFECTION AND STORAGE SCHEME (12 MGD CAPACITY) 9-16 - This page is intentionally left blank -
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-1 SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION
AND STORAGE SCHEMES
10.1 BACKGROUND
Per Workshop No.1 (Section 8 of this TM), Plans B and C, which include Nova ultrascreen filter, are discussed under this Section.
Several key decisions regarding filtration schemes were made during Workshop No.1, which are summarized below.
• Nova ultrascreen filters will be used for both Plans B and C as filtration system of choice. • UV Inline System (1 mgd capacity) will be used for disinfection of filtered effluent. Final selection of the UV system will be made during detailed design and will be based on competitive bidding between 1 mgd reactors and lager size reactors (2.3 mgd and others, as applicable).
• A pre-stressed concrete tank (5 MG capacity) will be used to store the recycled water. • Plan B will have a treatment capacity of 5 mgd (constant flow – no peaking factor) with provisions for phased expansion to 30 mgd of ultimate capacity. • Plan C will have a treatment capacity of 12 mgd (constant flow – no peaking factor) with provisions for phased expansion to 30 mgd of ultimate capacity.
Figure 10-1 below presents the schematic for Plans B and C.
Figure 10-1: Selected Filtration, Disinfection, and Storage Scheme
10.2 EVALUATION OF CONVENTIONAL FILTRATION PLANS (PLAN B AND PLAN C)
10.2.1 Plan B (5 mgd Capacity)
Under this scheme, the TTDF will be fed from distribution canal “B” from which secondary effluent can be withdrawn at a constant rate of 5 mgd, even during periods of low influent flow.
Considering this, the TTDF under Plan B will have a capacity of 5 mgd of constant flow (i.e. no flow peaking factor considered).
The design criteria for Plan B are summarized in Table 10-1 and the preliminary construction, O&M, and life-cycle cost estimates for Plan B are presented in Table 10-2. Note that, as per the CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-2 decision made during Workshop No. 1, 1 mgd capacity in-pipe UV reactors are considered; however, due to the lower quality of filtered water produced with conventional filtration, an inpipe UV reactor rated at 1 mgd when treating high quality membrane permeate is de-rated to
0.55 mgd when treating conventional filtrate. Figures 10-2 and 10-3 present the preliminary layout drawings for the Nova Ultrascreen filters and the in-pipe UV disinfection system, respectively. The layout drawings show the facilities for initial capacity of 5 mgd (i.e. the equipment required for Plan B) as well as for phased expansions to 15 mgd and 30 mgd.
Table 10-1: Plan B Design Criteria
Parameter Criteria
Design Flow, mgd 5 (constant flow)
Filtration – Nova Ultrascreen
CDPH Approved Filtration Rate, gpm/ft2 16
Number of Filter Units 2
Number of Disks per Unit 10
Total Filtration Area, ft2 444
Filtration Rate with One Filter Offline, gpm/ft2 15.6
Headloss Through Filter, ft (Operating) 2 - 2.5
Disinfection – Inline UV
Type of UV System In-pipe, Low Pressure, High Intensity Number of Reactors 12 (5 trains + 1 standby) each train has 2 reactors Flow Capacity per Reactor, mgd 0.55
Length of Reactor (ft) 8
Number of Lamps per Reactor 40
Total Number of Lamps Provided 480
Storage – Prestressed Concrete Tank
Design Capacity, mg 5
Number of Tanks 1
Dimensions of Tank,
Diameter (ft) x Side Water Depth (ft)
178 x 28
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-3 Figure 10-2: Plan B Nova Ultrascreen Filter Preliminary Layout CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-4 Figure 10-3: Plan B UV Disinfection System Preliminary Layout Table 10-2: Plan B (5 mgd Capacity) Preliminary Cost Summary Parameter Capital Cost ($
Millions)
O&M Cost
($ Thousands)
20-Year Life Cycle
Cost
($ Millions)
Filters (Nova Ultrascreen) 4.2 100 6.0
Disinfection (In-pipe UV) 6.5 230 10.6
Storage (5 MG Circular Prestressed
Concrete Tank) and Distribution
Pumping
7.5 290 12.71
TOTAL 18.2 620 29.3 1
Although the life of the storage structure is 50 years, a 20 year life cycle cost is presented for consistency.
10.2.2 Plan C (12 mgd Capcity)
The TTDF under Plan C is similar to Plan B discussed above, except that it has a capacity of 12 mgd of constant flow (i.e. no flow peaking factor considered). As discussed in Section 10, Plan A, which incorporates an MBR system in place of conventional filtration, has a capacity of 12 mgd. In order to compare the use of a MBR system to the use of conventional tertiary filtration, the design criteria, preliminary layout drawings, and preliminary construction, O&M, and lifecycle cost estimates for Plan C have been developed.
The design criteria for Plan C are summarized in the Table 10-3 and the preliminary construction, O&M, and life-cycle cost estimates are presented in Table 10-4. Figures 10-4 and 10-5 present the preliminary layout drawings for the Nova Ultrascreen filter and the in-pipe UV CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-5 disinfection system, respectively. Note that the Nova Ultrascreen units proposed for Plan C (16 disk units) are larger than the units proposed for Plan B (10 disk units). The layout drawings show the initial capacity of 12 mgd as well as the expansion to 30 mgd.
Table 10-3: Plan C Design Criteria
Parameter Criteria
Design Flow, mgd 12 (constant flow)
Filtration
CDPH Approved Filtration Rate, gpm/ft2 16
Number of Filter Units 3
Number of Disks per Unit 16
Total Filtration Area, ft2 1,056
Filtration Rate with One Filter Offline, gpm/ft2 11.8
Headloss Through Filter, ft (Operating) 2 - 2.5
Disinfection
Type of UV System In-pipe, Low Pressure, High Intensity Number of Reactors 24 (11 trains + 1 standby) each train has 2 reactors Flow Capacity per Reactor, mgd 0.55
Length of Reactor (ft) 8
Number of Lamps per Reactor 40
Total Number of Lamps Provided 960
Storage
Design Capacity, mg 5
Number of Tanks 1
Dimensions of Tank,
Diameter (ft) x Side Water Depth (ft)
178 x 28
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-6 Figure 10-4: Plan C Nova Ultrascreen Filter Preliminary Layout CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-7 Figure 10-5: Plan C UV Disinfection System Preliminary Layout Table 10-4: Plan C (12 mgd Capacity) Preliminary Cost Summary Parameter Capital Cost ($
Millions)
O&M Cost
($ Thousands)
20-Year Life Cycle
Cost
($ Millions)
Filters (Nova Ultrascreen) 7.3 155 10.1
Disinfection (In-pipe UV) 13.5 465 21.9
Storage (5 MG Circular Prestressed
Concrete Tank) and 12 mgd
Distribution Pumping
7.7 680 19.91
TOTAL 28.5 1,300 51.9 1
Although the life of the storage structure is 50 years, a 20 year life cycle cost is presented for consistency.
10.3 ADVANTAGES AND DISADVANTAGES OF PLAN A VERSUS PLANS C Section 11 of this TM summarizes the advantages and disadvantages of Plan A versus Plan C.
Both Plans A and C are of 12 mgd capacity, while Plan B is 5 mgd in capacity and therefore will not be used to compare against Plan A.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 10 - PLANS B AND C: NOVA FILTRATION, UV DISINFECTION, AND STORAGE SCHEME 10-8 - This page is intentionally left blank -
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA FILTRATION SYSTEM (PLAN A VS. PLAN C) 11-1 SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA
FILTRATION SYSTEM (PLAN A VS. PLAN C)
11.1 BACKGROUND
In this section, the Plan A (described in Section 9) and Plan C (described in Section 10) will be compared. The advantages and disadvantages of each Plan are presented along with preliminary construction, O&M, and life-cycle cost estimates of each Plan.
Under Plan A, the TTDF will produce an average of 12 mgd of denitrified Title 22 quality effluent and will be designed to handle peak flows of up to 14.76 mgd. The use of existing Train A facilities will be maximized: a secondary clarifier will be converted into a bioreactor for achieving organic and nitrogen (NDN) removal, a new structure will house the membranes, and Aeration Basin No. 3 will be converted into a recycled water storage tank. The option of housing the membranes in a new structure as opposed to inside secondary clarifier No. 5 is considered for Plan C due to lower cost (refer to Section 9). Under Plan C, the TTDF will produce 12 mgd of Title 22 quality effluent without a flow peaking factor. The TTDF feed water will be withdrawn from distribution Canal B at a constant rate of 12 mgd. No modifications to the upstream biological treatment facilities will be made - thus, the recycled water produced under Plan C will contain nitrogen in the form of ammonia, nitrates, and nitrites at concentrations approximately equal to current secondary effluent concentrations.
11.2 COMPARISON OF PLAN A AND PLAN C
The major difference between Plan A and Plan C is the means of filtration: Plan A will utilize membrane filtration (MBR) while Plan C utilizes media filtration (Nova Ultrascreen). This section will primarily focus on the benefits and drawbacks of these technologies.
The difference in filtration technology allows Plan A to achieve nitrogen removal without additional tanks, use an existing aeration basin for recycled water storage, and achieve disinfection meeting NWRI guidelines with a smaller UV disinfection system. These benefits are reflected in the preliminary Plan A construction, O&M, and life-cycle cost estimate.
11.2.1 Ease of Expandability
Figures 11-1 and 11-2 below show the preliminary layout drawings for Plan A and Plan C, respectively. The preliminary layout drawings show the footprint for a 12 mgd TTDF (in red) and the future footprint for a 30 mgd TTDF (in green).
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA FILTRATION SYSTEM (PLAN A VS. PLAN C) 11-2
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA FILTRATION SYSTEM (PLAN A VS. PLAN C) 11-3
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA FILTRATION SYSTEM (PLAN A VS. PLAN C) 11-4 Under Plan C, additional facilities will need to be constructed in order to increase the TTDF capacity to 30 mgd; however, the expansion would be straightforward. Nova Ultrascreen filters are supplied as prefabricated, packaged units ready for “plug and play” installation. The site work will consist of the extension of the concrete equipment pad and an equipment canopy or a building.
Under Plan A, two additional secondary clarifiers will need to be converted to bioreactors and a new structure will need to be constructed to house the additional membrane modules required for increasing the TTDF capacity to 30 mgd. Even though new structures do not need to be built for the additional bioreactor capacity required, the existing secondary clarifiers will need to be modified and therefore the construction sequencing for the expansion of Plan A will be more complex than for the expansion of Plan C.
11.2.2 Reliability
Both Plan A and Plan C will be provided with features to ensure adequate reliability. As discussed in Section 4, the TTDF under Plan C will be designed with multiple Nova Ultrascreen filter units capable of treating the entire flow with one unit not in operation.
The TTDF under Plan A will be provided with eight independent membrane tanks, each with six membrane cassettes. Sufficient membrane area will be provided to allow for redundancy.
11.2.3 Constructability
Plan A maximizes the use of existing Train A facilities. The use of existing facilities will not impact the sequence of construction due to the fact that at least one of the units in Train A is typically out of service and construction can be performed on one unit at a time. The constructability of Plan C is slightly easier since no modifications of existing facilities are planned. The secondary effluent will simply be withdrawn from distribution Canal B and fed to the new TTDF.
It is our understanding that a minimum SRT of 5 days in the upstream biological treatment system is required prior to filtration with disk filters (including Nova Ultrascreen filters) for consistent effluent quality. If the existing biological system does not provide an SRT of at least 5 days, modifications to the pertinent secondary treatment facilities’ operation will be required.
11.2.4 Simplicity of Operation
The treatment systems used in both Plan A and Plan C will be automated; however, since the MBR is a biological process as well as a filtration process, the operation of Plan A facilities will likely be somewhat more complex. However, trained and experienced City staff should be able to operate and maintain both the systems with similar ease.
11.2.5 History of Use
Nova Ultrascreen filters have a long history (~10 years) of use in overseas installations; however, the history of use in the US on municipal wastewater is limited. There are currently CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA FILTRATION SYSTEM (PLAN A VS. PLAN C) 11-5 no installations in California and the longest operating municipal wastewater installation in the US has been in operation for less than one year (in Orange Park, FL) and has a rated capacity of
3.0 mgd. If this filtration system is selected, site visits to a minimum of two operating installations is recommended to obtain firsthand knowledge of their performance and operation.
There are numerous MBR installations at municipal wastewater treatment plants producing water for recycle/reuse purposes and the history of use is well documented.
11.2.6 Environmental Impacts, Including Public Perception and Acceptance While both Plan A and Plan C are capable of producing an effluent that meets the requirement for unrestricted reuse water as set forth by the Department of Public Health, Plan A far exceeds the requirements for unrestricted reuse water. In addition to conventional uses of reuse water, MBR treated water has been used by industry for cooling water applications because of its high quality as a feed to additional treatment units, such as reverse osmosis, ahead of manufacturing processes. MBR effluent is also being used as the feed water to advanced water treatment in indirect potable water systems.
In terms of environmental impacts such as energy efficiency, however, Plan A is more energy intensive - even when considering the credit of reduced UV disinfection power consumption.
The estimated incremental power consumption for Plan A over Plan C is approximately 4,425 MWh per year (considering the power consumption credit for achieving nitrogen removal). This is primarily due to the power consumed by the air scour blowers and the sludge recirculation pumps.
11.2.7 Staffing Requirements
Plan A involving membrane system, requires relatively more operator attention due to the fact that periodic chemical cleaning and backwashing of membranes is required. Additionally more sophisticated controls are involved requiring skilled operators to run the system.
Comparatively, Plan C is simpler to operate. For the purposes of this TM, we have estimated 1 FTE for Plan A. For Plan C the required hours are half of that of Plan A.
11.2.8 Preliminary Capital, O&M, and Life-Cycle Costs
Table 11-1 below presents preliminary capital, O&M, and life-cycle cost estimates for Plan A and Plan C.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 11 – COMPARISON OF MBR SYSTEM WITH NOVA FILTRATION SYSTEM (PLAN A VS. PLAN C) 11-6 Table 11-1: Comparison of Plan A and Plan C Preliminary Capital, O&M, and Life-Cycle Costs Parameter Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20 Year Life-Cycle Cost
($ Millions)
MBR (Train A)1
34.8 1,165 55.9
Disinfection (In-line UV) 12.9 270 17.8
Storage (Converted Train A Aeration
Basin) and Distribution Pumping 3.1 680 15.42
Total Plan A Cost 50.8 2,115 89.1
Filters (Nova Ultrascreen) 7.3 155 10.1
Disinfection (In-line UV) 13.5 465 21.9
Storage (Circular, Prestressed Concrete
Storage Tank) and Distribution
Pumping
7.7 680 19.92
Total Plan C Cost 28.5 1,300 51.9
1 Includes credit of $8.9 million capital cost and $670,400 O&M cost for conventional NDN. 2 Although the life of the storage structure is 50 years, a 20 year life cycle cost is presented for consistency.
Table 11-2: Comparison of Plan A and Plan C Non-Economic Features Parameter Plan A Plan C
Ease of Expandability Good Good
Reliability Good Good
Constructability Good Good
Simplicity of Operation Average Good
History of Use Good Average
Environmental Impacts,
Including Public Perception and
Acceptance
Excellent Average
Staffing Requirements Good Good
Per the above cost data, Plan C is far more economical than Plan A, approximately $22.3 million lower than Plan A in capital costs and approximately $815,000 lower than Plan A in O&M costs.
However, per Table 11-2 above, Plan A does provide several non-economic advantages over Plan C that need to be considered in decision making. For more information on comparison of MBR system with conventional filtration system and key drivers for decision making, refer to Section 14. The results of this analysis including preliminary cost data were presented to the City during Workshop No. 2 (Section 14). Refer to Section 15 for an evaluation of further modified MBR alternatives.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-1 SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF
12.1 BACKGROUND
Per the contracted scope of work, an evaluation needs to be done to determine the feasibility of feeding the new loads of proposed TTDF from low voltage switchgear “R/W-SWG1” in the RAS/WAS Electrical Building. A draft version of this Section was submitted to the City in December 2010 as a part of the draft TM, which included evaluation of two power source options:
a. Utilizing low voltage switchgear “R/W-SWG1” in the RAS/WAS Electrical Building as the power source (per contract)
b. Utilizing the 4.16 KV medium voltage switchgear “BL-MVS3” at the Blower Building No.2 Electrical Room
Subsequent to the submission of a draft version of this TM, Parsons’ electrical engineer met with the City’s staff at the RWRF on January 20, 2011 to understand the facility’s electrical system and to review the “as-built” electrical drawings. During the meeting, estimated electrical loads associated with a 12 MGD TTDF for both conventional filtration and MBR systems were discussed. The City’s staff expressed keen interest in planning the electrical infrastructure for an ultimate future flow of 30 mgd.
The following electrical loads (operating) were estimated for each alternative.
Conventional Filtration System - 12 mgd - 1,311 HP
- 30 mgd – 3,307 HP
MBR System - 12 mgd – 2,272 HP
- 30 mgd – 5,617 HP
Detailed break-up of the loads are attached as Exhibit 1 at the end of this Section. Based on these estimated loads and discussions with the City’s staff, it was determined that the two power source options, existing low voltage switchgear “R/W-SWG1” in the RAS/WAS pump station electrical building and existing 4.16 KV Switchgear “BL-MVS3”, presented in the draft TM are no longer feasible. The estimated loads are deemed to be too large for the existing infrastructure at the two power sources.
During the meeting, the City’s staff noted that there are four “under-utilized” electrical transformers, TD, TE, TF and TG, located near Train A aeration basins and preference should be given to maximize the use of existing infrastructure. In addition, the existing 12 KV Subservice Switchgear “12-MS2” was identified as another potential power source. This 12 KV switchgear has available spare power circuit breakers and are of adequate capacity to serve the estimated power loads for both conventional filtration and MBR alternatives.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-2
12.2 EXISTING ELECTRICAL INFRASTRUCTURE
Currently, Pacific Gas and Electric Company (PG & E) is supplying power to the RWRF with one (1) 70 KV high voltage power line via one (1) 10 MVA power transformer (City owned) with secondary voltage of 12 KV. The secondary side of the transformer is connected to two (2) main circuit breakers 53-BKR-CMA and 53-BKR-CMB of Main 12 KV Service Switchgear,12-MS1.
Switchgear 12-MS1 is equipped with a normally open (NO) tie circuit breaker, 53-BKR-CMT. This switchgear is rated at 12 KV, 2000A, 500 MVA short circuit capacity with Bus “A” and Bus “B” separated by the NO tie circuit breaker.
In addition, there is a 12 KV back-up line from PG&E that has a capacity of 5 MVA for emergency use. This back-up line is tied to the Switchgear 12-MVS1 thru 29-BKR-201Circuit Breaker. This breaker is normally open with kirk key interlock and is operated manually.
From the Switchgear 12-MVS1, feeder circuit breakers and cables feed several electrical Substations /Electrical Buildings throughout the facility. Feeder circuit breakers 29-BKR-103 and 29-BKR-203 and corresponding two feeder cables connect the 12 KV service to Subservice Switchgear 12-MS2.
For future expansion of the TTDF to 30 MGD capacity, it is anticipated that the City will rely on the cooling fans equipped on the existing 10 MVA step-down transformer to increase the capacity by up to 12% to meet the additional load. Per the City’s staff, the facility’s established summer peak demand is about 6500 KVA.
12.3 EVALUATION OF THE POWER SOURCES FOR CONVENTIONAL FILTRATION AND MBR
SYSTEMS
As discussed earlier in this Section, the following two power source options will be discussed in detail.
A. 12 MGD Conventional Filtration System Expandable to 30 MGD Capacity B. 12 MGD MBR System Expandable to 30 MGD Capacity
1. Option 1 – Power from Swithgear 12-MS2 using spare circuit breakers and new duct banks
2. Option 2 – Power from Swithgear 12-MS2 using existing circuit breakers and extending existing duct banks via transformers TG and TF.
A. 12 MGD Conventional Filtration System Expandable to 30 MGD Capacity The proposed TTDF with conventional filtration and in-pipe disinfection will utilize the existing two (2) 12 KV circuit breakers 60-BKR-104 and 60-BKR-204 that are currently feeding existing transformers “TG” and “TF”. The two transformers, per City’s staff, are currently “underutilized” with minimal to no load and therefore can be disconnected. The existing # 2 15 KV Class cables will be removed as they are inadequate to carry the estimated loads of TTDF. The CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-3 existing 4” conduits will be used to route the new # 3/0 15 KV Class cables to 12 MGD TTDF. The TTDF will have a 15 KV Class Switchboard with a 600A main isolation switch and two (2) 600A fused disconnect feeder switches. Each feeder switch will feed one step-down transformer. The first feeder switch will feed the 12 MGD facility step-down transformer and the other will feed the second step-down transformer for the future loads up to an additional 18 MGD to make the total capacity of 30 MGD. The secondary sides of the two (2) step-down transformers will be tied to a double ended 480 V Switchboard/MCC with a normally open (NO) tie circuit breaker.
The 15 KV Class Switchboard and the transformers will be located outdoor in NEMA 3R enclosures.
The feeder cable length from the Subservice Switchgear 12-MS2 to the TTDF is approximately 1600 feet. Approximately 550 feet of two (2) new 4” conduit duct banks from the existing EMH6 to the TTDF switchboard/transformer pad will be required. Refer to Sketch No. 1 and 2 for the single line diagrams of the proposed electrical system.
B. 12 MGD MBR System Expandable to 30 MGD Capacity
The proposed MBR and in-pipe disinfection Facility will have similar features like the conventional TTDF discussed above, with same size conduits but with larger step-down transformers, and larger feeder cables.
Option 1 - This option utilizes the existing two spare circuit breakers in Switchgear 12-MS2 as well as (2) 4” spare conduits on the north side of the Switchgear Building and extending them to the MBR Facility site. This route requires approximately 1,300 feet of cables from the power source to the MBR Facility. Refer to Sketch No. 3 and 4 for the single line diagrams.
Option 2 - The second option utilizes the existing circuit breakers 60-BKR-104 and 60-BKR-204 as well as existing conduits from the 12 KV Subservice Switchgear Building to the existing Transformers “TF” and “TG”. As stated earlier, these transformers are under-utilized and can be disconnected. The existing # 2 - 15KV Class cables will be removed and the 4” conduits will be extended towards the West and up North to the MBR Facility transformer pad. The approximate length of the 1-4” conduit trench is about 1800 feet and the length of 2-4” conduit trench is about 600 feet. The approximate feeder cable length from the power source using the 4“conduit for transformer “TG” to the MBR Facility is about 2500 feet. For the feeder cables using the conduit for the Transformer “TF” to the MBR Facility is about 2200 feet. Refer to Sketch No. 5 and 6 for the single line diagrams.
12.4 LIST OF SINGLE LINE DIAGRAMS
The following sketches were developed as part of this technical memorandum and are enclosed in Appendix B for reference.
1. Sketch No. 1, Single Line Diagram - 12 MGD Conventional Filtration System
2. Sketch No. 2 , Single Line Diagram – Up to 30 MGD Conventional Filtration System CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-4
3. Sketch No. 3, Single Line Diagram – 12 MGD MBR System (Option 1)
4. Sketch No. 4, Single Line Diagram – Up to 30 MGD MBR System (Option1)
5. Sketch No. 5, Single Line Diagram – 12 MGD MBR System (Option 2)
6. Sketch No. 6, Single Line Diagram – Up to 30 MGD MBR System (Option2)
7. Dwg. E-1, City of Fresno Plant No. 1 – Site Plan Primary Distribution (Marked-up to show proposed TTDF)
12.5 FURTHER MODIFICATIONS
Subsequent to Workshop No.2 (See Section 14), further modifications to MBR system alternatives were made, which required certain revisions to the power source options discussed in this Section. These revisions are summarized under Section 15 of this TM.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-5 EXHIBIT 1
ESTIMATED ELECTRICAL LOADS
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-6 - This page is intentionally left blank -
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-7 Table 12-1: Proposed TTDF (MBR) Electrical Loads (30 MGD) Process Area Description Connected
Load (HP)
Duty Load (HP)
MBR System Primary Effluent Pumps 375 250
MBR System Fine Screens 12 9
MBR System Anoxic Mixers 72 72
MBR System Mixed Liquor Return Pumps 180 180
MBR System Sludge Recirculation Pumps 900 750
MBR System WAS Pumps 22.5 15
MBR System Air Scouring Blowers 1,500 1,250
MBR System Permeate Pumps 400 400
MBR System Backpulse Pumps 60 30
MBR System Instruments Air Compressors 30 15
Disinfection UV Lamp Ballasts 680 646
Distribution Distribution Pumps 2,400 2,000
Total (HP) 6,631.5 5,617
*Assume 1 KVA = 1 HP
Primary Effluent Pumps: 2+1; 125 hp each (12,800 gpm at 23’ TDH) Fine Screens: 3+1; 3 hp each
Anoxic Mixers: 18; 4 hp each
Mixed Liquor Return Pumps: 6; 30 hp each (13,900 gpm at 3-4’ TDH) Sludge Recirculation Pumps: 5+1; 150 hp each (16,700 gpm at 20’ TDH) WAS Pumps: 2+1; 7.5 hp each (1,000 gpm at 20’ TDH)
Air Scouring Blowers: 5+1; 250 hp each (7,900 scfm at 5 psi) Permeate Pumps: 20; 20 hp each (1,700 gpm at 25’ TDH)
Backpulse Pumps: 1+1; 30 hp each (1,480 gpm at 25’ TDH) Instruments Air Compressors: 1+1; 15 hp each
UV Lamps: 19 Duty Trains + 1 Standby Train; 34 hp per Train Distribution Pumps: 5 + 1; 400 hp each (4,200 gpm at 230’ TDH) CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-8 Table 12-2: Proposed TTDF (MBR) Electrical Loads (12 MGD) Process Area Description Connected
Load (HP)
Duty Load (HP)
MBR System Primary Effluent Pumps 200 100
MBR System Fine Screens 6 3
MBR System Anoxic Mixers 24 24
MBR System Mixed Liquor Return Pumps 60 60
MBR System Sludge Recirculation Pumps 450 300
MBR System WAS Pumps 15 7.5
MBR System Air Scouring Blowers 750 500
MBR System Permeate Pumps 160 160
MBR System Backpulse Pumps 60 30
MBR System Instruments Air Compressors 30 15
Disinfection UV Lamp Ballasts 306 272
Distribution Distribution Pumps 1,200 800
Total (HP) 3,261 2,271.5
*Assume 1 KVA = 1 HP
Primary Effluent Pumps: 1+1; 100 hp each (10,300 gpm at 20’ TDH) Fine Screens: 1+1; 3 hp each
Anoxic Mixers: 6; 4 hp each
Mixed Liquor Return Pumps: 2; 30 hp each (16,700 gpm at 3’ TDH) Sludge Recirculation Pumps: 2+1; 150 hp each (16,700 gpm at 20’ TDH) WAS Pumps: 1+1; 7.5 hp each (1,000 gpm at 20’ TDH)
Air Scouring Blowers: 2+1; 250 hp each (7,900 scfm at 5 psi) Permeate Pumps: 8; 20 hp each (1,700 gpm at 25’ TDH)
Backpulse Pumps: 1+1; 30 hp each (1,480 gpm at 25’ TDH) Instruments Air Compressors: 1+1; 15 hp each
UV Lamps: 8 Duty Trains + 1 Standby Train ; 34 hp per Train Distribution Pumps: 2 + 1; 400 hp each (4,200 gpm at 230’ TDH) CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-9 Table 12-3 : Proposed TTDF (Tertiary Filtration) Electrical Loads (30 MGD) Process Area Description Connected
Load (HP)
Duty Load (HP)
Tertiary Filtration Filter Feed Pumps 240 200
Tertiary Filtration Coagulant Dosing Pumps 1.0 0.75
Tertiary Filtration Backwash Pumps 52.5 52.5
Tertiary Filtration Washwater Return Pumps 80 60
Tertiary Filtration Filter Drive 42 42
Disinfection UV Lamp Ballasts 986 952
Distribution Distribution Pumps 2,400 2,000
Total (HP) 3,801.5 3,307.25
*Assume 1 KVA = 1 HP
Filter Feed Pumps - 5 + 1; 40 hp each (4,200 gpm at 20’ TDH) Coagulant Dosing Pumps - 3 + 1 at 0.25 hp
Backwash Pumps – 7; 7.5 hp each
Washwater Return Pumps - 3 + 1; 20 hp each (2,000 gpm at 20’ TDH) Filter Drive – 7; 6 hp each
UV Lamps – 28 duty Trains + 1 standby Train; 34 hp per Train Distribution Pumps - 5 + 1; 400 hp each (4,200 gpm at 230’ TDH) CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 12 – EVALUATION OF POWER SUPPLY OPTIONS FOR TTDF 12-10 Table 12-4: Proposed TTDF (Tertiary Filtration) Electrical Loads (12 MGD) Process Area Description Connected
Load (HP)
Duty Load (HP)
Tertiary Filtration Filter Feed Pumps 120 80
Tertiary Filtration Coagulant Dosing Pumps 0.75 0.5
Tertiary Filtration Backwash Pumps 22.5 22.5
Tertiary Filtration Washwater Return Pumps 40 20
Tertiary Filtration Filter Drive 18 18
Disinfection UV Lamp Ballasts 405 370
Distribution Distribution Pumps 1,200 800
Total (HP) 1,806.25 1,311
*Assume 1 KVA = 1 HP
Filter Feed Pumps - 2 + 1; 40 hp each (4,200 gpm at 20’ TDH) Coagulant Dosing Pumps - 2 + 1 at 0.25 hp
Backwash Pumps – 3; 7.5 hp each
Washwater Return Pumps - 1 + 1; 20 hp each (2,000 gpm at 20’ TDH) Filter Drive – 3; 6 hp each
UV Lamps – 11 duty Trains + 1 standby Train; 34 hp per Train Distribution Pumps - 2 + 1; 400 hp each (4,200 gpm at 230’ TDH) CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 13 – INTEGRATION OF TTDF CONTROLS WITH EXISTING SCADA SYSTEM 13-1 SECTION 13 – INTEGRATION OF TTDF CONTROLS WITH EXISTING SCADA SYSTEM
13.1 BACKGROUND
This Section of the TM describes the present condition and expansion philosophy of the Supervisory Control and Data Acquisition (SCADA) system and Instrumentation at the RWRF.
The expanded SCADA and Instrumentation, which will be consistent with the existing design, will be able to handle the control and communication requirements of the proposed TTDF.
13.2 EXISTING SCADA AND INSTRUMENTATION
Parsons reviewed the existing SCADA block diagram (refer to Carollo Engineers Dwg. 0N04, Rev. 1, dated 6/23/06). The existing SCADA consists of two independent communication networks:
Modbus Plus and Remote I/O. Each loop uses different communication media that includes shielded twisted pair cables and coaxial cables, respectively. Fiber optic cables are used for communications between buildings.
The existing SCADA consists of several Programmable Logic Controllers (PLCs) and Operator Interface Stations (OISs) located throughout the plant. Each PLC system on the plantwide network operates in a redundant processor configuration. The fiber optic communication modules are also configured with redundancy.
13.3 DISCUSSION
Parsons will design SCADA and instrumentation systems to match and be compatible with the existing SCADA. A new PLC control panel will be provided in a redundant processor configuration with an uninterruptible power supply (UPS). The PLC panel will be located in a new Electrical and Control Building located close to the proposed TTDF. The PLC will be linked to the existing PLCs and OISs by fiber optic cables routed to the existing RAS/WAS Pump Station Electrical Room and will communicate via Modbus Plus. The PLC control panel will also be linked to the vendor-supplied PLC control panels by digital data communication cables. Under Plan A, the PLC control panel will be linked to the new Membrane Bioreactor system and Inline Ultraviolet Disinfection system control panels. Under Plans B and C, the PLC control panel will be linked to the new Nova Ultrascreen Filtration system and Inline Ultraviolet Disinfection system control panels.
A new OIS will be provided in the new Electrical and Control Building. The new OIS will be configured with graphics and symbols to match the existing OISs. Parsons will incorporate the new process areas into the new OIS, which will be accessible at the existing SCADA OISs. New SCADA screens will be added to monitor and control the new process areas. Parsons will conduct further investigation of the existing SCADA hardware and software during Design Development Phase.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 13 – INTEGRATION OF TTDF CONTROLS WITH EXISTING SCADA SYSTEM 13-2 The above discussion assumes that the existing Modbus Plus network has the capacity to handle the additional data transfers required by the new PLC and OIS. However, there is a concern that the network may be near or at its maximum capacity and that the additional nodes will overload the network. Further investigation of the Modbus Plus network is required to determine its capabilities. Plants of this size are usually designed with or have converted to Ethernet communications, which has a much larger bandwidth (i.e. handles more data) and communicates at higher speeds (i.e. 100 Mbits/s compared to 2 Mbits/s maximum) than Modbus Plus communications. Parsons will further investigate the existing network during Design Development Phase.
A new Closed-Circuit Television (CCTV) camera will also be provided in the TTDF. The camera, control receiver, and Ethernet encoder will match the existing CCTV equipment. The new camera will be tied into the plant’s existing CCTV equipment.
For the proposed TTDF, Parsons will specify field instruments after consultation with the RWRF plant personnel and/or will match existing instruments to achieve instrument standardization throughout the plant. This criterion is intended to minimize spare parts inventory and improve operator familiarity with similar equipment. Instrument data sheets will be prepared to specify the same brand and model numbers already in use at the RWRF, as much as possible.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 14 – SUMMARY OF WORKSHOP NO.2 AND NEW PROJECT DIRECTION 14-1 SECTION 14 – SUMMARY OF WORKSHOP NO.2 AND NEW PROJECT
DIRECTION
14.1 BACKGROUND
A second Workshop (Workshop No.2) was conducted with the City on February 3, 2011 to present and discuss the comparison of Plan A with Plan C, as detailed under Section 11. The discussions included pros and cons of MBR system compared to conventional filtration system.
This Section summarizes the discussion carried out at the Workshop and highlights the important decisions made for subsequent work.
14.2 DISCUSSION AND KEY DECISIONS
During the Workshop No.2, very crucial plant operating and maintenance issues were discussed in detail with the City’s operations staff and the following key considerations were identified:
1. Train A facilities, reportedly, are old, of obsolete design and are difficult to operate and maintain. Further, nitrogen removal cannot be achieved reliably with the current configuration of the aeration basins in Train A. Discussions with the City’s operations staff indicated that the ceramic disc diffusers installed in the aerations basins need replacement/cleaning and it may not be possible to restore them to their original state due to their age. The aeration pipe grids that connect the diffusers are old and unique to the type of diffusers currently installed. Further, the secondary clarifiers in Train A are in need of central column and scraper mechanism replacement. Based on the above described extensive repair/replacement needs related to Train A infrastructure coupled with the long age of the equipment, it appears that replacement of Train A facilities in the near future would be a prudent measure, If the intention is to continue to use Train A for the long term.
2. North Fresno Wastewater Reclamation Facility, operated by the City, was issued a WDR/NPDES permit on December 10, 2009 by the Central Valley Regional Water Quality Control Board (RWQCB) with a Total Nitrogen (TN) limit of 10 mg/L for the recycled water used for golf course irrigation. It is expected that the proposed TTDF at the RWRF will also have a similar TN limit for irrigation water. This means that it will be short sighted to design the TTDF with no consideration for nitrogen removal.
3. In this report, all the options involving conventional filtration systems are designed to produce Title 22 recycled water without nitrogen removal. However, as discussed above, if nitrogen removal becomes a requirement per the anticipated WDR/NPDES permit for the TTDF, additional aeration basins and secondary clarifiers will be required to provide enough Solids Retention Time (SRT) in the system for consistent and reliable nitrogen removal. On the other hand, the MBR alternative will not only produce effluent exceeding Title 22 criteria, but will achieve nitrogen removal without additional basins.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 14 – SUMMARY OF WORKSHOP NO.2 AND NEW PROJECT DIRECTION 14-2 Based on the above discussion, it is evident that the MBR system alternative for TTDF has a clear advantage over the conventional filtration system alternatives. By converting Train A facilities into MBR (See Plan A), not only will the system be capable of producing effluent meeting all permit limitations, but also will avoid the future replacement and upgrading cost of Train A for nitrogen removal. This means that constructing an MBR system will, in effect, be an equivalent capacity replacement for Train A. Therefore, MBR will be more cost effective compared to conventional filtration systems, when considering both its ability to produce high quality effluent with nitrogen removal and the avoided cost of future upgrades/replacement of Train A facilities for nitrogen removal.
Moving forward, both Parsons and the City collectively decided to pursue MBR as the technology of choice for TTDF. In addition to the option of converting Train A facilities into MBR, the City expressed their interest to explore the option of having MBR designed and built as a separate stand-alone system with all new structures.
14.2 NEW PROJECT DIRECTION – POST WORKSHOP NO.1 AND WORKSHOP NO.2 The City asked Parsons to develop and compare the following two MBR alternatives for their review and final selection.
1. Converting Train A into MBR – (5 mgd constant flow; no peaking factor) – This is similar to Plan A as discussed in Section 9 of this report, except that the capacity will be 5 mgd constant flow instead of 12 mgd with peaking factor.
2. Constructing a separate standalone MBR system with all new tanks – (5 mgd constant flow; no peaking factor)
A new final section (Section No. 15) is added to this report to discuss and compare the two selected MBR system alternatives.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
POST-WORKSHOP ANALYSIS
POST-WORKSHOP NO.2 ANALYSIS (SECTION 15 - SECTION 16)
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-1
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS
15.1 BACKGROUND
Workshop No. 2 was held on February 3, 2011 and was attended by the City’s and Parsons’ staff. Tertiary filters, MBR, and electrical feed alternatives were discussed and several key decisions were made with respect to the tertiary treatment systems as summarized below:
• MBR alternative offers several advantages over the conventional filtration alternatives, which include higher quality recycled water and nitrogen removal. Also, as Train A is reportedly approaching the end of its useful life (see Section 14), implementation of an MBR system could be tied with Train A phase out. This would avoid substantial costs associated with replacing and/or upgrading of Train A facilities in the near future, if tertiary filters were used. Therefore, MBR will be more cost effective compared to conventional filtration systems, when considering both its ability to produce high quality effluent with nitrogen removal and the avoided cost of future upgrades/replacement of Train A facilities for nitrogen removal. Based on the discussions, it was decided to pursue the MBR alternative as the system of choice for filtration, nitrogen removal and future capacity replacement for Train A.
• The MBR system should be designed to handle 5 mgd of constant flow. The influent pipeline should be capable of conveying 15 mgd of flow, with a parallel pipeline added in the future when the demand for recycled water increases beyond 15 mgd. • The location of the MBR system should be evaluated considering a completely new structure for the system versus retrofitting the existing Train A structure for this purpose. In the case of using a new structure, the MBR system would be located north of Canal B. In the case of using existing Train A facilities, an existing secondary clarifier would be retrofitted into aeration basins and a new tank(s) would be constructed to house the membranes.
This Section develops and compares the two MBR system alternatives mentioned above.
15.2 DESIGN DEVELOPMENT
This subsection describes the design of MBR system for two different alternatives; 1) retrofitting existing Train A facilities, 2) using completely new structures.
15.2.1 Layout – 5 mgd Constant Flow – Retrofitting Train A Facilities into MBR In this alternative, secondary clarifier No. 4 (Train A) would be modified and converted into the pre-aeration bioreactors of MBR system (Figure 15-1). Primary effluent would be taken from the existing stub at Train C and delivered by gravity to bioreactors. The gravity pipeline would be routed underneath Canal B as an inverted siphon. Fine screens would be located at the upstream side of this gravity line (near Train C) to minimize solids accumulation within the pipe.
Following the pre-aeration bioreactors, the flow would be conveyed to the membrane tanks CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-2
located west of secondary clarifier No. 5. The MBR blower building would be located west of membrane tanks. Space is allowed for expansion to 30 mgd. The existing 24 inch diameter air line serving aeration basin No. 3 (Train A) would be used and extended to deliver process air to bioreactors. In-pipe UV system will be used to disinfect the MBR permeate to achieve Title 22 recycled water quality. Aeration basin No. 3 would be used for storage of the recycled water.
The power for the MBR system would be supplied from the 12 kV electrical building, located east of Train A secondary clarifiers, through new conduits. See Subsection 15.5 for electrical details.
15.2.2 Layout – 5 mgd Constant Flow – MBR with All New Construction The structures for MBR system would be located north of Canal B as shown in Figure 15-2.
Primary effluent would be taken from the existing stub at Train C and delivered by gravity to pre-aeration Bioreactors. The gravity pipeline will be routed underneath Canal B as an inverted siphon. Fine screens would be located at the upstream side of this gravity line (near Train C) to minimize solids accumulation within the pipe. Bioreactors, membrane tanks, and blower building would have common walls to minimize the concrete and piping costs. Space is allowed for expansion to 30 mgd. The existing 24 inch diameter air line serving aeration basin No. 4 (Train A) would be used and extended to deliver process air to bioreactors. In-pipe UV system will be used to disinfect the MBR permeate to achieve Title 22 recycled water quality. Aeration basin No. 4 would be used for storage of the recycled water. The power for the MBR system would be supplied from the 12 kV electrical building, located east of Train A secondary clarifiers, through existing and new conduits. See Subsection 15.5 for electrical details.
15.2.3 Capacity Analysis
Process analysis was performed to determine the volume of aeration basins required to handle 5 mgd of flow and to achieve NDN. The basins would be compartmentalized to incorporate several anoxic and oxic zones. The design criteria in Table 15-1 were developed as the basis for capacity analysis.
Table 15-1: Design Criteria for Capacity Analysis of MBR Aeration Basin to Achieve NDN Item Units Design Value Remarks
Flow Peaking Factor - 1 Peak:Average ratio
Primary Effluent - - Max month values
BOD mg/L 224 70% of raw wastewater
TSS mg/L 120 40% of raw wastewater
TKN mg/L 30 65% of raw wastewater
MLSS mg/L 10,000
SRT (Minimum) days 6 Oxic zone
Anoxic:Oxic Zone Ratio (Minimum) - 0.3
Maximum Oxygen Uptake Rate mg/L-hr 128
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-3
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-4
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-5
15.2.4 Fine Screens
The flow (i.e. primary effluent) would be conveyed by gravity to fine screens located southeast of aeration basins of Train C (Figures 15-1 and 15-2). Two fine screens would be installed with one of the units as standby. Each screen would be capable of handling 5 mgd of flow to provide prudent redundancy. The units would be installed in concrete channels equipped with isolation gates to allow for maintenance without interfering with the plant’s operation. Each fine screen would be equipped with an integrated washer/compactor for cleaning and concentrating the screenings prior to disposal off site.
The design characteristics for the fine screens and washer/compactors are shown in Table 15-2.
Table 15-2: Design Characteristics of Fine Screens and Washer/Compactors Item Units Design
Value Remarks
Screens
Type - - In-channel perforated-plate drum
Number - 2 (1+1)
Capacity, Each mgd 5
Effective Opening Size mm 2
Channel Width ft 5.3 Width at screen
Screenings Handling
Type - - Washer, dewatering, compactor unit
Number - 2 (1+1) Integrated with screens
Motor Power, Each hp 2 Also powers screen basket
15.2.5 Bioreactors and Associated Equipment
This subsection describes the structures and equipment located downstream of fine screens and upstream of membrane tanks.
Bioreactor (Pre-Aeration Basin):
Depending on the MBR alternative considered, the bioreactors (pre- aeration basins) would be provided by retrofitting the secondary clarifier No. 4 or by using a new structure. To provide redundancy, two bioreactors would be designed, each divided into several anoxic and oxic zones, with the first quarter of each bioreactor dedicated to the anoxic zone. Baffles would be placed in the bioreactors to separate the anoxic and oxic zones to minimize back-mixing as the flow passes through in a plug flow regime. Additional baffling would be used to divide each anoxic and oxic zone into 3 compartments, again to minimize back-mixing. The plug flow conditions increase the efficiency of biological treatment, optimizing carbonaceous matter removal, nitrification and denitrification. Submersible mixers would be used to provide mixing in the anoxic zones. Table 15-3 provides the design characteristics of the bioreactors. As can be seen in the Table, volume of bioreactors is larger for the first alternative (Retrofit MBR). This is CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-6
due to the fact that an existing structure (secondary clarifier No. 4) is being used and the volume available in this structure is more than what is actually needed to handle 5 mgd of flow.
Table 15-3: Bioreactors Design Characteristics
Item Units Design Value Remarks Retrofit MBR New MBR
Bioreactors
Number (In Parallel) - 2 2
Volume, Each MG 1.0 0.42
Anoxic Zone
Number per Bioreactor - 1 1
Dimensions of Zone
(L x W x SWD), Each ft x ft x ft 75 x 37.5 x 12 27.5 x 30 x 17 Number of
Compartments per Zone - 3 3 Equal volume (in series)
Oxic Zone
Number per Basin - 1 1
Dimensions of Zone
(L x W x SWD), Each ft x ft x ft 225 x 37.5 x 12 82.5 x 30 x 17 Number of
Compartments per Zone - 3 3 Equal volume (in series)
Anoxic Zone Mixers
Type Submersible
Number per Compartment - 1 1
Total Number - 7 (6+1) 7 (6+1) One shelf spare
Horsepower, Each hp 4 4
Aeration System:
The air would be transferred to the oxic zones in the bioreactors through fine bubble diffusers.
Either EPDM Membrane disks or more efficient aerator strips (e.g. AEROSTRIPTM), would be used to provide aeration. The aeration would be tapered so that approximately 70% of the oxygen is provided in the first half of the oxic zone to satisfy the high oxygen demand as the substrate enters the oxic zone.
The required air would be supplied to the oxic zones by the existing blowers. These blowers are of single-stage centrifugal type and have enough capacity to serve the biological needs of the MBR process as well as the remaining plant. The existing 24 inch diameter air pipeline of aeration basin No. 3 (Retrofit MBR Alternative) or aeration basin No. 4 (New MBR Alternative) would be used and extended to supply the air to the bioreactors. Aeration basin No. 3 (Retrofit-MBR Alternative) or aeration basin No. 4 (New-MBR Alternative) would no longer be in service and would be used as recycled water storage in the future.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-7
The design characteristics for the aeration system are presented in Table 15-4.
Table 15-4: Aeration System Design Characteristics
Item Units Design Value Remarks
Diffusers
Type Fine bubble, membrane (EPDM)
disk or strip type
Aeration Pattern Tapered along bioreactor length
Process Air Blowers
Type Single-stage centrifugal
Number - 6 (5+1) Existing blowers
Capacity, Each scfm 27,000
Discharge Pressure psig 7.8 or 8.5 4 units at 7.8 and 2 units at 8.5 Horsepower, Each hp 1,500
Mixed Liquor Return and Sludge Recirculation Pumps:
Two recirculation lines will be provided in the MBR system: mixed liquor return and sludge recirculation. The mixed liquor return system transfers mixed liquor from the tail end of the oxic zone back to the head of the anoxic zone at a rate up to four times (adjustable) the average flow. This system transfers nitrates resulting from nitrification back to the anoxic zone for denitrification as the oxygen molecules associated with nitrates are used by the biomass.
The sludge recirculation system transfers sludge from the membrane tanks to the head of the oxic zone at a rate also up to four times (adjustable) the average flow. The recirculation system prevents the solids concentration in the membrane tanks from increasing excessively and thus plugging the membranes, as permeate is removed from the mixed liquor. This sludge is highly oxygenated and provides a portion of the process oxygen needed for BOD removal and nitrification. Sludge would be wasted from the MBR system from the sludge recirculation line.
New pumps would be installed for this purpose.
The design characteristics for the recirculation and WAS pumps are presented in Table 15-5.
Table 15-5: Sludge Pumping Systems Design Characteristics Item Units Design Value Remarks
Mixed Liquor Return
Pumps
Returning flow from oxic zone to
anoxic zone
Type Axial propeller
Number - 3 (2+1) One shelf spare
Capacity, Each gpm 7,000
TDH ft 3
Horsepower hp 15
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-8
Item Units Design Value Remarks
Drive Variable speed
Sludge Recirculation
Pumps
Returning flow from membrane
tanks to oxic zone
Type Vertical propeller
Number - 2 (1+1)
Capacity, Each gpm 14,000
TDH ft 20
Horsepower hp 125
Drive Variable speed
WAS Pumps
Type Centrifugal
Number - 2 (1+1)
Capacity, Each gpm 450
TDH ft 20
Horsepower hp 5
Drive Variable speed
15.2.6 Membranes
The membranes would be installed in 4 new independent tanks. For the purpose of this Section, hollow-fiber membranes were considered. The following design criteria were developed as the basis for sizing the membranes:
• Minimum wastewater temperature of 16oC.
• Maximum flux rate of 12 gfd (all membrane tanks in service). • Maximum flux rate of 16 gfd (one membrane tank out of service).
Four membrane tanks, each housing 6 membrane cassettes plus space for a future cassette, would have enough capacity to handle 5 mgd of flow. The tankage would be configured to allow isolation of a tank for maintenance and cleaning.
Permeate pumps would draw the MBR effluent through the membranes, directing it to the disinfection system. A building would house new air scouring blowers and membrane control and electrical system. The building would be located adjacent to the membrane structure.
Table 15-6 summarizes the design characteristics of the MBR membrane system.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-9
Table 15-6: MBR Membrane System Design Characteristics
Item Units Design Value Remarks
Tanks
Number - 4
Cassettes per Tank
Number Installed - 6
Space for Future - 1
Total Membrane Surface Area ft2 417,360
Air Scouring Blowers
Type High-speed turbo
Number - 3 (2+1)
Capacity, Each scfm 3,950
Discharge Pressure psi 5
Horsepower, Each hp 125
Drive Variable speed
Permeate Pumps
Type Horizontal end suction
Number - 5 (4+1) One shelf spare
Capacity, Each gpm 1,350
TDH ft 25
Horsepower, Each hp 20
Drive Variable speed
Backpulse Pumps
Type Horizontal end suction
Number - 2 (1+1)
Capacity, Each gpm 1,480
TDH ft 25
Horsepower, Each hp 30
Drive Variable speed
Instrument Air Compressors If Plant air not available
Number - 2 (1+1)
Horsepower, Each hp 15
Chemical Cleaning
Sodium Hypochlorite 12.5% Solution
Frequency
Recovery Yearly 2 Per tank
Maintenance Weekly 1 Per tank
Annual Consumption gal 4,000
Citric Acid 50% Solution
Frequency Yearly 1-2 Part of Recovery Clean
Annual Consumption gal 750
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-10
15.3 DISINFECTION
During Workshop No.1, the City chose in-pipe UV disinfection as opposed to an open channel UV system. One of the major drivers was the positive feedback received from the staff at neighboring Clovis Water Reuse Facility in operating and maintaining their in-pipe UV system.
Therefore, for the purpose of this TM, 1-mgd capacity in-pipe UV reactors were considered.
The 1 MGD rating for each reactor is based upon high quality membrane permeate feed such as from the MBR system. Four reactor trains (3 operating + one standby) will be required to disinfect 5 mgd of flow and each train will accommodate two reactors. Table 15-7 and Figure 15-3 show the design criteria and preliminary layout for the in-pipe UV disinfection system, respectively. There are several larger in-pipe reactors currently available from other manufacturers that may be more economical for the present project and will be evaluated during detailed design.
Table 15-7: In-pipe UV Disinfection Design Characteristics Parameter Criteria
Design Flow, mgd 5
Type of UV System In-pipe, Low Pressure, High Intensity Number of Reactors 8 (3 trains + 1 standby) each train has 2 reactors Flow Capacity per Reactor, mgd 1.0
Length of Reactor (ft) 8
Number of Lamps per Reactor 40
Total Number of Lamps Provided 320
Figure 15-3: In-pipe UV Disinfection System Preliminary Layout
15.4 PRELIMINARY COSTS
Preliminary costs were developed for two alternatives: retrofitting the existing facilities in Train A for aeration basins of MBR system or using a completely new structure for this purpose. The costs estimated are according to Class 4 level per AACE (Association for the Advancement of Cost Engineering) guidelines. At this point in the design process, these costs are preliminary and should be used only for comparative purposes.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-11
The costs were estimated using several resources. Quotes from the manufacturers, information available from similar projects performed by Parsons, including construction in the Central Valley, were used to determine these costs.
The capital costs for the two alternatives are shown in Table 15-8. For both alternatives, the credit for conventional NDN is negligible. This is the investment the City would need to make on a secondary treatment system, if the plant had to be upgraded to an NDN process using conventional tertiary filters rather than MBR. As the existing secondary systems for both Train B and Train C are designed and constructed with future NDN in mind, the aerations basins provide required SRT to achieve NDN and only require installation of new mixed liquor recycle pumps, the cost of which is deemed insignificant for comparison purposes. As indicated in Table 15-8, there is little cost difference between the two alternatives. Retrofitting the existing structure would result in less concrete cost but in higher piping cost.
15.4.1 Avoided Cost of Future Upgrades/Replacement of Train A As discussed earlier, a credit could be given to compensate for the cost of replacing and upgrading Train A in the near future, which would occur under conventional filtration alternatives but not under MBR alternatives. To estimate this credit, $3-$4 per gal of wastewater treated was used as cost basis, which would translate into $15-$20 million of avoided future capital investment for a 5 mgd system. For the purposes of cost comparison in this Section, $18 million is considered as avoided capital replacement cost. Note that the estimated avoided cost is based on constructing new basins to remove nitrogen but without new aeration blowers.
Table 15-8: MBR Alternatives Capital Cost (5 mgd) a
Parameter
Capital Cost ($ Million)
Retrofit MBR New MBR
MBR Equipment and Structures Cost 8.4 8.7
MBR Total Capital Cost 24.5 b 24.4
Credit for Conventional NDN (0) b,c (0)
MBR Total Capital Cost Including NDN Credit 24.5 24.4
UV Disinfection Total Capital Cost 5.3 b 5.3
Storage (Aeration Basin No.3 or 4) Total Capital Cost 3.1 b 3.1 Total Capital Cost 32.9 32.8
a For detailed cost analysis see Appendix A. b Including installation, civil, mechanical, electrical and instrumentation, contractor overhead and profit, contingency (20%) and escalation to midpoint of construction (2012-2013) c NDN credit is insignificant (only involves installation of minor new equipment such as mixed liquor recycle pumps). NDN credit is based on the premise that if the City were to choose conventional filters instead of MBR and were required to achieve NDN in the conventional secondary treatment process. d Near future replacement cost of Train A facilities equivalent to 5 mgd capacity Train A Capacity Replacement (Avoided Cost) (18) d (18) Net Effective Capital Cost 14.9 14.8
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-12
An evaluation of the operation and maintenance (O&M) costs was also performed (Table 15-9).
The O&M cost difference between the two alternatives is insignificant and hence assumed to be the same. Credit is given to MBR system for avoided cost of operation and maintenance of a secondary treatment system to achieve NDN.
Table 15-9: MBR Alternatives O&M Cost (5 mgd)
Parameter
a
O&M Cost ($)
MBR Total Annual O&M Cost 833,000 b,c
Credit for Conventional NDN (280,000) b,c,d
MBR Total Annual O&M Cost Including NDN
Credit 553,000
UV Disinfection Total Annual O&M Cost 150,000 c,d
Recycled Water Storage and Distribution
Pumping Annual O&M Cost d 283,000
Total Annual O&M Cost 986,000 a For detailed cost analysis see Appendix A. b Including power and chemicals consumption, membrane/diffusers replacement, general maintenance, and labor.
c Assuming power usage rate of 14¢ per kWh.
d Proportioned using 12 mgd costs developed in previous Sections.
Using the estimated capital and O&M costs, a 20-year life cycle cost analysis was performed.
The results are shown in Table 15-10.
Table 15-10: MBR Alternatives Life-Cycle Cost (5 mgd)
Alternative Parameter Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20-Year Life
Cycle Cost
($ Millions)
RETROFIT
TRAIN A
INTO MBR
MBR System 24.5 5531 34.5
Disinfection (In-pipe UV) 5.3 150 8.0
Storage (Aeration Basin No.3) and
Distribution Pumping
3.1 283 8.22
TOTAL 32.9 986 50.7
Train A Capacity Replacement Cost (18)
Net Effective Capital Cost 14.9
NEW MBR
MBR System 24.41 5531 34.4
Disinfection (In-pipe UV) 5.3 150 8.0
Storage (Aeration Basin No.4) and
Distribution Pumping
3.1 283 8.22
TOTAL 32.8 986 50.6
Train A Capacity Replacement Cost (18)
Net Effective Capital Cost 14.8 1
Includes credit for conventional NDN
2 Although the life of the storage structure is 50 years, a 20 year life cycle cost is presented for consistency.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-13
15.5 REVISIONS TO POWER SOURCE OPTIONS
The power source options for TTDF for both conventional filtration and MBR alternative are described under Section 12 of this report. Single line diagram illustrating the proposed electrical system along with proposed electrical duct bank and cable routing plans are developed and enclosed as part of Section 12. The following revisions are made to the electrical strategy due to the new location for MBR.
A. 5 mgd Constant Flow – MBR with All New construction
For this option, feed will be drawn from existing Sub Service Switchgear “12KV-MS2” building.
Two (2) existing circuit breakers 60-BKR-104 and 60-BKR-204 will be utilized to provide a double ended feed to the new indoor type 12 KV switchgear. This new switchgear will be provided with two (2) main circuit breakers, a normally open (NO) tie circuit breaker, two (2) feeder circuit breakers and extra space for two (2) additional circuit breakers for future expansion. All the 480 V Motor Control Centers are also indoor type. The new 12 KV switchgear and all the 480V Motor Control Centers will be housed in a building close to the MBR structure. The step-down transformers, however, are all outdoor type and will be located on an open concrete pad close to the new electrical building. Refer to Sketch No. 7 for a single line diagram showing the proposed system. Two (2) existing – 4”C conduits on the north-south electrical duct bank will be utilized up to Manhole EMH-6. From Manhole EMH-6, two (2) new -4”C conduits will be installed down to the new 12 KV switchgear Electrical Building. Refer to revised drawing E-1 (Rev.1) for electrical conduits and cable routes for this option.
B. 5 mgd Constant Flow – Retrofitting Train A Facilities into MBR The proposed power source for this option is already discussed in detail in Section 12. The arrangement and type of equipment used will be similar to the option described above. The conduits and cable routes will utilize the two (2)-4”C spare conduits at Manhole EMH-2 on the north side of the Sub Service Switchgear “12KV-MS2” building. These conduits will be extended west and then south to the proposed location of the new electrical building. Refer to revised drawing E-1 (Rev.1) for electrical conduits and cable routes for this option.
15.6 DISCUSSION
It is evident from the data presented in Table 15-10 above, that the two MBR alternatives compared are very close to each other from a cost standpoint. The capital cost difference between the two alternatives is insignificant and is within the margin of error of our estimates.
The concrete savings realized by retrofitting existing structures are balanced by less extensive piping required by using new structures.
However, using all new structures offers a more flexible and compact design. By properly planning the new facilities, they can be built in a monolithic construction with common walls, which would make it easier to build and more efficient to operate. The future expansion of tertiary facilities would follow the same compact pattern. Also, the design would not need to be tailored based on the constraints of existing facilities, but based on the best design CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 15 – SELECTED MBR ALTERNATIVES ANALYSIS 15-14
practices. For example, deeper new aeration basins compared to the retrofitted basins would allow for a more efficient aeration system.
Further, a separate standalone MBR system will be easier to construct and will also provide some redundant treatment facilities associated with that particular train in the interim and for several years until the City decides to totally decommission that train due to its obsolescence.
15.7 CONCLUSION
Based on the above discussion, Parsons recommends using all new structures for constructing the MBR system, as it would be a more prudent and reliable approach to achieve filtration, nitrogen removal and future capacity replacement for Train A.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-1
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION
This Section provides a brief description of the recommended project for TTDF at RWRF. The location and selection of technology for TTDF was thoroughly evaluated considering a variety of factors as presented in this TM and summarized in Section 15. A simplified schematic of the project is presented in Figure 16-1 below.
Figure 16-1: Simplified Schematic of Recommended Project for TTDF
16.1 Summary of Recommended Project
The TTDF will have a design capacity of 5 mgd (constant flow) and the facilities would be located on a “green field” site north of Canal B as shown in Figure 16-2. Primary effluent would be taken from the existing stub at Train C and delivered by gravity to pre-aeration bioreactors.
The gravity pipeline will be routed underneath Canal B as an inverted siphon. Fine screens would be located at the upstream side of this gravity line (near Train C) to minimize solids accumulation within the pipeline. Bioreactors, membranes tanks, and blower building would have common walls to minimize the concrete and piping costs. In-pipe UV system will be used to disinfect the MBR permeate to achieve Title 22 recycled water quality. Aeration basin No. 4 would be used for storage of the recycled water. The facility will be laid out for ultimate design capacity of 30 mgd. The existing 24 inch diameter air line serving aeration basin No. 4 (Train A) would be used and extended to deliver process air to bioreactors. The power for this project would be supplied from the 12 kV electrical building, located east of Train A secondary clarifiers, through existing and new (extended) conduits.
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-2
16.2 Design Criteria
The design criteria in Table 16-1 were developed as the basis for the recommended project for TTDF.
Table 16-1: Design Criteria for TTDF
Item Units Design Value Remarks
Design Flow Rate mgd 5
Flow Peaking Factor - 1 Peak:Average ratio
Primary Effluent - - Max month values
BOD mg/L 224 70% of raw wastewater
TSS mg/L 120 40% of raw wastewater
TKN mg/L 30 65% of raw wastewater
MLSS mg/L 10,000
SRT (Minimum) days 6 Oxic zone
Anoxic:Oxic Zone Ratio (Minimum) - 0.3
Maximum Oxygen Uptake Rate mg/L-hr 128
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-3
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-4
16.3 Process Equipment List
A list of major processes and equipment is presented in Table 16-2 below. An appropriate level of redundancy is incorporated into the process design and equipment sizing for reliable operation and maintenance of the TTDF.
Table 16-2: List of Major Process Equipment
Item Units Design
Value Remarks
Screens
Type - - In-channel perforated-plate drum
Number - 2 (1+1) One duty, one standby
Capacity, Each mgd 5
Bioreactors
Number (In Parallel) 2 Anoxic and oxic zones in each
Volume, Each MG 0.42
Diffusers
Type Fine bubble, membrane (EPDM) disk
or strip type
Aeration Pattern Tapered along bioreactor length
Process Air Blowers
Type Single-stage centrifugal
Number - 6 (5+1) Existing blowers
Capacity, Each scfm 27,000
Discharge Pressure psig 7.8 or 8.5 4 units at 7.8 and 2 units at 8.5 Horsepower, Each hp 1,500
Mixed Liquor Return Pumps Returning flow from oxic zone to anoxic zone
Type Axial propeller
Number - 3 (2+1) Two duty, one shelf spare
Capacity, Each gpm 7,000
TDH ft 3
Horsepower hp 15
Drive Variable speed
Sludge Recirculation Pumps Returning flow from membrane tanks to oxic zone
Type Vertical propeller
Number - 2 (1+1) One duty, one standby
Capacity, Each gpm 14,000
TDH ft 20
Horsepower hp 125
Drive Variable speed
WAS Pumps
Type Centrifugal
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-5
Item Units Design
Value Remarks
Number - 2 (1+1) One duty, one standby
Capacity, Each gpm 450
TDH ft 20
Horsepower hp 5
Drive Variable speed
Membrane Tanks
Number - 4
Cassettes per Tank
Number Installed - 6
Space for Future - 1
Total Membrane Surface
Area ft2 417,360
Air Scouring Blowers
Type High-speed turbo
Number - 3 (2+1) Two duty, one standby
Capacity, Each scfm 3,950
Discharge Pressure psi 5
Horsepower, Each hp 125
Drive Variable speed
Permeate Pumps
Type Horizontal end suction
Number - 5 (4+1) Four duty, one shelf spare
Capacity, Each gpm 1,350
TDH ft 25
Horsepower, Each hp 20
Drive Variable speed
Backpulse Pumps
Type Horizontal end suction
Number - 2 (1+1) One duty, one standby
Capacity, Each gpm 1,480
TDH ft 25
Horsepower, Each hp 30
Drive Variable speed
Instrument Air Compressors If Plant air not available
Number - 2 (1+1) One duty, one standby
Horsepower, Each hp 15
Chemical Cleaning
Sodium Hypochlorite 12.5% Solution
Frequency
Recovery Yearly 2 Per tank
Maintenance Weekly 1 Per tank
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-6
Item Units Design
Value Remarks
Annual Consumption gal 4,000
Citric Acid 50% Solution
Frequency Yearly 1-2 Part of Recovery Clean
Annual Consumption gal 750
UV System
Design Flow mgd 5
Type of UV System In-pipe, Low Pressure, High Intensity Number of Trains 4 (3+1) Three duty, one standby
Number of Reactors 8 (6+2) Six duty, two standby
Flow Capacity per Reactor mgd 1.0
Length of Reactor ft 8
Number of Lamps per
Reactor 40
Total Number of Lamps
Provided 320
16.4 Preliminary Costs
Preliminary costs were developed according to Class 4 level per AACE (Association for the Advancement of Cost Engineering) guidelines. Using the estimated capital and O&M costs, a 20-year life cycle cost analysis was performed. The results are shown in Table 16-3.
Table 16-3: MBR System Life-Cycle Cost (5 mgd)
Parameter Capital Cost
($ Millions)
O&M Cost
($ Thousands)
20-Year Life
Cycle Cost
($ Millions)
MBR System 24.4 553 34.4
Disinfection (In-pipe UV) 5.3 150 8.0
Storage (Aeration Basin No.4) and
Distribution Pumping
3.1 283 8.2
TOTAL 32.8 986 50.6
Train A Capacity Replacement Cost (18)
Net Effective Capital Cost 14.8
16.5 Power Source
For the proposed TTDF on a “green field” site, power feed will be drawn from existing Sub Service Switchgear “12KV-MS2” building. Two (2) existing circuit breakers 60-BKR-104 and 60- BKR-204 will be utilized to provide a double ended feed to the new indoor type 12 KV switchgear. This new switchgear will be provided with two (2) main circuit breakers, a normally open (NO) tie circuit breaker, two (2) feeder circuit breakers and extra space for two (2) additional circuit breakers for future expansion. All new 480 V Motor Control Centers are also indoor type. The new 12 KV switchgear and all the 480V Motor Control Centers will be housed CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
SECTION 16 – RECOMMENDED PROJECT DESCRIPTION 16-7
in a building close to the MBR structure. The step-down transformers, however, are all outdoor type and will be located on an open concrete pad close to the new electrical building. Two (2) existing – 4”C conduits on the north-south electrical duct bank will be utilized up to Manhole EMH-6. From Manhole EMH-6, two (2) new -4”C conduits will be installed down to the new 12 KV switchgear Electrical Building.
CITY OF FRESNO –TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
APPENDIX A
APPENDIX A
PRELIMINARY CONSTRUCTION AND O&M COST ESTIMATES
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
APPENDIX B
APPENDIX B
REFERENCE DRAWINGS
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
APPENDIX C
APPENDIX C
REFERENCE DOCUMENTS
CITY OF FRESNO – TERTIARY TREATMENT AND DISINFECTION FACILITY Technical Memorandum
APPENDIX C
WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
CENTRAL VALLEY REGION
RESOLUTION NO. R5-2002-0254-A01
AMENDING WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 FOR
CITIES OF FRESNO AND CLOVIS
WASTEWATER TREATMENT FACILITY
FRESNO COUNTY
WHEREAS, the California Regional Water Quality Control Board, Central Valley Region, (hereafter Board) adopted Waste Discharge Requirements Order No. 5-01-254 for the Cities of Fresno and Clovis at its regularly scheduled public meeting on 19 October 2001; and WHEREAS, Order No. 5-01-254 references the Cities of Fresno and Clovis as Discharger and the City of Fresno as Operator; and
WHEREAS, Order No. 5-01-254 requires that the Discharger comply with all pretreatment requirements contained in Title 40, Code of Federal Regulations (CFR), Part 403, including implementing the necessary legal authorities; and
WHEREAS, when Order No. 5-01-254 was adopted, legal adequacy review of the Operator’s pretreatment program was still pending; and
WHEREAS, the legal adequacy review was completed and a 21 November 2001 letter from Board staff to the Operator identifies revisions that are necessary for the ordinance and the interjurisdictional agreements contained in the Operator’s pretreatment program to comply with the federal pretreatment regulations set forth in 40 CFR Part 403; and
WHEREAS, although the Discharger has been made aware of the required revisions, the process of effecting the revisions will take some time; and
WHEREAS, the action to amend Waste Discharge Requirements Order No. 5-01-254 for this existing facility is exempt from the provisions of the California Environmental Quality Act in accordance with Title 14, California Code of Regulations, Section 15301; and WHEREAS, the Board has notified the Discharger, interested agencies, and persons of its intent to amend waste discharge requirements for the Discharger and has provided them with an opportunity for public hearing and an opportunity to submit their views and recommendations; and WHEREAS, the Board, in a public meeting, heard and considered all comments pertaining to this action; therefore be it
RESOLVED, that the Board hereby amends Waste Discharge Requirements Order No. 5-01-254 as follows:
RESOLUTION NO. R5-2002-0254-A01
AMENDING WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-245
FOR CITIES OF FRESNO AND CLOVIS
WASTEWATER TREATMENT FACILITY
FRESNO COUNTY
REVISED FINDING
1. On Page 5, in Finding No. 20, delete last sentence and replace with “Pretreatment program review identified certain revisions to the City of Fresno’s Municipal Code and interjurisdictional agreements that are necessary for the pretreatment program to contain the legal authorities required for compliance with the federal pretreatment regulations set forth in 40 CFR 403. The required revisions are set forth in a 21 November 2001 letter from Board staff to the Operator, and it is reasonable that a schedule be established (Provision H.35) for completion of the required revisions.
The Operator’s current pretreatment program, with revisions and updates submitted by the Operator on 5 April 2001, shall remain in effect and is approved conditional upon completion of the required revisions to the program in accordance with the time schedule set forth herein.”
NEW PROVISION
2. On Page 35, add a new Provision H.35 that states: “The Operator shall, no later than 15 January 2003, submit sufficient documentation to demonstrate that its ordinance and interjurisdictional agreements contained in its pretreatment program contain adequate legal authorities to implement and enforce the pretreatment requirements in compliance with 40 CFR 403.”
I, GARY M. CARLTON, Executive Officer, do hereby certify the foregoing is a full, true, and correct copy of a Resolution adopted by the California Regional Water Quality Control Board, Central Valley Region, on 1 March 2002.
___________________________________
GARY M. CARLTON, Executive Officer
BLH:fmc
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
CENTRAL VALLEY REGION
ORDER NO. 5-01-254
WASTE DISCHARGE REQUIREMENTS
FOR
CITIES OF FRESNO AND CLOVIS
WASTEWATER TREATMENT FACILITY
FRESNO COUNTY
The California Regional Water Quality Control Board, Central Valley Region, (hereafter Board) finds that:
1. The Fresno-Clovis Metropolitan Regional Wastewater Reclamation Facility is a wastewater treatment facility (WWTF) that serves the cities of Fresno and Clovis; the Pinedale Water District and Pinedale Utilities District, both of which are within the city limits of Fresno; and some areas within Fresno County not within the city limits of Fresno or Clovis. The City of Clovis owns
9.5 percent of the WWTF’s treatment capacity, while the City of Fresno owns the rest. The cities of Fresno and Clovis are referred to as Discharger. The City of Fresno is responsible for day-today WWTF operations, and is referred to as Operator. The WWTF is on property owned by the City of Fresno and covers 3,290 acres in Sections 20, 21, 22, 27, and 33, of T14S, R19E, MDB&M, as shown in Attachment A, which is part of this Order.
2. The WWTF features two separate wastewater treatment plants. Plant 1 is an activated sludge treatment plant that includes headworks, primary and secondary clarifiers, aeration basins, and anaerobic digesters (see Attachment B). The Discharger recently expanded Plant 1 to increase its nominal treatment capacity from 68 million gallons per day (mgd) to 88 mgd. Plant 2 is a 6-mgd-capacity trickling filter treatment plant that includes primary and secondary clarifiers (see Attachment C). Plant 2 is remotely located from Plant 1 and is currently not utilized. Also included within the 3,290-acre WWTF property are 1,660 acres of effluent disposal ponds; a 145-acre winery stillage disposal site (Stillage Site), portions of which have been in service since 1974; and about 600 acres of farmland on which WWTF effluent is recycled by local growers under lease agreements with the Operator.
3. Waste Discharge Requirements (WDRs) Order No. 96-054, adopted by the Board 23 February 1996, prescribes requirements for an average dry weather flow discharge of 68 mgd from Plant 1 and of 6 mgd from Plant 2 (when in operation). Order No. 96-054 also regulates the 145-acre Stillage Site generally in accordance with guidelines for land disposal of stillage waste from wineries (Stillage Guidelines) adopted by the Board in 1983. Prior to 1996, WDRs Order No. 74-10 regulated the discharge of stillage to a 95-acre portion of the Stillage Site.
4. Cease and Desist (C&D) Order No. 96-055, adopted by the Board 23 February 1996, directed the Discharger to achieve compliance with its WDRs by implementing specific short-term and longterm tasks and measures. Tasks included a study regarding the expansion of WWTF treatment and disposal pond capacity and the possibility of reclaiming substantially all wastewater. Measures included salinity control and compliance with an effluent salinity limitation. The Operator has WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -2-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
implemented salinity source control, upgraded the WWTF to accommodate current and projected wastewater flow through 2008, increased disposal capacity, and submitted a study describing the feasibility of expanded water recycling operations. On 19 October 2001, the Board adopted Order No. 5-01-241 rescinding C&D Order No. 96-055.
5. The Operator submitted a Report of Waste Discharge, dated 31 December 1996, in support of a 20-mgd increase in Plant 1 treatment and disposal capacity (i.e., to 88 mgd) and a 30 percent increase over current permitted flow of 72 mgd (i.e., to 94 mgd). The Discharger projects the added capacity should be sufficient until 2008.
6. Currently, average and maximum daily discharge flows are 68 mgd (on an annual basis) and 72 mgd (on a maximum monthly average basis), respectively. Discharger monitoring reports from 2000 characterize the WWTF effluent and municipal source water as follows:
Constituent Units Average Minimum Maximum
Effluent 5-day biochemical oxygen
demand (BOD5) mg/L 26 8 53
Total dissolved solids (TDS) mg/L
Source water 240 220 250
Effluent 440 340 500
Conductivity at 25°C (EC) µmhos/cm
Source water 350 -- --
Effluent 780 690 870
Effluent Chloride mg/L 72 60 107
Effluent Sodium mg/L 81 74 100
Effluent bicarbonate alkalinity (as CaCO3) mg/L 208 164 255
7. The Discharger frequently adds ferric chloride to the influent prior to primary clarification. While this enhances pretreatment for organic and solids removal and control of hydrogen sulfide, it does increase the discharge’s chloride and EC concentration. From 1 January 1999 through 4 April 2001, the discharge’s monthly average chloride concentration ranged from 59 to 87 mg/L, averaged 70 mg/L, and had a 95% confidence level of 82 mg/L. Similarly, for this same period, the discharge’s monthly EC concentration ranged from 594 to 924 µmhos/cm, averaged 757 µmhos/cm, and had a 95% confidence level of 842 µmhos/cm.
EFFLUENT DISPOSAL AND REUSE
8. At the current average daily discharge flow of 68 mgd, the WWTF discharges about 76,000 acrefeet per year (af/yr). Of this amount, about 4,000 af/yr of effluent is recycled directly, an amount that represents about only five percent of the WWTF’s current annual discharge flow. Dedicated pumps and piping carry the effluent to reclamation areas for irrigation of crops such as alfalfa, cotton, silage corn, and wine grapes. Current and proposed on-site water recycling is by local farmers (hereafter Users) under lease agreements on 766 acres within the WWTF property (hereafter reclamation area). Off-site water recycling is by growers under separate water WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -3-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
reclamation requirements. Of the 72,000 af/yr discharged to the 1,660 acres of disposal ponds, about 63,400 af/yr (88 percent) percolates to groundwater and 8,600 af/yr (12 percent) is lost through evaporation.
9. The Discharger’s practice of disposing of most discharge flow by percolation has, over the years, created an extensive groundwater mound under the WWTF disposal ponds (hereafter effluent mound). The effluent mound appears to be about 10-feet high, ranges in depth from 25 to 60 feet below ground surface (bgs), extends well beyond the perimeter of the WWTF property, and affects groundwater contours throughout a 25-square-mile area.
10. The Fresno Irrigation District (FID) covers 245,000 acres in central Fresno County, extends from Pine Flat Dam along the Kings River to the Kerman area, and includes the Fresno-Clovis metropolitan area.
11. In 1974, the City of Fresno entered into an agreement with FID to establish a groundwater reclamation system consisting of onsite extraction wells and piping that delivers groundwater to FID’s Dry Creek and Houghton Canals during the growing season for agricultural use on the western side of FID. Both canals can each convey up to about 200 cubic feet per second. The 1974 agreement between FID and the Operator currently stipulates, in part, that the Operator may discharge a maximum of 30,000 af/yr of extracted groundwater to FID canals. To date, there are no restrictions on the use of extracted groundwater discharged to FID canals.
12. In 1975, the Operator installed 21 reclamation wells within the WWTF property. The amount of water extracted ranges between 10,000 af/yr (minimum) to 30,000 af/yr (maximum), an amount equivalent to 12 to 37 percent of the WWTF’s current annual discharge flow. As of 30 April 2001, all 21 reclamation wells were operational. The estimated delivery capacity is in excess of 30,000 af/yr. With the exception of several newly-installed “Flowpath™” reclamation wells, the Operator’s reclamation wells extract groundwater from depths exceeding 200 feet bgs, which is 140 to 175 feet below the top of the effluent mound. The Operator pumps from these depths rather than those associated with the effluent mound reportedly due to shallow zone’s low specific yields. The Flowpath ™ wells, installed in the fall of 2000, extract from depths ranging from 80 to 240 feet bgs.
The Operator periodically monitors the quality of groundwater extracted from the reclamation wells for TDS, EC, sodium, chloride, nitrogen compounds, and general minerals. The chloride concentration in extracted groundwater is comparable to WWTF effluent and not to groundwater extracted from the WWTF’s background monitoring wells. Consequently, the reclamation well network, while drawing from depths below the top elevation of the effluent mound, is effectively extracting percolated effluent and not regional groundwater. Water quality data from October 2000 for groundwater extracted from three Flowpath ™ reclamation wells indicate the following average concentrations in mg/L: chloride (79), dissolved iron (0.19), dissolved manganese (1.24), total nitrogen (< 2), sodium (76), TDS (490), and total organic carbon (5).
13. The Operator normally delivers between 15,000 and 20,000 af/yr to FID canals with its current reclamation well network. For the Operator to deliver in excess of 30,000 af/yr to FID canals, the Operator would have to add more reclamation wells. Any increase in the discharge of extracted groundwater beyond that specified in the 1974 agreement is subject to FID approval.
WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -4-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
14. The Discharger submitted a technical report, Fresno-Clovis Regional Wastewater Reclamation Facilities Master Plan Summary Report (Master Plan), dated November 1996, pursuant, in part, to C&D Order No. 96-055. The Master Plan describes several near- and long-term options for offsite effluent reuse/disposal to meet the Discharger’s disposal needs through 2020. The Master Plan further describes the institutional and structural elements of each option, including its financial analysis and multi-year implementation schedule.
15. The Master Plan recommends the following effluent disposal and reuse projects: (a) adding about 270 acres of on-site disposal ponds, (b) maximizing the discharge to FID canals from of its existing reclamation well network, and (c) implementing a reuse project that would recycle an amount equivalent of the annual WWTF discharge flow. At the full capacity of 80 mgd, the annual discharge flow is about 90,000 af/yr, which far exceeds the discharge of any municipal sewage treatment facility in the San Joaquin Valley. The Discharger has increased its on-site disposal pond acreage and has continued to explore opportunities for the direct reuse of effluent. The City currently is constructing pipelines that will provide effluent for the irrigation of an additional 630 acres of reclamation area. The City also has a project under way to increase the capacity of the existing reclamation well network.
16. Calpine Corporation (hereafter Calpine) is planning to construct a new gas-fired turbine in Fresno County (Central Valley Energy Center, hereafter referred to as CVEC). Calpine proposes to pump approximately 7,000 af/yr from the Operator's reclamation wells to provide cooling tower and industrial process water for the CVEC. Once extracted, the recycled water will be dosed with sodium hypochlorite prior to introduction into a 20.5 mile, 30-inch diameter pipeline, which will terminate into two 1.5 million gallon storage tanks at the CVEC site.
17. In addition to its Kings River entitlement, FID and the Operator have signed contracts to purchase up to 135,000 af/yr of surface water from the Friant Division of the Central Valley Project, operated by the U.S. Bureau of Reclamation (Bureau). The contract between FID, the Operator, and the Bureau is up for renewal, which may change the terms and conditions of the 1974 agreement between FID and the Operator. Until the contract renewal is consummated, the economic value of WWTF effluent as a source of agricultural supply is uncertain. This economic uncertainty influences the Discharger’s scheduling for implementing a large-scale effluent reuse project.
PRETREATMENT
18. Fifty-six significant industrial users discharge waste into the WWTF collection system, including 14 users from the metal finishing categories, according to data submitted by the Operator in February 2001. Other industrial users discharging into the WWTF include soft drink bottlers, meat packers, food processors (fruit, vegetable, grain, nuts, and seeds), dairy and poultry products processors, plastic manufacturers, wineries, and several linen and industrial laundries.
19. Pretreatment effluent standards established pursuant to section 307 of the Federal Clean Water Act (CWA) and amendments thereto are applicable to the discharge.
WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -5-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
20. The Discharger originally developed a pretreatment program in conformance with 40 CFR 403.
The Board approved the program on 17 June 1984. The Operator has subsequently submitted a revised pretreatment program (dated 6 June 1996), also in conformance with 40 CFR 403, which updates its original submission to bring it in line with current practices. The Operator updated its pretreatment program in 2001, in part, to reflect its latest municipal code and enforcement response plan, incorporate WWTF upgrades, and describe modifications in sampling procedures.
The Board is reviewing the revised pretreatment program for completeness and adequacy.
21. A pretreatment compliance inspection conducted in June 1999 indicated that all elements of the Discharger’s pretreatment program comply with the federal pretreatment regulations in 40 CFR 403.
SLUDGE MANAGEMENT AND BIOSOLIDS DISPOSAL
22. Pursuant to section 13274 of the California Water Code, the State Water Resources Control Board adopted on 17 August 2000 Water Quality Order No. 2000-10-DWQ, General Waste Discharge Requirements for the Discharge of Biosolids to Land for use as a Soil Amendment in Agricultural, Silvicultural, Horticultural, and Land Reclamation Activities (hereafter General Biosolids Order).
23. The WWTF produced 12,800 dry tons of sludge in 1999, or an average of 35 tons/day. Dissolved air flotation and gravity belt units thicken sludge, anaerobic digesters stabilize it, and belt filter presses dewater it.
24. Prior to 1993, the Operator pumped digested sludge to 62 acres of sludge drying beds consisting of unlined open earthen basins. The Operator has since constructed additional treatment facilities on the majority of the 62-acre site of the old sludge beds, with a small portion converted into effluent disposal ponds.
25. The Operator previously stockpiled over 75,000 cubic yards of biosolids that had been originally classified as “hazardous” waste due to its concentrations of lead and cadmium. In September 1994, the Discharger submitted a technical report, Work Plan To Collect and Analyze Sludge Samples. In July 1997, the California Department of Toxic Substances re-evaluated the biosolids and reclassified it as nonhazardous. During the fall of 1998, the Operator transported the stockpiled biosolids to the Fresno Sanitary Landfill as part of the landfill’s final closure project. From September 1998 through January 1999, the Operator diverted 25 percent of the biosolids previously produced at the WWTF to the Fresno Sanitary Landfill as part of its final closure project.
26. In August 1997, the Discharger entered into a contract with McCarthy Farms (MFF) to haul nonhazardous WWTF biosolids to MFF’s land application site near Corcoran or to MFF’s composting site in Lost Hills operated by San Joaquin Composting, Inc. These sites are regulated by waste discharge requirements adopted by the Board. In April 1999, the Operator certified that WWTF biosolids met the requirements for Class B biosolids and implemented a direct land application program in conjunction with MFF in Corcoran.
HYDROLOGY, SOILS AND GROUNDWATER
WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -6-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
27. The WWTF lies within the Fresno Hydrologic Area (No. 551.30), which is within the Kings River Basin, as depicted on interagency hydrologic maps prepared by the California Department of Water Resources (DWR) in August 1986. The WWTF is not within a 100-year floodplain, and all storm water runoff is reportedly contained on-site. Incidental on-site runoff (e.g., runoff along the canal banks) drains into Dry Creek Canal, which flows through the WWTF property.
28. Dry Creek Canal originates in the City of Fresno and flows seasonally downstream of the WWTF.
Houghton Canal flows seasonally downstream of the WWTF and originates at a junction with Dry Creek Canal in the City of Fresno. Dry Creek Canal has an undetermined terminus southwest of the WWTF. Houghton Canal has an undetermined terminus west of the WWTF.
29. Areal soils consist of unconsolidated alluvial deposits of interbedded layers of sand, gravel, silt, sandy clay, clay and localized cobble zones. Soils in the upper five feet of the Stillage Site are described as well-sorted sands with good permeability (i.e., 0.7 to 1.0 in/hr) and therefore suitable for rapid infiltration of stillage waste.
30. The WWTF is in a semiarid region. Average annual precipitation and evapotranspiration are about 11 inches and 62 inches, according to information published by DWR.
31. Areal groundwater comprises the north portion of an essentially closed groundwater basin (Tulare Lake Basin) and flows southwesterly under unconfined conditions from the foothills east of Fresno westward to a northwest-trending line through Kerman and Raisin City. West of that line, groundwater occurs under both unconfined and semiconfined conditions. Extensive groundwater pumpage near the cities of Fresno and Raisin City have caused local changes in groundwater flow direction.
32. Groundwater in the WWTF vicinity occurs in an unconfined aquifer at depths ranging from 30 to 60 feet below ground surface (bgs). The Operator has delineated two zones of groundwater quality within the unconfined aquifer: a shallow zone consisting of the upper 50 feet of the aquifer and a lower zone, the top of which is about 200 feet below the water table.
33. The Operator monitors area groundwater via a groundwater monitoring well network currently comprised of 22 wells in the WWTF vicinity. In August 1996, the Operator proposed constructing additional groundwater monitoring wells along the WWTF perimeter to further characterize groundwater quality further and to assess potential groundwater impacts pursuant to Monitoring and Reporting Program No. 96-054. The Operator has not constructed the additional proposed groundwater monitoring wells.
34. Background or upgradient groundwater quality is highly variable due to the presence of dairies and other land uses that impact water quality. The Discharger currently monitors upgradient water quality in three wells, two monitoring wells (MW-10A and MW-10B) approximately 10,000 feet north of the WWTF property’s north boundary and one domestic well (I) approximately 9,000 feet east of the WWTF’s property’s northeast corner. Of the two monitoring wells, MW-10A monitors the shallow zone and MW-10B, the deeper zone.
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35. Upgradient or background groundwater is of high quality and meets all primary and secondary maximum contaminant levels for drinking water, according to the Operator’s report, Technical Memorandum No. 1-Update of Groundwater Quality Conditions (April 1999). High quality groundwater conditions are generally associated with areas characterized by the absence of dairies or other localized sources of waste discharges.
36. Compared to background groundwater quality, groundwater passing under the WWTF contains elevated concentrations of TDS, EC, sodium, chloride, total phosphorus, and bicarbonate alkalinity. WWTF operations that have degraded groundwater for those constituents include stillage disposal and effluent disposal operations and the past use of sludge-drying beds.
Groundwater within and surrounding the WWTF property has been degraded by other activities (e.g., past and existing dairy operations, a closed landfill), which over the years have created localized areas of groundwater degradation (hereafter referred to as “hot spots”). The Discharger’s current groundwater monitoring well network is not adequate to distinguish groundwater impacts that are exclusively attributable to WWTF operations or to waste constituents originating from identified hot spots.
37. As indicated in Finding No. 8, evaporative losses account for about 12 percent of the current discharge flow to the disposal ponds. Evaporative losses will decrease to about 10 percent of the proposed increased discharge flow of 80 mgd, and result in an increase in the concentrations of waste constituents in effluent percolating to groundwater by about 10 percent. Therefore, groundwater underlying disposal ponds in areas unaffected by other waste discharges can be expected to contain salt constituents (e.g., chloride, EC, and TDS) in concentrations about 10 percent greater than that in WWTF effluent. A similar concentration increase can be expected for sodium provided there is no attenuation of sodium in the soil profile. The concentrating effect of evaporation appears to diminish as percolating effluent blends with regional groundwater, as indicated by the lower concentrations of chloride, TDS, and sodium in groundwater extracted in the recently-installed Flowpath ™ reclamation wells (as described in Finding No. 12).
38. As indicated in Finding No. 12, recent monitoring of groundwater extracted from the newlyinstalled Flowpath ™ reclamation wells has revealed very low concentrations of nitrogen and elevated concentrations of dissolved manganese (almost 25 times the drinking water standard of
0.05 mg/L). In contrast, monitoring of shallow groundwater has revealed nitrate-nitrogen concentrations approaching and even exceeding the drinking water standard of 10 mg/L and very low dissolved manganese concentrations.
STILLAGE SITE
39. The Operator’s 145-acre stillage disposal site, or Stillage Site, consists of a 95-acre site (SS-1), 95 acres of which have been in service since 1974, and a 50-acre site (SS-2) in service since December 1998 (see Attachment A). Stillage waste is generated from the distillation of wine in continuous stills and pot stills (infrequently used) for the production of distilled spirits. Stillage waste is conveyed year-round to the Stillage Site by a dedicated pipeline.
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40. Prior to 1974, four wineries discharged a maximum of 1.1 mgd of stillage waste to the Operator’s sanitary sewer system. This practice resulted in nuisance conditions and other problems at the domestic wastewater treatment plant’s infiltration beds. In 1974, the Operator began discharging up to 1.07 mgd of stillage via dedicated pipelines to the 95-acre SS-1 under the terms and conditions of WDRs Order No. 74-10. The Stillage Site has been operated generally in accordance with the minimum requirements of Board-adopted Stillage Guidelines. The Operator has not, however, adjusted its stillage disposal operation to ensure that it is protective of groundwater quality, even when groundwater monitoring data revealed that it had degraded and continues to degrade groundwater quality (discussed below).
41. The Stillage Site is divided into long narrow checks, approximately 500 feet long by 100 feet wide, most of which are equipped with concrete inlet structures to prevent erosion. Stillage is discharged to individual checks until it reaches depths ranging from 2.5 to about 4 inches, depending on the time of year. Once applied, the stillage is allowed to dry from six days to several weeks until all that remains is a thin, dry layer (called leathers). Checks are ripped and disked to a depth of 18 to 24 inches prior to reapplication of stillage. Prior to 1996, leathers were disked into disposal area soils. In 1996, the Operator began removing leathers from checks to help reduce the nutrient build-up in disposal area soils. Scraped leathers are stockpiled on site and reportedly used as soil amendment on landscaped areas within the WWTF property.
42. Recent monitoring data characterizes the BOD5 and nitrogen concentrations in stillage as averaging about 12,000 mg/L and 400 mg/L, respectively. About 90 percent of the BOD5 is in the soluble form; nitrogen occurs predominantly in the organic form, expressed as total Kjeldahl nitrogen (TKN). Typically, the peak discharge season is from August through November, during which discharge flows average about 0.215 mgd. Off-season discharge flow averages about 0.15 mgd.
43. The Operator discharged a total of about 79 million gallons of stillage in 2000. Peak daily flows occurred in mid-June, and ranged from 1.1 to 1.27 mgd. At an average TKN concentration of 400 mg/L, this discharge to the entire 145 acres of the Stillage Site equates to a nitrogen load in excess of 1,800 lbs/acre/year.
44. The Operator began growing crops in the Stillage Site in 1996 to reduce residual nitrogen, as recommended by the Stillage Guidelines. Soil monitoring data collected by the Operator in 1992 indicate that the Operator’s long-term stillage disposal operation has resulted in a massive accumulation of nitrogen in the upper two feet of disposal area soils (i.e., 21,300 lbs TKN/acre).
45. Order No. 96-054, Stillage Discharge Specification B.8, requires the Discharger to grow crops in the Stillage Site to assist in the removal of residual nitrogen from the soil. The Discharger is exempt from this requirement if it can demonstrate that its stillage disposal operation has been and can be accomplished without nitrogen control and without violating Groundwater Limitations.
The Discharger was required to submit a report on measures to be implemented to provide for nutrient uptake in the Stillage Site, or justification why such measures are unnecessary, pursuant to Order No. 96-054, Provision G.7. The Operator submitted a report that describes (a) alternatives to current disposal practices (i.e., implementing pretreatment by anaerobic digestion or discharging WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -9-
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to a different site) and (b) plans to plant crops on portions of the Stillage Site and to monitor soils before and after cropping.
46. In 1996, the Operator conducted a field experiment in which it planted Sudan grass on 35 acres of SS-1, allowed the crop to mature, and harvested it twice. Before and after cropping, the Operator analyzed soil samples for various constituents, including TKN, ammonia, phosphorus, and calcium.
After harvesting, the Operator found that while reductions of these constituents occurred as a result of the planting, the concentrations were still quite elevated compared to background levels. The Operator has yet to initiate systematic cropping and harvesting of portions of the SS.
47. Excessive application of stillage waste to land can overload the shallow soil profile, cause anaerobic soil conditions, retard the degradation, stabilization, transformation, and immobilization of waste constituents, and create objectionable odors that lead to public nuisance. Degradation of waste constituents within the soil profile increases the concentration of alkalinity in soil pore water. Anaerobic soil conditions can lead to the dissolution of soil minerals such as calcium and magnesium. Hydraulic overloading flushes waste constituents, their decomposition by-products, and dissolved minerals into the soil profile. If attenuation is inadequate, these compounds may be released at concentrations in excess of applicable water quality objectives or could reasonably be expected to affect beneficial uses underlying groundwater.
48. The Operator’s decades-long stillage disposal operation has degraded groundwater beneath SS-1 to the degree that its beneficial uses as a domestic and agricultural supply are impaired. Data from a monitoring well in this area (MW-2) shows that the EC of groundwater passing under SS-1 consistently exceeds the recommended secondary maximum contaminant levels for drinking water of 900 µmhos/cm. Additional monitoring data shows groundwater degradation for TDS, total alkalinity, calcium, magnesium, and manganese.
49. Currently, the Stillage Site receives stillage waste year round from only one winery, Cribari Winery, which is owned and operated by Canandaigua Wine Company, a New York corporation.
Canandaigua Wine Company intends to cease discharge of stillage waste to the Stillage Site by the end of fall 2003.
50. The Operator reports that Plant 1 lacks the treatment capacity to handle all of the stillage waste currently generated by the Cribari Winery.
BASIN PLAN AND REGULATORY CONSIDERATIONS
51. The Water Quality Control Plan for the Tulare Lake Basin, 2nd Edition, (hereafter Basin Plan) designates beneficial uses, establishes water quality objectives, contains implementation plans and policies for protecting all waters of the Basin, and incorporates by reference plans and policies of the State Water Resources Control Board. These requirements implement the Basin Plan.
52. The Dry Creek and Houghton Canals carry irrigation deliveries from the Kings River and Friant Kern Canal, both waters of the United States. They also carry urban storm water runoff and surface waters from upgradient ephemeral streams. The Dry Creek and Houghton Canals are WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -10-
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valley floor waters. The designated beneficial uses of valley floor waters, according to the Basin Plan, are municipal and domestic, agricultural, industrial service, and industrial process supply; water contact and noncontact water recreation; warm freshwater, wildlife, and rare, threatened, or endangered species habitat; and groundwater recharge.
53. Historically, groundwater has been the sole source of municipal and domestic supply for the Fresno-Clovis metropolitan area, and for thousands of residents in surrounding rural areas. The Basin Plan designates the beneficial uses of groundwater in the vicinity of the WWTF and its discharges to land as municipal, agricultural, industrial service, and industrial process supply and water contact and noncontact water recreation.
54. In 1977, the United States Environmental Protection Agency (EPA) determined that the groundwater aquifer serving the Fresno-Clovis metropolitan area is a sole source of drinking water pursuant to section 1424 of the Safe Drinking Water Act.
55. Water in the Tulare Lake Basin is in short supply, requiring importation of surface waters from other parts of the State. The Basin Plan encourages reclamation on irrigated crops wherever feasible and indicates that evaporation of reclaimable wastewater is not an acceptable permanent disposal method where the opportunity exists to replace an existing use or proposed use of fresh water with recycled water. The Basin Plan further requires plans for new or expanded wastewater treatment facilities to include wastewater reclamation, or reasons why this is not possible.
56. Section 13050(h) of the California Water Code defines water quality objectives as “. . . the limits or levels of water quality constituents or characteristics which are established for the reasonable protection of beneficial uses of water or the prevention on nuisance within a specific area.”
57. The Basin Plan establishes numerical and narrative water quality objectives for surface and groundwaters within the basin, and recognizes that water quality objectives are achieved primarily through the Board’s adoption of waste discharge requirements and enforcement orders. Where numerical water quality objectives are listed, these are the limits necessary for the reasonable protection of beneficial uses of the water. Where compliance with narrative water quality objectives is required, the Board will, on a case-by-case basis, adopt numerical limitations in orders which will implement the narrative objectives to maintain existing and anticipated beneficial uses of waters in the subject area.
58. The Basin Plan identifies numerical water quality objectives for waters designated as municipal supply. These are the maximum contaminant levels (MCLs) specified in the following provisions of Title 22, California Code of Regulations: Tables 64431-A (Inorganic Chemicals) and 64431-B (Fluoride) of section 64431, Table 64444-A (Organic Chemicals) of section 64444, and Table 64449-A (Secondary Maximum Contaminant Levels-Consumer Acceptance Limits) and 64449-B (Secondary Maximum Contaminant Levels-Ranges) of section 64449. The Basin Plan’s incorporation of these provisions by reference is prospective, and includes future changes to the incorporated provisions as the changes take effect. The Basin Plan requires the application of objectives more stringent than MCLs as necessary to ensure that waters do not contain chemical constituents in concentrations that adversely affect beneficial uses, whether the use is domestic drinking water supply, agricultural supply, or some other use.
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59. The Basin Plan contains narrative water quality objectives for chemical constituents in and toxicity of groundwater that address constituents in the discharge that are potentially harmful to beneficial uses. The toxicity objective requires that groundwater be maintained free of toxic substances in concentrations that produce detrimental physiological responses in plants or animals. The chemical constituent objective states groundwater shall not contain chemical constituents in concentrations that adversely affect beneficial uses. Guidelines for identifying the quality of irrigation water necessary to sustain various crops were compiled by Ayers and Westcot in 1985 (Food and Agriculture Organization of the United Nations – Irrigation Drainage Paper No. 29). The Basin Plan recognizes these Guidelines for providing relevant numerical criteria to evaluate compliance with the previously described narrative water quality objectives. The Guidelines are intended for use in estimating the potential hazards to crop production associated with long term use of the particular water being evaluated. The Guidelines divide water quality characteristics as having “No Problem – Increasing Problems – Severe Problems” based on large numbers of field studies and observations, and carefully controlled greenhouse and small plot research. In general, crops sensitive to sodium or chloride are most sensitive to foliar absorption from sprinkler applied water.
Bicarbonate has been a problem when fruit crops or nursery crops are sprinkler irrigated during periods of very low humidity and high evaporation. The following table contains numerical criteria adapted from the Guidelines for protection of a range of crops under various circumstances, but the most stringent is not necessarily the concentration that assures no adverse affect on any nonagricultural beneficial use:
Problem and Related Constituent No Problem
Increasing
Problem
Salinity of irrigation water (EC, µmhos/cm) < 750 750 – 3,000 Salinity of irrigation water (TDS, mg/L)* < 450 450 – 1,800 Specific Ion Toxicity
from ROOT absorption
Sodium (mg/L) < 69 69 – 207
Chloride (mg/L) < 142 142 – 355
Boron (mg/L) < 0.5 0.5 – 2.0
from FOLIAR absorption
Sodium (mg/L) < 69 > 69
Chloride (mg/L) < 106 > 106
Miscellaneous
NH4-N (mg/L) (for sensitive crops) < 5 5 – 30
NO3-N(mg/L) (for sensitive crops) < 5 5 – 30
HCO3 (mg/L) (only with overhead sprinklers) < 90 90 - 520 pH normal range = 6.5 – 8.4
* Assumes an EC:TDS ratio of 0.6:1
60. The existing and anticipated beneficial uses of area groundwater for agricultural supply include irrigation of crops sensitive to salt and boron. According to the 1994 DWR land use map, irrigated crops within five miles of the WWTF consist of alfalfa, almonds, beans, corn, cotton, grain and hay, melons, peaches, plums, tomatoes, and vineyards. Based on climate, soil type, and water WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -12-
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quality, other crops sensitive to salt and boron might be capable of being grown in the area, and changing market conditions could drive a change in cropping patterns, but neither is expected to necessitate greater protection than crops already identified.
61. The Guidelines presents the maximum EC of irrigation water for various crops with respect to percent crop reductions (i.e., 0, 10, 25, and 50). The table below extracts irrigation water EC data (in µmhos/cm) for crops cultivated in the WWTF vicinity (as described in Finding No. 60). As indicated below, zero crop yield reductions are not evident when irrigating all but one crop (bean) with water having an EC of less than 1,000 !mhos/cm.
Crop 0% Reduction 10% Reduction
Beans 700 1,000
Almonds 1,000 1,400
Plums 1,000 1,400
Vineyards 1,000 1,700
Corn (Sweet) 1,100 1,700
Peaches 1,100 1,400
Corn (Forage) 1,200 2,100
Alfalfa 1,300 2,200
Melon (Cantaloupe) 1,500 2,400
Tomatoes 1,700 2,300
Hay (Barley) 4,000 4,900
Cotton 5,100 6,400
62. The Guidelines indicate that boron sensitive crops such as stone fruit and grapes may show injury when irrigated with water with boron ranging from 0.5 to 1.0 mg/L and reduced yield and vigor when irrigated with water with boron ranging from 1.0 to 2.0 mg/L. Bicarbonate has been a problem when fruit crops or nursery crops are sprinkler irrigated during periods of very low humidity and high evaporation.
63. To maintain the beneficial uses of flood irrigation of stone fruit, and sprinkler irrigation of vegetables and fruit, it is necessary that area groundwater have EC values of 1,000 µmhos/cm or less, and low concentrations of chloride, sodium, boron, and bicarbonate.
64. The average EC of WWTF effluent in 2000 was about 430 µmhos/cm above source water EC and the average bicarbonate of WWTF effluent in 2000 was 208 mg/L as CaCO3 (as indicated in Finding No. 6). Despite the Discharger’s implementation of an effective salinity source control program, however, the average sodium concentration of WWTF effluent (81 mg/L in 2000) exceeds the 69 mg/L recommended by the Guidelines for sodium sensitive crops (for either root or foliar absorption). Unless other means of sodium control are possible, irrigating at night is one method to mitigate potential adverse effects of sprinkler irrigation of sodium-sensitive crops with water containing elevated levels of sodium and of bicarbonate. Because the groundwater degradation from sodium can be mitigated by reasonable changes in irrigation management practices and because the Discharger has implemented best practicable source control for sodium and bicarbonate alkalinity (a matter that will require further documentation by means of studies WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -13-
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required herein), the consequent degradation from sodium and bicarbonate alkalinity for the time can be found at the present time to be consistent with Resolution No. 68-16.
65. As explained in the attached Information Sheet, this Order implements water quality objectives established as necessary to maintain the existing and anticipated beneficial uses of area groundwater for the production of stone fruit, grape, and other crops that are sensitive to salt (i.e., sodium and chloride), boron, or both. The numerical values reflect the highest tolerable level of quality necessary to sustain sprinkler application, as these are more restrictive than for flood irrigation. These objectives include EC (990 µmhos/cm), and the following expressed as mg/L:
chloride (106), sodium (103), boron (0.7), and TDS (560). The Order’s nitrogen limit of 10 mg/L is for total nitrogen because all forms of nitrogen can convert to nitrate in groundwater and the nitrate standard is 10 mg/L as nitrogen in drinking water. It is reasonable to conclude that a total nitrogen limit of 10 mg/L is adequately protective of existing and anticipated agricultural land uses. This Order implements a narrative groundwater limitation for taste and odor by prescribing a groundwater limitation of 0.5 mg/L for ammonia. This concentration is based on a European Union drinking water standard. Discharger monitoring data indicate that effluent ammonia concentrations typically exceed 5 mg/L. As such, there is reasonable potential for the discharge to cause violations of the narrative water quality limitation for taste. There are numerous domestic wells in the area encompassed by the groundwater mound created by percolating effluent. The groundwater ammonia limitation is protective of the beneficial uses of area groundwater for domestic supply.
66. California Department of Water Resources standards for the construction and destruction of groundwater wells (hereafter DWR Well Standards), as described in California Well Standards Bulletin 74-90 (June 1991) and Water Well Standards: State of California Bulletin 94-81 (December 1981), and any more stringent standards adopted by the Discharger or county pursuant to CWC section 13801, apply to all monitoring wells.
67. The discharge authorized herein and the treatment and storage facilities associated with the discharge of treated municipal wastewater, except for discharges of residual sludge and solid waste, are exempt from the requirements of Title 27, California Code of Regulations (CCR), section 20380 et seq. (hereafter Title 27). The exemption, pursuant to Title 27 CCR section 20090(a), is based on the following:
a. The waste consists primarily of domestic sewage and treated effluent; b. The waste discharge requirements are consistent with water quality objectives; and c. The treatment and storage facilities described herein are associated with a municipal wastewater treatment plant.
68. The discharge of stillage waste authorized herein is exempt from the requirements of Title 27. The exemption, pursuant to section 20090(b), is based on the following:
a. The Board is issuing these waste discharge requirements, WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -14-
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b. These waste discharge requirements implement the Basin Plan and allow discharge only in accordance with the Basin Plan, and
c. The wastewater is not hazardous waste and need not be managed according to Title 22, CCR, Division 4.5, Chapter 11, as a hazardous waste.
69. In the process of crop irrigation, evaporation and crop transpiration remove water from and result in accumulation of residual salts in the soil root zone. These salts would retard or inhibit plant growth except for a fraction of irrigation water applied to leach the harmful salt from the root zone. The leached salts eventually enter groundwater and concentrate above the uppermost layer of the uppermost aquifer. As this is the general condition throughout the agricultural Tulare Lake Basin, water supply wells for all beneficial uses typically are constructed to extract groundwater from below this level.
70. Infiltration from wastewater treatment and wastewater disposal ponds results in wastewater intersecting and accumulating on and in the uppermost layer of the uppermost groundwater until dispersed horizontally and vertically into the main mass of the aquifer. Compliance with the various water quality objectives necessary to protect present and future beneficial uses within the aquifer should be determined by water representative of the uppermost zones. Site-specific studies to determine the appropriate zones and geographical locations should be conducted by the Discharger subject to Executive Officer approval.
TITLE 22
71. Domestic wastewater contains pathogens harmful to humans that are typically measured by means of total and fecal coliform, as indicator organisms. The California Department of Health Services (DHS) has primary statewide responsibility for protecting public health. In 1977, DHS established statewide criteria in Title 22, California Code of Regulations (CCR), section 60301 et seq., (hereafter Title 22) for the use of recycled water and has developed guidelines for specific uses.
Revisions of the water recycling criteria in Title 22 became effective on 2 December 2000. The revised Title 22 expands the range of allowable uses of recycled water, establishes criteria for these uses, and clarifies some of the ambiguity contained in the previous regulations.
72. The 1988 Memorandum of Agreement (MOA) between DHS and the State Water Resources Control Board on the use of recycled water establishes basic principles relative to the agencies and the regional boards. Under terms of the MOA, the Board implements Title 22 and DHS recommendations for the protection of public health. In addition, the MOA allocates primary areas of responsibility and authority between these agencies, and provides for methods and mechanisms necessary to assure ongoing, continuous future coordination of activities relative to the use of recycled water in California.
73. Title 22 requires recyclers of treated municipal wastewater to submit an engineering report detailing the use of recycled water, contingency plans, and safeguards. The Discharger submitted an engineering report to DHS pursuant to Title 22 for on-site water reclamation operations on WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -15-
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1 February 2001. The DHS commented on the Discharger’s Title 22 Engineering Report by letter dated 22 March 2001. The Discharger is in the process of responding to these comments.
74. By letter dated 10 May 2001, DHS recommended that the Discharger expedite efforts to expand recycling and curtail discharge to groundwater. The DHS recommends that the Board require the Discharger to (a) assess the current status of all private and domestic wells that exist within the 25-square-mile area described in Finding No. 9, (b) monitor domestic supply wells within this area for contaminants to assure they are producing safe water for domestic use, and (c) conduct a comprehensive study to assess the fate and effects of the discharge on groundwater.
75. By letter dated 24 August 2001, DHS further recommended that the Board require the Discharger, in collaboration with FID, to (a) identify the types of crops grown in the area served by FID canals that receive groundwater extracted by the Operator’s reclamation wells and (b) provide information on the dilution of the extracted groundwater with fresh water prior to irrigation application. If food crops are found to be grown in the subject area, DHS recommends the Discharger be required to evaluate the degree of filtration and virus removal provided. The DHS also recommended the Discharger provide continuous turbidity monitoring of representative reclamation wells for at least one year.
DEGRADATION
76. State Water Resources Control Board (SWRCB) Resolution No. 68-16 (hereafter Resolution 68-16 or the “Antidegradation” Policy) requires the Board in regulating the discharge of waste to maintain high quality waters of the state until it is demonstrated that any change in quality will be consistent with maximum benefit to the people of the State, will not unreasonably affect beneficial uses, and will not result in water quality less than that described in the Board’s policies (e.g., quality that exceeds water quality objectives).
77. The Basin Plan identifies the greatest long-term problem facing the entire Tulare Lake Basin as the increase in salinity in groundwater, which has accelerated due to the intensive use of soil and water resources by irrigated agriculture. The Basin Plan recognizes that degradation is unavoidable until a valley wide drain is constructed to carry salts out of the basin. Until the drain is available, the Basin Plan describes numerous salt management recommendations and requirements. The later includes the requirement that discharges to land from wastewater treatment facilities not have an EC greater than source water plus 500 !mhos/cm. Accordingly, the Basin Plan allows for salinity degradation and focuses on controlling the rate of increase.
78. The Board finds that some degradation of groundwater beneath the WWTF and reclamation and disposal areas is consistent with Resolution 68-16 provided that:
" the degradation is confined to a specified area
" the Discharger minimizes the degradation by fully implementing, regularly maintaining, and optimally operating best practicable treatment and control (BPTC) measures WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -16-
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" the degradation is limited to waste constituents typically encountered in municipal wastewater as specified in the groundwater limitations in this Order " the degradation does not result in water quality less than that prescribed in the Basin Plan
79. Some degradation of groundwater by some of the typical waste constituents released with discharge from a municipal wastewater utility after effective source control, treatment, and control is consistent with maximum benefit to the people of California. The technology, energy, water recycling, and waste management advantages of municipal utility service for the Cities of Fresno and Clovis far exceed any benefits derived from a metropolitan area otherwise reliant on numerous concentrated individual wastewater systems, and the impact on water quality will be substantially less. When allowed, the degree of degradation allowed depends upon many factors (i.e., background water quality, the waste constituent, the beneficial uses and most stringent water quality objective, source control measures, waste constituent treatability).
80. The WWTF described in Finding No. 2 provides treatment and control of the discharge that incorporates:
" technology for secondary treatment of municipal wastewater " biosolids handling and treatment for reuse
" constituent attenuation within the vadose zone
" concrete treatment structures
" recycling of wastewater on cropped properties
" a pretreatment program that includes effective salinity source control " an active inflow and infiltration (I/I) rehabilitation program " a capital recovery fund
" an operation and maintenance (O&M) manual
" staffing to assure proper operation and maintenance
81. Discharger practices that may not constitute BPTC as used in Resolution 68-16 include the reliance of effluent disposal by evaporation and percolation. The impact to area groundwater caused by this practice is mitigated to some degree by the Operator’s discharge to FID canals of about 15,000 af/yr of groundwater extracted from a network of reclamation wells situated throughout the disposal pond area. However, as indicated in Finding No. 12, the concentrations of dissolved manganese in groundwater extracted from several reclamation wells exceed the water quality objective of 0.05 mg/L (as referenced in Finding No. 58). Neither WWTF effluent nor groundwater sampled from shallow monitoring wells exhibit such high dissolved manganese concentrations. Further, the Discharger’s stillage disposal operation appears to have degraded and polluted groundwater underlying SS-1 (Finding No. 48). The existing impacts on groundwater and the appropriate level of degradation that complies with Resolution 68-16 has not been evaluated.
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82. This Order, therefore, establishes schedules of tasks to evaluate BPTC for each treatment, storage, and disposal component of the WWTF and to characterize groundwater for all waste constituents.
83. This Order establishes groundwater limitations that will not unreasonably threaten present and anticipated beneficial uses or result in groundwater quality that exceeds water quality objectives set forth in the Basin Plan. This means that where the stringency of the limitations for the same waste constituent differs according to beneficial use, the most stringent applies as the governing limitation for that waste constituent. This Order contains tasks for assuring that BPTC and the highest water quality consistent with the maximum benefit to the people of the State will be achieved. Accordingly, the discharge is consistent with the antidegradation provisions of Resolution 68-16. Based on the results of the scheduled tasks, the Board may reopen this Order to reconsider groundwater limitations and other requirements to comply with Resolution 68-16.
CEQA FINDINGS
84. The City of Fresno certified a final environmental impact report (EIR) dated 31 October 1995 for an expansion in WWTF treatment and disposal capacity in accordance with the California Environmental Quality Act (CEQA) (Public Resources Code section 21000 et seq.) and the State CEQA Guidelines. The expansion project includes (a) increasing Plant 1 treatment capacity to 80 mgd to accommodate urban growth in the Discharger’s service area, (b) discontinuing use of Plant 2 to improve the WWTF’s overall air emissions, reliability, and operations, and (c) constructing an additional 600 acres of infiltration basins (i.e., effluent disposal ponds) to provide disposal capacity for the increased flows and to comply with Board-prescribed pond freeboard requirements. The EIR estimates that, at full build out, the project would discharge an additional 11,200 af/yr of effluent to area groundwater. While the EIR states that the infiltration of effluent over the years has caused concentrations in groundwater of TDS, EC, and sodium to increase, the EIR states that the project would not affect public or private water supplies. The EIR identifies the project’s impact on groundwater as temporary, as the City “shall commit to developing a plan for the reclamation of water infiltrated at the plant by 1997.” The EIR further states that the City of Fresno “shall continue to develop and implement a reuse program for its treated wastewater to reduce the need for future infiltration basins. The EIR indicates the City “is also developing a reuse program for its treated wastewater to alleviate groundwater conditions under the treatment plant…[to]…mitigate the cumulative effects to water resources to a level of less than significant.” The City’s proposed mitigation measure must result in implementation of additional projects that recycle a total of at least 11,200 af/yr, but these projects have yet to be realized.
85. The project certified by the City of Fresno as described in the EIR differs from the project characterized in the Discharger’s 31 December 1996 Report of Waste of Discharge (RWD). The RWD describes a project in which the City would increase Plant 1’s treatment capacity to 88 mgd, continue use of Plant 2, and construct an additional 600 acres of disposal ponds. The increase in amount of effluent percolating from the project described in the RWD is nearly 25,000 af/yr, not the 11,200 af/yr identified in the EIR. Since submitting the RWD, the Discharger indicates that (a) it plans, as necessary, to treat some industrial flows in Plant 2 prior to full treatment in Plant 1; (b) the 80 mgd specified in the EIR represents the annual monthly average daily discharge flow; and (c) the EIR did not accurately reflect that Plant 1 would be designed, constructed, and operated WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -18-
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to treat a maximum monthly average daily discharge flow of 88 mgd. The additional 8 mgd shortterm treatment capacity accommodates seasonal peaks from food-processing industries that generally occur in September.
86. As described in Finding No. 16, Calpine proposes to recycle up to 7,000 af/yr of effluent extracted by reclamation wells. If Calpine completes its project utilizing extracted effluent, the Discharger will still need to implement reuse projects for an additional 4,200 af/yr to accomplish its goal of reusing the 11,200 af/yr discharge flow to groundwater resulting from the WWTF expansion project.
87. The Board, as a responsible agency under CEQA, has reviewed the City’s EIR for the project relative to impacts to groundwater quality and concurs that the increased percolation will have a significant effect on water quality by contributing to increases in salts and increasing the already dominant groundwater mound and affected geographic area. Further, the Board concurs that the City’s mitigation measure of implementing reuse projects to offset the project’s increase in flow (i.e., 11,200 af/yr) will mitigate the project’s potential incremental impact, but observes that the measure has yet to be implemented. Given that the full increase will be reached in 2008, the stated commitment of the City to mitigate, and applicable reclamation policies, full mitigation by 2004 is not unreasonable. Regardless, the scale of the reuse program is not sufficient to mitigate the same adverse water quality impacts occurring from the pre-project discharge, which must be evaluated by the Board in accordance with Resolution No. 68-16. The following provisions mitigate or avoid the adverse impact of the project on water quality: (a) annual monthly average daily discharge flow is limited to 80 mgd and maximum monthly average daily discharge flow is limited to 88 mgd (WWTF Discharge Specification B.1); reuse projects must recycle 11,200 af/yr by 2004 (Provision H.15); (c) water quality of private domestic and agricultural wells within the influence of the discharge must be evaluated (Provision H.18); and treatment and control practices must be evaluated along with consequent degradation of groundwater for consistency with Resolution No. 68-16 (Provisions H.12, H13, and H14).
88. On 25 March 1998, the City of Fresno adopted a negative declaration (Environmental Assessment 98-03), in accordance with CEQA and State CEQA Guidelines for the discharge of stillage to the 50-acre stillage disposal site (SS-2) adjacent to the existing 95-acre stillage disposal site (SS-1).
Mitigation measures 3 – 15 are identical to Stillage Discharge Specifications C.1 – C.13 from WDRs Order No. 96-054. The negative declaration does not adequately mitigate the potentially significant effect on groundwater from accumulation of nitrogen in stillage disposal area soils, nor adequately monitor the fate of waste constituents that percolate through the soil profile. The following provisions mitigate or avoid the adverse impact of the project on water quality: (a) planting and harvesting of crops will reduce the nitrogen content in soils (Stillage Disposal Specification D.1) and (b) vadose zone monitoring for waste constituents and their decomposition by-products will provide adequate monitoring (Monitoring and Reporting Program).
GENERAL FINDINGS
89. Section 13263 of the CWC authorizes the Board to prescribe discharge requirements that implement the Basin Plan and other applicable plans and take into consideration other factors, WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -19-
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including the factors in CWC section 13241, which includes economic considerations. The State Water Resources Control Board, however, has held that a regional board need not specifically address section 13241 factors when implementing existing water quality objectives in waste discharge requirements because the factors were already considered in adopting water quality objectives. These waste discharge requirements implement adopted water quality objectives.
Therefore, no additional analysis of the section 13241 factors is required.
90. Pursuant to CWC section 13263(g), discharge is a privilege, not a right, and adoption of this Order does not create a vested right to continue the discharge.
91. California Water Code (CWC) section 13267 authorizes the Board to require anyone who discharges waste that could affect the quality of water, as the Discharger does, to furnish, under penalty of perjury, technical and monitoring program reports.
92. The Board considered all the above and the supplemental information and details in the attached Information Sheet, which is incorporated by reference herein, in establishing the following conditions of discharge.
93. The Board has notified the Discharger and interested agencies and persons of its intent to prescribe waste discharge requirements for this discharge and has provided them with an opportunity for a public hearing and an opportunity to submit their written views and recommendations.
94. The Board, in a public meeting, heard and considered all comments pertaining to the discharge.
IT IS HEREBY ORDERED that Order No. 96-054 is rescinded and that, pursuant to CWC sections 13263 and 13267, the Cities of Fresno and Clovis, their agents, successors, and assigns, in order to meet the provisions contained in the Clean Water Act and Division 7 of the California Water Code and regulations adopted there under, shall comply with the following:
A. Discharge Prohibitions
1. Discharge of wastes from the WWTF and of stillage from the Stillage Site to surface waters or surface water drainage courses is prohibited.
2. Discharge of waste classified as “hazardous” as defined in section 2521(a) of Title 23, CCR, section 2510 et seq., or “designated” as defined in section 13173 of the California Water Code, is prohibited.
3. Bypass or overflow of untreated or partially treated waste from the WWTF to disposal ponds, to reclamation areas, or to the Stillage Site, is prohibited.
4. By 31 December 2003 discharge of stillage to SS-1 is prohibited.
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5. Discharge of stillage to areas within or beyond the WWTF property other than to the Stillage Site (as defined in Finding No. 39) without Board-adopted waste discharge requirements or waiver from said requirements is prohibited.
6. Discharge of effluent to areas outside of the WWTF property boundary without Boardadopted water reclamation requirements or waiver from said requirements is prohibited.
7. Grazing of animals producing milk for human consumption within areas irrigated with effluent is prohibited.
B. WWTF Discharge Specifications
1. The discharge flow from WWTF (i.e., the combined flow from Plant 1 and Plant 2 when in service and discharging directly to disposal ponds) shall not exceed:
a. an annual monthly average daily discharge flow of 80 mgd; and b. a maximum monthly average daily discharge flow of 88 mgd.
2. The discharge from Plant 1 (including that from Plant 2 when in service and discharging directly to disposal ponds) shall not exceed the following limits:
Constituent Units Monthly Average1 Daily Maximum
BOD5
2 mg/L 40 80
Total Suspended Solids (TSS) mg/L 40 80
Settleable Solids mL/L 0.2 0.5
1 Arithmetic mean of measurements made during the month 2 Five-day, 20° Celsius biochemical oxygen demand
3. The arithmetic mean of BOD5 and of total suspended solids in effluent samples collected over a monthly period shall not exceed 20 percent of the arithmetic mean of the values for influent samples collected at approximately the same times during the same period (80 percent removal).
4. The monthly average EC of the discharge, shall not exceed the flow-weighted average EC of the source water plus 500 µmhos/cm, or a maximum of 900 µmhos/cm, whichever is less.
The flow-weighted average for the source water shall be a moving average for the most recent twelve months.
5. The discharge shall not have a pH less than 6.0 or greater than 9.0.
6. Objectionable odors shall not be perceivable beyond the limits of the WWTF property at an intensity that creates or threatens to create nuisance conditions.
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7. Notwithstanding WWTF Discharge Specifications B.1 through B.6, no waste constituent shall be released or discharged, or placed where it will be released or discharged, in a concentration or in a mass that causes violation of Groundwater Limitations.
C. Disposal Pond Specifications
1. The dissolved oxygen content in the upper zone (1 foot) of effluent in disposal ponds shall not be less than 1.0 mg/L.
2. Disposal ponds shall be managed to prevent breeding of mosquitoes. In particular:
a. An erosion control program should assure that small coves and irregularities are not created around the perimeter of the water surface.
b. Weeds shall be minimized through control of water depth, harvesting, or herbicides. c. Dead algae, vegetation, and debris shall not accumulate on the water surface. d. Vegetation management operations in areas in which nesting birds have been observed shall be carried out either before or after, but not during, the 1 April to 30 June bird nesting season.
3. Public contact with effluent shall be precluded through such means as fences, signs, or acceptable alternatives. Signs shall be as shown in Attachment D, a part of this Order.
4. Disposal ponds shall have sufficient capacity to accommodate allowable discharge flow and design seasonal precipitation and ancillary inflow and infiltration, excluding effluent discharged as authorized by valid requirements to reclamation areas and to off-site effluent storage and disposal areas. Design seasonal precipitation shall be based on total annual precipitation using a return period of 100 years, distributed monthly in accordance with historical rainfall patterns. Freeboard shall never be less than two feet (measured vertically) or a lesser freeboard if certified in writing by a registered civil engineer as adequate to prevent overtopping, overflows, or levee failures.
5. On or about 15 November of each year, available disposal pond storage capacity shall at least equal the volume necessary to comply with Disposal Pond Specification C.4.
D. Stillage Discharge Specifications
1. Effective immediately, the Discharger shall commence regularly planting and harvesting crops in the Stillage Site to reduce the nitrogen content in stillage disposal area soils.
2. Objectionable odors originating from stillage disposal areas shall not be perceivable beyond the limits of the WWTF property boundary.
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3. The maximum daily stillage discharge shall not exceed the following limits:
Period of Year Maximum Discharge (mgd)
1 May to 30 Sep 1.36
1 Oct to 30 Nov 0.77
1 Dec to Apr 30 0.46
4. Stillage shall be discharged to land in long narrow checks or basins. The check or basin surface should be leveled within 0.1 foot per 100 feet and be free of potholes.
5. At the inlet of the checks, stillage shall be distributed using splash plates or other devices to prevent deep holes from forming.
6. The depth of applied stillage shall not exceed the following in any one application:
Period of Year Maximum Depth (inches)
1 May to 30 Sep 3.7
1 Oct to 30 Nov 3.0
1 Dec to Apr 30 2.5
7. Standing stillage shall not be present 24 hours after application has ceased.
8. Checks receiving stillage applications shall be allowed to dry for at least the following period before re-application of waste:
Period of Year Drying Time (days)
1 May to 30 Sep 6
1 Oct to 30 Nov 9
1 Dec to Apr 30 13
9. Land area used for disposal shall equal or exceed the following:
Period of Year
Land Area
(acres per 100,000 gpd of stillage waste)
1 May to 30 Sep 6
1 Oct to 30 Nov 9
1 Dec to Apr 30 13
10. Once applied stillage has dried, the Discharger shall remove leathers prior to re-application.
The Discharger shall store collected leathers in a manner that precludes infiltration of waste constituents into soils in a mass or concentration that will violate Groundwater Limitations.
Further, the Discharger shall dispose of collected leathers not recycled as a soil amendment WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -23-
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in a manner that precludes infiltration of waste constituents into soils in a mass or concentration that will violate Groundwater Limitations.
11. The resulting effect of the stillage discharge on soil pH shall be such as not to exceed the buffering capacity of the soil profile.
12. Soil depth in the Stillage Site shall be 10 feet or greater above unbroken hardpan, groundwater, or impermeable soils. There shall be no unripped hardpan within the top 10 feet of the soil profile.
E. Sludge Specifications
Sludge in this document means the solid, semisolid, and liquid residues removed during primary, secondary, or advanced wastewater treatment processes. Solid waste refers to grit and screening material generated during preliminary treatment. Residual sludge means sludge that will not be subject to further treatment at the WWTF. Biosolids refers to sludge that has undergone sufficient treatment and testing to qualify for reuse pursuant to federal and state regulations as a soil amendment for agriculture, silviculture, horticulture, and land reclamation.
1. Sludge and solid waste shall be removed from screens, sumps, ponds, clarifiers, etc. as needed to ensure optimal plant operation.
2. Treatment and storage of sludge generated by the WWTF and solids from the Operator’s stillage disposal operation (i.e., leathers) shall be confined to the WWTF property and conducted in a manner that precludes infiltration of waste constituents into soils in a mass or concentration that will violate Groundwater Limitations.
3. Any storage of residual sludge, solid waste (including stillage leathers), and biosolids on property of the WWTF shall be temporary and controlled and contained in a manner that minimizes leachate formation and precludes infiltration of waste constituents into soils in a mass or concentration that will violate Groundwater Limitations.
4. Residual sludge, biosolids, and solid waste shall be disposed of in a manner approved by the Executive Officer and consistent with Title 27. Removal for further treatment, disposal, or reuse at sites (i.e., landfill, WWTF, composting site, soil amendment sites) operated in accordance with valid waste discharge requirements issued by a regional water quality control board will satisfy this specification.
5. Use of biosolids as a soil amendment shall comply with General Biosolids Order (State Water Resources Control Board Water Quality Order No. 2000-10-DWQ, General Waste Discharge Requirements for the Discharge of Biosolids to Land for Use as a Soil Amendment in Agricultural, Silvicultural, Horticultural, and Land Reclamation Activities). The Discharger must obtain a “Notice of Applicability” of the General Biosolids Order from the Executive Officer prior to discharge of biosolids to any site. Alternatively, use of biosolids WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -24-
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as a soil amendment shall comply with valid waste discharge requirements issued by a regional water quality control board.
6. Use and disposal of biosolids should comply with the self-implementing federal regulations of 40 CFR 503, which are subject to enforcement by the U.S. Environmental Protection Agency (EPA), not the Board. If during the life of this Order the State accepts primacy for implementation of 40 CFR 503, the Board may also initiate enforcement where appropriate.
F. Reclamation Specifications
The following specifications apply to reclamation areas under the control of the Discharger within the WWTF property boundary. Other reclamation sites are covered by separate waste reclamation requirements.
1. Recycled water (i.e., effluent) shall remain within the Discharger’s on-site reclamation areas.
Recycled water provided off-site shall only be provided to users that hold Board-adopted water reclamation requirements, or users who have obtained a waiver of reclamation requirements from the Board.
2. Use of recycled water shall be limited to flood irrigation of fodder, fiber, seed crops, and of crops such as wine grapes that undergo extensive commercial, physical, or chemical processing before human consumption, and shall comply with the provisions of Title 22.
3. The Discharger shall maintain the following setback distances from areas irrigated with recycled water:
Setback Distance (feet) To
25 Property Line
30 Public Roads
50 Drainage courses
100 Irrigation wells
150 Domestic wells
4. No physical connection shall exist between recycled water piping and any domestic water supply or domestic well, or between recycled water piping and any irrigation well that does not have an air gap or reduced pressure principle device.
5. The perimeter of reclamation areas shall be graded to prevent ponding along public roads or other public areas.
6. Areas irrigated with recycled water shall be managed to prevent breeding of mosquitoes.
More specifically:
a. All applied irrigation water must infiltrate completely within a 48-hour period.
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b. Ditches not serving as wildlife habitat should be maintained free of emergent, marginal, and floating vegetation.
c. Low-pressure and unpressurized pipelines and ditches accessible to mosquitoes shall not be used to store recycled water.
7. Recycled water shall be managed to minimize runoff onto adjacent properties not owned or controlled by the Discharger.
8. Recycled water shall be managed to minimize contact with workers.
9. If recycled water is used for construction purposes, it shall comply with the most current edition of Guidelines for Use of Reclaimed Water for Construction Purposes. Other uses of recycled water not specifically authorized herein shall be subject to the approval of the Executive Officer and shall comply with Title 22.
10. Public contact with recycled water shall be precluded through such means as fences or acceptable alternatives. Signs with proper wording (shown below) of a size no less than four inches high by eight inches wide shall be placed at all areas of public access and around the perimeter of all areas used for effluent disposal or conveyance to alert the public of the use of recycled water. All signs shall display an international symbol similar to that shown in Attachment D, a part of this Order, and present the following wording:
“RECYCLED WATER—DO NOT DRINK”
“AGUA DE DESPERDICIO RECLAMADA—POR FAVOR NO TOME”
11. Reclamation of WWTF effluent shall be at reasonable agronomic rates considering the crop, soil, climate, and irrigation management plan. The annual nutrient loading of reclamation areas, including the nutritive value of organic and chemical fertilizers and of the recycled water, shall not exceed the crop demand.
G. Groundwater Limitations
Release of waste constituents from any storage, treatment, or disposal component associated with the WWTF shall not, in combination with other sources of the waste constituents, cause groundwater under and beyond the WWTF and discharge area(s) to exceed any of the following:
1. Constituent concentrations specified below or natural background concentration, whichever is greater:
a. Total coliform organisms of 2.2 MPN/100 mL.
b. Total nitrogen in excess of 10 mg/L.
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c. For constituents identified in Title 22 (as described in Finding No. 58), the MCLs quantified therein.
2. Constituent concentrations listed below or natural background concentration, whichever is greater:
Constituent Units Limitation
Boron mg/L 0.7
Chloride mg/L 106
EC µmhos/cm 990
Sodium mg/L 103
Total Dissolved Solids1 mg/L 560
1 A cumulative constituent comprised of dissolved matter consisting mainly of inorganic salts, small amounts of organic matter, and dissolved gases [e.g., ammonia, bicarbonate alkalinity, boron, calcium, chloride, copper, iron, magnesium, manganese, nitrate, phosphorus, potassium, sodium, silica, sulfate, total alkalinity]
3. Taste- or odor-producing substances in concentrations that cause nuisance or adversely affect beneficial uses, including but not limited to ammonia (as N) in excess of 0.5 mg/L, or natural background, whichever is greater.
4. Constituent concentrations identified as follows or natural background concentration, whichever is greater: toxic substances in concentrations that produce detrimental physiological responses in human, plant, or animal, or aquatic life; or chemical constituents and pesticides in concentrations that adversely affect beneficial uses.
H. Provisions
1. For purposes of day-to-day communication regarding compliance with terms of this Order, the Board will communicate directly with the City of Fresno. Correspondence and notifications between the Board and City of Fresno shall be as if to or from all parties identified in Finding No. 1 as “Discharger.”
2. The Discharger shall comply with the Standard Provisions and Reporting Requirements for Waste Discharge Requirements, dated 1 March 1991, which are attached hereto and by reference a part of this Order. This attachment and its individual paragraphs are commonly referenced as Standard Provision(s).
3. The Discharger shall comply with Monitoring and Reporting Program No. 5-01-254 that is part of this Order, and any revisions thereto as ordered by the Executive Officer.
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4. The Discharger shall submit to the Board on or before each report due date the specified document or, if an action is specified, a written report detailing evidence of compliance with the date and task. If noncompliance is being reported, the reasons for such noncompliance shall be stated, plus an estimate of the date when the Discharger will be in compliance. The Discharger shall notify the Board by letter when it returns to compliance with the time schedule.
5. By 15 April 2002, the Discharger shall submit a technical report describing a work plan for monitoring its stillage disposal operation. The technical report shall at a minimum describe:
a. The methods the Discharger will employ for determining the daily quantity of stillage discharge and the amount of acreage covered by the discharge on a daily basis. b. Alternatives for disposal should the Discharger be in threatened violation of any conditions of this Order.
c. The location, depths, and number of soil sampling points. d. Vadose zone monitoring procedures, specifically:
i) The location, depths, and number of vadose zone liquid sampling points. ii) The method for collecting samples of liquid percolating through the soil.
The technical report must be prepared by a qualified professional such as a California registered civil engineer, agricultural engineer, or a certified soil scientist experienced in land treatment of food processing wastewater. The Discharger shall implement the Stillage Site monitoring program within 30 days following Executive Officer approval of the technical report.
6. By 15 April 2002, the Discharger shall submit a sludge management plan that satisfies the information requirements of Attachment E, “Information Needs For Sludge Management Plan.” A California registered civil engineer experienced in sludge disposal must prepare and certify the sludge management plan. Following written approval of the sludge management plan from the Executive Officer, this Provision shall be considered satisfied.
7. By 15 July 2002, the Discharger shall complete a hydrogeologic investigation within the area affected and potentially affected by the WWTF and submit a technical report to the Executive Officer. The technical report, which shall be prepared and professionally certified by a geologist registered to practice in California, shall describe the underlying geology, existing wells (active and otherwise), local well construction practices and standards, well restrictions, and hydrogeology. The report shall recommend representative monitoring zones of the uppermost aquifer with consideration given to the Discharger’s existing data and provide a detailed evaluation of the existing monitoring well network. The recommendations shall be reviewed and approved as appropriate by the Executive Officer.
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8. Within 210 days following Executive Officer approval of representative monitoring zones in accordance with Provision H.7, the Discharger shall submit a technical report proposing a modified groundwater monitoring network. The technical report shall consist of a Monitoring Well Installation Work Plan for a network that satisfies Attachment F, “Standard Monitoring Well Provisions for Waste Discharge Requirements.” The network shall include one or more background wells and sufficient number of wells to evaluate performance of BPTC measures and to determine compliance with this Order’s Groundwater Limitations.
These include monitoring wells immediately downgradient of components that do or may release waste constituents to groundwater (e.g., disposal ponds, Stillage Site, former sludge drying bed area, biosolids storage areas). Every monitoring well shall comply with applicable Well Standards. Monitoring of wells constructed to yield representative samples from approved monitoring zones within the uppermost aquifer in accordance with this Order’s Monitoring and Reporting Program shall comprise the representative zone monitoring program. Implementation of the Monitoring Well Installation Work Plan shall be subject to the prior approval of the Executive Officer.
9. The Discharger shall comply with the following compliance schedule in implementing the groundwater monitoring network approved by the Executive Officer in Provision H.8:
Task Compliance Date
a. Implement Monitoring Well Installation
Work Plan
180 days following Work Plan approval by
Executive Officer
b. Complete Monitoring Well Installation 120 days following Work Plan implementation
c. Commence Groundwater Monitoring 30 days following completion of task 9.b d. Submit Monitoring Well Installation
Report of Results
60 days following completion of task 9.b
e. Submit technical report that characterizes
natural background water quality in
approved representative monitoring zones
for all monitored constituents
365 days following completion of task 9.d
Technical reports submitted pursuant to this Provision shall be prepared and certified by a California registered civil engineer or geologist, and are subject to Executive Officer approval.
10. Compliance with Groundwater Limitations will be evaluated based on the approved representative zone monitoring program following completion of Provision H.9, task e.
Should the Discharger fail to comply with the schedule to characterize natural background groundwater quality at the approved monitoring zone(s) by the date specified in Provision H.9, task e, the Board shall not consider the lack of natural background characterization as sufficient defense to enforcement for violations of Groundwater Limitations G.1 through G.4.
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11. By 15 October 2002, the Discharger shall submit a written work plan in the form of a technical report that sets forth a schedule for a systematic and comprehensive technical evaluation of each component of the WWTF’s waste treatment and control to determine for each waste constituent best practicable treatment and control as used in Resolution 68-16.
The technical report shall contain a preliminary evaluation of each component and propose a time schedule for completing the comprehensive technical evaluation. The technical report shall be prepared and certified by a California registered civil engineer. The schedule to complete all comprehensive technical evaluations shall be as short as practicable, and shall not exceed two years. Upon written determination of adequacy by the Executive Officer of the technical report, this Provision shall be considered satisfied.
12. By two years from satisfaction of Provision H.11, the written comprehensive technical evaluation shall be submitted with the Discharger’s written recommendations for any WWTF modifications (e.g., component upgrade and retrofit) and/or operational modifications that are necessary to ensure BPTC. Comprehensive technical evaluations shall be prepared and certified by a California registered civil engineer. The proposed schedule for modifications shall be identified. The schedule shall be as short as practicable but in no case shall completion of the necessary improvement exceed four years past the Executive Officer’s determination of the adequacy of the comprehensive technical evaluation submitted pursuant to this provision unless the schedule is reviewed and specifically approved by the Board.
The adequacy of the component evaluation, recommended improvements, and schedule are subject to the Executive Officer’s review and determination.
13. The groundwater limitations set forth in this Order are not final and not an entitlement.
By 15 June 2005, the Discharger shall submit a technical report that proposes specific numeric groundwater limitations for each waste constituent that reflects full implementation of BPTC and compliance with the most stringent applicable water quality objectives for that waste constituent. The report shall describe how these were determined considering actual data from monitoring wells comprising the approved representative zone monitoring program, impact reductions through full implementation of BPTC, reasonable growth, the factors in Water Code section 13241, State Water Resources Control Board Resolution No. 68-16, the Basin Plan, etc. The most stringent applicable water quality objective shall be interpreted based on the Regional Board policy entitled Application of Water Quality Objectives on pages IV-21 through IV-23 of the Basin Plan. Where the stringency of a proposed water quality objective can vary according to land use, the Discharger must provide documentation from similar third party government authorities that there is no potential for the more sensitive land use to occur, and the reason, if it wishes the Board to consider a proposed water quality objective, that provides protection for only less sensitive uses. The Board will consider the documentation and recommendation for the governing water quality objective, and it is this accepted value that will establish the maximum permissible groundwater limitation the Board will consider in Phase 2 evaluation. The Discharger may, at its discretion, submit results of a validated groundwater model or other hydrogeologic information to support its proposal.
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14. Upon completion of tasks set forth in Provisions H.12 and H.13, the Board shall consider the evidence provided and make a determination regarding (a) whether the Discharger has justified BPTC and (b) the appropriate final numeric groundwater limitations that comply with Resolution 68-16.
15. The Discharger shall expand its WWTF effluent reuse operation to recycle an additional 11,200 af/yr over that recycled currently (as described in Finding Nos. 8 and 12). This amount may include the 7,000 af/yr reuse project proposed by Calpine (described in Finding No. 16). The Discharger shall comply with the following time schedule in implementing additional reuse project(s):
Task Compliance Date
a. Submit technical report and
implementation schedule
15 October 2002
b. Submit Title 22 Engineering Report to
DHS
90 days following Executive Officer
approval of Task 15.a
c. Comply with CEQA 270 days following completion of Task 15.b d. Submit Report of Water Reclamation
for additional reuse project(s)
60 days following completion of Task 15.c
e. Implement additional reuse project(s) 110 days following completion of Task 15.d Reports submitted pursuant to Tasks a, b, d of this Provision shall be prepared and certified by a California registered civil engineer.
16. By 1 April 2002, the Discharger, in collaboration with FID, shall submit a technical report that (a) identifies the types and acreages of crops in the FID service area that receives groundwater extracted from the Operator’s reclamation wells and (b) provides information on the dilution of the extracted groundwater with fresh water prior to irrigation. The crop identification should provide information on fluctuations in cropping patters in the subject area. The dilution information should provide and interpret historic flow data of FID surface water deliveries to cropland receiving extracted groundwater for a range of water year types (e.g., drought, normal, and wet). The Discharger shall submit a copy of the technical report to DHS. Upon written approval of the Executive Officer of the technical report, this Provision shall be considered satisfied.
17. By 15 February 2002, the Discharger shall submit a technical report for Executive Officer approval that describes a work plan and implementation schedule for installing and operating continuous turbidity monitoring devices on representative reclamation wells for at least a one-year period. The Discharger shall submit a copy of the technical report to DHS. The Discharger shall implement continuous turbidity monitoring on approved representative WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -31-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
monitoring wells prior to the startup of reclamation well discharge in the spring 2002 irrigation season.
18. By 15 July 2002, the Discharger shall submit a technical report describing a work plan and implementation schedule for sampling a representative number of private domestic and agricultural wells in the 25-square-mile area surrounding and downgradient of the WWTF (as described in Finding No. 9). The technical report shall, at a minimum, include:
a. A map depicting the location of all individual and agricultural wells in the subject area. b. A map depicting the land use within the subject area. c. A map and listing of individual and agricultural wells proposed for sampling, and a justification of why each well was selected for sampling. d. The driller’s log for the selected wells.
e. A proposed list of monitored constituents, including, at a minimum, the following:
TDS, EC, general minerals (defined in the Monitoring and Reporting Program), nitrogen compounds (i.e., nitrate, nitrite, ammonia, organic nitrogen), total organic carbon, endocrine disrupting compounds, and pharmaceuticals. f. A thorough description of the sampling and testing protocol.
A California registered civil engineer or geologist shall certify the technical report. The Discharger shall submit a copy of the technical report to DHS. Within 30 days following Executive Officer written approval of the technical report, the Discharger shall commence sampling of approved domestic and agricultural wells and continue sampling in accordance with the approved work plan. Upon evaluation of submitted data, the Executive Officer may require the Discharger to sample additional wells.
19. By 15 July 2002, the Discharger shall submit a technical report describing a work plan and implementation schedule for an evaluation of the degree of soil treatment provided by the current recharge and extraction operation. The evaluation shall include, at a minimum, a determination of the level of filtration and virus removal treatment provided. A California registered civil engineer or geologist shall certify the technical report. The Discharger shall submit a copy of the technical report to DHS. Within 30 days following Executive Officer written approval of the technical report, the Discharger shall implement the work plan.
Within 120 days following the work plan implementation, the Discharger shall submit a technical report describing the results of the evaluation. The Discharger shall submit a copy of the technical report to DHS. Following written acceptance of the technical report by the Executive Officer, this Provision will be considered satisfied.
WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -32-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
20. By 1 March 2002, the Discharger shall submit a report for Executive Officer approval outlining EPA test methods and detection limits for priority pollutants listed in Title 40, Code of Federal Regulations, Part 131.
21. By 15 March 2002, the Discharger shall submit a technical report that shows whether the disposal ponds have adequate capacity for the 100-year annual rainfall at design flow of 80 mgd. The technical report shall also include a nutrient balance that estimates the amount of nitrogen (tons and lbs/acre) that will percolate annually to groundwater underlying the disposal ponds at the design flow. A California registered civil engineer must oversee and certify the technical report. Following written approval of the technical report from the Executive Officer, this Provision shall be considered satisfied.
22. At least 90 days prior to termination or expiration of any lease, contract, or agreement involving the Stillage Site, reclamation areas, or off-site reuse of effluent, used to justify the capacity authorized herein and assure compliance with this Order, the Discharger shall notify the Board in writing of the situation and of what measures have been taken or are being taken to assure full compliance with this Order.
23. The Discharger shall not allow pollutant-free wastewater to be discharged into the WWTF collection, treatment, and disposal systems in amounts that significantly diminish the system’s capability to comply with this Order. Pollutant-free wastewater means stormwater (i.e., inflow), groundwater (i.e., infiltration), cooling waters, and condensates that are essentially free of pollutants.
24. The Discharger shall use best practicable treatment or control, including proper operation and maintenance, to comply with terms of this Order.
25. Each User of recycled water who is farming lands within the WWTF property should receive appropriate employee training to assure proper operation of recycling facilities, worker protection, and compliance with this Order. The Operator and Users shall each designate a Recycled Water Supervisor responsible for compliance with these waste discharge requirements. The Recycled Water Supervisor shall be responsible for the avoidance of cross-connections during the installation, operation and maintenance of the reclamation area’s pipelines and equipment.
26. If the Board determines that waste constituents in the discharge have reasonable potential to cause or contribute to an exceedance of an objective for groundwater, this Order may be reopened for consideration of addition or revision of appropriate numerical effluent or groundwater limitations for the problem constituents.
27. The Discharger shall report to the Board any toxic chemical release data it reports to the State Emergency Response Commission within 15 days of reporting the data to the Commission pursuant to section 313 of the “Emergency Planning and Community Right to Know Act of 1986.”
WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -33-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
28. The Discharger shall comply with all pretreatment requirements contained in 40 CFR 403 and shall be subject to enforcement actions, penalties, fines, and other remedies by EPA or other appropriate parties, as provided in the CWA, as amended, and the CWA. The Discharger shall implement and enforce its approved Publicly-Owned Treatment Works (POTW) Pretreatment Program, which is hereby made an enforceable condition of these requirements. EPA may initiate enforcement action against an industrial user for noncompliance with applicable standards and requirements as provided in the CWA.
29. The Discharger shall enforce the requirements promulgated under Sections 307(b), (c), (d), and 402(b) of the CWA. The Discharger shall cause industrial users subject to federal categorical standards to achieve compliance no later than the date specified in those requirements or, in the case of a new industrial user, upon commencement of the discharge.
30. The Discharger shall perform the pretreatment functions required in 40 CFR 403, including, but not limited to:
a. Implementing the necessary legal authorities as provided in 40 CFR 403.8(f)(1); b. Enforcing the pretreatment requirements under 40 CFR 403.5 and 403.6; c. Implementing the programmatic functions as provided in 40 CFR 403.8(f)(2); d. Providing the requisite funding and personnel to implement the pretreatment program as provided in 40 CFR 403.8(f)(3);
e. Publishing a list of industrial users that were in significant noncompliance of applicable pretreatment requirements as required by 40 CFR 403.8(f)(2)(vii); and f. Conducting inspections in accordance with provisions of 40 CFR 403.8(f)(1)(v) and 403.8(f)(2)(v) and ensuring compliance with pretreatment standards and requirements by (1) assessing and collecting, when appropriate, civil penalties and civil administrative penalties in accordance with Government Code Sections 54740, 54740.5, and 54740.6, or (2) other equally effective means.
31. In the event of any change in control or ownership of land or waste discharge facilities described herein, the Discharger shall notify the succeeding owner or operator of the existence of this Order by letter, a copy of which shall be immediately forwarded to this office. To assume operation under this Order, the succeeding owner or operator must apply in writing to the Executive Officer requesting transfer of the Order. The request must contain the requesting entity's full legal name, the state of incorporation if a corporation, the name and address and telephone number of the persons responsible for contact with the Board, and a statement. The statement shall comply with the signatory paragraph of Standard Provision B.3 and state that the new owner or operator assumes full responsibility for compliance with this Order. Failure to submit the request shall be considered a discharge WASTE DISCHARGE REQUIREMENTS ORDER NO. 5-01-254 -34-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
without requirements, a violation of the California Water Code. Transfer shall be approved or disapproved by the Executive Officer.
32. The Discharger must comply with all conditions of this Order, including timely submittal of technical and monitoring reports as directed by the Executive Officer. Violations may result in enforcement action, including Board or court orders requiring corrective action or imposing civil monetary liability, or in revision or rescission of this Order.
33. A copy of this Order shall be kept at the discharge facility for reference by operating personnel. Key operating personnel shall be familiar with its contents.
34. The Board will review this Order periodically and will revise requirements when necessary.
I, GARY M. CARLTON, Executive Officer, do hereby certify the foregoing is a full, true, and correct copy of an Order adopted by the California Regional Water Quality Control Board, Central Valley Region, on 19 October 2001.
GARY M. CARLTON, Executive Officer
Order Attachments:
Monitoring and Reporting Program No.
A: Vicinity Map
B: Plant 1 Diagrammatic Layout
C: Plant 2 Diagrammatic Layout
D: Symbol For Recycle Water Signs
E: Information Needs for Sludge Management Plan
F: Standard Monitoring Well Provisions for Waste Discharge Requirements G: Recommended Recycled Water Monitoring Form
Information Sheet
Standard Provisions (1 March 1991 version) (separate attachment to Discharger only) BLH:jlk:fmc 10/19/01 AMENDED
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
CENTRAL VALLEY REGION
ORDER NO. 5-01-254
MONITORING AND REPORTING PROGRAM
FOR
CITIES OF FRESNO AND CLOVIS
WASTEWATER TREATMENT FACILITY
FRESNO COUNTY
This Monitoring and Reporting Program (MRP) is issued pursuant to Water Code Section 13267. The Discharger shall not implement any changes to this MRP unless and until a revised MRP is issued by the Executive Officer. Sample station locations are depicted on Attachments B and C. Changes to sample location shall be established with concurrence of Board’s staff, and a description of the revised stations shall be submitted to the Board and attached to this Order. All samples should be representative of the volume and nature of the discharge or matrix of material sampled. The time, date, and location of each sample shall be recorded on the sample chain of custody form.
WWTF INFLUENT MONITORING
Samples shall be collected at the headworks and should be representative of the influent for the period sampled. Time and date of collection of samples shall be recorded. Influent monitoring shall include at least the following:
Constituent Units Type of Sample Sampling Frequency
Maximum Daily Flow mgd Continuous Daily
Average Daily Flow mgd Continuous Daily
Monthly Average Flow mgd Computed Monthly
Annual Monthly Average Daily
Flow1 mgd Computed Monthly
Settleable Solids mL/L Grab 2/week2
pH pH units Continuous Daily4
BOD5
2 mg/L 24-hr Composite 2/week3
Monthly Average BOD5 mg/L Calculated Monthly
Total Suspended Solids mg/L 24-hr Composite 2/week3
Monthly Average TSS mg/L Calculated Monthly
1 Based on the previous twelve months
2 Five-day biochemical oxygen demand at 20ºC
3 Nonconsecutive days
4 Median value for 24-hour period
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -2-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
WWTF DISCHARGE MONITORING
Effluent samples shall be collected just prior to discharge to the disposal ponds and should be representative of the volume and nature of the discharge. Time of collection of composite and grab samples shall be recorded. Effluent monitoring from Plant 1 (and from Plant 2 when in operation and discharging directly to disposal ponds) shall include at least the following:
Constituent Units Type of Sample Sampling Frequency1
pH pH Units Continuous Daily2
Settleable Solids mL/L Grab 2/Week3
BOD5
Concentration mg/L 24-hr Composite 2/Week3
Monthly Average mg/L Calculated Monthly
Percent Removal % Calculated Monthly
Total Suspended Solids
Concentration mg/L 24-hr Composite 2/Week3
Monthly Average mg/L Calculated Monthly
Percent Removal % Calculated Monthly
Total Dissolved Solids (TDS)4
mg/L 24-hr Composite Weekly5
EC6 µmhos/cm 24-hr Composite 2/Weekly
Chloride mg/L 24-hr Composite 2/Week3,5
Ammonia Nitrogen (as NH3-N) mg/L 24-hr Composite Weekly Nitrate Nitrogen (as NO3-N) mg/L 24-hr Composite Weekly Nitrite Nitrogen (as NO2-N) mg/L 24-hr Composite Weekly Total Kjeldahl Nitrogen (TKN) mg/L 24-hr Composite Weekly Total Nitrogen mg/L Calculated7
Weekly
General Minerals8 mg/L 24-hr Composite Quarterly9
Metals10,11 µg/L 24-hr Composite Semiannually12
Priority Pollutants13 µg/L Grab Semiannually12,14
1 If results of monitoring a pollutant appear to violate discharge specifications, but monitoring frequency is not sufficient to validate violation (e.g., the monthly mean for BOD5), or indicate a violation and potential upset of the treatment process (e.g., less than minimum dissolved oxygen concentration), the frequency of sampling shall be increased to confirm the magnitude and duration of violation, if any, and aid in identification and resolution of the problem.
2 Median value for 24-hour period
3 Nonconsecutive days
4 TDS as referred to in this program shall be determined using EPA Method No. 160.1 for combined organic and inorganic TDS and EPA Method No. 160.4 for inorganic. 5 Concurrent with EC sampling (i.e., on the same day)
6 Conductivity at 25º
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -3-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
7 Total Nitrogen as referred to in this program shall be calculated as : TKN + NO2-N + NO3-N 8 General Minerals as referred to in this program shall include the constituents in the Analyte listed below. 9 January, April, July, and October
10 Metal analyses as referred to in this program shall include aluminum arsenic, barium, copper, cadmium, chromium, lead mercury, molybdenum, selenium, silver, zinc, and nickel. 11 Samples shall pass through a 0.45 !m filter prior to analysis. 12 April and October, coincident with general minerals analyses 13 The Discharger must submit a report for approval by 1 March 2002 outlining EPA test methods and detection limits for priority pollutants listed in Title 40, Code of Federal Regulations, Part 131). 14 Sampling to commence in April 2002
General Minerals Analyte List
Alkalinity (as CaCO3), unfiltered Phosphorus, total dissolved (P) Boron Hardness (as CaCO3), calculated Potassium
Bicarbonate (as CaCO3), unfiltered Iron Sodium
Calcium Magnesium Sulfate
Carbonate (as CaCO3), unfiltered Manganese
Sample Collection and Preservation: Any sample placed in an acid-preserved bottle must first be filtered through a 0.45 µm nominal pore size filter. If field filtering is not feasible, samples shall be collected in unpreserved containers and submitted to the laboratory within 24-hours with a request (on the chain-of-custody form) to filter immediately then preserve the sample.
DISPOSAL POND MONITORING
Disposal pond monitoring shall include at least the following:
Constituent/Parameter Unit Type of Sample Sampling Frequency1 Dissolved Oxygen (DO) mg/L Grab2 As Required3
Temperature °C Grab As Required4
Freeboard feet5
Observation
External Disposal Ponds Daily
Internal Disposal Ponds Weekly6
1 If results of monitoring appear to violate Disposal Pond Specifications, but monitoring frequency is not sufficient to validate violation or indicate a violation and potential upset of the treatment process (e.g., less than minimum dissolved oxygen concentration), the frequency of sampling shall be increased to confirm the magnitude and duration of violation, if any, and aid in identification and resolution of the problem. 2 Samples shall be collected at a depth of one foot from each pond in use, opposite the inlet, and analyzed for DO. Samples shall be collected between 0700 and 0900 hours. 3 If offensive odor detected by or brought to the attention of WWTF personnel, monitor affected pond(s) daily until dissolved oxygen > 1.0 mg/L. If DO results for any pond in use indicate noncompliance with Disposal Pond Specification C.1, the Discharger shall implement corrective measures as specified in the O&M manual and monitor said pond daily until its DO stabilizes above 1.0 mg/L. 4 Concurrent with DO monitoring
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -4-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
5 For freeboard measurements greater than 2 feet, estimate to nearest half foot. For freeboard measurements less than 2 feet, estimate to nearest quarter foot.
6 At least once every seventh calendar day on nonconsecutive days Markers (e.g., staff gages) shall be placed in disposal ponds adjacent to public roads, private properties, and surface waters. The markers shall have calibrations indicating the water level at design capacity and available operational freeboard. The Discharger shall inspect all disposal ponds daily to determine compliance with Disposal Pond Specification D.4, which requires freeboard of all disposal ponds to never be less than two feet (measured vertically). In addition, the Discharger shall inspect the condition of the disposal ponds in use daily and write visual observations of developing potential problems in a bound logbook. Notations shall include observations of whether weeds are developing in the water or along the bank, and their location; whether dead algae, vegetation, scum, or debris are accumulating on the disposal pond surface and their location; whether burrowing animals or insects are present; and the general color of effluent in the disposal pond. A summary of entries made in the log during each month shall be submitted along with the monitoring report the following month. The Discharger shall certify in each November monitoring report that it is in compliance with Disposal Pond Specification C.5.
RECLAMATION OPERATION MONITORING
The type of crop(s) irrigated, amounts of water and/or reclaimed water applied to the crops(s) (in acrefeet) and amounts of sludge and chemical fertilizers (in pounds of nitrogen per acre) shall be measured and reported to the Board quarterly in accordance with the following schedule:
Monitoring Period Reports Due
January – March 1 May
April – June 1 August
July – September 1 November
October – December 1 February
The Discharger shall utilize the form presented in Attachment G (or variation thereof subject to Board staff approval) for reporting the reclamation area monitoring data.
STILLAGE DISCHARGE MONITORING
The areas of land utilized for stillage disposal shall be reported monthly. Additionally, a sampling station shall be established where a representative sample of the stillage can be obtained. Stillage discharge monitoring shall include at least the following:
Constituent Units Type of Sample Frequency
Flow mgd Measured Daily
pH pH units Grab Weekly
BOD5, total mg/L Grab Weekly
BOD5, soluble mg/L Grab Weekly
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -5-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
Constituent Units Type of Sample Frequency
COD, total mg/L Grab Weekly
COD, soluble mg/L Grab Weekly
Total Suspended Solids mg/L Grab Weekly
Volatile Suspended Solids mg/L Grab Weekly
Total Kjeldahl Nitrogen (TKN) mg/L Grab Weekly
Nitrate Nitrogen (as NO3-N) mg/L Grab Monthly1
Total Nitrogen mg/L Calculated Monthly1
Total Phosphorus (P) mg/L Grab Monthly1
Total Organic Carbon (TOC) mg/L Grab Monthly1
Carbon/Nitrogen/Phosphorus ratio --- Calculated Monthly1 EC µmhos/cm Grab Monthly1
TDS mg/L Grab April, October
1 Coincident with time of weekly sample
STILLAGE SITE APPLICATION MONITORING
Constituent Units Type of Sample Frequency
Precipitation1inches Rain gauge Daily
Flow mgd Measured Daily
Area acres Measured Daily
Drying Time2
days Calculated Per Application
BOD5, maximum3lbs/acre/day Calculated Monthly
BOD5, average4lbs/acre/ day Calculated Weekly
Total Kjeldahl Nitrogen (TKN)5 lbs/acre/day Calculated Monthly 1 On-site rain gauge, National Weather Service, or California Irrigation Management Information System 2 Report per active application area
3 Maximum daily BOD5 loading rate shall be calculated using the total volume of stillage applied on the day of application, estimated daily application area, and a running average of the three most recent results of BOD5, which shall also be reported along with supporting calculations. 4 Average BOD5 loading rate shall be calculated using the total volume of stillage applied on the day of application, the total application period (i.e., day of application and drying time), estimated application area on day of application, and a running average of the three most recent results of BOD5, which shall also be reported along with supporting calculations. 5 Loading rate for nitrogen shall be calculated using the daily applied load and the estimated daily application area.
STILLAGE SITE SOILS MONITORING
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -6-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
The Discharger shall inspect and document the condition of the Stillage Site at least once a week.
Notations should be made in a bound log book and include observations on whether ponding waste, soil clogging, odors, insects, or other potential nuisance conditions are present. The notations shall also document any corrective actions taken. A summary of entries made in the log during each month shall be submitted along with the monitoring report the following month.
The Discharger shall establish representative soil surface and soil profile monitoring locations within and outside the Stillage Site. There shall be at least one monitoring location per 20 acres. The samples shall be collected and analyzed for at least the following constituents:
Constituent Units Sample1
Frequency
Soil pH pH Units Grab Semiannually2
Total Alkalinity (as CaCO3) mg/kg Grab Semiannually2
Cation Exchange Capacity meq/100 grams Grab Semiannually2 Total Phosphorus (P) mg/kg Grab Semiannually2
Nitrate Nitrogen (as NO3-N) mg/kg Grab Semiannually2
Total Kjeldahl Nitrogen (TKN) mg/kg Grab Semiannually2
Total Nitrogen mg/kg Calculated Semiannually2
1 Samples shall be collected at 0.5, 1, 2, 3-foot depths. 2 April and October
STILLAGE SITE VADOSE ZONE MONITORING
The Discharger shall establish representative vadose monitoring locations in the Stillage Site in accordance with the approved work plan required by Provision H.5. The samples shall be collected and analyzed for at least the following constituents:
Method Constituent Minimum Sample (mL) Frequency
pH 5 Twice/year1
EC 10 Twice/year1
EPA 351.3 or
4500N-org
TKN 20 Twice/year1
EPA 300.0 Nitrate 20 Twice/year1
Phosphorus Twice/year1
Sulfate Twice/year1
Chloride Twice/year1
EPA 200.7 Calcium 5 Twice/year1
Iron Twice/year1
Magnesium Twice/year1
Manganese Twice/year1
Potassium Twice/year1
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -7-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
Method Constituent Minimum Sample (mL) Frequency
EPA 310.1
Total Alkalinity 20 Twice/year1
EPA 415.1 TOC 150 Twice/year1
1 In accordance with the vadose zone monitoring program described in the Discharger’s approved work plan for monitoring its stillage disposal operation (Provision H.5).
GROUNDWATER MONITORING
Prior to collecting samples, the monitoring well shall be adequately purged to remove water that has been standing within the well screen and casing that may not be chemically representative of formation water. Depending on the hydraulic conductivity of the geologic setting, the volume removed during purging is typically from 3 to 5 volumes of the standing water within the well casing and screen, or additionally the filter pack pore volume.
At least quarterly and concurrently with groundwater quality sampling, the Discharger shall in each well measure groundwater level and report the data as groundwater depth (in feet and hundredths) and as groundwater surface elevation (in feet and hundredths above mean sea level). The horizontal geodetic location for each monitoring well shall be provided where the point of beginning shall be described by the California State Plane Coordinate System, 1983 datum.
Samples shall be collected from approved monitoring wells and analyzed for the following constituents at the following frequency:
Constituent Units Type of Sample Frequency
Total Coliform Organisms MPN/100 mL Grab Quarterly1
Total Organic Carbon (TOC) mg/L Grab Quarterly1
Ammonia Nitrogen (as NH3-N) mg/L Grab Quarterly1
Nitrate Nitrogen (as NO3-N) mg/L Grab Quarterly1
Total Kjeldahl Nitrogen (TKN) mg/L Grab Quarterly1
Total Organic Nitrogen (as N) mg/L Calculated Quarterly1 EC µmhos/cm Grab Quarterly1
Total dissolved solids (TDS) mg/L Grab Quarterly1
General Minerals mg/L Grab Quarterly1
Metals2
µg/L Grab Quarterly1
Dissolved Oxygen mg/L Grab Quarterly1
Oxidation-Reduction Potential mV Grab Quarterly1
1 January, April, July and October
2 Samples shall pass through a 0.45 µm filter prior to analysis.
In reporting the results of the first sampling event pursuant to this MRP, the Discharger shall include a MONITORING AND REPORTING PROGRAM NO. 5-01-254 -8-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
detailed description of the procedures and techniques for: (a) sample collection, including purging techniques, sampling equipment, and decontamination of sampling equipment; (b) sample preservation and shipment; (c) analytical procedures; and (d) chain of custody control.
EXTRACTED GROUNDWATER MONITORING
Prior to collecting samples, the reclamation well shall be adequately purged to remove water that has been standing within the well screen and casing that may not be chemically representative of formation water. Depending on the hydraulic conductivity of the geologic setting, the volume removed during purging is typically from 3 to 5 volumes of the standing water within the well casing and screen, or additionally the filter pack pore volume. Samples shall be collected from the reclamation wells and analyzed for the following constituents at the following frequency:
Constituent / Parameter Units Type of Sample Frequency
Flow million gallons metered Monthly
acre-feet Calculated Monthly
Total Coliform Organisms MPN / 100 mL Grab Quarterly1
Total Dissolved Solids (TDS) mg/L Grab Quarterly
1 pH pH Units Grab Quarterly1
EC µmhos/cm Grab Quarterly1
Total Kjeldahl Nitrogen (TKN) mg/L Grab Quarterly
1 Ammonia Nitrogen (as NH3-N) mg/L Grab Quarterly1
Nitrate Nitrogen (as NO3-N) mg/L Grab Quarterly1
Total Nitrogen mg/L Calculated Quarterly1
Total Phosphorus (P) mg/L Grab Quarterly1
Chloride mg/L Grab Quarterly1
General Minerals mg/L Grab Semiannually2
Total Organic Carbon (TOC) mg/L Grab Semiannually
2 Metals3 µg/L Grab Semiannually2
1 January, April, July and October
2 April and October, coincident with general minerals
3 Samples shall pass through a 0.45 µm filter prior to preservation.
PRETREATMENT MONITORING
The Discharger shall submit an annual report to the Board, with copies to the U.S. Environmental Protection Agency (EPA) Regional Administrator and the State Water Resources Control Board, describing the Discharger’s pretreatment activities over the previous 12 months. In the event that the Discharger is not in compliance with any conditions or requirements of this Order, the Discharger shall include the reasons for the noncompliance and state how and when the Discharger shall comply with such conditions and requirements. This annual report shall be submitted by 28 February and shall contain, but not be limited to item E.7 of Standard Provisions and Reporting Requirements for Waste MONITORING AND REPORTING PROGRAM NO. 5-01-254 -9-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
Discharge Requirements, dated 1 March 1991 (Standard Provisions).
Signed copies of the reports shall also be submitted to the EPA Regional Administrator and the State Board at the following addresses, or as advised in writing subsequent to adoption of this Order:
Regional Administrator
U.S. EPA, Region 9
Water Management Division (W-5-2)
75 Hawthorne Street
San Francisco, CA 94105
Pretreatment Program Manager
Division of Water Quality
State Water Resources Control Board
P.O. Box 944213
Sacramento, CA 94244-2130
BIOSOLIDS MONITORING
To monitor whether discharges to the WWTF are interfering with the treatment process or lessening biosolids quality, the Discharger shall collect monthly composite samples of sludge in accordance with EPA's POTW Sludge Sampling And Analysis Guidance Document, August 1989, Test Methods for Evaluating Solid Waste, Physical Chemical Methods (SW-846). Monthly the Discharger shall submit a certification statement for biosolids classification, how the pathogen reduction and the vector reduction were met. Supporting documentation and analytical results must be submitted with the certification.
The certification statement and report shall be submitted to the Executive Officer.
Biosolids monitoring shall include the following:
Constituent1
Sampling
Frequency2 Constituent1
Sampling
Frequency2
pH Monthly Molybdenum Monthly
Total Solids Monthly Nickel Monthly
Total Nitrogen Monthly Selenium Monthly
Nitrate Nitrogen (as NO3-N) Monthly Silver Monthly
Ammonia Nitrogen (as NH3-N) Monthly Zinc Monthly
Total Phosphorus (P) Monthly Fecal Coliform3 Monthly
Potassium Monthly Vector Reduction3 Monthly
Arsenic Monthly Salmonella4 Quarterly5
Cadmium Monthly Enteric Viruses4 Quarterly5
Chromium Monthly Helminth Ova4 Quarterly5
Cobalt Monthly Semi-Volatile Organics Quarterly5
Copper Monthly Pesticides Quarterly5
Lead Monthly PCBs Quarterly5
Mercury Monthly
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -10-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
Constituent1
Sampling
Frequency2 Constituent1
Sampling
Frequency2
1 In metal analyses, ICAP may not be used for arsenic, mercury, and selenium. 2 The Discharger shall sample for these parameters at the specified frequency if biosolids are to be landapplied. 3 If biosolids are classified as Class B and land applied and do not meet 40 CFR 503 Alternatives for Processes to Significantly Reduce Pathogens (PSRP) or Processes to Further Reduce Pathogens (PFRP). Vector reduction as defined in 40 CFR 503.33(b)(1) through 503.33(b)(8). 4 If biosolids are classified as Class A.
5 January, April, July, and October
WATER SUPPLY MONITORING
Discharger shall utilize its computerized database of the production from municipal wells supplying the cities of Fresno and Clovis. The chemical analysis shall be the most recent analysis in accordance with Title 22 requirements. The flow weighted average concentration shall be calculated and reported for each mineral listed in the following table. The electronic form of the data shall accompany the written calculations.
Constituent1
Units Reporting Frequency2
Total Dissolved Solids mg/L Quarterly3
EC µmhos/cm Quarterly3
1 Constituents shall be reported as a flow-weighted average of all wells during the quarter. 2 Moving average shall include the most recent analysis for each well. 3 January, April, July, October.
REPORTING
Monthly monitoring reports containing samples collected at frequencies of monthly or greater shall be submitted to the Board by the 1
st day of the second month following sampling. Quarterly reports shall be submitted to the Board by the 1
st day of the second month following the calendar quarter.
In reporting the monitoring data, the Discharger shall arrange the data in tabular form so that the date, the constituents, and the concentrations are readily discernible. The data shall be summarized in a manner that illustrates clearly whether the Discharger complies with waste discharge requirements, including calculation of all averages, etc. If any pollutant is monitored at the locations designated herein more frequently than is required by this Order, the results of such monitoring shall be included in the calculation and reporting of the values required in the discharge monitoring report form. Such increased frequency shall be indicated on the discharge monitoring report form. Monthly and quarterly monitoring reports shall discuss the compliance record for the reporting period. If violations have occurred, the report shall also discuss the corrective actions taken and planned to bring the discharge into full compliance with this Order.
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -11-
CITIES OF FRESNO AND CLOVIS WWTF
FRESNO COUNTY
The Discharger may also be requested to submit an annual report to the Board with tabular and graphical summaries of the monitoring data obtained during the previous year. Any such request shall be made in writing. The report shall discuss the corrective actions taken and planned to bring the discharge into full compliance with the waste discharge requirements.
By 1 February of each year, the Discharger shall submit a written Annual Report to the Executive Officer containing the following:
1. The names, certificate grade and general responsibilities of persons operating and maintaining the wastewater treatment plant (Standard Provision E.1).
2. The names and telephone numbers of (a) persons to contact regarding plant emergency and routine situations and (b) persons designated as Recycled Water Supervisors.
3. A statement certifying when the flow meter and other monitoring instruments and devices were last calibrated, including identification of who performed the calibration (Standard Provision C.4).
4. A statement identifying whether the current operation and maintenance manual, and contingency plan, reflect the wastewater treatment plant as currently constructed and operated, and the dates when these documents were last reviewed for adequacy.
5. The results of an evaluation conducted pursuant to Standard Provision E.4 and a figure depicting monthly average discharge flow for the past five years.
6. A statement describing whether the disposal ponds have adequate capacity for a 100-year rainfall at a design flow of 80 mgd. The statement shall include a summary of disposal pond monitoring of percolation rates for the previous year. The summary shall describe the method(s) used to determine percolation rates and shall include for each disposal pond. a. Period during which percolation rate was determined (i.e., initial and final dates) b. Measured percolation rate and calculated percolation rate (adjusted for evaporation losses) in inches/day
7. The most recent Annual Water Supply Report for the City of Fresno.
8. A summary of onsite reclamation operations for the previous water year (i.e., from October through September). The summary shall discuss total monthly water application; total wastewater recycled annually; total nutrient loading annually from applied wastewater, biosolids, and chemical fertilizers; and total estimated amount of nutrients removed through crop harvest. In short, the summary shall present a mass balance relative to constituents of concern and hydraulic loading along with supporting data and calculations. The summary shall also include a tabulation and interpretation of analytical results of reclamation soil monitoring.
MONITORING AND REPORTING PROGRAM NO. 5-01-254 -12-
CITIES OF FRESNO AND CLOVIS WWTF