Appendix I2
Priority Development Project Stormwater Quality
Management Plan
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CHUIA VISfA
PDPSWQMP
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
P . N Yards at the Bay roJect ame ____________ _
A , p 1 N b ( ) 571-330-36 Through 571-330-45 ssessor s arce um er s P · A Ii · N b City of Chula Vista TMP# __ , CDP# ernut pp cation um er -- Drawing Numbers ______________ _
Chelisa Pack 71026
CIVIL ENGINEER NAME: ________________ ; PE# ___ _
Wet Signature and Stamp
PREPARED FOR:
WOHL Property Group Applicant Name: ______________ _
2251 San Diego Avenue, Suite A247 Address: ________________ _ (619) 296-4113
T 1 h # 858. 794.2500
e ep one
PREPARED BY: Project Design Consultants
Company Name: ______________ _
Add 701 B Street, Suite 800
ress: ________________ _
San Diego, CA 9211 O
619-235-6471 Telephone# _______________ _
DATE: August 1st 2023
Approved By: City of Chula Vista
(print Name & Sign)
P:\4508\Engr\Reports\SWQMP-Prelim
Job# 4508
Date:
PDP SWQMP Template Date: March 2019
Page intentional!J left blank for double-sided printing Yards at the Bay
Project Name/ ____________________________ _
TABLE OF CONTENTS
The checklist on this page summarized the table and attachments to be included with this PDP SWQMP Submittal. Tables & attachments with boxes already checked ( ✓ ) are required for all Projects [j Acronym Sheet
[j Certification Page
Iii Submittal Record
[j Project Vicinity Map
[j Attach a copy of the Intake Form: Storm Water Requirements Applicability Checklist [j HMP Exemption Exhibit (if Applicable)
Iii FORM I-3B Site Information Checklist for PDPs
Iii FORM 1-4: Source Control BMP Checklist for All Development Projects Iii FORM 1-5: Site Design BMP Checklist for All Development Projects Iii FORM 1-6: Summary of PDP Structural BMPs
Iii ATTACHEMNT 1: Backup for PDP Pollutant Control BMPs Attachment 1A: DMA Exhibit
Attachment 1B: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1C: FORM 1-7 Harvest and Use Feasibility Screening (when applicable) Attachment 1D: Infiltration Information Attachment 1E: Pollutant Control BMP Design Worksheets/ Calculations for each DMA and Structural BMP Worksheets from Appendix B, as applicable
Iii ATTACHMENT 2: Backup for PDP Hydromodification Control Measures ► Attachment 2A: Hydromodification Management Exhibit
► Attachment 2B: Management of Critical Coarse Sediment Yield Areas ► Attachment 2C: Geomorphic Assessment of Receiving Channels ► Attachment 2D: Flow Control Facility Design; Overflow Design Summary for each structural BMP
Iii ATTACHMENT 3: Structural BMP Maintenance Plan
[j ATTACHMENT 4: Copy of Plan Sheets Showing Permanent Storm Water BMPs [j ATTACHMENT 5: Project's Drainage Report
Iii ATTACHMENT 6: Project's Geotechnical and Groundwater Investigation Report CCV BMP Manual
PDP SWQMP Template Date: March 2019
CllYOf
CHULA VISTA
Yards at the Bay
Project Name/ ____________________________ _
ACRONYMS
APN Assessor's Parcel Number
BMP Best Management Practice
HMP Hydromodification Management Plan
HSG Hydrologic Soil Group
MS4 Municipal Separate Storm Sewer System
N/ A Not Applicable
NRCS Natural Resources Conservation Service
PDP Priority Development Project
PE Professional Engineer
SC Source Control
SD Site Design
SDRWQCB San Diego Regional Water Quality Control Board
SIC Standard Industrial Classification
SWQMP Storm Water Quality Management Plan
CCV BMP Manual
PDP SWQMP Template Date: March 2019
CllYOf
CHULA VISTA
Yards at the Bay
Project Name/ _____________________________ _
Certification Page
Project Name: Yards at the Bay
Permit Application Number: __________________ _
I hereby declare that I am the Engineer in Responsible Charge of design of storm water best management practices (BMPs) for this project, and that I have exercised responsible charge over the design of the BMPs as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the PDP requirements of the City of Chula Vista BMP Design Manual, which is based on the requirements of the San Diego Regional Water Quality Control Board Order No. R9- 2013-0001 as amended by R9-2015-0001 and R9-2015-0100 (MS4 Permit).
I have read and understand that the City Engineer has adopted minimum requirements for managing urban runoff, including storm water, from land development activities, as described in the BMP Design Manual. I certify that this PDP SWQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this PDP SWQMP by the City Engineer is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of storm water BMPs for this project, of my responsibilities for project design.
Engineer of Work's Signature
71026
PE#
Chelisa Pack
Print Name
Project Design Consultants
Company
CCV BMP Manual
PDP SWQMP Template Date: March 2019
6/30/25
Expiration Date
Date
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CHUIAVISTA
Yards at the Bay
Project Name/ ____________________________ _
SUBMITTAL RECORD
Use this Table to keep a record of submittals of this PDP SWQMP. Each time the PDP SWQMP is re-submitted, provide the date and status of the project. In column 4 summarize the changes that have been made or indicate if response to plancheck comments is included. When applicable, insert response to plancheck comments behind this page.
Submittal Date Project Status
Number
1 ii Preliminary Design / 08/01/2023 Planning/ CEQA
□ Final Design
2 □ Preliminary Design /
Planning/ CEQA
□ Final Design
3 □ Preliminary Design /
Planning/ CEQA
□ Final Design
4 □ Preliminary Design /
Planning/ CEQA
□ Final Design
CCV BMP Manual
PDP SWQMP Template Date: March 2019
Summary of Changes
Initial Submittal
CllYOf
CHULA VISTA
Yards at the Bay
Project Name/ ______________________ _
Project Vicinity Map
SAN DIEGO BAY
NA TIONAL WILDLIFE
REFUGE
SAN DIEGO BAY
CCV BMP Manual
VICINITY MAP
NOT TO SCALE
PDP SWQMP Template Date: March 2019
CllYOf
CHULA VISTA
~U,e... Storm Water Requirements Applicability --.- Intake Form '~- ; .... _.e
CllYOF Checklist for All Permit Applications June 2022 Update CHUIAVISTA Project Information
Project Address: Project Application #
NEC H St and Marina Parkway
Project Name: APN(s)
Yards at the Bay 571-330-36 through 45
Bfriwef Dkespcriptiond _Construction of four industrial warehouse buildings and drive aisles and parking lots on a 0 or repose ·previously demolished site.
The project is (select one):
□ New Development Total Impervious Area ft2
(New development is the creation of impervious surface on an undeveloped site.) ii Redevelopment Total new and/or replaced Impervious Area 958269 ft2 (Redevelopment is the creation and/or replacement of impervious surface on an already developed site). □ Other:
(Includes projects such as: Roof Mount Solar, Residential Minor Utility, Residential Interior Remodel, Commercial Interior Tenant Improvement, Cell Site Modification, etc.) Name of Person Completing this Form: Chelisa Pack (Agent on behalf of developer) Role: D Property Owner D Contractor D Architect Ii Engineer Other Email: [email protected] Phone: 619-881-2575
Signature: Date Completed: 0810112023
Answer each section below, starting with Section 1 and progressing through each section. Additional information for determining the requirements is found in the Chula Vista BMP Design Manual available on the City's website at httg://www.chulavistaca.gov/degartments/gublic-works/services/storm-water-gollutiongrevention/documents-and-regorts.
SECTION 1: Storm Water BMP Requirements
Please answer the following two questions:
1) Does the project involve repair or improvements to an existing building or structure that do not Yes alter the size such as: tenant improvements, interior remodeling, electrical work, fire alarm, fire sprinkler system, HVAC work, gas, plumbing, etc.? ~No
2) Does the project involve routine maintenance activities such as: roof or exterior structure surface replacement; resurfacing existing roadways and parking lots including dig outs, slurry seal, overlay and restriping; repair damaged sidewalks or pedestrian ramps on existing roads Yes without expanding the impervious footprint; routine replacement of damaged pavement, lriNo trenching and resurfacing associated with utility work (i.e. sewer, water, gas or electrical laterals, etc.), and pot holing or geotechnical investigation borings? CHECK ONE:
□ If you answered YES to either question 1 or 2, review and sign "Construction Storm Water BMP Certification Statement" on Page 2. DO NOT complete Sections 2, 3, or 4. The Project is NOT subject to Permanent Storm Water BMP requirements. It IS subject to Construction BMP requirements.
Iii If you answered NO to both questions 1 and 2, Skip to Section 2, Page 3. ❖ City of Chula Vista ❖ Storm Water Applicability Checklist (Intake Form) Construction Storm Water BMP Certification Statement
❖ Page2of5
(June 2022 Update)
The following storm water quality protection measures are required by City Chula Vista Municipal Code Chapter 14.20 and the City's Jurisdictional Runoff Management Program. 1) All applicable construction BMPs and non-stormwater discharge BMPs shall be installed and maintained for the duration of the project in accordance with the Appendix K "Construction BMP Standards" of the Chula Vista BMP Design Manual. 2) Erosion control BMPs shall be implemented for all portions of the project area in which no work has been done or is planned to be done over a period of 14 or more days. All onsite drainage pathways that convey concentrated flows shall be stabilized to prevent erosion. 3) Run-on from areas outside the project area shall be diverted around work areas to the extent feasible. Run-on that cannot be diverted shall be managed using appropriate erosion and sediment control BMPs.
4) Sediment control BMPs shall be implemented, including providing fiber rolls, gravel bags, or other equally effective BMPs around the perimeter of the project to prevent transport of soil and sediment offsite. Any sediment tracked onto offsite paved areas shall be removed via sweeping at least daily.
5) Trash and other construction wastes shall be placed in a designated area at least daily and shall be disposed of in accordance with applicable requirements. 6) Materials shall be stored to avoid being transported in storm water runoff and non-storm water discharges. Concrete washout shall be directed to a washout area and shall not be washed out to the ground.
7) Stockpiles and other sources of pollutants shall be covered when the chance of rain within the next 48 hours is at least 50%.
I certify that the storm water quality protection measures listed above will be implemented at the project described on Intake Form. I understand that failure to implement these measures may result in monetary penalties or other enforcement actions. This certification is signed under penalty of perjury and does not require notarization.
Name: Title: ----------------- -------------
Signature: __________________ Date: __________ _
❖ City of Chula Vista ❖ Storm Water Applicability Checklist (Intake Form) ❖ Page 3 of 5 (June 2022 Update)
SECTION 2: Determine if Project is a Standard Project or Priority Development Project Is the project in any of the following categories, (a) through (f)? (a) New development that creates 10,000 square feet or more of impervious surfaces ( collectively over the entire project site). This includes commercial, industrial, residential, D Yes ljNo mixed-use, and public development projects on public or private land. (b) Redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site of 10,000 ii Yes No square feet or more of impervious surfaces). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land. (c) New development or redevelopment projects that creates and/or replaces a combined total of 5,000 square feet or more of impervious surface (collectively over the entire Iii Yes No project site) and support one or more of the following uses:
(i) Restaurant. This category is defined as a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification Code 5812). (ii) Hillside development projects. This category includes development on any natural slope that is twenty-five percent or greater.
(iii) Parking Lots. This category is defined as a land area or facility for the temporary parking or storage of motor vehicles used personally, for business, or for commerce. (iv) Streets, roads, highways, freeways, and driveways. This category is defined as any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles.
(d) New development or redevelopment project that creates and/or replaces 2,500 square feet or more of impervious surface (collectively over the entire project site), discharging directly to an Environmentally Sensitive Area (ESA). "Discharging directly to" includes D y flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, es !iNo or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands). (e) New development or redevelopment project that creates and/or replaces a combined total of 5,000 square feet or more of impervious surface, that support one or more of the D Yes Iii No following used:
(i) Automotive repair shops. This category is defined as a facility that is categorized in any one of the following Standard Industrial Classification (SIC) codes: 5013, 5014, 5541, 7532-7534, or 7536-7539. (ii) Retail gasoline outlets. This category includes retail gasoline outlets that meet the meet one of the following criteria: (a) 5,000 square feet or more or (b) a projected Average Daily Traffic (ADT) of 100 or more vehicles per day.
(f) New development or redevelopment that result in the disturbance of one or more acres of land and are expected to generate pollutants post construction.
NOTE: Pollutant generating development projects are those projects that generate pollutants at levels greater than background levels. Background pollutant levels means Iii y the pollutants generated from an undeveloped sites. Projects disturbing one or more es No acres of land are presumed to generate pollutants post construction unless the applicant presents a design that satisfies the City Engineer that pollutants in storm water discharges will not exceed preconstruction background levels.
The project is (select one):
□ If "No" is checked for every category in Section 2, Project is a "Standard Development Project." Site design and source control BMP requirements apply. Complete and submit Standard SWQMP (refer to Chapter 4 and Appendix E of the BMP Design Manual for guidance).
Skip to Section 4.
lj If "Yes" is checked for ANY category in Section 2, Project is a "Priority Development Project (PDP}." Complete next part, if applicable, and continue to Section 3. ❖ City of Chula Vista ❖ Storm Water Applicability Checklist (Intake Form) ❖ Page 4 of 5 (June 2022 Update)
Complete for PDP Redevelopment Projects ONLY:
The total existing (pre-project) impervious area at the project site is: 1417 4 78 ft2 (A) The total proposed newly created or replaced impervious area is _9_5_8_2_6_9 _____ ft2 (B) Percent impervious surface created or replaced (B/A) x 100 = _6_8 _____ % The percent impervious surface created or replaced is (select one based on the above calculation):
D Less than or equal to fifty percent (50%)- only new impervious areas are considered a PDP OR
Iii Greater than fifty percent (50%)- the entire project site is considered a PDP Continue to Section 3
SECTION 3: Determine if Project is PDP Exempt
1) Does the project ONLY include new or retrofit sidewalk, bicycle lane or trails that:
• Are designed and constructed to direct storm water runoff to adjacent vegetated areas, or other nonerodible permeable areas? Or; • Are designed and constructed to be hydraulically disconnected from paved streets or roads? Or; • Are designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets guidance?
□ Yes. Project is PDP Exempt.
Complete and submit Standard SWQMP
(refer to Chapter 4 of the BMP Design Manual
for guidance). Continue to Section 4.
lj No. Next question
2) Does the project ONLY include retrofitting or redevelopment of existing paved alleys, streets or roads designed and constructed in accordance with Green Streets standards? □ Yes. Project is PDP Exempt.
Complete and submit Standard SWQMP
(refer to Chapter 4 of the BMP Design Manual
for guidance). Continue to Section 4.
Iii No. Project is a PDP.
Site design, source control, and structural
pollutant control BMPs apply. Complete
and submit PDP SWQMP (refer to
Chapters 4, 5 & 6 of the BMP Design
Manual for guidance). Continue to
Section 4.
❖ City of Chula Vista ❖ Storm Water Applicability Checklist (Intake Form) ❖ Page 5 of 5 (June 2022 Update)
SECTION 4: Construction Storm Water BMP Requirements:
All construction sites are required to implement construction BMPs in accordance with the performance standards in the BMP Design Manual. Some sites are additionally required to obtain coverage under the State Construction General Permit (CGP), which is administered by the State Water Resource Control Board. 1) Does the project include Building/Grading/Construction permits proposing less than 5,000 square feet of ground disturbance and has less than 5-foot elevation change over the entire project area? D Yes. Review and sign Construction Storm Water Certification Statement on Page 2, skip questions 2-4
Ii No; next question
2) Does the project propose construction or demolition activity, including but not limited to, clearing grading, grubbing, excavation, or other activity that results in ground disturbance of less than one acre and more than 5,000 square feet?
D Yes. Complete & submit Construction Storm Water Pollution Control Plan (CSWPCP), skip questions 3-4
Ii No; next question
3) Does the project result in the disturbance of an acre or more of total land area and is considered a regular maintenance project performed to maintain original line and grade, hydraulic capacity, or original purpose of the facility? (Projects such as sewer/storm drain/utility replacement) D Yes. Complete and submit Construction Storm Water Pollution Control Plan (CSWPCP), skip question 4
Ii No; next question
4) Is the project proposing land disturbance greater than or equal to one acre OR the project is part of a larger common plan of development disturbing 1 acre or more? Iii Yes. Storm Water Pollution Prevention Plan (SWPPP) is required. Refer to online CASQA or Caltrans Template. Visit the SWRCB web site at:
http://www.waterboards.ca.gov/water issues/programs/stormwater/construction .shtml.
Note: Projects that result in disturbance of one to five acres of total land area and can demonstrate that there will be no adverse water quality impacts by applying for a Construction Rainfall Erosivity Waiver, may be allowed to submit a CSWPCP in lieu of a SWPPP.
FIGURE 1 -
NORTH
DRAINAGE
SYSTEM
POC2 :~ - ~ ~•,:
HYDRMODIFICATION EXEMPTION EXHIBIT FIGURE 1 NORTH DRAINAGE SYSTEM POC 1 Existing 54" RCP storm
~--..idrain discharges into
slough which extends
from San Diego Bay
isting 72'
ain disch
an Diego
~-Xe¾
~ \ . . .
'
• '
HYDRMODIFICATION EXEMPTION EXHIBIT FIGURE 2 SOUTH DRAINAGE SYSTEM POC 1 Yards at the Bay
Project Name: ____________________________ _
• 1nn--;n ... t'l.~.JIL~ I • • •
Project Summary Information
Project Name Yards at the Bay
Project Address NEC H St and Marina Parkway
Assessor's Parcel Number(s) (APN(s)) 571-330-36 Through 571-330-45 Permit Application Number
Project Watershed ~ San Diego Bay
Hydrologic Subarea name with Numeric Select One:
Identifier up to two decimal places D Pueblo San Diego 908 ~ Sweetwater 909
DOtay 910
Project Area
35.92 ( 1,564,661 (total area of Assessor's Parcel(s) associated Acres Square Feet) with the project or total area of the right-ofway)
Area to be Disturbed by the Project
32.54 (Project Footprint) Acres ( 1,417,478 Square Feet) Project Proposed Impervious Area
22.00 ( subset of Project Footprint) Acres ( 958,269 Square Feet) Project Proposed Pervious Area
( subset of Project Footprint) 10.54 Acres ( 459,209 Square Feet) Note: Proposed Impervious Area+ Proposed Pervious Area= Area to be Disturbed by the Project.
This may be less than the Parcel Area.
The proposed increase or decrease in
impervious area in the proposed condition as
compared to the pre-project condition
CCV BMP Design Manual
Form I-3B, March 2019 Update
-32 %
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CHUI.AVISTA
Yards at the Bay
Project Name: ___________________________ _
Descri
Current Status of the Site (select all that apply):
lj Existing development
D Previously graded but not built out
lj Demolition completed without new construction
D Agricultural or other non-impervious use
D Vacant, undeveloped/ natural
Description / Additional Information:
e Patterns
Presently there are two industrial buildings on site which take up a large portion of the site. They are in the process of being demolished. The remainder of the site consists of an AC parking lot, half of G-Street, and the G Street Sewer Lift Station.
Existing Land Cover Includes (select all that apply):
D Vegetative Cover
D Non-Vegetated Pervious Areas
!i Impervious Areas
Description / Additional Information:
Mostly AC Parking Lots, and industrial building roofs.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
D NRCS Type A Per NRCS Site Soil Survey majority of the site consists of HuC □ NRCS Type B (Huerhuero-Urban Land) which is Group D.
□ NRCS Type c A small westerly portion is Md (Made Land) which is unknown 11 NRCS T e D Hydrologic Soil Group.
Approximate Depth to Groundwater (GW):
D GW Depth < 5 feet Per Geocon report section 5, ground water depth □ 5 feet < GW Depth < 10 feet ranges from 3' to 11' below existing grade. □ 10 feet< GW Depth< 20 feet Fluctuating due to tidal influences. □ GW De th > 20 feet
Existing Natural Hydrologic Features (select all that apply):
D Watercourses
□ Seeps
D Springs
□ Wetlands
lj None
Description / Additional Information:
N/A
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: ___________________________ _
Descri e Patterns
How is storm water runoff conveyed from the site? At a minimum, this description should answer:
1. whether existing drainage conveyance is natural or urban;
2. Is runoff from off site conveyed through the site? if yes, quantify all offsite drainage areas, design flows, and locations where offsite flows enter the project site, and summarize how such flows are conveyed through the site;
3. Provide details regarding existing project site drainage conveyance network, including any existing storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels; and
4. Identify all discharge locations from the existing project site along with a summary of conveyance system size and capacity for each of the discharge locations. Provide summary of the pre-project drainage areas and design flows to each of the existing runoff discharge locations.
Describe existing site drainage patterns:
1. The existing drainage conveyance is entirely Urban.
2. There is a very small portion of offsite run-on 0.3 acres in then north easterly corner of the site, which sheet flows onto the site and then enters storm drain to the north side of G Street.
3. The site has various grate inlets and storm drain pipes throughout the site. The existing storm drain infrastructure collects drainage from the AC parking Lots, concrete drive aisles, and building rooftops. The north half of the site is conveyed to a 36" storm drain stub to the north side of G Street. The south half of the site is conveyed to the south westerly corner of the site and thence to the existing 60" storm drain stub and then to 72" RCP in H Street.
4. The site is roughly split north and south, the North side of the site is conveyed to the 36" stub, and then westerly transitioning to 54" RCP, ultimately discharging into an existing slough north west of the site. The slough is directly connected to the San Diego Bay. The South side of the site is conveyed to the H Street 60" Storm Drain and then south westerly to the 84" RCP and then outlets directly to the San Diego Bay.
Please see Attachment 2 Hydromodification Exemption letter with exhibits and further explanation of the existing storm drain system.
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _________________________ _
Descri tion of Pro
Project Description / Proposed Land Use and/ or Activities:
The intent of the project is to provide commercial/light industrial uses on the project site. There are two undeveloped graded pads with temporary sediment traps proposed for this project, to be developed by others in the future. These pads are not treated for water quality on this project. The developed portion of this project includes four buildings, parking, and drive aisles. These buildings will provide the light industrial uses. One Biofiltration Basin is proposed at the northeasterly corner of the site, and multiple Modular Wetlands for stormwater treatment for the majority of the site.
List/ describe proposed impervious features of the project ( e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features):
This project proposes building roofs, driveways, sidewalks along the buildings, loading docks, and drive aisles for impervious features.
List/ describe proposed pervious features of the project (e.g., landscape areas):
The pervious features of the project consist landscaping areas in medians between the buildings and parking, a large planting area on the west side of the project, and a biofiltration basin. Some of the landscape areas where impervious area drain to them, will be used as Site Design BMP's Dispersion Areas to meet volume retention requirements. Please see DMA map in attachment 1 A for more information.
Does the project include grading and changes to site topography? RI Yes
□ No
Description / Additional Information:
The site will be cleared of debris, and graded to create building pads. The proposed site grading generally follows the existing, as roughly half of the proposed site drains north and the other half south. Fill will be imported in to the site to elevate the proposed buildings above existing grades. Please see DMA Map in attachment 1 A for more information.
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: __________________________ _
Form I-3B Page 5 of10
Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)?
~ Yes
□ No
If yes, provide details regarding the proposed project site drainage conveyance network, including storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels, and the method for conveying offsite flows through or around the proposed project site. Identify all discharge locations from the proposed project site along with a summary of the conveyance system size and capacity for each of the discharge locations. Provide a summary of pre- and post-project drainage areas and design flows to each of the runoff discharge locations. Reference the drainage study for detailed calculations.
Describe proposed site drainage patterns:
The proposed site drainage conveyance network includes trench drains, grate inlets, B-lnlets, ribbon gutters, earthen swales in the westerly dispersion area, and storm drain. The majority of the site drainage is collected and then directed to Modular Wetland units for water treatment. After collection in the storm drain system, the modular wetland units treat flows via pipe inflows, and also curb openings (if applicable. There is one Biofiltration Basin located at the Northeasterly Corner of the site, this is the only bBofiltration basin proposed on the project. The loading docks are depressed areas below the building finish floor and have trench drains to pick up drainage in those areas. Trench drains are also used on the east side of the site within the SDG&E Easement to pickup the AC. The project area east of the daylight line within the SDG&E Easement drains is not proposed to be disturbed by the project, only re-striping is proposed and therefore that portion of the drainage area is considered "runon".
The site is roughly split north and south, the North side of the site is conveyed to the 36" stub, and then westerly transitioning to 54" RCP, ultimately discharging into an existing slough north west of the site. The slough is directly connected to the San Diego Bay. The South side of the site is conveyed to the H Street 60" Storm Drain and then south westerly to the 84" RCP and then outlets directly to the San Diego Bay.
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: ___________________________ _
Form I-3B Page 6 of10
Identify whether any of the following features, activities, and/ or pollutant source areas will be present (select all that apply):
[j On-site storm drain inlets
[j Interior floor drains and elevator shaft sump pumps
□ Interior parking garages
□ Need for future indoor & structural pest control
[j Landscape/ Outdoor Pesticide Use
□ Pools, spas, ponds, decorative fountains, and other water features □ Food service
[j Refuse areas
□ Industrial processes
□ Outdoor storage of equipment or materials
□ Vehicle and Equipment Cleaning
□ Vehicle/Equipment Repair and Maintenance
□ Fuel Dispensing Areas
[j Loading Docks
ii Fire Sprinkler Test Water
ii Miscellaneous Drain or Wash Water
ii Plazas, sidewalks, and parking lots
Description / Additional Information:
There are various on-site storm drain inlets for surface run-off collection. Interior floor drains will be needed for bathrooms and/or other areas in the building per plumbing routed to the sewer system. There are various trash enclosures adjacent to the buildings, which shall be enclosed. Depressed loading docks are needed for the project, and shall be graded such that water in the loading dock is collected and treated before discharging offsite. Fire sprinklers are proposed for these buildings, and test water shall drain to sanitary sewer. Any miscellaneous drains shall be directed to sewer as per the plumbing plans. There are sidewalk along the building and many parking lots, the owner shall maintain them to keep debris from entering the storm drain system.
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: ____________________________ _
utmnllffl~TlmnDJ
Identification and Narrative of Receiving Water and Pollutants of Concern Describe flow path of storm water from the project site discharge location(s), through urban storm conveyance systems as applicable, to receiving creeks, rivers, and lagoons as applicable, and ultimate discharge to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable):
Both discharge locations outlet directly to the San Diego Bay through RCP Storm drain and/or slough which extends into the San Diego Bay. Please see Attachment 2 for the Hydromodification exemption letter and full description of drainage conveyance after the runoff leaves the site.
Llst any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs and/ or Highest Priority Pollutants from the WQIP for the impaired water bodies:
303( d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs / WQIP Highest Priority Pollutant
San Diego Bay Mercury, PAH's, PCB's TMDL's-N/A / WQIP-Trash :::;an u1ego tsay .::,norenne,
Chula Copper TMDL's-N/A / WQIP-N/A Vi!':t~ Marina
Identification of Project Site Pollutants*
*Identification of project site pollutants is only required if flow-thru treatment BMPs are implemented onsite in lieu of retention or biofiltration BMPs (note the project must also participate in an alternative compliance program unless prior lawful approval to meet earlier PDP requirements is demonstrated)
Identify pollutants expected from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix B.6):
Pollutant
Sediment
Nutrients
Heavy Metals
Organic Compounds
Trash & Debris
Oxygen Demanding
Substances
Oil & Grease
Bacteria & Viruses
Pesticides
CCV BMP Design Manual
Form I-3B, March 2019 Update
Not Applicable to
the Project Site
□
□
□
□
□
□
□
□
□
Expected from the
Project Site
□
□
□
□
□
□
□
□
□
Also a Receiving Water
Pollutant of Concern
□
□
□
□
□
□
□
□
□
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CHUI.AVISTA
P . N Yards at the Bay ro1ect ame: ____________________________ _ uirements
Do hydromodification management requirements apply (see Section 1.6)? □ Yes, hydromodification management flow control structural BMPs required. j No, the project will discharge runoff directly to existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. □ No, the project will discharge runoff directly to conveyance channels whose bed and bank are concrete-lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
□ No, the project will discharge runoff directly to an area identified as appropriate for an exemption by the WMAA for the watershed in which the project resides.
Description/ Additional Information (to be provided if a 'No' answer has been selected above):
The site is roughly split north and south, the North side of the site is conveyed to the 36" stub, and then westerly transitioning to 54" RCP, ultimately discharging into an existing slough north west of the site. The slough is directly connected to the San Diego Bay. The South side of the site is conveyed to the H Street 60" Storm Drain and then south westerly to the 84" RCP and then outlets directly to the San Diego Bay.
Please see attachment 2 Hydromodification Exemption letter with exhibits and further explanation of the existing storm drain system.
Note: If "No" answer has been selected the SWQMP must include an exhibit that shows the storm water conveyance system from the project site to an exempt water body. The exhibit should include details about the conveyance system and the outfall to the exempt water body.
Critical Coarse Sediment Yield Areas*
*This Section onl re uired if h dromodification mana ement re uirements a 1 Based on Section 6.2 and Appendix H does CCSYA exist on the project footprint or in the upstream area draining through the project footprint?
□ Yes
Ii No
Description / Additional Information:
Since this project does not require hydromodification management requirements, this section is not applicable. Furthermore, there are no CCSYA's existing on-site or in any area up-stream draining through the project.
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Flow Control for Post-Project Runoff'C
*This Section onl re uired if h dromodification mana ement re uirements a 1 List and describe point(s) of compliance (POCs) for flow control for hydromodification management (see Section 6.3.1). For each POC, provide a POC identification name or number correlating to the project's HMP Exhibit and a receiving channel identification name or number correlating to the project HMP Exhibit.
As described on the previous sheet, hydromodification management requirements do not apply to this site.
Has a geomorphic assessment been performed for the receiving channel(s)? □ No, the low flow threshold is 0.1Q2 (default low flow threshold) □ Yes, the result is the low flow threshold is 0.1 Q2
□ Yes, the result is the low flow threshold is 0.3Q2
□ Yes, the result is the low flow threshold is 0.SQ2
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion / Additional Information: ( optional)
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: ___________________________ _
When applicable, list other site requirements or constraints that will influence storm water management design, such as zoning requirements including setbacks and open space, or local codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements.
There are large amounts of impervious areas proposed by the project.
The site is constrained by the low ground water (3'-8') below existing grade.
The site was formerly used for agricultural uses and later for industrial uses. There are significant contaminated soils on-site, requiring treatment of the soils where the project proposes improvements below ground. These site constraints influenced the project water quality decision to use modular wetland units to treat the majority of the site, and only one biofiltration basin in the only location feasible.
Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed.
Because the site plan includes modular wetlands for the majority of the treatment,additional site design BMP's are required to meet the volume retention requirement. The project is utilizing dispersion areas in two locations on the site.
Please see the OMA map for the dispersion area locations, and Attachment 1 D for the calculations showing Volume Retention requirements are met for the site.
CCV BMP Design Manual
Form I-3B, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: ________________________ _
All development projects must implement source control BMPs. Refer to Chapter 4 and Appendix E of the BMP Design Manual for information to implement BMPs shown in this checklist.
Note: All selected BMPs must be shown on the site/ construction plans.
Answer each category below pursuant to the following:
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/ or Appendix E of the BMP Design Manual. Discussion / justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement.
Discussion / justification must be provided.
• "N/ A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials stora e areas . Discussion / • ustification ma be rovided.
Source Control Re uirement A lied?
4.2.1 Prevention of Illicit Discharges into the MS4 Iii Yes □ No □ N/A Discussion / justification if 4.2.1 not implemented:
Illicit Discharges to MS4 shall be prohibited.
4.2.2 Storm Drain Stenciling or Signage ii Yes □ No □ N/A Discussion / justification if 4.2.2 not implemented:
All storm drain curb inlets or grated inlets shall be stenciled or contain signage.
4.2.3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind Dis ersal
Discussion / justification if 4.2.3 not implemented:
4.2.4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dis ersal
Discussion / justification if 4.2.4 not implemented:
4.2.5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dis ersal
Discussion / justification if 4.2.5 not implemented:
D Yes □ No Iii N/ A
D Yes □ No ilN/A
Iii Yes □ No N/A
Trash enclosures shall be used by the project in accordance with city requirements.
CCV BMP Design Manual
Form I-4, March 2019 Update
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CHULA VISTA
Yards at the Bay
Project Name: ________________________ _
i:t1 ,u.w:..1.-;;1HU,U~~ I 1£fil~llltl 1;,,o ,~ttlo~:..-~ umml~ (lH!rgg~ ... .. 4.2.6 Additional BMPs Based on Potential Sources of Runoff Pollutants (must answer for each source listed Iii Yes □ No N/A below)
SC-A Onsite storm drain inlets Iii Yes □ No N/A
SC-B Interior floor drains and elevator shaft sump pumps Iii Yes □ No N/A SC-C Interior parking garages D Yes □ No Iii N/ A
SC-D1 Need for future indoor & structural pest control D Yes □ No ilN/A SD-D2 Landscape/outdoor pesticide use Iii Yes □ No N/A
SC-E Pools, spas, ponds, decorative fountains, and other D Yes □ No Iii N/ A water features SC-F Food Service D Yes □ No Iii N/ A
SC-G Refuse areas Iii Yes □ No □ N/A
SC-H Industrial processes D Yes □ No Iii N/ A
SC-I Outdoor storage of equipment or materials D Yes □ No Iii N/ A SC-J Vehicle and equipment cleaning D Yes □ No Iii N/ A SC-K Vehicle/equipment repair and maintenance D Yes □ No Iii N/ A SC-L Fuel dispensing areas D Yes □ No Iii N/ A
SC-M Loading docks Iii Yes □ No □ N/A
SC-N Fire sprinkler test water Iii Yes □ No □ N/A
SC-0 Miscellaneous drain or wash water Iii Yes □ No N/A SC-P Plazas, sidewalks, and parking lots Iii Yes □ No N/A SC-Q: Large Trash Generating Facilities D Yes □ No Iii N/ A SC-R: Animal Facilities D Yes □ No Iii N/ A
SC-S: Plant Nurseries and Garden Centers D Yes □ No Iii N/ A SC-T: Automotive Facilities D Yes □ No Iii N/ A
Discussion/ justification if 4.2.6 not implemented. Justification must be provided for all "No" answers shown above.
CCV BMP Design Manual
Form I-4, March 2019 Update
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CHULA VISTA
Yards at the Bay
All development projects must implement site design BMPs where applicable and feasible. See Chapter 4 and Appendix E of the manual for information to implement site design BMPs shown in this checklist. Note: All selected BMPs must be shown on the site/construction plans.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMP as described in Chapter 4 and/or Appendix E of the manual. Discussion / justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
• "N/ A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project site has no existing natural areas to conserve).
Discussion / justification may be provided.
Site Design Requirement Applied?
4.3.1 Maintain Natural Drainage Pathways and Hydrologic Features Yes No iiN/A No natural drainage pathways exist on-site.
4.3.2 Conserve Natural Areas, Soils, and Vegetation Yes No No Natural areas, soils, or Vegetation existing on-site.
4.3.3 Minimize Impervious Area i!Yes No N/A
Site impervious areas are minimized, while meeting the proposed project needs.
4.3.4 Minimize Soil Compaction ..iiYes No N/A
Landscape areas will contain amended soils to keep landscaping compacting minimal.
4.3.5 Impervious Area Dispersion i!Yes No N/A
Impervious Area Dispersion SD-E is implemented to meet site retention requirements.
CCV BMP Design Manual
Form I-5, March 2019 Update
CITYOF
CHULAVISTA
Yards at the Bay
Project Name/Address/N ____________________ _
Site Design Requirement Applied?
4.3.6 Runoff Collection Yes No ~N/A
4.3.7 Landscaping with Native or Drought Tolerant Species .iYes No N/A
4.3.8 Harvesting and Using Precipitation Yes ~No N/A
Discussion/ justification for all "No" answers shown above:
Harvest and Reuse not feasible for this project, please see calculations form 1-7 in the subsequent sheets.
CCV BMP Design Manual
Form I-5, March 2019 Update
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-CITYOF
CHULA VISTA
Yards at the Bay
Project Name: _________________________ _
PDP Structural BMPs
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s).
PDP structural BMPs must be verified by City at the completion of construction. This may include requiring the project owner or project owner's representative to certify construction of the structural BMPs (see Section 1.12 of the manual). PDP structural BMPs must be maintained into perpetuity ( see Section 7 of the manual).
Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet (page 3 of this form) for each structural BMP within the project ( copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP).
Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated or separate.
OMA 1 includes Lined Biofiltration Basin for water treatment:
We have chosen to use a lined biofiltration basin because the project geotechnical engineer has determined the site to be no-infiltration site for storm water purposes.
Please see appendix 1 D for infiltration feasibility letter. The biofiltration basin includes 18-inches of engineered sandy loam growing media on top of a minimum depth of 12 inches of gravel. In addition to the two main layers for biofiltration, a barrier/filter layer underneath the soil media (and above the gravel layer) is also included. The filter layer includes a 3-inch layer of washed sand on top of 3-inch layer of #8 choking stone. For the BMP sizing calculation included in Attachment 1 E, the 3-inches of washed sand and 3-inches of mulch was added to the biofiltration media depth, and the #8 choking stone was added to the gravel depth.
CCV BMP Design Manual
Form I-6, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _______________________ _
PDP Structural BMPs
General strategy for structural BMP implementation (Continued) DMA's 2-14 includes Modular Wetland Units for the following reasons:
•The project geotechnical engineer has determined the site to be no-infiltration site for storm water purposes. Please see appendix 1 D for infiltration feasibility letter. •Due to the large amount of impervious areas proposed by the project and the high groundwater, using biofiltration basins to treat the site is not feasible. •The site is constrained by the high ground water (3'-8') a biofiltration basin will not work in most locations of the site, since the outlet needs to be above the ground water level.
•The site was formerly used for agricultural uses and later for industrial uses thus there are significant contaminated soils on-site, requiring remediation of the soils where we are proposing improvements so shallow structural BMP's are preferred. •The Modular Wetland units can be designed to mitigate the high-water table conditions. All Modular Wetland units are proposed to be vegetated.
Modular Wetlands are used on several projects throughout San Diego County, and have been found to be effective. The Washington State Department of Ecology has granted Modular Wetlands Units General use Level Designation (GULD), which provides further evidence of their wide use. Washington State GULD statement in Attachment 1 E for reference.
Refer to Attachment 1 e for the BMP calculations. The worksheets in Attachment 1 e were provided to show the proposed BMPs will be compliant with the City's volume retention requirements. The project proposes to meet the volume retention requirements for the entire site on a composite basis instead of on a OMA basis. The volume retention requirements are achieved on-site through a combination of the biofiltration planter and the proposed dispersion areas. The proposed combination of BMPs retains a much larger fraction of the DCV than is required for the site, so all required retention credits are satisfied.
The project includes importing fill to raise the site above existing grades. The northerly driveways along G Street are proposed to be mitigated with a treatment swap approach, since the driveways are too large to be considered de minimis areas.
The easterly portion of the site collects runon area outside of the project footprint consisting of the existing parking lot. Due to grading restrictions within this SDG&E area, this area was collected into the site's drainage system and commingled for treatment with the onsite runoff. Because the project proposes to treat an equivalent or larger amount of impervious surface due to treating the runon, the perimeter areas of the site that could not be graded to drain to onsite treatment BMPs are addressed with the proposed treatment swap. Refer to the OMA Map in Attachment 1A for further detail.
CCV BMP Design Manual
Form I-6, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page 3 of __3Q__(Copy and attach as many as needed) Structural BMP ID No. 1
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) ii Biofiltration (BF-1)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Property Owner
Property Owner
Property Owner
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CHUI.AVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page 4 of 30
Structural BMP ID No. 1
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP # 1 is a lined Biofiltration basin with a bottom footprint of 3,130 SF. This basin consists of 12" of aggregate storage, 3" of ASTM No. 8 Stone, 18" Biofiltration media, 3" of ASTM 33 fine aggregate sand and 3" mulch with 6" of ponding.
Sizing worksheet B.5-1 is included in Attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page 5 of __3Q__(Copy and attach as many as needed) Structural BMP ID No. 2
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page 6 of 30
Structural BMP ID No. 2
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 2 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page 7 of __3Q__(Copy and attach as many as needed) Structural BMP ID No. 3
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page 8 of 30
Structural BMP ID No. 3
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 3 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page 9 of __3Q__(Copy and attach as many as needed) Structural BMP ID No. 4
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page10 of 30
Structural BMP ID No. 4
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 4 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
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CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page11 of 30 .(Copy and attach as many as needed) Structural BMP ID No. 5
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page12 of 30
Structural BMP ID No. 5
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 5 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page13of 30 .(Copy and attach as many as needed) Structural BMP ID No. 6
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page14 of 30
Structural BMP ID No. 6
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 6 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page15 of 30 .(Copy and attach as many as needed) Structural BMP ID No. 7
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page16 of 30
Structural BMP ID No. 7
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 7 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page17 of 30 .(Copy and attach as many as needed) Structural BMP ID No. 8
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page18of 30
Structural BMP ID No. 8
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 8 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page19 of 30 .(Copy and attach as many as needed) Structural BMP ID No. 9
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page20 of 30
Structural BMP ID No. 9
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 9 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page 21 of 30 .(Copy and attach as many as needed) Structural BMP ID No. 10
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page22of 30
Structural BMP ID No. 1 Q
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BM P's# 1 O is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page23of 30 .(Copy and attach as many as needed) Structural BMP ID No. 11
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page24of 30
Structural BMP ID No. 11
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 11 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page25of 30 .(Copy and attach as many as needed) Structural BMP ID No. 12
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page26of 30
Structural BMP ID No. 12
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 12 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page27of 30 .(Copy and attach as many as needed) Structural BMP ID No. 13
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page28of 30
Structural BMP ID No. 13
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 13 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name: _____________________________ _
Form 1-6 Page29of 30 .(Copy and attach as many as needed) Structural BMP ID No. 14
Construction Plan Sheet No.
Type of structural BMP:
D Retention by harvest and use (e.g. HU-1, cistern)
D Retention by infiltration basin (INF-1)
D Retention by bioretention (INF-2)
D Retention by permeable pavement (INF-3)
D Partial retention by biofiltration with partial retention (PR-1) IXI Proprietary Biofiltration (BF-3)
D Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/ description in discussion section below) D Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/ description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) D Flow-thru treatment control with alternative compliance (provide BMP type/ description in discussion section below)
D Detention pond or vault for hydromodification management D Other (describe in discussion section below)
Purpose:
lj Pollutant control only
D Hydromodification control only
D Combined pollutant control and hydromodification control D Pre-treatment/forebay for another structural BMP
D Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the City Engineer (See Section 1.12 of
the manual)
Chelisa Pack, RCE 71026
Project Design Consultants
(619) 235-6471
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
CCV BMP Design Manual
Form 1-6, March 2019 Update
Property Owner
Property Owner
Property Owner
CllYOF
CHUlAVISTA
Yards at the Bay
Project Name: __________________________ _
Form 1-6 Page30of 30
Structural BMP ID No. 14
Construction Plan Sheet No.
Discussion (as needed, must include worksheets showing BMP sizing calculations in the SWQMP):
BMP's # 14 is an compact biofiltration BF-3 type Modular Wetland Unit from Manufacturer Contech. For sizes of each Modular Wetland Unit per OMA, please see OMA Map Attachment 1 A.
Sizing calculations are included in attachment 1 E.
CCV BMP Design Manual
Form 1-6, March 2019 Update
~Vt-
,.,.._ -:_ .. ---11"' - -CITYOF
CHUI.AVISTA
Yards at the Bay
Project Name/ ___________________ _
ATTACHMENT 1
Backup for PDP Pollutant Control BMPs
CCV BMP Manual
PDP SWQMP Template Date: March 2019
Yards at the Bay Project Name/ ______________________________ _ Indicate which Items are Included:
Attachment
Sequence
Attachment 1A
Attachment 1B
Attachment 1C
Attachment 1D
Attachment 1E
CCV BMP Manual
Contents
DMA Exhibit (Required)
See DMA Exhibit Checklist.
Tabular Summary of DMAs Showing DMA ID
matching DMA Exhibit, DMA Area, and DMA Type
(Required)*
*Provide table in this Attachment OR on DMA
Exhibit in Attachment 1a
Checklist
Iii Included
Iii Included on DMA Exhibit
in Attachment 1A
D Included as Attachment 1B,
separate from DMA
Exhibit
Form 1-7, Harvest and Use Feasibility Screening Iii
Checklist (Required unless the entire project will use
Included
infiltration BMPs) D Not included because the
entire project will use
infiltration BMPs
Refer to Appendix B.3-1 of the BMP Design Manual
to complete Form I-7.
Infiltration Feasibility Information. Contents of
Attachment 1D depend on the infiltration condition:
Ii No Infiltration Condition:
D Infiltration Feasibility Condition
D Letter (Note: must be stamped & signed by
licensed geotechnical engineer)
D Form l-8A (optional)
D Form I-8B (optional)
D Partial Infiltration Condition:
D Infiltration Feasibility Condition
D Letter (Note: must be stamped & signed by
licensed geotechnical engineer)
D Form l-8A
D Form l-8B
D Full Infiltration Condition:
□ Form I-SA
□ Form I-SB
D Worksheet C.4-3
D Form 1-9
Refer to Appendices C and D of the BMP Design
Manual for 2.Uidance.
Iii Included
D Not included because the
entire project will use
harvest and use BMPs
Pollutant Control BMP Design Worksheets/ Iii Included
Calculations (Required)
Refer to Appendices B and E of the BMP Design
Manual for structural pollutant control BMP design
2.Uidelines
PDP SWQMP Template Date: March 2019
Yards at the Bay
Project Name/ ____________________________ _
Use this checklist to ensure the required information has been included on the DMA Exhibit:
The DMA Exhibit must identify all the following:
Iii Underlying hydrologic soil group
Iii Approximate depth to groundwater
Iii Existing natural hydrologic features (watercourses, seeps, springs, wetlands) ii Critical coarse sediment yield areas to be protected Iii Existing topography and impervious areas
Iii Existing and proposed site drainage network and connections to drainage offsite Iii Proposed grading
ii Proposed impervious features
Iii Proposed design features and surface treatments used to minimize imperviousness Iii Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square footage or acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating) ii Potential pollutant source areas and corresponding required source controls (see Chapter 4, Appendix E.1, and Form I-3B)
ii Structural BMPs (identify location, type of BMP, and size/ detail, and include cross-sections) CCV BMP Manual
PDP SWQMP Template Date: March 2019
ATTACHMENT lA,1B-DMAMAP
I
'j,
f ' -
' , POC 2 '1,: CONNECT TO EXIS1/HG
STOOi DRNN 1
(P£R DIIG 20006-JO} }".
BMP #8
(MODULA
WET1-AND
sc-r I
19,980
PERVI A
IMPERVIOUS A 0/SPER SD-
,
I
~ s
32 \
~ \
\I ~e_.
?j
I
I
I
I
OMA 10------"fl-~
(2.83 AC)
BMP #10
(MODULAR
WET1-AND)
SC-A
BMP /5
(MODULAR
WET1-AND)
SC-A
OMAS
'"
I
(
I ,,
I
\ - -
POC 1 I I/
:_1 /I -,,
-f'"ll!/
. rt!J,: I 1° 1111
. //~\:r.rr I /1.._r./11 l~ \
J I
I > I~"6
OMA 20
(0.004 AC)
(DE -MIN/MIS 190 SF)
OMA 21
(0.004 AC)
I
½--ll~~~ ~ OMA 7: BMP 19
(/. 36 AC ) I (MODULAR
WET1-AND)
-+---5c-A
I
I
I
FF=ts. l o
I
I
I OMA 111~::".I-,l-1 --"---,rlstclll
I w .5 ~
_J ll .. ::P2 AC) ' '
I BMP #11
I (MODULAR
I WET1-AND) I SC-A
I
·OMA 15 1 FUTURE DEVELOPMENT BY OTHERS. FUTURE PROJECT llfLL ADDRESS (SELF-MIT/GA TING) FUTURE POLLUTANT CONTROL . ' REQUIREMENTS
C
1 "' • TEMPORAR
,.~ A-2,JJB5F
SEDIMENT
OMA 23 /he--'-
~ (0.06 AC)
UNTREATED OMA
(PER TREA TI.IENT SWAP)
2,618 SF
BMP #6 (MciJULAR
WET1-AND) SC~A .. ,.;_]_;;, ~c:i,....----....lb.,.,,;;;:==--:c-::1t1 OMA 6 ,,, /, 0.97 A°C .•
~ G STR_EET =-
I
I
--m1
I
I
I
I
9,JDD SF----m-- PERVIOUS
AREA
F, 15.00
-~-~~~~-----~.,--~~~~ ~~---~:-~-:-~~ -------,,~------ \ I
File Nom• P;\4508\Er,gr\R,ports\SDP-Prelim\ATTACHMENTS\M-Pollutor,t C011trol 81,iPa\~DMA-w.P.d~ 8/1/2023 J:22:JB PM 'I
LEGEN?
PRa'ERTY BOUNOMY
£MP DIWHAGE SUBAREA
(OMA BOONlMRY)
SB.F-/IITJGMING CR DE-11/NIM/S
DRAINAGE SUBAR[A (DMA BOONOARY)
OMA. DRAINAGE AREA
PCUUTANT CCNTR<J.. 811P: MOOULAR llrn.AND UNIT
CW~ PRCPOSED TRENCH DRAIN
:s~ - FLOWPA7H
'4,;~.~
, Fl.OWDIRECTlai / ~::,~
f--1,f'----as-----
Dl,/A 2A
T SWAP AREA
TS/DE OF PDP PROJECT
TO BE 7REA TED)
--~9-A-C~
OMA 12
SWAP AREA
TS/DE OF PDP PROJECT
TO BE TREATED)
AC
NOFDMA4
ENT SWAP AREA
N OUTSIDE OF PDP PROJECT
~INT TO BE TREATED)
.69 AC
SCALE, ,·-so·
11/PfRWOIJS AREA DISPERSION
TREA111£NT SWAP
(RUNCN OUTSIDE a: PDP PRO.ECT F001PRINT ro 8E 11ifA1cD
TREATllENT SWAP
(UNTRVt7cD DMA)
OMA# OMA TYPE
1 DRAINS TO
81,/P 1
2A DRAINS TO
BMP 2
28 DRAINS TO
BMP 2
2C DRAINS TO
BMP 2
J DRAINS TO
BMP J
DRAINS TO 4 BMP 4
5 DRAINS TO
BMP 5
6 DRAINS TO
BMP 6
7 DRAINS TO BMP 7
DRAINS TO 8 8MP 8
g DRAINS TO
BMP 9
10 DRAINS TO
BMP 10
11 DRAINS TO
BMP 11
DRAINS TO 12 BMP 12
13 DRAINS TO
BMP 13
14 DRAINS TO
BMP 14
15 SELFMITIGATING
16 SELFMITIGATING
17 SELFMITIGATING
18 SELF1,//TIGAllNG
19 SELF1,//TIGAllNG
20 DE-MIN/MUS
21 DE-MIN/MUS
22 TREATMENT
SWAP
23 TREATMENT
SWAP
SUM
PREP.ARID BY:
( X.XX AC)
Ill
__ ,,, __
~
---
1 : <I
~
~
BMP# POC
1 DRAINS TO
POC 2
2 DRAINS TO
POC 2
2 DRAINS TO
POC 2
2 DRAINS TO
POC 2
J DRAINS TO
POC 1A
DRAINS TO 4 POC 1A
5 DRAINS TO
POC 1A
6 DRAINS TO
POC 2
7 DRAINS TO
POC 2
DRAINS TO 8 POC 2
9 DRAINS TO
POC 2
10 DRAINS TO
POC 1A
11 DRAINS TO
POC IA
DRAINS TO 12 POC 1A
/J DRAINS TO
POC 1A
14 DRAINS TO
POC IA
N/A DRAINS TO
PDC 1A
N/A DRAINS TO
POC 18
N/A DRAINS TO
POC 2
N/A DRAINS TO
POC 2
N/A DRAINS TO
POC 2
N/A DRAINS TO
POC 2
N/A DRAINS TO
POC 2
N/A DRAINS TO
POC 2
N/A DRAINS TO
POC 2
JIXJ ~ ''"" r; PIIOJEcr DHIGN coN ULTANTB I Pining ll.andlolpel«illlllclnl~ISlawy CRfATID: 7/12/2J
71iEATIENT SWAP ME'A TAEIE
UN-1REA1ED £WA's
/JOA I .ff'A (AC)
22 I 007
2J I aa,
WTAI.: I .,, ""'"""" /JOA M£A (AC)
PORTION CF ()l,IA 2A ... PORT/CW C,:- OIIA 4 ... PORTION OF DNA 12 O.J2 WTAL: 1.71
BECAUSE THE TOTAL TREATED RUNON AREAS
(POR110NS OF DMA'S 2A, 4, AND 12) IS GREATER
THAN UN-TREATED BYPASS AREAS (DMA 'S 22 AND
2J) TREATMENT SWAP IS ACCEPTABLE
BMPNOTES
1. SITE DESIGN BMPS INCLUDE:
MINIMIZA 110N OF IMPERVIOUS FOOTPRINT
CONSERVA 110N OF NATURAL AREAS
SD-B IMPERVIOUS AREA DISPERSION
SD-F AMENDED SOILS
2. SOURCE CONTROL BMPs FOR PROJECT INCLUDE:
PREVEN110N OF ILLICIT DISCHARGES SC-A STORM DRAIN STENCILING
SC-B INTERIOR FLOOR DRAINS
SD-D2 LANDSCAPE / OUTDOOR PES11CIDE USE
SC-G PROTECTION OF TRASH STORAGE AREAS
SC-M LOADING DOCKS
SC-N RRE SPRINKLER TEST WATER TO DRAIN TO SE'N[R
SC-Q LARGE TRASH GENERA 11NG FACILl11ES
EFFICIENT LANDSCAPE AND /RR/GA 110N DESIGN
STORMWA TER EDUCA 110N
BUILDING MANAGEMENT PRAC11CES (MANAGEMENT OF FIRE
SPRINKLER SYSTEM DISCHARGES, AIR COND/110NING
CONDENSATE DISCHARGES, AND THE USE OF NON- TOXIC
ROOFING MATERIALS.
3. THE TREA TI.IENT BMPS SELECTED FOR THIS PROJECT ARE ONE LINED BIOFILTRA 110N BASIN AND MUL11PLE COMPACT
BIOFIL TRA 110N UNIT (MODULAR 'N[TLAND UNIT). SEE
ATTACHMENT 4 FOR BMP DETAILS/PLANS.
4. PROJECT 111LL DIRECTLY DISCHARGE TO SAN DIEGO BAY AND IS EXEMPT FROM HYDROMODJRCATION REQUIREMENTS.
5. THE NRCS SOIL SURVEY CLASSIFIES THE SITE AS HAVING
SOILS OF THE HYDROLOG/C SOIL GROUP 'D'.
6. GROUNDWATER DEPTHS RANGE FROM ABOUT 3' TO 11' BELOW
GRADE AS PER THE CEOTECHNICAL REPORT 11TLED: COLLINS
AEROSPACE REDEVELOPMENT SITE - PARCEL B NORTHEAST
CORNER OF H STREET AND MARINA PARKWAY CHULA VISTA,
CALIFORNIA, DA TED DECEMBER 17 2021. SEE GEO TECHNICAL
REPORT FOR MORE INFORMATION
7. THERE ARE NO CCSYA 'S ON-SITE.
DMA/BMP TABLE
BMP TYPE OMA TRIBUTARY BMP BOTTOM
DRAINAGE AREA (AC) AREA (SQFT)
BIOFIL TRA 110N (BF- 1) LINED 2.17 J120 810FIL TRA 110N PROPRIETARY BIOFILTRA110N 1.9J N/A SYSTEMS (BF-3} MWS-L-8-20 PROPRIETARY BIOFJL TRA 110N 0.17 N/A SYSTEMS (BF-3} MWS-L-8-20 PROPRIETARY BIOFILTRA110N D.J2 N/A SYSTEMS (BF-J) MWS-L-8-20 PROPRIETARY B/OFIL TRA 110N J.31 N/A SYSTEMS (BF-3) MWS-L-8-24
PROPRIETARY BJOFJL TRA TION
SYSTEMS (BF-3} MWS-L-8-20 2.01 N/A
PROPRIETARY BIOF/L TRA 110N 1.DJ N/A SYSTEMS (BF-J) MWS-L-8-8 PROPRIETARY BIOFIL TRA 110N 0.97 N/A SYSTEMS (BF-J} MWS-L-8-8 PROPRIETARY 8/0FIL TRA 110N 1.36 N/A SYSTEMS {8F-3} MWS-L-8-12 PROPRIETARY BJOFJL TRA 110N
SYSTEMS (BF-3} MWS-L-8-16 2.54 N/A
PROPRIETARY BIOFJL TRA 110N 2.33 N/A SYSTEMS (8F-3) l,/WS-L-8-12 PROPRIETARY BIOFIL TRA 110N 2.83 N/A SYSTEMS (BF-3) MWS-L-8-16 PROPRIETARY B/OFIL TRA 110N 1.32 N/A SYSTEMS (BF-J) MWS-L -8-8
PROPRIETARY BJOFJL TRA TION
SYSTEMS (BF-3} MWS-L-8-20 1.85 N/A
PROPRIETARY BIOF/L TRA 110N 1.58 N/A SYSTEMS (BF-J) MWS-L-8-8 PROPRIETARY BIOFIL TRA 110N 0.58 N/A SYSTEMS (BF-3} MWS-L-8-16 N/A J.24 N/A
N/A 4.27 N/A
N/A 0.12 N/A
N/A 0.07 N/A
N/A D.02 N/A
N/A 0.004 N/A
N/A 0.004 N/A
N/A 0.07 N/A
N/A 0.06 N/A
34.15 J/20
CITY OF CHULA VISTA
YARDS AT THE BAY • PARCEL B
Nli.a,QJI- -■----- -N DMA EXH/BfT"
PROPOSED CONDmONS
EXH/BfT" A-1
Project Name: Yards at the Bay
Tabular Summary of DMAs Worksheet B-1
DMA Unique Area Impervious %Imp HSG Area Weighted DCV Treated by Pollutant Identifier (acres) Area Runoff (Cubic (BMP ID) Control Type (acres) Coefficient feet)
Summary of OMA Information (Must match Project description and SWQMP narrative) No. of DMAs Total OMA Total % Impervious Area Weighted
Where:
Area Impervious
(acres) Area
(acres)
DMA = Drainage Management Area
HSG = Hydrologic Soil Group
BMP = Best Management Practice
Runoff
Coefficient
Imp = Imperviousness
DCV= Design Capture Volume
POC = Point of Compliance
DCV Total Area
(Cubic Treated (acres)
feet)
ID = identifier
No. = Number
I PLEASE SEE WORKSHEET 8.2-1 FOR ENTIRE SITE DCV.
*Volume Retention for the site as a whole will be met with Biofiltration Basins and Impervious Dispersion.
CCV BMP Design Manual
Worksheet B-1 March 2019 Update
Drains to
(POC ID)
No. of
POCs
~Vt-
--•.: .. _ .. -CllYOf
G
CHULA VISTA
ATTACHMENT lC - HARVEST & USE FEASIBILITY
CHECKLIST
Yards at the Bay
Project Name: _______________________ _
H d U F "bill S . FORM 1-7 arvest an se east ty creenmg (W k h B 3 t) ors s eet . -
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season?
D Toilet and urinal flushing
.iJ Landscape irrigation
D Other: -------
2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section B.3.2.
[Provide a summary of calculations here]
Landscape Irrigation:
Landscape area=2.87 Ac. Assumed Water Use:
14 70 g/ac/36 hours x 2.87 Ac=4219 Gallons 1 CF= 7.48 gallons, water use=564 CF /36 hours
3. Calculate the DCV using worksheet B-2.1.
[Provide a result here]
45,536 CF see site DCV B-2.1 .
3a. Is the 36-hour demand greater
than or equal to the DCV?
Yes / -i N_o _c:g_
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing calculations
to confirm that DCV can be used
at an adequate rate to meet
drawdown criteria.
3b. Is the 36-hour demand greater than
0.25DCV but less than the full DCV?
Yes I
,().
45,536*0.25=11,384>564
Harvest and use may be feasible.
Conduct more detailed evaluation and
sizing calculations to determine
feasibility. Harvest and use may only be
able to be used for a portion of the site,
or ( optionally) the storage may need to be
upsized to meet long term capture targets
while draining in longer than 36 hours.
3c. Is the 36-hour demand
less than 0.25DCV?
Yes
Harvest and use is
considered to be infeasible.
Note: 36-hour demand calculations are for feasibility analysis only, once the feasibility analysis is complete the applicant may be allowed to use a different drawdown time provided they meet the 80 percent of average annual (long term) runoff volume performance standard.
CCV BMP Design Manual
Form I-7 (Worksheet B.3-1) March 2019 Update
CITYOF
CHULA VISTA
ATTACHMENT 1D - INFILTRATION FEASIBILITY LETTER
GEOCON
INCORPORATED
GEOTECHNICA L ■
Project No. G2560-52-01
August 1, 2023
Wohl Property Group
ENVIRONMENTA L . MATERIALS O
1081 Camino Del Rio South, Suite 115
San Diego, California 92108
Attention:
Subject:
Mr. Emil Wohl
STORM WATER INFILTRATION FEASIBILITY EVALUATION
COLLINS AEROSPACE REDEVELOPMENT SITE - PARCEL B
NORTHWEST CORNER OF H STREET AND MARINA PARKWAY
CHULA VISTA, CALIFORNIA
References: 1. Updated Limited Geotechnical Investigation, Collins Aerospace Redevelopment Site - Parcel B, Northeast Corner of H Street and Marina Parkway, Chula Vista, California, prepared by Geocon Incorporated, dated December 17, 2021 (Project No. G2560-52-01).
2. DMA Exhibit Proposed Conditions, Exhibit 1-A, Yards at the Bay - Parcel B, Chula Vista, CA 91910, prepared by Project Design Consultants, dated August 1, 2023.
Dear Mr. Wohl:
In accordance with the request of Ms. Chelisa Pack with Project Design Consultants, we prepared this letter to describe the infiltration feasibility characteristics of the subject site for the proposed project.
We reviewed the referenced update geotechnical investigation report to evaluate the current geologic conditions on the property in accordance with the City of Chula Vista Best Management Practices (BMP) Design Manual (dated August 2021).
As noted in the referenced project geotechnical report, the site is underlain at relatively shallow depths by clayey soils that are considered to be "expansive" as defined by the California Building Code.
Infiltration of storm water into these expansive soils could cause distress to existing and proposed surfaces and structures. Additionally, the NRCS Web Soil Survey indicates that the site is mapped as being underlain by Soil Type D. The observed and mapped soil characteristics of the near-surface onsite clayey soils indicate that they are considered to have poor infiltration characteristics (poor to no permeability). In addition, the site is underlain by a shallow-static ground water table that varies from 3 to 12 feet below the existing site surface and is tidally influenced. As such, we opine that infiltration of storm water in any amount should not be allowed at the subject site. Any BMPs should be lined with 6960 Flanders Drive ■ San Diego, California 92 121-297 4 ■ Telephone 858.558.6900 ■ Fax 858 .558 .6 159 impermeable liners and piped to a suitable discharge facility. We have completed a City of Chula Vista Form I-8A (Worksheet C.4-1) for this evaluation and it is attached.
If you have any questions regarding this response, or if we may be of further service, please contact the undersigned at your convenience.
Very truly yours,
GEOCON IN CORPORA TED
AWH:ML:arm
Attachments:
Matt Love
RCE 84154
City of Chula Vista Form I-8A (Worksheet C.4-1)
( e-mail) Addressee
Geocon Project No. G2560-52-01 - 2 - August 1, 2023
Yards at the Bay - Parcel B
(Geocon, Inc. Project No. G2560-52-01)
Project Name: _______________________ _
Categorization of Infiltration Feasibility Condition based on Form I-8A1 Geotechnical Conditions (Worksheet C.4-1)
Part 1 - Full Infiltration Feasibility Screening Criteria DMA(s) Being Analyzed: Project Phase:
OMA exhibit prepared by Project Design Consultants
dated 8-1-2023
Criteria 1: Infiltration Rate Screening
1A
1B
1C
1D
1E
Is the mapped hydrologic soil group according to the NRCS Web Soil Survey or UC Davis Soil Web Mapper Type A or Band corroborated by available site soil data2? D Yes; the DMA may feasibly support full infiltration. Answer ''Yes" to Criteria 1 Result or continue to Step 1B if the applicant elects to perform infiltration testing.
D No; the mapped soil types are A or B but is not corroborated by available site soil data (continue to Step 1B).
i No; the mapped soil types are C, D, or "urban/ unclassified" and is corroborated by available site soil data. Answer "No" to Criteria 1 Result.
D No; the mapped soil types are C, D, or "urban/ unclassified" but is not corroborated by available site soil data (continue to Step 1B).
Is the reliable infiltration rate calculated using planning phase methods from Table D.3-1? D Yes; Continue to Step 1 C.
□ No; Skip to Step 1D.
Is the reliable infiltration rate calculated using planning phase methods from Table D.3-1 greater than 0.5 inches per hour?
D Yes; the DMA may feasibly support full infiltration. Answer ''Yes" to Criteria 1 Result.
D No; full infiltration is not required. Answer "No" to Criteria 1 Result.
Infiltration Testing Method. Is the selected infiltration testing method suitable during the design phase (see Appendix D.3)? Note: Alternative testing standards may be allowed with appropriate rationales and documentation.
D Yes; continue to Step 1E.
D No; select an appropriate infiltration testing method.
Number of Percolation/Infiltration Tests. Does the infiltration testing method performed satisfy the minimum number of tests specified in Table D .3-2? D Yes; continue to Step 1F.
D No; conduct appropriate number of tests.
1 This form must be completed each time there is a change to the site layout that would affect the infiltration feasibility condition. Previously completed forms shall be retained to document the evolution of the site storm water design. 2 Available data includes site-specific sampling or observation of soil types or texture classes, such as obtained from borings or test pits necessary to support other design elements.
CCV BMP Design Manual
Form I-8A (Worksheet C.4-1) March 2019 Update
CllYOf
CHULA VISTA
Yards at the Bay - Parcel B
Project Name: (Geocon, Inc. Project No. G2560-52-01)
Categorization of Infiltration Feasibility Condition based on Form I-8A1 IF
1G
Criteria 1
Result
Geotechnical Conditions (Worksheet C.4-1)
Factor of Safety. Is the suitable Factor of Safety selected for full infiltration design? See guidance in D.5; Tables D.5-1 and D.5-2; and Worksheet D.5-1 (Form I-9).
D Yes; continue to Step 1G.
D No; select appropriate factor of safety.
Full Infiltration Feasibility. Is the average measured infiltration rate divided by the Factor of Safety greater than 0.5 inches per hour?
D Yes; answer ''Yes" to Criteria 1 Result.
D No; answer "No" to Criteria 1 Result.
Is the estimated reliable infiltration rate greater than 0.5 inches per hour within the DMA where runoff can reasonably be routed to a BMP?
D Yes; the DMA may feasibly support full infiltration. Continue to Criteria 2.
D No; full infiltration is not required. Skip to Part 1 Result.
Summarize infiltration testing methods, testing locations, replicates, and results and summarize estimates of reliable infiltration rates according to procedures outlined in D.S. Documentation should be included in project geotechnical report.
As noted in the referenced project geotechnical report (Updated Limited Geotechnical Investigation, Collins Aerospace Redevelopment Site - Parcel B, Northeast Corner of H Street and Marina Parkway, Chula Vista, California, prepared by Geocon Incorporated, dated December 17, 2021 (Project No. G2560-52-01 )), the site is underlain at relatively shallow depths by clayey soils that are expansive. Infiltration of storm water into these expansive soils could cause distress to existing and proposed surfaces and structures. Also, the NRCS Web Soil Survey indicates that the site is mapped as being underlain by Soil Type D. The near surface onsite clayey soils are considered to have poor permeability. In addition, the site is underlain by a shallow-static ground water table that varies from 3 to 12 feet below the existing site surface. As such, we opine that infiltration of storm water in any amount should not be allowed at the subject site. Any BMPs should be lined with impermeable liners and piped to a suitable discharge facility.
Criteria 2: Geologic/Geotechnical Screening
2A
If all questions in Step 2A are answered ''Yes," continue to Step 2B.
For any "No" answer in Step 2A answer ''No" to Criteria 2 and submit an "Infiltration Feasibility Condition Letter" that meets the requirements in Appendix C.1.1.
The geologic/ geotechnical analyses listed in Appendix C.2.1 do not apply to the DMA because one of the following setbacks cannot be avoided and therefore result in the DMA being in a no infiltration condition. The setbacks must be the closest horizontal radial distance from the surface edge (at the overflow elevation) of the BMP.
CCV BMP Design Manual ~VtForm I-8A (Worksheet C.4-1) March 2019 Update ·•.: .. . . -CllYOf
CHULA VISTA
Yards at the Bay - Parcel B
(Geocon, Inc. Project No. G2560-52-01) Project Name: _______________________ _ Categorization of Infiltration Feasibility Condition based on Form I-8A1 2A-1
2A-2
2A-3
2B
2B-1
2B-2
2B-3
2B-4
2B-5
Geotechnical Conditions (Worksheet C.4-1)
Can the proposed full infiltration BMP(s) avoid areas with existing fill materials greater than 5 feet thick below the infiltrating surface? Can the proposed full infiltration BMP(s) avoid placement within 10 feet of existing underground utilities, structures, or retaining walls? Can the proposed full infiltration BMP(s) avoid placement within 50 feet of a natural slope (>25%) or within a distance of 1.5H from fill slopes where His the height of the fill slope?
Yes
Yes
Yes
No
No
No
When full infiltration is determined to be feasible, a geotechnical investigation report must be prepared that considers the relevant factors identified in Appendix C.2.1 .
If all questions in Step 2B are answered ''Yes," then answer ''Yes" to Criteria 2 Result.
If there are "No" answers continue to Step 2C.
Hydroconsolidation. Analyze hydroconsolidation potential per approved ASTM standard due to a proposed full infiltration BMP.
Can full infiltration BMPs be proposed within the DMA without increasing hydroconsolidation risks?
Expansive Soils. Identify expansive soils (soils with an expansion index greater than 20) and the extent of such soils due to proposed full infiltration BMPs.
Can full infiltration BMPs be proposed within the DMA without increasing expansive soil risks?
Liquefaction. If applicable, identify mapped liquefaction areas. Evaluate liquefaction hazards in accordance with Section 6.4.2 of the City of San Diego's Guidelines for Geotechnical Reports (2011 or most recent edition).
Liquefaction hazard assessment shall take into account any increase in groundwater elevation or groundwater mounding that could occur as a result of proposed infiltration or percolation facilities.
Can full infiltration BMPs be proposed within the DMA without increasing liquefaction risks?
Slope Stability. If applicable, perform a slope stability analysis in accordance with the ASCE and Southern California Earthquake Center (2002) Recommended Procedures for Implementation of DMG Special Publication 11 7, Guidelines for Analyzing and Mitigating Landslide Hazards in California to determine minimum slope setbacks for full infiltration BMPs. See the City of San Diego's Guidelines for Geotechnical Reports (2011) to determine which type of slope stability analysis is required.
Can full infiltration BMPs be proposed within the DMA without increasing slope stability risks?
Other Geotechnical Hazards. Identify site-specific geotechnical hazards not already mentioned (refer to Appendix C.2.1).
Can full infiltration BMPs be proposed within the DMA without increasing risk of geologic or geotechnical hazards not already mentioned? Yes
Yes
Yes
Yes
Yes
No
jNo
No
No
Kl No
CCV BMP Design Manual ~VtForm I-8A (Worksheet C.4-1) March 2019 Update ·•.: .. . . -CllYOf
CHULA VISTA
Yards at the Bay - Parcel B
(Geocon, Inc. Project No. G2560-52-01) Project Name: _______________________ _ Categorization of Infiltration Feasibility Condition based on Form I-8A1 Geotechnical Conditions (Worksheet C.4-1)
Setbacks. Establish setbacks from underground utilities, structures, and/ or retaining walls. Reference applicable ASTM or other recognized standard in 2B-6 the geotechnical report. D Yes D No
2C
Can full infiltration BMPs be proposed within the DMA using established setbacks from underground utilities, structures, and/ or retaining walls? Mitigation Measures. Propose mitigation measures for each geologic/ geotechnical hazard identified in Step 2B. Provide a discussion of geologic/ geotechnical hazards that would prevent full infiltration BMPs that cannot be reasonably mitigated in the geotechnical report. See Appendix C.2.1.8 for a list of typically reasonable and typically unreasonable mitigation measures.
Can mitigation measures be proposed to allow for full infiltration BMPs? If the question in Step 2 is answered ''Yes," then answer "Yes" to Criteria 2 Result.
If the question in Step 2C is answered "No," then answer "No" to Criteria 2 Result.
Can infiltration greater than 0.5 inches per hour be allowed without increasing Yes D No
Criteria 2
Result risk of geologic or geotechnical hazards that cannot be reasonably mitigated to D Yes an acceptable level?
!ii No
Summarize findings and basis; provide references to related reports or exhibits.
As noted in the referenced project geotechnical report, the site is underlain at relatively shallow depths by clayey soils that are expansive. Infiltration of storm water into these expansive soils could cause distress to existing and proposed surfaces and structures.
Also, the NRCS Web Soil Survey indicates that the site is mapped as being underlain by Soil Type D. The near surface onsite clayey soils are considered to have poor permeability. In addition, the site is underlain by a shallow-static ground water table that varies from 3 to 12 feet below the existing site surface. As such, we opine that infiltration of storm water in any amount should not be allowed at the subject site. Any BMPs should be lined with impermeable liners and piped to a suitable discharge facility.
Part 1 Result - Full Infiltration Geotechnical Screening 3 If answers to both Criteria 1 and Criteria 2 are ''Yes", a full infiltration design is potentially feasible based on Geotechnical conditions only.
If either answer to Criteria 1 or Criteria 2 is "No", a full infiltration design is not required.
Result
D Full infiltration Condition
Iii Complete Part 2
3 To be completed using gathered site information and best professional judgement considering the definition ofMEP in the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings.
CCV BMP Design Manual
Form I-8A (Worksheet C.4-1) March 2019 Update
~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Yards at the Bay - Parcel B
(Geocon, Inc. Project No. G2560-52-01) Project Name: _______________________ _ Categorization of Infiltration Feasibility Condition based on Form I-8A1 Geotechnical Conditions (Worksheet C.4-1)
Part 2 - Partial vs. No Infiltration Feasibility Screening Criteria DMA(s) Being Analyzed: Project Phase:
Criteria 3 : Infiltration Rate Screening
3A
3B
Criteria 3
Result
NRCS Type C, D, or "urban/unclassified": Is the mapped hydrologic soil group according to the NRCS Web Soil Survey or UC Davis Soil Web Mapper is Type C, D, or "urban/unclassified" and corroborated by available site soil data? D Yes; the site is mapped as C soils and a reliable infiltration rate of 0.15 in/hr. is used to size partial infiltration BMPS. Answer "Yes" to Criteria 3 Result.
D Yes; the site is mapped as D soils or "urban/unclassified" and a reliable infiltration rate of 0.05 in/hr. is used to size partial infiltration BMPS. Answer "Yes" to Criteria 3 Result.
D No; infiltration testing is conducted (refer to Table D .3-1), continue to Step 3B.
Infiltration Testing Result: Is the reliable infiltration rate (i.e. average measured infiltration rate/2) greater than 0.05 in/hr. and less than or equal to 0.5 in/hr? D Yes; the site may support partial infiltration. Answer "Yes" to Criteria 3 Result.
D No; the reliable infiltration rate (i.e. average measured rate/2) is less than 0.05 in/hr., partial infiltration is not required. Answer "No" to Criteria 3 Result.
Is the estimated reliable infiltration rate (i.e., average measured infiltration rate/2) greater than or equal to 0.05 inches/hour and less than or equal to 0.5 inches/hour at any location within each DMA where runoff can reasonably be routed to a BMP?
D Yes; Continue to Criteria 4.
D No: Skip to Part 2 Result.
Summarize infiltration testing and/ or mapping results (i.e. soil maps and series description used for infiltration rate).
As noted in the referenced project geotechnical report, the site is underlain at relatively shallow depths by clayey soils that are expansive. Infiltration of storm water into these expansive soils could cause distress to existing and proposed surfaces and structures.
Also, the NRCS Web Soil Survey indicates that the site is mapped as being underlain by Soil Type D. The near surface onsite clayey soils are considered to have poor permeability. In addition, the site is underlain by a shallow-static ground water table that varies from 3 to 12 feet below the existing site surface. As such, we opine that infiltration of storm water in any amount should not be allowed at the subject site. Any BMPs should be lined with impermeable liners and piped to a suitable discharge facility.
CCV BMP Design Manual
Form I-8A (Worksheet C.4-1) March 2019 Update
~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Yards at the Bay - Parcel B
Project Name: (Geocon, Inc. Project No. G2560-52-01)
Categorization of Infiltration Feasibility Condition based on Form I-8A1 Geotechnical Conditions (Worksheet C.4-1)
Criteria 4: Geologic/Geotechnical Screening
4A
4A-1
4A-2
4A-3
4B
4B-1
4B-2
4B-3
If all questions in Step 4A are answered ''Yes," continue to Step 2B.
For any "No" answer in Step 4A answer "No" to Criteria 4 Result, and submit an "Infiltration Feasibility Condition Letter" that meets the requirements m Appendix C.1.1 . The geologic/ geotechnical analyses listed in Appendix C.2.1 do not apply to the DMA because one of the following setbacks cannot be avoided and therefore result in the DMA being in a no infiltration condition. The setbacks must be the closest horizontal radial distance from the surface edge (at the overflow elevation) of the BMP.
Can the proposed partial infiltration BMP(s) avoid areas with existing fill materials greater than 5 feet thick?
Can the proposed partial infiltration BMP(s) avoid placement within 10 feet of existing underground utilities, structures, or retaining walls? Can the proposed partial infiltration BMP(s) avoid placement within 50 feet of a natural slope (>25%) or within a distance of 1.5H from fill slopes where H is the height of the fill slope?
Yes No
Yes No
Yes No
When full infiltration is determined to be feasible, a geotechnical investigation report must be prepared that considers the relevant factors identified in Appendix C.2.1.
If all questions in Step 4B are answered ''Yes," then answer ''Yes" to Criteria 4 Result. If there are any "No" answers continue to Step 4C.
Hydroconsolidation. Analyze hydroconsolidation potential per approved ASTM standard due to a proposed full infiltration BMP.
Can partial infiltration BMPs be proposed within the DMA without increasing hydroconsolidation risks?
Expansive Soils. Identify expansive soils (soils with an expansion index greater than 20) and the extent of such soils due to proposed full infiltration BMPs.
Can partial infiltration BMPs be proposed within the DMA without increasing expansive soil risks?
Liquefaction. If applicable, identify mapped liquefaction areas. Evaluate liquefaction hazards in accordance with Section 6.4.2 of the City of San Diego's Guidelines for Geotechnical Reports (2011). Liquefaction hazard assessment shall take into account any increase in groundwater elevation or groundwater mounding that could occur as a result of proposed infiltration or percolation facilities.
Can partial infiltration BMPs be proposed within the DMA without increasing liquefaction risks?
Yes No
Yes K)No
Yes No
CCV BMP Design Manual ~VtForm ·•.: I-8A (Worksheet C.4-1) March 2019 Update .. . . -CllYOf
CHULA VISTA
Project Name: _______________________ _
Categorization of Infiltration Feasibility Condition based on Form I-8A1 Geotechnical Conditions (Worksheet C.4-1)
4B-4
4B-5
4B-6
4C
Criteria 4
Result
Slope Stability. If applicable, perform a slope stability analysis in accordance with the ASCE and Southern California Earthquake Center (2002) Recommended Procedures for Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating Landslide Hazards in California to determine minimum slope setbacks for full infiltration BMPs. See the City of San Diego's Guidelines for Geotechnical Reports (2011) to determine which type of slope stability analysis is required.
Can partial infiltration BMPs be proposed within the DMA without increasing slope stability risks?
Other Geotechnical Hazards. Identify site-specific geotechnical hazards not already mentioned (refer to Appendix C.2.1).
Can partial infiltration BMPs be proposed within the DMA without increasing risk of geologic or geotechnical hazards not already mentioned? Setbacks. Establish setbacks from underground utilities, structures, and/ or retaining walls. Reference applicable ASTM or other recognized standard in the geotechnical report.
Can partial infiltration BMPs be proposed within the DMA using recommended setbacks from underground utilities, structures, and/ or retaining walls?
Mitigation Measures. Propose mitigation measures for each geologic/ geotechnical hazard identified in Step 4B. Provide a discussion on geologic/ geotechnical hazards that would prevent partial infiltration BMPs that cannot be reasonably mitigated in the geotechnical report. See Appendix C.2.1.8 for a list of typically reasonable and typically unreasonable mitigation measures.
Can mitigation measures be proposed to allow for partial infiltration BMPs? If the question in Step 4C is answered ''Yes," then answer ''Yes" to Criteria 4 Result.
If the question in Step 4C is answered "No," then answer "No" to Criteria 4 Result.
Can infiltration of greater than or equal to 0.05 inches/hour and less than or equal to 0.5 inches/hour be allowed without increasing the risk of geologic or geotechnical hazards that cannot be reasonably mitigated to an acceptable level?
CCV BMP Design Manual
Form I-8A (Worksheet C.4-1) March 2019 Update
Yes
Yes
Yes
Yes
Yes
No
No
No
No
ljNo
~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Yards at the Bay - Parcel B
Project Name: (Geocon, Inc. Project No. G2560-52-01)
Categorization of Infiltration Feasibility Condition based on Form I-8A1 Geotechnical Conditions (Worksheet C.4-1)
Summarize findings and basis; provide references to related reports or exhibits.
As noted in the referenced project geotechnical report, the site is underlain at relatively shallow depths by clayey soils that are expansive. Infiltration of storm water into these expansive soils could cause distress to existing and proposed surfaces and structures.
Also, the NRCS Web Soil Survey indicates that the site is mapped as being underlain by Soil Type D. The near surface onsite clayey soils are considered to have poor permeability. In addition, the site is underlain by a shallow-static ground water table that varies from 3 to 12 feet below the existing site surface. As such, we opine that infiltration of storm water in any amount should not be allowed at the subject site. Any BMPs should be lined with impermeable liners and piped to a suitable discharge facility.
Part 2 - Partial Infiltration Geotechnical Screening Result4 Result If answers to both Criteria 3 and Criteria 4 are ''Yes", a partial infiltration design is potentially feasible based on geotechnical D Partial Infiltration conditions only. Condition
If answers to either Criteria 3 or Criteria 4 is "No", then II No Infiltration Condition infiltration of any volume is considered to be infeasible within the site.
4 To be completed using gathered site information and best professional judgement considering the definition of MEP in the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings.
CCV BMP Design Manual
Form I-8A (Worksheet C.4-1) March 2019 Update
~Vt-
·•.: .. . -CllYOf
CHULA VISTA
ATTACHMENT 1E - POLLUTANT CONTROL BMP DESIGN
WORKSHEETS/CALCULATIONS
San Diego County
85 th Percentile lsopluvials
Legend
- 85th PERCENTILE ISOPLUVIAL
[~_~] INCORPORATED CITY
NOTE·
The 85th percentile 1s a 24 hour rainfall total.
It represetns a value such that 85% of the
observed 2_4 hour rainfall totals will be less
than that value.
N
+ ~ .... 0 ! 2 .. S 8
WEG ~ GIS
=t==
85th PERCENTILE
24-HR STORM
DEPTH= 0.58
ATTACHMENT 18: Worksheet B.2-1: DCV
85th percentile 24-hr storm depth from Figure B.1.= 0.58 in Amended Natural A Natural B
BMP Drainage BMP Drainage Impervious Soils (ac) Soils (ac) Soils (ac) DMAID BMPID Area (ac) Area (SF) Area (ac) (C=0.l) (C=0.l) (C=0.14) Project Site 1 THRU 14 26.30 1145628 23.27 3.03
Notes:
1) Equation for composite C factor= (0.9*Impervious Area +C*Pervious Area)/Total Area per BMP Design Manual.
C factors are from Table B.1-1 of August 2021 City BMP Design Manual. 2) Volume Retention will be met with Biofiltration Basins and Impervious Dispersion Design
Natural C Natural D Rain Barrels Capture
Soils (ac) Soils (ac) % Tree Credit Credit Volume
(C=0.23) (C=0.3) Impervious Composite C1 Volume (ct) Volume (cf) (DCV) (CF) 88% 0.808 44727
~Vt-
'~4-•:;:,; --.- Project Name Yards at the bay
........ CITY ---OF
CHUlAVISTA BMP ID Site
um~] ~ f :.Ir :.I ... ~ n I nin,~mr m ru I If; 11(11 I .CitiT'i'r'f.. .~ n 11 I 1 Area draining to the biofiltration BMP
2 Adjusted runoff factor for drainage area (Refer to Appendix B.1 and B.2) 3 Effective impervious area draining to the BMP [Line 1 x Line 21 4 Required area for Evapotranspiration [Line 3 x 0.031
5 Biofiltration BMP Footprint
Landscape Area (must be identified on DS-3247)
Identification
6 Landscape area that meet the requirements
in SD-Band SD-F Fact Sheet (sq. ft.)
Impervious area draining to the landscape
7 area (sq. ft.)
Impervious to Pervious Area ratio
8 [Line 7 /Line 61
Effective Credit Area
1 19980
97921
4.90 9 ~9~ If (Line 8 >1.5, Line 6, Line 7/1.51
10 Sum of Landscape area [sum of Line 9 Id's 1 to 51
2 3009
3144
2096
11 Provided footprint for evapotranspiration [Line 5 + Line 101 Volume Retention Performance Standard
•
1145628 sq.ft.
0.807746
925376 sq.ft.
27761 sq.ft.
3120 sq.ft.
3 4 5
9771
9342
0.96 0.00 0.00
6228 0 0
28304 sq.ft.
31424 sq.ft.
12 Is Line 11 2: Line 4? Volume Retention Performance Standard is Met Fraction ot the pertormance stanctarct met through the BMP tootprmt 13 and/or landscaoine: rune 11/Line 1,_ l
14 Target Volume Retention [Line 10 from Worksheet B.5.21 Volume retention required from other site design BMPs
15 [(1-Line n) x Line 141
Site Design BMP
16 Identification Site Design Type
1 2
3 4
5 Sum of volume retention benefits from other site design BMPs ( e.g. trees; rain barrels etc.). [sum of Line 16 Credits for Id's 1 to 51 Provide documentation of how the site design credit is calculated in the PDP SWQMP.
1.13 1029 cu.ft.
-133. 7323127 cu.ft.
Credit
cu.ft.
cu.ft.
cu.ft.
cu.ft.
cu.ft.
0 cu.ft.
17 Is Line 16 ~ Line 15? Volume Retention Performance Standard is Met ATTACHMENT 18: Worksheet B.2-1: DCV
85th percentile 24-hr storm depth from Figure B.1.= 0.58 in Amended Natural A Natural B
BMP Drainage BMP Drainage Impervious Soils (ac) Soils (ac) Soils (ac) DMAID BMPID Area (ac) Area (SF) Area (ac) (C=0.l) (C=0.l) (C=0.14) 1 1 2.17 94382 1.91 0.26
Notes:
1) Equation for composite C factor= (0.9*Impervious Area +C*Pervious Area)/Total Area per BMP Design Manual.
C factors are from Table B.1-1 of August 2021 City BMP Design Manual. 2) Volume Retention will be met with Biofiltration Basins and Impervious Dispersion Design
Natural C Natural D Rain Barrels Capture
Soils (ac) Soils (ac) % Tree Credit Credit Volume
(C=0.23) (C=0.3) Impervious Composite C1 Volume (ct) Volume (cf) (DCV) (CF) 88% 0.805 3673
~V?- Project Name Yards at the bay
'~..::--,.:t--=,,. ---.-
-.... CllYOF
CHUIAVISTA BMP ID 1
~YA~,. 1~1r, J:l i1ri'fa1rnnrRi]_l 11 tt-: It IC) ~f'~ 11 Ill'I: 1U • - • f~ 1 \ UliT'il ~ m:r:l ~] ~ .... 1 Area draining to the BMP 94382 sq. ft. 2 Adjusted runoff factor for drainage area (Refer to Appendix B.1 and B.2) 0.805176764 3 85th percentile 24-hour rainfall depth 0.58 inches
4 Design capture volume [Line 1 x Line 2 x (Line 3/12)] 3673 cu. ft.
BMP Parameters
5 Surface ponding [ 6 inch minimum, 12 inch maximum] 6 inches 6 Media thickness (18 inches minimum], also add mulch layer and washed 24 inches ASTM 33 fine aggregate sand thickness to this line for sizing calculations 1.&'"1.551.c5aLc .-:>L'-'&.'-'-b'- ,...._ .. ..,_ ......... '-' ~...,.Ll.Yl. .1.""" u ..,L.._, .. 1c1 au-•'-• --Qlll lllVCLL \L~ 7 inches typical) - use o inches if the aggregate is not over the entire bottom 12 inches .r ........ .,_ .... _ 8 Aggregate storage below underdrain invert (3 inches minimum) - use o 3 inches inches if the aggregate is not over the entire bottom surface area 9 Freely drained pore storage of the media 0.2 in/in
10 Porosity of aggregate storage 0.4 in/in
Media filtration rate to be used for sizing (maximum filtration rate of 5 11 in/hr. with no outlet control; if the filtration rate is controlled by the outlet 5 in/hr.
use the outlet controlled rate (includes infiltration into the soil and flow rate through the outlet structure) which will be less than 5 in/hr.) Baseline Calculations
12 Allowable routing time for sizing 6 hours
13 Depth filtered during storm [ Line 11 x Line 12] 30 inches 14 Depth of Detention Storage 16.8 inches [Line 5 + (Line 6 x Line 9) + (Line 7 x Line 10) + (Line 8 x Line 10)] 15 Total Depth Treated [Line 13 + Line 14] 46.8 inches
Option 1- Biofilter 1.5 times the DCV
16 Required biofiltered volume [1.5 x Line 41 5510 cu. ft. 17 Required Footprint [Line 16/ Line 15] x 12 1413 sq. ft.
Option 2 - Store o. 75 of remaining DCV in pores and ponding 18 Required Storage (surface+ pores) Volume (0.75 x Line 41 2755 cu. ft. 19 Required Footprint [Line 18/ Line 14] x 12 1968 sq. ft.
Footprint of the BMP
20 BMP Footprint Sizing Factor (Default 0.03 or an alternative minimum
0.03 footprint sizing factor from Line 11 in Worksheet B.5-4) 21 Minimum BMP Footprint [Line 1 x Line 2 x Line 20] 2280 sq. ft. 22 Footprint of the BMP = Maximum(Minimum(Line 17, Line 19), Line 21) 2280 sq. ft. 23 Provided BMP Footprint 3120 sq. ft.
24 ls Lme 23 <!: Lme Yes, Performance Standard is Met 1 ...... 7 Modular Wetland Sizing Calculations
Impervious
BMP-1D A (sf) Area (sf) %IMP C 1.5 X Q (cfs)
2 105534 104725 99% 0.89
3 143976 142175 99% 0.89
4 87959.8 80174.8 91% 0.83
5 45054 32738 73% 0.68
6 42135 40277 96% 0.86
7 59002 56022 95% 0.86
8 110578 83719 76% 0.71
9 101425 90190 89% 0.81
10 123084 98265 80% 0.74
11 57360 53772 94% 0.85
12 80456 78622 98% 0.88
13 54752 47467 87% 0.79
14 101899 96224 94% 0.86
(*) Please note BMP sizes are based on specific vertical constraints per OMA.
0.650
0.882
0.502
0.211
0.251
0.349
0.537
0.567
0.626
0.336
0.489
0.299
0.600
Q100 (cfs)
15.0 20.1
12.2 5.1
5.8 7.0
14.2 12.7
15.9 7.4
11.1 8.8
3.4 *BMPSize
MWS-L-8-20
MWS-L-8-24
MWS-L-8-20
MWS-L-8-8
MWS-L-8-8
MWS-L-8-12
MWS-L-8-16
MWS-L-8-12
MWS-L-8-16
MWS-L-8-8
MWS-L-8-20
MWS-L-8-8
MWS-L-8-16
SITE SPECIFIC DATA
PROJECT NUMBER
PROJECT NAME
PROJECT LOCATION
STRUCTURE ID
TREATMENT REQUIRED
FLOW BASED (CFS}
0.231
PEAK BYPASS REQUIRED (CFS} - IF APPLICABLE OFFLINE
PIPE DATA I.E. MATERIAL DIAMETER
INLET PIPE 1
INLET PIPE 2 NIA NIA NIA
OUTLET PIPE
PRETREATMENT BIOFILTRA TION DISCHARGE
RIM ELEVATION
SURFACE LOAD PEDESTRIAN
NOTES:
* PRELIMINARY NOT FOR CONSTRUCT/ON
INSTALLATION NOTES
1. CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS AND
INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE SYSTEM AND
APPURTENANCES IN ACCORDANCE WITH THIS DRAWING AND THE
MANUFACTURERS' SPECIFICATIONS, UNLESS OTHERWISE STATED IN MANUFACTURER'S CONTRACT.
2. UNIT MUST BE INSTALLED ON LEVEL BASE. MANUFACTURER
RECOMMENDS A MINIMUM 6 » LEVEL ROCK BASE UNLESS SPECIFIED BY THE PROJECT ENGINEER. CONTRACTOR IS RESPONSIBLE FOR VERIFYING PROJECT ENGINEER'S RECOMMENDED BASE SPECIFICATIONS.
WETL.ANDMEDIA
BED
PATENTED
PERIMETER
VOID AREA
null
IE IN
C/L
DRAIN DOWN UNE
PLAN VIEW
VEtmCAL
UNDERDRAJN
MANIFOLD
OUTLET PIPE
SEE NOTES
null
RIM/FG
FLOW CONTROL
RISER
td::i::!i:zrl~ ::i.:I:Ii:r:tt;:b:£:~cl.l _ _ _ _ _ _ _ null IE OUT
4. CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL CONNECTING PIPES. ALL PIPES MUST BE FLUSH WITH INSIDE SURFACE OF
CONCRETE (PIPES CANNOT INTRUDE BEYOND FLUSH). INVERT OF OUTFLOW PIPE MUST BE FLUSH WITH DISCHARGE CHAMBER FLOOR.
ALL PIPES SHALL BE SEALED WATERTIGHT PER MANUFACTURER's STANDARD CONNECTION DETAIL.
5. CONTRACTOR RESPONSIBLE FOR INSTALLATION OF ALL PIPES, RISERS, MANHOLES, AND HATCHES. CONTRACTOR TO USE GROUT AND/OR
BRICKS TO MATCH COVERS WITH FINISHED SURFACE UNLESS SPECIFIED OTHERWISE.
6-~ .-----r=g:-----. f--6·
6. VEGETATION SUPPLIED AND INSTALLED BY OTHERS. ALL UNITS WITH
VEGETATION MUST HAVE DRIP OR SPRAY IRRIGATION SUPPLIED AND INSTALLED BY OTHERS.
7. CONTRACTOR RESPONSIBLE FOR CONTACTING CONTECH FOR ACTIVATION OF UNIT. MANUFACTURER'S WARRANTY IS VOID WITHOUT PROPER ACTIVATION BY A CONTECH REPRESENTATIVE.
GENERAL NOTES
1. MANUFACTURER TO PROVIDE ALL MATERIALS UNLESS OTHERWISE NOTED.
2. ALL DIMENSIONS, ELEVATIONS, SPECIFICATIONS AND CAPACITIES ARE SUBJECT TO CHANGE. FOR PROJECT SPECIFIC DRAWINGS DETAILING EXACT DIMENSIONS, WEIGHTS AND ACCESSORIES PLEASE CONTACT CONTECH.
ELEVATION VIEW
~bS
FOR PATENT INFORMATION, GO TO
www.ContechES.com/lP
C(1jNTEcH·
ENGINEERED SOLUTIONS LLC
www.CordechES.com
LEFT END VIEW
RIGHT END VIEW
TREATMENT FLOW (CFS) 0.577
OPERATING HEAD (FT) 8.5
PRETREATMENT LOADING RATE (GPM/SF} 5.1
WETLAND MEDIA LOADING RATE (GPM/SF) 1.0
MWS-L-8-8-V
STORMWATER 8/0FILTRATION SYSTEM
STANDARD DETAIL
SITE SPECIFIC DATA
PROJECT NUMBER
PROJECT NAME
PROJECT LOCATION
STRUCTURE ID
TREATMENT REQUIRED
VOLUME BASED {CF) FLOW BASED {CFS)
N/A 0.346
PEAK BYPASS REQUIRED {CFS) - IF APPLICABLE OFFLINE
PIPE DATA I.E. MATERIAL DIAMETER
INLET PIPE 1
INLET PIPE 2 NIA NIA NIA
OUTLET PIPE
PRETREATMENT BIOFILTRA TION DISCHARGE
RIM ELEVATION
SURFACE LOAD PEDESTRIAN
FRAME & COVER 2EA ¢JO" OPEN PLANTER ¢24"
NOTES:
* PRELIMINARY NOT FOR CONSTRUCTION
INSTALLATION NOTES
1. CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS AND
INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE SYSTEM AND
APPURTENANCES IN ACCORDANCE WITH THIS DRAWING AND THE
MANUFACTURERS SPECIFICATIONS, UNLESS OTHERWISE STATED IN MANUFACTURERS CONTRACT.
2. UNIT MUST BE INSTALLED ON LEVEL BAS£ MANUFACTURER
RECOMMENDS A MINIMUM 6" LEVEL ROCK BASE UNLESS SPECIFIED BY THE PROJECT ENGINEER. CONTRACTOR IS RESPONSIBLE TO VERIFY PROJECT ENGINEERS RECOMMENDED BASE SPECIF/CATIONS.
4. CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL CONNECTING PIPES. ALL PIPES MUST BE FLUSH WITH INSIDE SURFACE OF
CONCRETE. {PIPES CANNOT INTRUDE BEYOND FLUSH). INVERT OF OUTFLOW PIPE MUST BE FLUSH WITH DISCHARGE CHAMBER FLOOR.
ALL PIPES SHALL BE SEALED WATER TIGHT PER MANUFACTURERS STANDARD CONNECTION DETAIL.
5. CONTRACTOR RESPONSIBLE FOR INSTALLATION OF ALL RISERS, MANHOLES, AND HATCHES. CONTRACTOR TO GROUT ALL MANHOLES AND HATCHES TO MATCH FINISHED SURFACE UNLESS SPECIFIED OTHERWISE.
6. VEGETATION SUPPLIED AND INSTALLED BY OTHERS. ALL UNITS WITH
VEGETATION MUST HAVE DRIP OR SPRAY IRRIGATION SUPPLIED AND INSTALLED BY OTHERS.
7. CONTRACTOR RESPONSIBLE FOR CONTACTING BIO CLEAN FOR
ACTIVATION OF UNIT. MANUFACTURERS WARRANTY IS VOID WITH OUT PROPER ACTIVATION BY A BIO CLEAN REPRESENTATIVE.
GENERAL NOTES
WETLANDMEDIA
BED
PATENTED
PERIMETER
VOID AREA
C/L
VERTICAL
UNDERDRAIN
MANIFOLD
~---1--,;..'.~~~::::::::: ~~~➔~ ~~~~=:'.::1~~--I- ~
PRE-FILTER
CARTRIDGE
null
IE IN
C/L
null
RIM/FG
t!:3::;:i.::l!l!f~~~ rli!:l!Z'.'tln::m:>l:'i:!rtt:mr~tL~ --------- i::::::ijf-----,-,~~u~~1u--=T ··~ .--------~r=~:--------J-•·
ELEVATION VIEW
VEGETATION~
PLANT
ESTABLISHMENT
MEDIA
1. MANUFACTURER TO PROVIDE ALL MATERIALS UNLESS OTHERWISE NOTED.
2. ALL DIMENSIONS, ELEVATIONS, SPECIFICATIONS AND CAPACITIES ARE SUBJECT TO CHANGE. FOR PROJECT SPECIFIC DRAWINGS DETAILING EXACT DIMENSIONS, WEIGHTS AND ACCESSORIES PLEASE CONTACT BIO CLEAN.
~- .. - PROPRIETARY AND CONFIDENTIAL:
~ TLANb! TH£ INFORMATION CONTAINED IN THIS DOCUMENT IS TH£ SOL£ PROPER'TY OF FORTfRRA AND ITS CO/JPANl£S. THIS OOCU/JfNT, :: ::t=,; ~ :~~ ~ 4~=- OF NOR ANY PART THEREOF, A44Y Bf USED, RfPRODUCED OR I.IODIRED Bio6 Clean
7.1174.Jll; AJIIUl6; RBJ,1fD RJRt/1111 W.TENIS OR IN ANY A44NN£R WITH OUT TH£ WR1TTfN CONSENT OF FORTfRRA. 01IER W.TENIS PE10NIJ
LEFT END VIEW
RIGHT END VIEW
TREATMENT FLOW (CFS) 0.577
OPERATING HEAD {FT) 5.7
PRETREATMENT LOADING RATE {GPM/SF} 3.4
WETLAND MEDIA LOADING RATE {GPM/SF) 1.0
MWS-L-8-12-V
STORMWATER 8/0FILTRA TION SYSTEM
STANDARD DETAIL
SITE SPECIFIC DATA
PROJECT NUMBER
PROJECT NAME
PROJECT LOCATION
STRUCTURE ID
TREATMENT REQUIRED
VOLUME BASED {CF) FLOW BASED {CFS)
N/A 0.462
PEAK BYPASS REQUIRED {CFS) - IF APPLICABLE OFFLINE
PIPE DATA I.E. MATERIAL DIAMETER
INLET PIPE 1
INLET PIPE 2 NIA NIA NIA
OUTLET PIPE
PRETREATMENT BIOFILTRA TION DISCHARGE
RIM ELEVATION
SURFACE LOAD PEDESTRIAN
FRAME & COVER 2EA ¢JO" OPEN PLANTER ¢24"
NOTES:
* PRELIMINARY NOT FOR CONSTRUCTION
INSTALLATION NOTES
1. CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS AND
INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE SYSTEM AND
APPURTENANCES IN ACCORDANCE WITH THIS DRAWING AND THE
MANUFACTURERS SPECIFICATIONS, UNLESS OTHERWISE STATED IN MANUFACTURERS CONTRACT.
WETLANDMEDIA
BED
PATENTED
PERIMETER
VOID AREA
INLET PIPE
SEE NOTES
2. UNIT MUST BE INSTALLED ON LEVEL BAS£ MANUFACTURER
RECOMMENDS A MINIMUM 6" LEVEL ROCK BASE UNLESS SPECIFIED BY null THE PROJECT ENGINEER. CONTRACTOR IS RESPONSIBLE TO VERIFY IE IN PROJECT ENGINEERS RECOMMENDED BASE SPECIF/CATIONS.
PRE-FILTER
CARTRIDGE
C/L
PLAN VIEW
C/L
VERTICAL
UNDERDRAIN
MANIFOLD
null
RIM/FG
FLOW
CONTROL
RISER
~~:m:.::i;m:E!!'!~l!!:l:~~~= ~$~m.:r:t'fum;mrl;:i;:;~ h1---------i::::::lo..------,,;~u~~u=T VEGETATION~
PLANT
ESTABLISHMENT
MEDIA ,..........,:r,,m.~ r,,;,r:.a::,;
6"_J _-----a'-o"-----
-I'-· ----------9'-o"------
LEFT END VIEW
4. CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL CONNECTING PIPES. ALL PIPES MUST BE FLUSH WITH INSIDE SURFACE OF
CONCRETE. {PIPES CANNOT INTRUDE BEYOND FLUSH). INVERT OF OUTFLOW PIPE MUST BE FLUSH WITH DISCHARGE CHAMBER FLOOR.
ALL PIPES SHALL BE SEALED WATER TIGHT PER MANUFACTURERS STANDARD CONNECTION DETAIL.
5. CONTRACTOR RESPONSIBLE FOR INSTALLATION OF ALL RISERS, MANHOLES, AND HATCHES. CONTRACTOR TO GROUT ALL MANHOLES AND HATCHES TO MATCH FINISHED SURFACE UNLESS SPECIFIED OTHERWISE. ..-, .-----------~r=g:-----------. r-·· RIGHT END VIEW
6. VEGETATION SUPPLIED AND INSTALLED BY OTHERS. ALL UNITS WITH
VEGETATION MUST HAVE DRIP OR SPRAY IRRIGATION SUPPLIED AND INSTALLED BY OTHERS.
7. CONTRACTOR RESPONSIBLE FOR CONTACTING BIO CLEAN FOR
ACTIVATION OF UNIT. MANUFACTURERS WARRANTY IS VOID WITH OUT PROPER ACTIVATION BY A BIO CLEAN REPRESENTATIVE.
GENERAL NOTES
1. MANUFACTURER TO PROVIDE ALL MATERIALS UNLESS OTHERWISE NOTED.
2. ALL DIMENSIONS, ELEVATIONS, SPECIFICATIONS AND CAPACITIES ARE SUBJECT TO CHANGE. FOR PROJECT SPECIFIC DRAWINGS DETAILING EXACT DIMENSIONS, WEIGHTS AND ACCESSORIES PLEASE CONTACT BIO CLEAN.
ELEVATION VIEW
~- .. - PROPRIETARY AND CONFIDENTIAL:
~ TLANb! TH£ INFORMATION CONTAINED IN THIS OOCU/JfNT IS TH£ SOL£ PROPfR'TY OF FORTfRRA AND ITS CO/JPANlfS. THIS OOCU/JfNT, :: ::t=,; ~ :~~ ~ 4~=- OF NOR ANY PART THEREOF, A44Y Bf USED, RfPRODUCED OR I.IODIRED
7.1174.Jll; AJIIUl6; Rt/J.1FD RJRt/1111 W.TENIS OR IN ANY A44NN£R WITH OUT TH£ WR1TTfN CONSENT OF FORTfRRA. 01IER W.TENIS PE10NIJ Bio6 Clean
TREATMENT FLOW (CFS) 0.577
OPERATING HEAD {FT) 4.2
PRETREATMENT LOADING RATE {GPM/SF} 2.5
WETLAND MEDIA LOADING RATE {GPM/SF) 1.0
MWS-L-8-16-V
STORMWATER 8/0FILTRA TION SYSTEM
STANDARD DETAIL
SITE SPECIFIC DATA
PROJECT NUMBER
PROJECT NAME
PROJECT LOCATION
STRUCTURE ID
TREATMENT REQUIRED
VOLUME BASED {CF) FLOW BASED {CFS)
N/A 0.577
PEAK BYPASS REQUIRED {CFS) - IF APPLICABLE OFFLINE
PIPE DATA I.E. MATERIAL DIAMETER
INLET PIPE 1
INLET PIPE 2
OUTLET PIPE
PRETREATMENT BIOFILTRA TION DISCHARGE
RIM ELEVATION
SURFACE LOAD PEDESTRIAN
FRAME & COVER JEA ¢JO" OPEN PLANTER ¢24"
NOTES:
* PRELIMINARY NOT FOR CONSTRUCTION
INSTALLATION NOTES
1. CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS AND
INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE SYSTEM AND
APPURTENANCES IN ACCORDANCE WITH THIS DRAWING AND THE
MANUFACTURERS SPECIFICATIONS, UNLESS OTHERWISE STATED IN MANUFACTURERS CONTRACT.
2. UNIT MUST BE INSTALLED ON LEVEL BAS£ MANUFACTURER
RECOMMENDS A MINIMUM 6" LEVEL ROCK BASE UNLESS SPECIFIED BY THE PROJECT ENGINEER. CONTRACTOR IS RESPONSIBLE TO VERIFY PROJECT ENGINEERS RECOMMENDED BASE SPECIF/CATIONS.
4. CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL CONNECTING PIPES. ALL PIPES MUST BE FLUSH WITH INSIDE SURFACE OF
CONCRETE. {PIPES CANNOT INTRUDE BEYOND FLUSH). INVERT OF OUTFLOW PIPE MUST BE FLUSH WITH DISCHARGE CHAMBER FLOOR.
ALL PIPES SHALL BE SEALED WATER TIGHT PER MANUFACTURERS STANDARD CONNECTION DETAIL.
5. CONTRACTOR RESPONSIBLE FOR INSTALLATION OF ALL RISERS, MANHOLES, AND HATCHES. CONTRACTOR TO GROUT ALL MANHOLES AND HATCHES TO MATCH FINISHED SURFACE UNLESS SPECIFIED OTHERWISE.
6. VEGETATION SUPPLIED AND INSTALLED BY OTHERS. ALL UNITS WITH
VEGETATION MUST HAVE DRIP OR SPRAY IRRIGATION SUPPLIED AND INSTALLED BY OTHERS.
7. CONTRACTOR RESPONSIBLE FOR CONTACTING BIO CLEAN FOR
ACTIVATION OF UNIT. MANUFACTURERS WARRANTY IS VOID WITH OUT PROPER ACTIVATION BY A BIO CLEAN REPRESENTATIVE.
GENERAL NOTES
WETLANDMEDIA BED
null
IE IN
VERTICAL UNDERDRAIN MANIFOLD
DRAIN
DOWN LINE
PLAN VIEW
C/L
OUTLET PIPE
SEE NOTES
null
RIM/FG
··~ .--------------~~:=~:--------------. r-··
ELEVATION VIEW
VEGETATION~
PLANT
ESTABLISHMENT •
MEDIA
6"_J _-----a'-o"-----
-I'-· ----------9'-o"------
LEFT END VIEW
RIGHT END VIEW
TREATMENT FLOW (CFS)
OPERATING HEAD {FT)
PRETREATMENT LOADING RATE {GPM/SF}
WETLAND MEDIA LOADING RATE {GPM/SF)
0.577
3.4 2.0
1.0 1. MANUFACTURER TO PROVIDE ALL MATERIALS UNLESS OTHERWISE NOTED.
2. ALL DIMENSIONS, ELEVATIONS, SPECIFICATIONS AND CAPACITIES ARE SUBJECT TO CHANGE. FOR PROJECT SPECIFIC DRAWINGS DETAILING EXACT DIMENSIONS, WEIGHTS AND ACCESSORIES PLEASE CONTACT BIO CLEAN.
~- .. - PROPRIETARY AND CONFIDENTIAL:
~ TLANb! TH£ INFORMATION CONTAINED IN THIS OOCU/JfNT IS TH£ SOL£ PROPfR'TY OF FORTfRRA AND ITS CO/JPANlfS. THIS OOCU/JfNT, :: ::t=,; ~ :~~ ~ 4~=- OF NOR ANY PART THEREOF, A44Y Bf USED, RfPRODUCED OR I.IODIRED Bio6 Clean MWS-L-8-20-V STORMWATER 8/0FILTRA TION SYSTEM
STANDARD DETAIL 7.1174.Jll; AJIIUl6; RBJ,1fD RJRt/1111 W.TENIS OR IN ANY A44NN£R WITH OUT TH£ WRJTTfN CONSENT OF FORTfRRA. 01IER W.TENIS PE10NIJ
SITE SPECIFIC DATA
PROJECT NUMBER
PROJECT NAME
PROJECT LOCATION
STRUCTURE ID
TREATMENT REQUIRED
TREATMENT FLOW {CFS}
OPERA TING HEAD {FT)
PRETREATMENT LOADING RATE {GPM/SF}
WETLAND MEDIA LOADING RATE {GPM/SF)
PEAK BYPASS REQUIRED {CFS) - IF APPLICABLE
PIPE DATA I.£ MATERIAL DIAMETER
INLET PIPE 1
INLET PIPE 2
OUTLET PIPE
PRETREATMENT BIOFILTRA TION DISCHARGE
RIM ELEVATION
SURFACE LOAD
NOTES:
INSTALLATION NOTES
1. CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS
AND INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE
SYSTEM AND APPURTENANCES IN ACCORDANCE WITH THIS
DRAWING AND THE MANUFACTURER's SPECIFICATIONS, UNLESS
OTHERWISE STATED IN MANUFACTURER'S CONTRACT.
2. UNIT MUST BE INSTALLED ON LEVEL BAS£ MANUFACTURER
RECOMMENDS A MINIMUM 6" LEVEL ROCK BASE UNLESS
SPECIFIED BY THE PROJECT ENGINEER. CONTRACTOR IS
RESPONSIBLE FOR VERIFYING PROJECT ENGINEER'S
RECOMMENDED BASE SPECIFICATIONS.
3. CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL
CONNECTING PIPES. ALL PIPES MUST BE FLUSH WITH INSIDE
SURFACE OF CONCRETE {PIPES CANNOT INTRUDE BEYOND
FLUSH). INVERT OF OUTFLOW PIPE MUST BE FLUSH WITH
DISCHARGE CHAMBER FLOOR. ALL PIPES SHALL BE SEALED
WATERTIGHT PER MANUFACTURER'S STANDARD CONNECTION DETAIL.
4. CONTRACTOR RESPONSIBLE FOR CONTACTING CONTECH FOR
ACTIVATION OF UNIT. MANUFACTURER'S WARRANTY IS VOID
WITHOUT PROPER ACTIVATION BY A CONTECH REPRESENTATIVE
5. VERTICAL HEIGHT VARIES BASED ON SITE SPECIFIC
REQUIREMENTS.
IC)
~
~~
WETLANDMEDIA BED
DRAIN
DOWN LINE
PLAN VIEW
C/L
VERTICAL UNDERDRAIN MANIFOLD
BYPASS OVERFLOW WEIR
PLANT ESTABLISHMENT
MEDIA
C/L
IE IN
LEFT END VIEW
RIM/FG
'c:,~ FLOW
~~I _i_~ ~~9µ .!l:!~~~~~ ~===±;µ:!:!ia~;pz;:;~~~ ----: -------------- ~ ---~~::::YIL--- I
(Q)_ ---~---~~
------------------24'-o·------------------
~M
FOR PATENT INFORMATION, GO TO
www.ContechES.com/lP
ELEVATION VIEW
PROPRIETARY AND CONFIDENTIAL:
TH£ INFORMATION CONTNNED IN THIS DOCUMENT IS TH£ SOL£
PROPERTY OF CONTECH ANO ITS COMPANIES. THIS DOCUMENT,
NOR ANY PART THEREOF, MAY 8£ US£D, R£PROOUC£D OR MODIFIED IN ANY MANNER WITH OUT TH£ WRITT£N CONSENT OF CONTECH.
Ci'jNTECH.
ENGINEERED SOLUTIONS LLC
www.ContachES.com
IE OUT
RIGHT END VIEW
MWS-L-8-24-V
STORMWATER 8/0FILTRA TION SYSTEM
STANDARD DETAIL
WASH ING T ON ST AT E
0 E P A R T M E N T O F
E C O L O G Y
July 2017
GENERAL USE LEVEL DESIGNATION FOR BASIC, ENHANCED, AND
PHOSPHORUS TREATMENT
Ecology's Decision:
Forthe
MWS-Linear Modular Wetland
Based on Modular Wetland Systems, Inc. application submissions, including the Technical Evaluation Report, dated April 1, 2014, Ecology hereby issues the following use level designation:
1. General use level designation (GULD) for the MWS-Linear Modular Wetland Stormwater Treatment System for Basic treatment
• Sized at a hydraulic loading rate of 1 gallon per minute (gpm) per square foot (sq ft) of wetland cell surface area. For moderate pollutant loading rates (low to medium density residential basins), size the Prefilters at 3.0 gpm/sq ft of cartridge surface area. For high loading rates ( commercial and industrial basins), size the Prefilters at 2.1 gpm/sq ft of cartridge surface area.
2. General use level designation (GULD) for the MWS-Linear Modular Wetland Stormwater Treatment System for Phosphorus treatment
• Sized at a hydraulic loading rate of 1 gallon per minute (gpm) per square foot (sq ft) of wetland cell surface area. For moderate pollutant loading rates (low to medium density residential basins), size the Prefilters at 3.0 gpm/sq ft of cartridge surface area. For high loading rates ( commercial and industrial basins), size the Prefilters at 2.1 gpm/sq ft of cartridge surface area.
3. General use level designation (GULD) for the MWS-Linear Modular Wetland Stormwater Treatment System for Enhanced treatment
• Sized at a hydraulic loading rate of 1 gallon per minute (gpm) per square foot (sq ft) of wetland cell surface area. For moderate pollutant loading rates (low to medium density residential basins), size the Prefilters at 3.0 gpm/sq ft of cartridge surface area. For high loading rates ( commercial and industrial basins), size the Prefilters at 2.1 gpm/sq ft of cartridge surface area.
4. Ecology approves the MWS - Linear Modular Wetland Stormwater Treatment System units for Basic, Phosphorus, and Enhanced treatment at the hydraulic loading rate listed above.
Designers shall calculate the water quality design flow rates using the following procedures:
• Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology-approved continuous runoff model.
• Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual.
• Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility.
5. These use level designations have no expiration date but may be revoked or amended by Ecology, and are subject to the conditions specified below.
Ecology's Conditions of Use:
Applicants shall comply with the following conditions:
1. Design, assemble, install, operate, and maintain the MWS - Linear Modular Wetland Stormwater Treatment System units, in accordance with Modular Wetland Systems, Inc. applicable manuals and documents and the Ecology Decision.
2. Each site plan must undergo Modular Wetland Systems, Inc. review and approval before site installation. This ensures that site grading and slope are appropriate for use of a MWS - Linear Modular Wetland Stormwater Treatment System unit.
3. MWS-Linear Modular Wetland Stormwater Treatment System media shall conform to the specifications submitted to, and approved by, Ecology.
4. The applicant tested the MWS - Linear Modular Wetland Stormwater Treatment System with an external bypass weir. This weir limited the depth of water flowing through the media, and therefore the active treatment area, to below the root zone of the plants. This GULD applies to MWS - Linear Modular Wetland Stormwater Treatment Systems whether plants are included in the final product or not.
5. Maintenance: The required maintenance interval for stormwater treatment devices is often dependent upon the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a "one size fits all" maintenance cycle for a particular model/size of manufactured filter treatment device. • Typically, Modular Wetland Systems, Inc. designs MWS - Linear Modular Wetland systems for a target prefilter media life of 6 to 12 months. • Indications of the need for maintenance include effluent flow decreasing to below the design flow rate or decrease in treatment below required levels. • Owners/operators must inspect MWS - Linear Modular Wetland systems for a minimum of twelve months from the start of post-construction operation to determine site-specific maintenance schedules and requirements. You must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to SWMMEW, the wet season in eastern Washington is October 1 to June 30). After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections.
• Conduct inspections by qualified personnel, follow manufacturer's guidelines, and use methods capable of determining either a decrease in treated effluent flowrate and/or a decrease in pollutant removal ability.
• When inspections are performed, the following findings typically serve as maintenance triggers:
• Standing water remains in the vault between rain events, or • Bypass occurs during storms smaller than the design storm. • If excessive floatables (trash and debris) are present (but no standing water or excessive sedimentation), perform a minor maintenance consisting of gross solids removal, not prefilter media replacement.
• Additional data collection will be used to create a correlation between pretreatment chamber sediment depth and pre-filter clogging (see Issues to be Addressed by the Company section below)
6. Discharges from the MWS - Linear Modular Wetland Stormwater Treatment System units shall not cause or contribute to water quality standards violations in receiving waters.
Applicant:
Applicant's Address:
Application Documents:
Modular Wetland Systems, Inc.
PO. Box 869
Oceanside, CA 92054
• Original Application for Conditional Use Level Designation, Modular Wetland System, Linear Stormwater Filtration System Modular Wetland Systems, Inc., January 2011 • Quality Assurance Project Plan: Modular Wetland system - Linear Treatment System performance Monitoring Project, draft, January 2011.
• Revised Application for Conditional Use Level Designation, Modular Wetland System, Linear Stormwater Filtration System Modular Wetland Systems, Inc., May 2011 • Memorandum: Modular Wetland System-Linear GULD Application Supplementary Data, April 2014
• Technical Evaluation Report: Modular Wetland System Stormwater Treatment System Performance Monitoring, April 2014.
Applicant's Use Level Request:
General use level designation as a Basic, Enhanced, and Phosphorus treatment device in accordance with Ecology's Guidance for Evaluating Emerging Stormwater Treatment Technologies Technology Assessment Protocol - Ecology (TAPE) January 2011 Revision.
Applicant's Performance Claims:
• The MWS - Linear Modular wetland is capable of removing a minimum of 80-percent of TSS from stormwater with influent concentrations between 100 and 200 mg/1. • The MWS - Linear Modular wetland is capable of removing a minimum of 50-percent of Total Phosphorus from stormwater with influent concentrations between 0.1 and 0.5 mg/1.
• The MWS - Linear Modular wetland is capable of removing a minimum of 30-percent of dissolved Copper from stormwater with influent concentrations between 0.005 and
0.020 mg/1.
• The MWS - Linear Modular wetland is capable of removing a minimum of 60-percent of dissolved Zinc from stormwater with influent concentrations between 0.02 and 0.30 mg/1.
Ecology Recommendations:
• Modular Wetland Systems, Inc. has shown Ecology, through laboratory and fieldtesting, that the MWS - Linear Modular Wetland Stormwater Treatment System filter system is capable of attaining Ecology's Basic, Total phosphorus, and Enhanced treatment goals.
Findings of Fact:
Laboratory Testing
The MWS-Linear Modular wetland has the:
• Capability to remove 99 percent of total suspended solids (using Sil-Co-Sil 106) in a quarter-scale model with influent concentrations of 270 mg/L. • Capability to remove 91 percent of total suspended solids (using Sil-Co-Sil 106) in laboratory conditions with influent concentrations of 84.6 mg/L at a flow rate of 3 .0 gpm per square foot of media.
• Capability to remove 93 percent of dissolved Copper in a quarter-scale model with influent concentrations of 0.757 mg/L.
• Capability to remove 79 percent of dissolved Copper in laboratory conditions with influent concentrations of 0.567 mg/Lat a flow rate of 3.0 gpm per square foot of media.
• Capability to remove 80.5-percent of dissolved Zinc in a quarter-scale model with influent concentrations of 0.95 mg/Lat a flow rate of 3.0 gpm per square foot of media. • Capability to remove 78-percent of dissolved Zinc in laboratory conditions with influent concentrations of 0.75 mg/Lat a flow rate of 3.0 gpm per square foot of media.
Field Testing
• Modular Wetland Systems, Inc. conducted monitoring of an MWS-Linear (Model # MWS-L-4-13) from April 2012 through May 2013, at a transportation maintenance facility in Portland, Oregon. The manufacturer collected flow-weighted composite samples of the system's influent and effluent during 28 separate storm events. The system treated approximately 75 percent of the runoff from 53.5 inches ofrainfall during the monitoring period. The applicant sized the system at 1 gpm/sq ft. (wetland media) and 3gpm/sq ft. (prefilter).
• Influent TSS concentrations for qualifying sampled storm events ranged from 20 to 339 mg/L. Average TSS removal for influent concentrations greater than 100 mg/L (n=7) averaged 85 percent. For influent concentrations in the range of 20-100 mg/L (n=18), the upper 95 percent confidence interval about the mean effluent concentration was
12.8 mg/L.
• Total phosphorus removal for 17 events with influent TP concentrations in the range of
0.1 to 0.5 mg/L averaged 65 percent. A bootstrap estimate of the lower 95 percent confidence limit (LCL95) of the mean total phosphorus reduction was 58 percent. • The lower 95 percent confidence limit of the mean percent removal was 60.5 percent for dissolved zinc for influent concentrations in the range of 0.02 to 0.3 mg/L (n=l 1).
The lower 95 percent confidence limit of the mean percent removal was 32.5 percent for dissolved copper for influent concentrations in the range of 0.005 to 0.02 mg/L (n=14) at flow rates up to 28 gpm (design flow rate 41 gpm). Laboratory test data augmented the data set, showing dissolved copper removal at the design flow rate of 41 gpm (93 percent reduction in influent dissolved copper of 0.757 mg/L).
Issues to be addressed by the Company:
1. Modular Wetland Systems, Inc. should collect maintenance and inspection data for the first year on all installations in the Northwest in order to assess standard maintenance requirements for various land uses in the region. Modular Wetland Systems, Inc. should use these data to establish required maintenance cycles.
2. Modular Wetland Systems, Inc. should collect pre-treatment chamber sediment depth data for the first year of operation for all installations in the Northwest. Modular Wetland Systems, Inc. will use these data to create a correlation between sediment depth and pre-filter clogging.
Technology Description:
Download at http://www.modularwetlands.com/
Contact Information:
Applicant: Zach Kent
BioClean A Forterra Company.
398 Vi9a El Centro
Oceanside, CA 92058
zach.kent@(orterrabp.com
Applicant website: http://www.modularwetlands.com/
Ecology web link: http://www.ecy. wa. gov/programs/wg/stormwater/newtech/index.html Ecology:
Revision History
Date
June 2011
September 2012
January 2013
December 2013
April 2014
December 2015
July 2017
Douglas C. Howie, P .E.
Department of Ecology
Water Quality Program
(360) 407-6444
douglas.howie@ecy. wa. gov
Revision
Original use-level-designation document
Revised dates for TER and expiration
Modified Design Storm Description, added Revision Table, added maintenance discussion, modified format in accordance with Ecology standard
Updated name of Applicant
Approved GULD designation for Basic, Phosphorus, and Enhanced treatment
Updated GULD to document the acceptance of MWS-Linear
Modular Wetland installations with or without the inclusion of plants Revised Manufacturer Contact Information (name, address, and email)
Appendix E.20
BF-3: Proprietary Bio:filtration Systems
l!.20 BF-3 Proprietary Biofiltration Systems
The purpose of this fact sheet is to help explain the potential role of proprietary BMPs in meeting biofiltration requirements, when full retention of the DCV is not feasible. The fact sheet does not describe design criteria like the other fact sheets in this appendix because this information varies by BMP product model.
Criteria for Use of a Proprietary BMP as a Biofiltration BMP A proprietary BMP may be acceptable as a "biofiltration BMP" under the following conditions:
1. The BMP meets the minimum design criteria listed in Appendix F, including the pollutant treatment performance standard in Appendix F .1;
2. The BMP meets the performance standard for compact BMPs in Table B.5-1 in Appendix B.5;
3. The BMP is designed and maintained in a manner consistent with its performance certifications (See explanation in Appendix F.2); and
4. The BMP is acceptable at the discretion of the City Engineer. In determining the acceptability of a BMP, the City Engineer should consider, as applicable, (a) the data submitted; (b) representativeness of the data submitted; (c) consistency of the BMP performance claims with pollutant control objectives; certainty of the BMP performance claims; (d) for projects within the public right of way and/ or public projects: maintenance requirements, cost of maintenance activities, relevant previous local experience with operation and maintenance of the BMP type, ability to continue to operate the system in event that the vending company is no longer operating as a business; and (e) other relevant factors. If a proposed BMP is not accepted by the City Engineer, a written explanation/ reason will be provided to the applicant.
Guidance for Sizing a Proprietary BMP as a Biofiltration BMP Proprietary biofiltration BMPs must meet the same sizing guidance as non-proprietary BMPs. Sizing is typically based on capturing and treating 1.50 times the DCV not reliably retained. Guidance for sizing biofiltration BMPs to comply with requirements of this manual is provided in Appendix B.5 and Appendix F .2.
Maintenance Overview
Refer to manufacturer for maintenance information.
BMP Design Manual-Appendices
August 2021 Update E-122
1..18 BF-1 Biofiltration
Location: 43rd Street and Logan Avenue, San Diego, California Description
Appendix E.18
BF-1: Biofiltration
MS4 Permit Catego
Biofiltration
Manual Category
Biofiltration
Applicable Performance
Standard
Pollutant Control
Flow Control
Primary Benefits
Treatment
Volume Reduction (Incidental)
Peak Flow Attenuation (Optional)
Biofiltration (Bioretention with underdrain) facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Bioretention with underdrain facilities are commonly incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because these types of facilities have limited or no infiltration, they are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system.
Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and plant uptake.
Typical bioretention with underdrain components include:
• Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips) • Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap) • Shallow surface ponding for captured flows
• Side slope and basin bottom vegetation selected based on expected climate and ponding depth • Non-floating mulch layer (Optional)
• Media layer (planting mix or engineered media) capable of supporting vegetation growth • Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer
• Aggregate storage layer with underdrain(s)
• Impermeable liner or uncompacted native soils at the bottom of the facility • Overflow structure
BMP Design Manual-Appendices
August 2021 Update E-106
Design Adaptations for Project Goals
Appendix E.18
BF-1: Biofiltration
Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un-lined to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered runoff. This configuration is considered to provide biofiltration treatment via flow through the media layer. Storage provided above the underdrain within surface ponding, media, and aggregate storage is considered included in the biofiltration treatment volume. Saturated storage within the aggregate storage layer can be added to this design by raising the underdrain above the bottom of the aggregate storage layer or via an internal weir structure designed to maintain a specific water level elevation.
Integrated storm water flow control and pollutant control configuration. The system can be designed to provide flow rate and duration control by primarily providing increased surface ponding and/ or having a deeper aggregate storage layer above the underdrain. This will allow for significant detention storage, which can be controlled via inclusion of an outlet structure at the downstream end of the underdrain.
Recommended Siting Criteria
□
□
□
□
Placement observes geotechnical
recommendations regarding potential
hazards (e.g., slope stability, landslides,
liquefaction zones) and setbacks (e.g.,
slopes, foundations, utilities).
An impermeable liner or other hydraulic
restriction layer is included if site
constraints indicate that infiltration or
lateral flows should not be allowed.
Contributing tributary area shall be ~ 5
acres
( ~ 1 acre pref erred).
Finish grade of the facility is ~ 2%.
BMP Design Manual-Appendices
August 2021 Update
Intent 'Rationale
Must not negatively impact existing site
geotechnical concerns.
Lining prevents storm water from impacting
groundwater and/ or sensitive environmental
or geotechnical features. Incidental infiltration,
when allowable, can aid in pollutant removal
and groundwater recharge.
Bigger BMPs require additional design features
for proper performance.
Contributing tributary area greater than 5 acres
may be allowed at the discretion of the City
Engineer if the following conditions are met:
1) incorporate design features (e.g. flow
spreaders) to minimizing short circuiting of
flows in the BMP and 2) incorporate additional
design features requested by the City Engineer
for proper performance of the regional BMP.
Flatter surfaces reduce erosion
channelization within the facility.
E-107
and
Example Schematic Design - Plan and Section View
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...... . ~- ., . ....... _
, .. . ":· '.:.;,; ' . . ' . - . ' 'I • • •
~:."i; .- ·~ , ••• -. •: •. • .. . .. . . . . -
••. . ' ~ ' _i-
' . .
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u 'W~~ .... .'M~. • r ·>;'!!"~~· .,..,,,:,..,.,....,,..,..,~~ - · Appendix E.18
BF-1: Biofiltration
Figure E.18-1: Typical plan and Section view of a Biofiltration BMP BMP Design Manual-Appendices
August 2021 Update E-108
Appendix E.18
BF-1: Biofiltration
Recommended BMP Component Dimensions
Free board
Surface Ponding
Ponding Area
Side Slopes
Mulch
Media Layer
Underdrain
Diameter
Cleanout Diameter
2: 2 inches
2: 6 and :S 12 inches
3H:1V or shallower
2: 3 inches
2: 18 inches
2: 6 inches
2: 6 inches
BMP Design Manual-Appendices
August 2021 Update
Intent/.__Rationale
Freeboard provides room for head over overflow
structures and minimizes risk of uncontrolled surface
discharge.
Surface ponding capacity lowers subsurface storage
requirements. Deep surface ponding raises safety
concerns.
Surface ponding depth greater than 12 inches (for
additional pollutant control or surface outlet
structures or flow-control orifices) may be allowed at
the discretion of the City Engineer if the following
conditions are met: 1) surface ponding depth
drawdown time is less than 24 hours; and 2) safety
issues and fencing requirements are considered
( typically ponding greater than 18" will require a fence and/ or flatter side slopes) and 3) potential for
elevated clogging risk is considered.
Gentler side slopes are safer, less prone to erosion,
able to establish vegetation more quickly and easier to maintain.
Mulch will suppress weeds and maintain moisture for
plant growth. Aging mulch kills pathogens and weed
seeds and allows the beneficial microbes to multiply.
A deep media layer provides additional filtration and
supports plants with deeper roots. Standard
specifications shall be followed. For non-standard or
proprietary designs, compliance with F.1 ensures that
adequate treatment performance will be provided.
Smaller diameter underdrains are prone to clogging.
Properly spaced cleanouts will facilitate underdrain
maintenance.
E-109
Appendix E.18
BF-1: Biofiltration
Design Criteria and Considerations
Bioretention with underdrain must meet the following design criteria. Deviations from the below criteria may be approved at the discretion of the City Engineer if it is determined to be appropriate:
Siting Design Criteria Intent/Rationale
Surface Ponding
□
Surface ponding 1s limited to a 24-hour
drawdown time.
Vegetation
□
□
Plantings are suitable for the climate and
expected ponding depth. A plant list to aid
in selection can be found in Appendix E.26.
An irrigation system with a connection to
water supply should be provided as needed.
Mulch
□
A milllmum of 3 inches of well-aged,
shredded hardwood mulch that has been
stockpiled or stored for atleast 12 months is
provided.
Media Layer
□
□
Media maintains a minimum filtration rate
of 5 in/hr over lifetime of facility. An initial
filtration rate of 8 to 12 in/hr is
recommended to allow for clogging over
time; the initial filtration rate should not
exceed 12 inches per hour.
Media is a milllmum 18 inches deep,
meeting either of these two media
specifications:
Section F.3 Bioretention Soil Media (BSM)
or specific jurisdictional guidance.
Alternatively, for proprietary designs and
BMP Design Manual-Appendices
August 2021 Update E-110
Surface ponding limited to 24 hours for plant
health. Surface ponding drawdown time
greater than 24-hours but less than 96 hours
may be allowed at the discretion of the [City
Engineer] if certified by a landscape architect
or agronomist.
Plants suited to the climate and ponding depth
are more likely to survive.
Seasonal irrigation might be needed to keep
plants healthy.
Mulch will suppress weeds and maintain
moisture for plant growth. Aging mulch kills
pathogens and weed seeds and allows the
beneficial microbes to multiply.
A filtration rate of at least 5 inches per hour
allows soil to drain between events. The initial
rate should be higher than long term target
rate to account for clogging over time.
However an excessively high initial rate can
have a negative impact on treatment
performance, therefore an upper limit is
needed.
A deep media layer provides additional
filtration and supports plants with deeper
roots.
Standard specifications shall be followed.
Appendix E.18
BF-1: Biofiltration
Siting Design Criteria Intent/Rationale
□
□
custom media mixes not meeting the media
specifications contained in the 2016 City
Storm Water Standards or County LID
Manual, the media meets the pollutant
treatment performance criteria in Section
F.1.
Media surface area is 3% of contributing
area times adjusted runoff factor or greater.
Unless demonstrated that the BMP surface
area can be smaller than 3%.
Where receiving waters are impaired or have
a TMDL for nutrients, the system is
designed with nutrient sensitive media
design (see fact sheet BF-2).
Filter Course Layer
□
□
□
A filter course is used to prevent migration
of fines through layers of the facility. Filter
fabric is not used.
Filter course is washed and free of fines.
Filter course calculations assessing
suitability for particle migration prevention
have been completed.
BMP Design Manual-Appendices
August 2021 Update E-111
For non-standard or proprietary designs,
compliance with F.1 ensures that adequate
treatment performance will be provided.
Greater surface area to tributary area ratios: a)
maximizes volume retention as required by
the MS4 Permit and b) decrease loading rates
per square foot and therefore increase
longevity.
Adjusted runoff factor is to account for site
design BMPs implemented upstream of the
BMP (such as rain barrels, impervious area
dispersion, etc.). Refer to Appendix B.2
guidance.
Use Worksheet B.5-1 Line 26 to estimate the
rrurumum surface area required per this
criteria.
Potential for pollutant export is partly a
function of media composition; media design
must minimize potential for export of
nutrients, particularly where receiving waters
are impaired for nutrients.
Migration of media can cause clogging of the
aggregate storage layer void spaces or
subgrade. Filter fabric is more likely to clog.
Washing aggregate will help eliminate fines
that could clog the facility and impede
infiltration.
Gradation relationship between layers can
evaluate factors (e.g., bridging, permeability,
and uniformity) to determine if particle sizing
is appropriate or if an intermediate layer is
needed.
Appendix E.18
BF-1: Biofiltration
Siting Design Criteria Intent/Rationale
Aggregate Storage Layer
□
□
Class 2 Permeable per Caltrans specification
68-1.025 is recommended for the storage
layer. Washed, open-graded crushed rock
may be used, however a 4-6 inch washed pea
gravel filter course layer at the top of the
crushed rock is required.
The depth of aggregate provided (12-inch
typical) and storage layer configuration is
adequate for providing conveyance for
underdrain flows to the outlet structure.
In.iow, Underdrain, and Out.iow Structures
□
□
□
□
□
□
□
Inflow, underdrains and outflow structures
are accessible for inspection and
maintenance.
Inflow velocities are limited to 3 ft/ s or less
or use energy dissipation methods. (e.g.,
riprap, level spreader) for concentrated
inflows.
Curb cut inlets are at least 12 inches wide,
have a 4-6 inch reveal (drop) and an apron
and energy dissipation as needed.
Underdrain outlet elevation should be a
minimum of 3 inches above the bottom
elevation of the aggregate storage layer.
Minimum underdrain diameter is 6 inches.
Underdrains are made of slotted, PVC pipe
conforming to ASTM D 3034 or equivalent
or corrugated, HDPE pipe conforming to
AASHTO 252M or equivalent.
An underdrain cleanout with a minimum 6-
inch diameter and lockable cap is placed
every 250 to 300 feet as required based on
underdrain length.
BMP Design Manual-Appendices
August 2021 Update E-112
Washing aggregate will help eliminate fines
that could clog the aggregate storage layer
void spaces or subgrade.
Proper storage layer configuration and
underdrain placement will minimize facility
drawdown time.
Maintenance will prevent clogging and ensure
proper operation of the flow control
structures.
High inflow velocities can cause erosion,
scour and/ or channeling.
Inlets must not restrict flow and apron
prevents blockage from vegetation as it grows
in. Energy dissipation prevents erosion.
A minimal separation from subgrade or the
liner lessens the risk of fines entering the
underdrain and can improve hydraulic
performance by allowing perforations to
remain unblocked.
Smaller diameter underdrains are prone to
clogging.
Slotted underdrains provide greater intake
capacity, clog resistant drainage, and reduced
entrance velocity into the pipe, thereby
reducing the chances of solids migration.
Properly spaced cleanouts will facilitate
underdrain maintenance.
Appendix E.18
BF-1: Biofiltration
Siting Design Criteria Intent/Rationale
□
Overflow 1s safely conveyed to a
downstream storm drain system or
discharge point Size overflow structure to
pass 100-year peak flow for on-line
infiltration basins and water quality peak
flow for off-line basins.
Planning for overflow lessens the risk of
property damage due to flooding.
Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only To design bioretention with underdrain for storm water pollutant control only (no flow control required), the following steps should be taken:
1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio.
2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas.
3. Use the sizing worksheet presented in Appendix B.5 to size biofiltration BMPs.
Conceptual Design and Sizing Approach when Storm Water Flow Control is Applicable Control of flow rates and/ or durations will typically require significant surface ponding and/ or aggregate storage volumes, and therefore the following steps should be taken prior to determination of storm water pollutant control design. Pre-development and allowable post-project flow rates and durations should be determined as discussed in Chapter 6 of the manual.
1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio.
2. Iteratively determine the facility footprint area, surface ponding and/ or aggregate storage layer depth required to provide detention storage to reduce flow rates and durations to allowable limits. Flow rates and durations can be controlled from detention storage by altering outlet structure orifice size(s) and/or water control levels. Multi-level orifices can be used within an outlet structure to control the full range of flows.
3. If bioretention with underdrain cannot fully provide the flow rate and duration control required by this manual, an upstream or downstream structure with significant storage volume such as an underground vault can be used to provide remaining controls.
4. After bioretention with underdrain has been designed to meet flow control requirements, calculations must be completed to verify if storm water pollutant control requirements to treat the DCV have been met.
BMP Design Manual-Appendices
August 2021 Update E-113
Maintenance Overview
Appendix E.18
BF-1: Biofiltration
Normal Expected Maintenance. Biofiltration reqmres routine maintenance to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health; maintain infiltration capacity of the media layer; replenish mulch; and maintain integrity of side slopes, inlets, energy dissipators, and outlets. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure. If any of the following scenarios are observed, the BMP is not performing as intended to protect downstream waterways from pollution and/ or erosion.
Corrective maintenance, increased inspection and maintenance, BMP replacement, or a different BMP type will be required.
• The BMP is not drained between storm events. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected.
• Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume within one month. This means the load from the tributary drainage area is too high, reducing BMP function or clogging the BMP. This would require pretreatment measures within the tributary area draining to the BMP to intercept the materials. Pretreatment components, especially for sediment, will extend the life of components that are more expensive to replace such as media, filter course, and aggregate layers.
• Erosion due to concentrated storm water runoff flow that is not readily corrected by adding erosion control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the City Engineer shall be contacted prior to any additional repairs or reconstruction.
Other Special Considerations. Biofiltration is a vegetated structural BMP. Vegetated structural BMPs that are constructed in the vicinity of, or connected to, an existing jurisdictional water or wetland could inadvertently result in creation of expanded waters or wetlands. As such, vegetated structural BMPs have the potential to come under the jurisdiction of the United States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the United States Fish and Wildlife Service. This could result in the need for specific resource agency permits and costly mitigation to perform maintenance of the structural BMP. Along with proper placement of a structural BMP, routine maintenance is key to preventing this scenario.
Summary of Standard Inspection and Maintenance
The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district.
Maintenance frequencies listed in this table are average/ typical frequencies. Actual maintenance needs BMP Design Manual-Appendices
August 2021 Update E-114
Appendix E.18
BF-1: Biofiltration
are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May.
Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections.
Accumulation of sediment, litter, or
debris
Obstructed inlet or outlet structure
Maintenance Action
Remove and properly dispose
of accumulated materials,
without damage to the
vegetation or compaction of
the media layer.
Clear blockage.
Damage to structural components Repair or replace as applicable such as weirs, inlet or outlet
structures
Poor vegetation establishment Re-seed, re-plant, or reestablish vegetation per original plans.
• Inspect monthly. If the BMP is
25% full* or more in one month,
increase inspection frequency to
monthly plus after every 0.1-inch
or larger storm event.
• Remove
materials
inspection.
any
found
accumulated
at each
• Inspect monthly and after every
0.5-inch or larger storm event.
• Remove
materials
inspection.
any
found
• Inspect annually.
accumulated
at each
• Maintain when needed.
• Inspect monthly.
• Maintain when needed.
Dead or diseased vegetation Remove dead or diseased • Inspect monthly. vegetation, re-seed, re-plant, or
re-establish vegetation per • Maintain when needed.
Overgrown vegetation
2/3 of mulch has decomposed, or
mulch has been removed
BMP Design Manual-Appendices
August 2021 Update
original plans.
Mow or trim as appropriate.
Remove decomposed fraction
and top off with fresh mulch to
a total depth of 3 inches.
E-115
• Inspect monthly.
• Maintain when needed.
• Inspect monthly.
Erosion due
irrigation flow
to concentrated
Erosion due to concentrated storm
water runoff flow
Standing water in BMP for longer
than 24 hours following a storm
event
Surface ponding longer than
approximately 24 hours following a
storm event may be detrimental to
vegetation health
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa,
and adult mosquitos, see
http:/ /www.mosquito.org/biology
BMP Design Manual-Appendices
August 2021 Update
Maintenance Action
Repair/ re-seed/ re-plant
eroded areas and adjust the
irrigation system.
Repair/ re-seed/ re-plant
eroded areas, and make
appropriate corrective
measures such as adding
erosion control blankets,
adding stone at flow entry
points, or minor re-grading to
restore proper drainage
according to the original plan.
If the issue is not corrected by
restoring the BMP to the
original plan and grade, the City
Engineer shall be contacted
prior to any additional repairs
or reconstruction.
Make appropriate corrective
measures such as adjusting
irrigation system, remoVllg
obstructions of debris or
invasive vegetation, clearing
underdrains, or
repairing/ replacing clogged or
compacted soils.
If mosquitos/larvae are
observed: first, immediately
remove any standing water by
dispersing to nearby
landscaping; second, make
corrective measures as
applicable to restore BMP
drainage to prevent standing
water.
If mosquitos persist following
corrective measures to remove
standing water, or if the BMP
desi does not meet the 96-
E-116
Appendix E.18
BF-1: Biofiltration
• Replenish mulch annually, or
more frequently when needed
based on inspection.
• Inspect monthly.
• Maintain when needed.
• Inspect after every 0.5-inch or
larger storm event. If erosion due
to storm water flow has been
observed, increase inspection
frequency to after every 0.1-inch
or larger storm event.
• Maintain when needed. If the
issue is not corrected by
restoring the BMP to the original
plan and grade, the City Engineer
shall be contacted prior to any
additional repairs or
reconstruction.
• Inspect monthly and after every
0.5-inch or larger storm event. If
standing water is observed,
increase inspection frequency to
after every 0.1-inch or larger
storm event.
• Maintain when needed.
• Inspect monthly and after every
0.5-inch or larger storm event. If
mosquitos are observed, increase
inspection frequency to after
every 0.1-inch or larger storm
event.
• Maintain when needed.
Underdrain clogged
BMP Design Manual-Appendices
August 2021 Update
Maintenance Action
hour drawdown criteria due to
release rates controlled by an
orifice installed on the
underdrain, the City Engineer
shall be contacted to determine
a solution. A different BMP
type, or a Vector Management
Plan prepared with
concurrence from the County
of San Diego Department of
Environmental Health, may be
required.
Clear blockage.
E-117
Appendix E.18
BF-1: Biofiltration
• Inspect if standing water is
observed for longer than 24-96
hours following a storm event.
• Maintain when needed.
Appendix E.2
SC-Q: Larage Trash Generating Facilities
E.2 SC-Q: Large Trash Generating Facilities
MS4 Permit Category
Source Control
BMP Manual Category
Source Control
Applicable Performance
Standard
Source Control
Primary Benefits
Source Control
Description
Storm water runoff from areas where trash is stored or disposed of can be polluted. In addition, loose trash and debris can be easily transported by water or wind to nearby storm drain inlets, channels, and/ or creeks. Trash generating facilities that generate large amounts of trash require special attention to protect trash storage areas from rainfall, run-on, runoff, and wind dispersal. Large trash generating, or trash build-up areas, include but are not limited to restaurants, supermarkets, "big box" retail stores serving food, and pet stores. The City Engineer may designate additional facilities if they are likely to generate or accumulate large quantities of trash.
Design Adaptations for Project Goals
Source control BMPs reduce the amount of pollutants that are generated. This fact sheet contains details on the additional measures required to prevent or reduce pollutants in storm water runoff associated with trash storage and handling for large trash generating facilities. The requirements presented here are in addition to the requirements of SC-5 which requires all development projects to protect trash storage areas from rainfall, run-on, runoff, and wind dispersal:
•
•
•
Areas where trash containers are stored must be enclosed on four sides to prevent offsite transport of trash. Four-sided trash enclosures typically consist of three walled sides and one gated side. Trash enclosures limit the potential for trash to pollute storm water runoff by limiting mobilization mechanisms (runoff, run-on, and wind dispersal).
Trash enclosures must be covered to minimize direct precipitation and prevent rainfall from entering enclosures. Structural overhead covers are required as container lids are often left open.
Enclosures must be hydraulically isolated from surrounding areas. Slabs shall be sloped such that any leaked materials will be contained within the enclosure. Drains must be provided BMP Design Manual-Appendices
August 2021 Update E-16
~M!t.-
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Appendix E.2
SC-Q: Larage Trash Generating Facilities
that capture and direct potential leaks to the sanitary sewer or appropriate BMPs. Divert runoff from surrounding areas away from the enclosure to prevent contamination and dispersion of collected materials.
• Owner must provide BMP storm water training to employees. Employee participation is required to ensure that enclosures are properly maintained and kept clean.
Design Guidelines
All trash shall be stored in weather-protected receptacles/bins and recyclable materials shall be protected against adverse weather conditions, which might render the collected materials unmarketable. Trash enclosure dimensions will vary based on projected usage and the following information is offered as an aid in planning new projects. Businesses that use dumpsters must design the enclosure to accommodate three-yard containers at a minimum. The tenants may use any dumpster size that is appropriate for their needs, but the enclosure must be able to accommodate different tenants with varying waste production, including any recycling requirements. The design of the enclosure must be signed and sealed by a California licensed engineer. Substantiating structural calculations may be required. The location and design of the enclosure will require review and approval by the City Engineer. Building permits may be required.
The following recommendations for typical bin sizes are adopted from the City of Escondido trash enclosure guidelines. The following bin/ container measurements are approximate (add 8" to width for side pockets):
Typical Trash Bin Sizes
3 cubic yard 72" bin, 81" plus lid 43" 42" 70"
4 cubic yard 72" bin, 81" plus lid 56" 72" 72"
Filled weight should not exceed 1,000 pounds.
Design Criteria
1. Enclosures shall be structurally strong and constructed of reinforced masonry block or wood panels/boards. Structural requirements for enclosures are detailed in the City of San Diego specification for Woods and masonary Fences.
http://www.sandiego.gov/ development-services /pdf /industry/infobulletin/ib223.pdf
2. The enclosure should be constructed to the following minimum inside dimensions to accommodate three cubic-yard dumpsters (larger enclosures may be necessary to accommodate additional trash bins, recycling bins, and accessibility):
One Front
One Side
Two Front
Two Side
BMP Design Manual-Appendices
August 2021 Update E-17
8' 6'
7.5' 8'
16' 6'
8' 16'
6'
6'
6'
6'
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CH8~~STA
Appendix E.2
SC-Q: Larage Trash Generating Facilities
3. The enclosure slab should be designed to keep storm water drainage out of the enclosure area, typically sloped at 0.5%. Slab construction specifications will vary according to methods of construction, but should be at least 4 inches of reinforced concrete.
4. Sturdy gates/ doors shall be installed on all enclosures. Gates should not be mounted directly onto the block wall or inside of enclosure. The enclosure should include hardware to secure the gate's doors both open and closed (i.e., cane bolt w / sleeve and latch between doors and sleeve in pavement).
5. To prevent trash enclosures from contributing to storm water runoff pollution, all enclosures must be fitted with a roof deigned to drain into on-site landscape areas (where necessary) and/ or to appropriate BMPs. The roof must provide sufficient clearance to allow the dumpster lid to open to the 90 degree position.
6. Enclosure roofs not conforming to City specifications for Patio Covers may require a building permit. Generally roofs not more than 12 feet in height above grade and constructed with conventional light-frame wood construction are considered acceptable. The use of metal roofs is not recommended as they can act as a source of pollutants. http://www.sandiego.gov/ development-services /pdf /industry/infobulletin/ib206.pdf
7. Dumpsters associated with food establishments shall be sized per County Health Department requirements for wash down. Drains shall be connected to the business grease interceptor.
BMP Design Manual-Appendices
August 2021 Update E-18
~Mlt.-
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CH8~~STA
Appendix E.2
SC-Q: Larage Trash Generating Facilities
Example isometric view and plan view of an allowable trash enclosure facility is presented below. The project applicant may be allowed to use an alternative trash enclosure design that might be more appropriate for a project site if the alternative design is approved by the City Engineer. " ',/'/ ""
w \ : .. "w'~::w O"
~RIO~
....,_ ___ .·:e:a~, .... -__ _.
Typical Isometric and Plan View of a Trash Enclosure BMP BMP Design Manual-Appendices
August 2021 Update E-19
' M.t~-: -~"~-
fflllllsM.
Appendix E. 7
SD-B: Impervious Area Dispersion
IE. 7 SD-B Impervious Area Dispersion
MS4 Permit Category
Site Design
Manual Category
Site Design
Applicable Performance
Criteria
Site Design
Primary Benefits
Volume Reduction
Peak Flow Attenuation
Photo Credit: Orange County Technical Guidance Document Description
Impervious area dispersion (dispersion) refers to the practice of effectively disconnecting impervious areas from directly draining to the storm drain system by routing runoff from impervious areas such as rooftops (through downspout disconnection), walkways, and driveways onto the surface of adjacent pervious areas. The intent is to slow runoff discharges, and reduce volumes. Dispersion with partial or full infiltration results in significant volume reduction by means of infiltration and evapotranspiration.
Typical dispersion components include:
• An impervious surface from which runoff flows will be routed with minimal piping to limit concentrated inflows
• Splash blocks, flow spreaders, or other means of dispersing concentrated flows and providing energy dissipation as needed
• Dedicated pervious area, typically vegetated, with in-situ soil infiltration capacity for partial or full infiltration
• Optional soil amendments to improve vegetation support, maintain infiltration rates and enhance treatment of routed flows
• Overflow route for excess flows to be conveyed from dispersion area to the storm drain system or discharge point
BMP Design Manual-Appendices
August 2021 Update E-32
~~ft..
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Appendix E. 7
SD-B: Impervious Area Dispersion
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~
'
'
'
'
I
!
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:
!
'
~
• • .:..ill"~
·=--~) ,.
'. ·-, : ~ · ,m.:, -. ' . · . . . .. ~ .. .
~a«
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Figure E.7-1: Typical plan and section view of an Impervious Area Dispersion BMP Design Adaptations for Project Goals
Site design BMP to reduce impervious area and DCV. Impervious area dispersion primarily functions as a site design BMP for reducing the effective imperviousness of a site by providing partial or full infiltration of the flows that are routed to pervious dispersion areas and otherwise slowing down excess flows that eventually reach the storm drain system. This can significantly reduce the DCV for the site.
BMP Design Manual-Appendices
August 2021 Update E-33
~~ft..
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Design Criteria and Considerations
Appendix E. 7
SD-B: Impervious Area Dispersion
Dispersion must meet the following design criteria. Deviations from the below criteria may be approved at the discretion of the City Engineer if it is determined to be appropriate:
Siting and Design Intent/Rationale
□
Dispersion is over areas with soil types capable
of supporting or being amended (e.g., with sand
or compost) to support vegetation. Media
amendments must be tested to verify that they
are not a source of pollutants.
Dispersion has vegetated sheet flow over a
□ relatively large distance (minimum 10 feet)
from inflow to overflow route.
□ Pervious areas should be flat (with less than 5%
slopes) and vegetated.
In.iow velocities
Inflow velocities are limited to 3 ft/ s or less or
□ use energy dissipation methods (e.g., riprap,
level spreader) for concentrated inflows.
Dedication
□
Dispersion areas must be owned by the project
owner and be dedicated for the purposes of
dispersion to the exclusion of other future uses
that might reduce the effectiveness of the
dispersion area.
Vegetation
□
Dispersion typically requires dense and robust
vegetation for proper function. Drought
tolerant species should be selected to minimize
irrigation needs. A plant list to aid in selection
can be found in Appendix E.26.
Soil must have long-term infiltration
capacity for partial or full infiltration and
be able to support vegetation to provide
runoff treatment. Amendments to improve
plant growth must not have negative
impact on water quality.
Full or partial infiltration requires relatively
large areas to be effective depending on the
permeability of the underlying soils.
Flat slopes facilitate sheet flows and
minimize velocities, thereby improving
treatment and reducing the likelihood of
erosion.
High inflow velocities can cause erosion,
scour and/ or channeling.
Dedicated dispersion areas prevent future
conversion to alternate uses and facilitate
continued full and partial infiltration
benefits.
Vegetation improves resistance to erosion
and aids in runoff treatment.
Conceptual Design and Sizing Approach for Site Design
1. Determine the areas where dispersion can be used in the site design to reduce the DCV for pollutant control sizing.
2. Calculate the DCV for storm water pollutant control per Appendix B.2, taking into account reduced runoff from dispersion.
BMP Design Manual-Appendices
August 2021 Update E-34
Appendix E. 7
SD-B: Impervious Area Dispersion
3. Determine if a DMA is considered "Self-retaining" if the impervious to pervious ratio is:
a. 2:1 when the pervious area is composed of Hydrologic Soil Group A b. 1:1 when the pervious area is composed of Hydrologic Soil Group B
4. If the top 12 inches uses amended soils in accordance with SD-F, the runoff coefficient (cfactor) for the amended area is 0.1 Conceptional Design and Sizing Approach for Storm Water Pollutant Treatment and Flow Control DMAs using impervious area dispersion are considered to meet both pollutant control and hydromodification flow control requirements if ALL of the following criteria are met:
1. All impervious area within the DMA discharges to the pervious area before the runoff discharges from the DMA.
2. As a minimum, the top 11 inches of the pervious area uses amended soils in accordance with the SD-F fact sheet and the pervious area also meets the requirements for dispersion (e.g. slope, inflow velocities, etc.) in the SD-B fact sheet.
3. The impervious to pervious area ratio is 1:1 or less.
Maintenance Overview
Normal Expected Maintenance. Vegetated area shall be maintained as part of normal landscape maintenance. Additionally, ensure that storm water runoff can be conveyed into the vegetated area as designed. That is, the mechanism that allows storm water runoff from impervious area to flow into the pervious area (e.g., a curb cut allows runoff from a parking lot to drain onto adjacent landscaping area, or a roof drain outlet is directed to a lawn) shall not be removed, blocked, filled, or otherwise changed in a manner that prevents storm water from draining into the pervious area. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure. Impervious area dispersion is a site design BMP that normally does not require maintenance actions beyond routine landscape maintenance. If changes have been made to the area, such as the vegetated area has been replaced with impervious area, or the mechanism that allows storm water runoff from impervious area to flow into the pervious area has been removed (e.g., roof drains previously directed to vegetated area have been directly connected to the street or storm drain system), the BMP is not performing as intended to protect downstream waterways from pollution and/ or erosion. Corrective maintenance will be required to restore drainage into the pervious area as designed. If the pervious area has been removed, contact the City Engineer to determine a solution.
Runoff directed into vegetated areas is expected to be drained within 24-96 hours following a storm event. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging or compaction of the soils. Loosen or replace the soils to restore drainage.
Other Special Considerations. Site design BMPs, such as impervious area dispersion, installed within a new development or redevelopment project are components of an overall storm water management strategy for the project. The presence of site design BMPs within a project is usually a factor in the BMP Design Manual-Appendices
August 2021 Update E-35
~~ft..
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CH~~~STA
Appendix E. 7
SD-B: Impervious Area Dispersion
determination of the amount of runoff to be managed with structural BMPs (i.e., the amount of runoff expected to reach downstream retention or biofiltration basins that process storm water runoff from the project as a whole). When site design BMPs are not maintained or are removed, this can lead to clogging or failure of downstream structural BMPs due to greater delivery of runoff and pollutants than intended for the structural BMP. Therefore, the City Engineer may require confirmation of maintenance of site design BMPs as part of their structural BMP maintenance documentation requirements. Site design BMPs that have been installed as part of the project should not be removed, nor should they be bypassed by re-routing roof drains or re-grading surfaces within the project. If changes are necessary, consult the City Engineer to determine requirements.
Summary of Standard Inspection and Maintenance
The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district.
Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May.
Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections.
"'.I ■ rr-..r.;:i:-r.11flr• rm- • III ~
-
Poor vegetation establishment
Dead or diseased vegetation
Overgrown vegetation
Standing water in vegetated pervious
area for longer than 24 hours
following a storm event
Surface ponding longer than
approximately 24 hours following a
storm event may be detrimental to
vegetation health
BMP Design Manual-Appendices
August 2021 Update
]~,~:; .. a ,.,. .. .n ~
• ir~..-.tUiiljr,111.
Re-seed, re-plant, or re-establish
vegetation per original plans.
Remove dead or diseased
vegetation, re-seed, re-plant, or
re-establish vegetation per
original plans.
Mow or trim as appropriate.
Disperse any areas of standing
water to nearby landscaping 0,e.,
spread it out to another portion
of the pervious area so it drains
into the soil). Make appropriate
corrective measures such as
adjusting irrigation system, or
E-36
"'.I ~ - ~
11 # 11~"'..-::1111•:.. .
~ -
1 ....... , ....
• Inspect monthly.
• Maintain when needed.
• Inspect monthly.
• Maintain when needed.
• Inspect monthly.
• Maintain when needed.
• Inspect monthly and after every
0.5-inch or larger storm event. If
standing water lS observed,
increase inspection frequency to
after every 0.1-inch or larger
storm event.
• Maintain when needed.
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa,
and adult mosquitos, see
http:/ /www.mosquito.org/biology
Entrance / opening to the vegetated
pervious area is blocked such that
storm water from impervious area will
not drain into the pervious area (e.g., a
curb cut opening is blocked by debris
or a roof drain outlet has been directly
connected to the storm drain system)
BMP Design Manual-Appendices
August 2021 Update
Appendix E. 7
SD-B: Impervious Area Dispersion
Maintenance Action
repairing/ replacing clogged or
compacted soils.
Disperse any areas of standing
water to nearby landscaping (i.e.,
spread it out to another portion
of the pervious area so it drains
into the soil). Loosen or replace
soils to restore drainage (and
prevent standing water)
Make repairs as appropriate to
restore drainage into the
vegetated pervious area.
E-37
• Inspect monthly and after every
0.5-inch or larger storm event. If
mosquitos are observed,
increase inspection frequency to
after every 0.1-inch or larger
storm event.
• Maintain when needed
• Inspect monthly.
• Maintain when needed.
E.11 SD-F Amended Soils
Description
Appendix E.11
SD-F: Amended Soils
MS4 Permit Category
Site Design
Manual Category
Site Design
Applicable Performance Standard
Site Design
Primary Benefits
Volume Reduction
Peak Flow Attenuation
Amended soils are soils whose physical, chemical, and biological characteristics have been altered from the natural condition to promote beneficial storm water characteristics. Amended soils shall be used as part of SD-B Impervious Area Dispersion, where applicable. Typical storm water management benefits associated with amended soils include:
• Improved hydrologic characteristics-amended soils can promote infiltration, decrease runoff rates and volumes, and more effectively filter pollutants from storm water runoff • Improved vegetation health-amended soils provide greater moisture retention, and altered chemical and biological characteristics that can result in healthier plant growth, reduced irrigation demands, and reduced need for fertilization and maintenance • Reduced erosion-amended soils produce healthier plant growth and reduced runoff which results in reduced soil erosion
Not all amended soils have the same storm water benefits, the soil amendment used should be suited for the design purpose and design period of the amended area.
Design Adaptations for Project Goals
Varying categories of soil amendments have different benefits and applications. Mulch is a soil amendment that is added at grade, rather than mixed into the soil. Mulch reduces evaporation and improves retention. Shavings and compost are common soil amendments that improve biological and chemical properties of the soil. Sand can be used as an amendment to improve the drainage rates of amended soils. Native soil samples may need to be analyzed by a lab to determine the specific soil amendments needed to achieve the desired infiltration, retention, and/ or filtration rates, as well as, to provide a growing medium for healthy plant growth.
Important Considerations
Maintenance: Annual maintenance may be required to determine reapplication requirements of amended soils. Amended soils should be regularly inspected for signs of compaction, waterlogging, and unhealthy vegetation.
BMP Design Manual-Appendices
August 2021 Update E-52
Appendix E.11
SD-F: Amended Soils
Limitations: Not all amended soils have the same storm water benefits, the soil amendment used should be suited for the design purpose and design period of the amended area.
Design Criteria and Considerations
Soil amendments must meet the following design criteria and considerations. Deviations from the below criteria may be approved at the discretion of the City Engineer if appropriate:
□
□
□
□
□
□
□
□
Siting and Design Intent/Rationale
When mulch is used as an amendment, it is
applied at grade over all planting areas to a
depth of 3".
When shavings or compost is used as an
amendment, it is rototilled into the native soil
to a minimum depth of 6" (12 inches
preferred).
Mulch should be applied on top and not
mixed into underlying soils
If soil is not completely mixed the overall
benefit will be reduced.
Compost meets the criteria ill Appendix If poor quality compost is used, it will have F.3.1.2 negative impact to water quality.
Soil amendments are free of stones, stumps,
roots, glass, plastic, metal, and other
deleterious materials.
Mixing of soils are done prior to planting
Care is taken around existing trees and shrubs
to prevent root damage during construction
and soil amendment application.
Soil amendments are applied at the end of
construction
Soil amendments
planned vegetation
are compatible with
Large debris in amended soils can cause
localized erosion. Trash/harmful materials
can result ill personal injury or
contamination.
Soil mixing before planting results in a more
homogeneous mixing and will reduce the
stress on plants.
Preservation of existmg established
vegetation is an important part of site design
and erosion control.
Soil amendments applied too soon in the
construction process may become over
compacted reducing effectiveness.
The soil amendments impact the pH and
salinity of the soil. Some plants have sensitive
pH and/ or salinity tolerance ranges.
Conceptual Design and Sizing Approach for Site Design
• When soil amendments are used a runoff factor of 0.1 can be used for DCV calculation for the amended area.
• Amended soils should be used as part of SD-B Impervious Area Dispersion, and to increase the retention volume in other BMPs.
Maintenance
Annual maintenance may be required to determine reapplication requirements of amended soils.
Amended soils should be regularly inspected for signs of compaction, waterlogging, and unhealthy vegetation.
BMP Design Manual-Appendices
August 2021 Update E-53
Project Name/ Yards at the Bay
ATTACHMENT 2
Backup for PDP Hydromodification Control
Measures
[j Mark this box if this attachment is empty because the project is exempt from PDP hydromodification management requirements.
CCV BMP Manual
PDP SWQMP Template Date: March 2019 ~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Yards at the Bay Project Name/ ______________________________ _ Letter indicating Hydromodification exemption
Indicate which Items are Included is provided after this sheet.
Attachment
Sequence
Contents Checklist
H ydromodification
Exhibit (Required)
Management 1u1
IAJ Included
Attachment 2A
Attachment 2B
Attachment 2C
Attachment 2D
CCV BMP Manual
Management of Critical Coarse
Sediment Yield Areas (WMAA
Exhibit 1s required, additional
analyses are optional)
See Section 6.2 of the BMP Design
Manual.
CCSYA requirements
are not applicable since
the project is
Hydromodification Exempt.
Geomorphic Assessment of
Receiving Channels (Optional)
See Section 6.3.4 of the BMP
Design Manual.
Flow Control Facility Design and
Structural BMP Drawdown
Calculations (Required)
Overflow Design Summary for each
Structural BMP
See Chapter 6 and Appendix G of
the BMP Design Manual
PDP SWQMP Template Date: March 2019
See Hydromodification Management
Exhibit Checklist.
D Exhibit showing project drainage
boundaries marked on WMAA Critical
Coarse Sediment Yield Area Map
(Required)
Optional analyses for Critical Coarse
Sediment Yield Area Determination
D 6.2.1 Verification of Geomorphic
Landscape Units Onsite
D 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
D 6.2.3 Optional Additional Analysis of
Potential Critical Coarse Sediment
Yield Areas Onsite
D Not performed
D Included
D Submitted as separate stand-alone
document
D Included
D Submitted as separate stand-alone
document
~Vt-
·•.: .. . . -CllYOf
CHULA VISTA
Chanurnmuo~rn~oo
Civil Engineering0 Hydrology0 Hydraulics0Sedimentation
May 2, 2023
Mike Knapton
PSIP Wohl Bay Boulevard LLC
2251 San Diego Avenue, Suite A-247
San Diego, CA 92110
Subject: Parcel B Hydromodification Exemption
Dear Mike:
P.O. Box 9496
Rancho Santa Fe, CA 92067-4496
T: 858.692.0760
F: 858.832.1402
[email protected]
I have performed a hydromodification assessment of the Parcel B redevelopment project and determined that the project meets the hydromodification exemption criteria. The site is located on the north side ofH Street east of Marina Parkway in the city of Chula Vista (see Figure 1). The redevelopment will occur over a currently impervious site comprising approximately 35.5 acres.
The future site plan is undetermined, but the Specific Plan will re-zone the property around two distinct Planning Areas, B-1 and B-2. The project will install stormwater quality best management practices in accordance with the City of Chula Vista's BMP Design Manual.
The project's treated storm runoff will be conveyed by separate storm drain systems in two directions (north and south) towards San Diego Bay west of the site. The north system outlets at a 54-inch RCP into a slough just northwest of the site (see Figure 1 ). The slough is directly connected to San Diego Bay. This storm drain system extends along the northerly edge of the site, so will collect the project's northerly storm runoff.
The south system outlet is from an 84-inch RCP that discharges into San Diego Bay at the Chula Vista Marina (see Figure 2). This storm drain system extends along H Street adjacent to Parcel B.
Storm runoff from the southerly project area will be collected by this system. The 84-inch RCP outlet into San Diego Bay is the same one that is below your 795 H Street project. Chang Consultants prepared a March 13, 2023, hydromodification exemption letter for the 795 H Street project that was approved by the City of Chula Vista. Since both project's have the same outlet into San Diego Bay, the portion of Parcel B that drains to the south system is hydromodification exempt.
The north storm drain system to San Diego Bay is an uninterrupted, hardened conveyance, so potentially qualifies for a hydromodification exemption. The BMP Design Manual outlines criteria for a hydromodification exemption. Attached Figure 1-2 is a flow chart to determine if an exemption applies. The project is a priority development project under Step 1. The north system does not discharge to the Pacific Ocean per Step 2, but does have a direct discharge to a nonprotected enclosed embayment per Step 3. San Diego Bay is identified as an enclosed embayment in the BMP Design Manual. Step 3 states that an outfall must not be located within a wildlife refuge. The US Fish & Wildlife Service maps wildlife refuges along San Diego Bay (see Figure 3). Figure 3 shows that the only refuge in the area is the San Diego Bay National Wildlife Refuge.
The north system's outfall is south of and not within this refuge. The Step 3 hydromodification exemption criteria requires proper energy dissipation at the drainage outlet and the outlet invert elevation be equal to or below the mean high tide elevation. Figure 4 shows that the storm drain outfall discharges below the San Diego Bay water surface. The water will effectively dissipate outflow. The plans for the 54-inch outlet are attached and show that the flow line elevation is 2.04 feet MLL W datum. The attached NOAA Tides & Currents web-site information indicates that mean high tide is 4.99 feet MLL W. Therefore, the outlet is below the mean tide level and all of the Step 3 criteria are met.
This information indicates that the Parcel B redevelopment project meets the City of Chula Vista's criteria for a hydromodification exemption. Storm runoff from the southerly portion of the project will be conveyed to a storm drain outlet into the Chula Vista Marina that was determined to be exempt by a March 13, 2023, Chang Consultants letter approved by the City. Furthermore, this letter shows that the project's northerly storm runoff will be conveyed directly in a non-erodible storm drain system to the hydromodification exempt San Diego Bay.
Sincerely,
Wayne W. Chang, M.S., P.E.
Attachments
FIGURE 1 -
NORTH
DRAINAGE
SYSTEM
POC2 :~ - ~ ~•,:
Existing 54" RCP storm
.,;.i;;i;i&..,Jdrain discharges into
slough which extends
from San Diego Bay
isting 72'
ain disch
n Diego
.,_,r_- . ,c::mt
- \ . . .
• '
Figure 2: South Storm Drain System POC 1A AND 1 B
Figure 3. USFWS Refuge Mapping
Figure 4. Submerged 54 .. RCP Outlet
NO
Exempt from hydromodification
management re uirements
YES
YES
YES
YES
YES
Chapter 1:
Policies and Procedural Requirements
NO
o water stora
servoir or la
elow spillway
mal o er
Hydromodification management
controls required
*Direct discharge refers to an uninterruRted hardened conveyance system; Note to be used in conjunction with Node D escriptions.
Figure 1-2: Applicability ofHydromodification Management BMP Requirements BMP Design Manual
Addenda 1 to August 2021 Update 1-20
CITY OF
CHULAVISTA
~Vt-
'.i!Sbi --.-
"""""~""" CITY OF
CHULAVISTA
MAP NOTE:
This map isintendedfor studyonly and
should not be used for any other purpose.
Informationonthismap isalsosubjectto
change(or revision) periodically. The
City of Chula Vista does not 11uarantee
theaccuracyofinformationcontainedon
thismapandcautionsagainsttheuseof
thisdatainmaking landusedecisions
r-s-1 ,,, f
;
r'
SAN DIEGO BAY IS
HYDROM D EXEMPT.
LEGEND
c:::J City of Chula Vista - Exempt Systems
- Major Roads
Minor Roads
Water Body
- Exempt Water Bodies
- Rivers
- Streams
Folder: C:\Users\kvalenzuela\Documents\ArcGIS\Projects\Hydromod Exemptions 2022\ Date: 4/20/2022 10:42 AM 7 3600 ()
0 1800
- Feet
RECEIVING WATERS & CONVEYANCE SYSTEMS EXEMPT FROM
HYDROMODIFICATION MANAGEMENT REQUIREMENTS
. .
'·······--+-··-···-------·-t··--··
..
.....
:=·=···===· -=;:. ·1·.·.:._ ••.•• ··._···=·~·=::--=.:.: --··===·==--····=··_··.=·=·.1.:_. _. ·-··· .... ······-·· . ·_"···. ;·····•·•·-.. -.· .. ···.·.·.·.··.·•····.== •· •·==·••·· ·.·.·.·· .• ·.·.-.. ·-... ·-_····.·.. .L .... ::==: • SPEC. NO. 67• Ji w,o. N0.R4O">n
REFERENCES
CONTRACTOR
CONSTRUCTION STARTED
CONSTRUCTION COMPLETED
COST INSPECTOR
. I
TYPICAL SECTION
CHANNEL EXCAVATION
1,/0 SCALe.
REVISION$ DATE APPROVED
-····-······~---+·---····-····-···-········-···-····--· ·-·-····-··· .,. _ ,. __ -' •· ···-·--
PLAN
SCALE:
Sa n Diego Unified
Port District
San Diego • California
- ····· ·-·············. --·•··• .....
········· ••
A. T :::;, 5. i"' R/F ca _J.E./.-.,_ ---+--
GRAPHIC
R 50f00
,n M.LLµ/
w
SC.ALES
PHILLIPS __ RECOMMENDED ------------ Storm Drains In & Adjacent MEAN ,~;;;~~v: WATER D>AWN ASST. c""' ENO'"''"- to Tidelands Ave . . & 6'G" St. 3 -16 _J.A.L./t ___ t-A-PP-RO_V_ED---"-=;...;..;.;;=-1 CHULA VISTA, CALIF. SHEET vr ------------ t--::-:-:-:==:-:-:-----=~_;;:;,:::.::.::;~-------l~~-~ OUTF'ALL-PLAN &_ PROFILE 9· 43 NORTH OF "c;" ST. 4.... DE:TAll..5. .
CHECKED
J E Fi,j:E,lE.5 - --- CHIEF ENGINEER-
~
/ 4- ~ · TIDES& 1~ j (https.//www.noaa.gov/) CURR ..... NTS (/) ·~· IJ Home(/) / Products (products.html) / Datums (stations.html?type=Datums) / 9410170 San Diego, CA Favorite Stations
Station Info Tides/Water Levels Meteorological Obs. (/met.html?id=9410170) Phys. Oceanography (/physocean.html?id=9410170)
OFS (/ofs/ofs_station.html?stname=San Diego&ofs=wc&stnid=9410170&subdomain=sca) Datums for 9410170, San Diego CA
NOTICE: All data values are relative to the MLLW.
Elevations on Mean Lower Low Water
Station: 9410170, San Diego, CA
Status: Accepted (Sep 20 2017)
Units: Feet
Control Station:
T.M.: 0
Epoch: (/datum_options.html#NTDE) 1983-2001
Datum: MLLW
Datum
MHHW (/datum_options.html#MHHW)
MHW (/datum_options.html#MHW)
MTL (/datum_options.html#MTL)
MSL (/datum_options.html#MSL)
DTL (/datum_options.html#DTL)
MLW (/datum_options.html#MLW)
MLLW (/datum_options.html#MLLW)
NAVD88 (/datum_options.html)
STND (/datum_options.html#STND)
GT (/datum_options.html#GT)
MN (/datum_options.html#MN)
Value
5.72 4.99
2.96 2.94
2.86 0.94
0.00 0.43
-3.79
5.72 4.05
Description
Mean Higher-High Water
Mean High Water
Mean Tide Level
Mean Sea Level
Mean Diurnal Tide Level
Mean Low Water
Mean Lower-Low Water
North American Vertical Datum of 1988
Station Datum
Great Diurnal Range
Mean Range of Tide
Datums for 9410170, San Diego, CA
All figures in feet relative to MLLW
6 +------------ MHHW: 5.72
DHQ: 0.74
5 MHW: 4.99:r-======----I---
4 -+-----------
Showing datums for
[ 9410170 San Diego, San Die ...
Datum
MLLW
Data Units @ Feet
0 Meters
V
Epoch @ Present (1983-2001)
0 Superseded (1960-1978)
Submit
Show nearby stations
DLQ: 0.94
Yards at the Bay
Project Name/ ____________________ _
ATTACHMENT 3
Structural BMP Maintenance Information
Hydromodification Control Measures
CCV BMP Manual
PDP SWQMP Template Date: March 2019 ~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Yards at the Bay
Project Name/ _____________________________ _
Use this checklist to ensure the required information has been included in the Structural BMP Maintenance Information Attachment:
Attachment 3: For private entity operation and maintenance, Attachment 3 must include a Storm Water Management Facilities Maintenance Agreement with Grant of Access and Covenant's ("Maintenance Agreement") Template can be found at the following link (also refer to Chapter 8.2.1 for more information's):
The following information must be included in the exhibits attached to the Maintenance Agreement:
lj Vicinity map (Depiction of Project Site)
II Legal Description for Project Site
lj Site design BMPs for which DCV reduction is claimed for meeting the pollutant Iii control obligations.
lj BMP and HMP type, location, type, manufacture model, and dimensions, specifications, cross section
Iii LID features such as (permeable paver and LS location, dim, SF). lj Maintenance recommendations and frequency
CCV BMP Manual
PDP SWQMP Template Date: March 2019 ~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Inspection Guidelines for
Modular Wetland System - Linear
Inspection Summary
MODULAR
WETLANDS
o Inspect Pre-Treatment, Biofiltration and Discharge Chambers - average inspection interval is 6 to 12 months.
• (15 minute average inspection time).
o NOTE: Pollutant loading varies greatly from site to site and no two sites are the same. Therefore, the first year requires inspection monthly during the wet season and every other month during the dry season in order to observe and record the amount of pollutant loading the system is receiving.
System Diagram
Access to separation chamber
and pre-filter cartridges
Curb Inlet
Individual Media Filters
Pre-filter Cartridge
Vertical Underdrain
Manifold
G) Pre-treatment Chamber
@ Biofiltration Chamber
,, @ Discharge Chamber
GioMedioGREEN M rlond
MEDIA
Drain-Down Line
www.modularwetlands.com
cess t~ _discharge
M OD ULA R
Inspection Overview WETLANDS
As with all stormwater BMPs inspection and maintenance on the MWS Linear is necessary.
Stormwater regulations require that all BMPs be inspected and maintained to ensure they are operating as designed to allow for effective pollutant removal and provide protection to receiving water bodies. It is recommended that inspections be performed multiple times during the first year to assess the site specific loading conditions. This is recommended because pollutant loading and pollutant characteristics can vary greatly from site to site. Variables such as nearby soil erosion or construction sites, winter sanding on roads, amount of daily traffic and land use can increase pollutant loading on the system. The first year of inspections can be used to set inspection and maintenance intervals for subsequent years to ensure appropriate maintenance is provided. Without appropriate maintenance a BMP will exceed its storage capacity which can negatively affect its continued performance in removing and retaining captured pollutants.
Inspection Equipment
Following is a list of equipment to allow for simple and effective inspection of the MWS Linear:
• Modular Wetland Inspection Form
• Flashlight
• Manhole hook or appropriate tools to remove access hatches and covers • Appropriate traffic control signage and procedures
• Measuring pole and/or tape measure.
• Protective clothing and eye protection.
• 7/16" open or closed ended wrench.
• Large permanent black marker (initial inspections only - first year) • Note: entering a confined space requires appropriate safety and certification. It is generally not required for routine inspections of the system.
www.modularwetlands.com
MODULAR
WETLANDS
Inspection Steps
The core to any successful stormwater BMP maintenance program is routine inspections. The inspection steps required on the MWS Linear are quick and easy. As mentioned above the first year should be seen as the maintenance interval establishment phase. During the first year more frequent inspections should occur in order to gather loading data and maintenance requirements for that specific site. This information can be used to establish a base for long term inspection and maintenance interval requirements.
The MWS Linear can be inspected though visual observation without entry into the system. All necessary pre-inspection steps must be carried out before inspection occurs, especially traffic control and other safety measures to protect the inspector and near-by pedestrians from any dangers associated with an open access hatch or manhole. Once these access covers have been safely opened the inspection process can proceed:
• Prepare the inspection form by writing in the necessary information including project name, location, date & time, unit number and other info (see inspection form). • Observe the inside of the system through the access hatches. If minimal light is available and vision into the unit is impaired utilize a flashlight to see inside the system and all of its chambers.
• Look for any out of the ordinary obstructions in the inflow pipe, pre-treatment chamber, biofiltration chamber, discharge chamber or outflow pipe. Write down any observations on the inspection form.
• Through observation and/or digital photographs estimate the amount of trash, debris and sediment accumulated in the pre-treatment chamber. Utilizing a tape measure or measuring stick estimate the amount of trash, debris and sediment in this chamber. Record this depth on the inspection form.
www.modularwetlands.com
MODULAR
WETLANDS
• Through visual observation inspect the condition of the pre-filter cartridges. Look for excessive build-up of sediments on the cartridges, any build-up on the top of the cartridges, or clogging of the holes. Record this information on the inspection form. The pre-filter cartridges can further be inspected by removing the cartridge tops and assessing the color of the BioMediaGREEN filter cubes (requires entry into pre-treatment chamber- see notes above regarding confined space entry). Record the color of the material. New material is a light green in color. As the media becomes clogged it will turn darker in color, eventually becoming dark brown or black. Using the below color indicator record the percentage of media exhausted.
New
BioMediaGREEN
0% -- Percent Clogged --
85%
Exhausted
BioMediaGREEN
• The biofiltration chamber is generally maintenance free due to the system's advanced pretreatment chamber. For units which have open planters with vegetation it is recommended that the vegetation be inspected. Look for any plants that are dead or showing signs of disease or other negative stressors. Record the general health of the plants on the inspection and indicate through visual observation or digital photographs if trimming of the vegetation is needed.
• The discharge chamber houses the orifice control structure and is connected to the outflow pipe. It is important to check to ensure the orifice is in proper operating conditions and free of any obstructions. Generally, the discharge chamber will be clean and free of debris. Inspect the water marks on the side walls. If possible, inspect the discharge chamber during a rain event to assess the amount of flow leaving the system while it is at 100% capacity (pretreatment chamber water level at peak HGL). The water level of the flowing water should be compared to the watermark level on the side walls which is an indicator of the highest discharge rate the system achieved when initially installed. Record on the form is there is any difference in level from watermark in inches.
www.modularwetlands.com
MODULAR
WETLANDS
• NOTE: During the first few storms the water level in the outflow chamber should be observed and a 6" long horizontal watermark line drawn (using a large permanent marker) at the water level in the discharge chamber while the system is operating at 100% capacity. The diagram below illustrates where a line should be drawn. This line is a reference point for future inspections of the system:
Mark
, Using a permanent marker draw a 6 inch long horizontal line, as shown, at the ,:S higher water level in the MWS Linear discharge chamber. • Water level in the discharge chamber is a function of flow rate and pipe size. Observation of water level during the first few months of operation can be used as a benchmark level for future inspections. The initial mark and all future observations shall be made when system is at 100% capacity (water level at maximum level in pre-treatment chamber). If future water levels are below this mark when system is at 100% capacity this is an indicator that maintenance to the pre-filter cartridges may be needed. • Finalize inspection report for analysis by the maintenance manager to determine if maintenance is required.
www.modularwetlands.com
MODULAR
WETLANDS
Maintenance Indicators
Based upon observations made during inspection, maintenance of the system may be required based on the following indicators:
• Missing or damaged internal components or cartridges. • Obstructions in the system or its inlet or outlet.
• Excessive accumulation of floatables in the pre-treatment chamber in which the length and width of the chamber is fully impacted more than 18".
• Excessive accumulation of sediment in the pre-treatment chamber of more than 6" in depth. www.modularwetlands.com
MODULAR
WETLANDS
• Excessive accumulation of sediment on the BioMediaGREEN media housed within the prefilter cartridges. The following chart shows photos of the condition of the BioMediaGREEN contained within the pre-filter cartridges. When media is more than 85% clogged replacement is required.
New
BioMediaGREEN
0%
• Overgrown vegetation.
85%
-- Percent Clogged --
Exhausted
BioMediaGREEN
• Water level in discharge chamber during 100% operating capacity (pre-treatment chamber water level at max height) is lower than the watermark by 20%. www.modularwetlands.com
MODULAR
WETLANDS
Inspection Notes
1. Following maintenance and/or inspection, it is recommended the maintenance operator prepare a maintenance/inspection record. The record should include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanisms.
2. The owner should keep maintenance/inspection record(s) for a minimum of five years from the date of maintenance. These records should be made available to the governing municipality for inspection upon request at any time.
3. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements.
4. Entry into chambers may require confined space training based on state and local regulations.
5. No fertilizer shall be used in the Biofiltration Chamber.
6. Irrigation should be provided as recommended by manufacturer and/or landscape architect. Amount of irrigation required is dependent on plant species. Some plants may not require irrigation after initial establishment.
www.modularwetlands.com
MODULAR
-u WETLANDS
Maintenance Guidelines for
Modular Wetland System - Linear
Maintenance Summary
o Remove Sediment from Pre-Treatment Chamber - average maintenance interval is 12 to 24 months.
• ( 10 minute average service time).
o Replace Pre-Filter Cartridge Media - average maintenance interval 12 to 24 months. • ( 10-15 minute per cartridge average service time).
o Trim Vegetation - average maintenance interval is 6 to 12 months. • (Service time varies).
System Diagram
Access to separation chamber
and pre-filter cartridge
Curb Inlet
Individual Media Filters
Pre-filter Cartridge
Vertical Underdrain
Manifold
OioMedioGREEN M rlond
MEDIA
G) Pre-treatment Chamber
@ Biofiltration Chamber
@ Discharge Chamber
www.modularwetlands.com
M OD ULA R
Maintenance Overview WETLANDS
The time has come to maintain your Modular Wetland System Linear (MWS Linear). To ensure successful and efficient maintenance on the system we recommend the following. The MWS Linear can be maintained by removing the access hatches over the systems various chambers. All necessary pre-maintenance steps must be carried out before maintenance occurs, especially traffic control and other safety measures to protect the inspector and near-by pedestrians from any dangers associated with an open access hatch or manhole. Once traffic control has been set up per local and state regulations and access covers have been safely opened the maintenance process can begin. It should be noted that some maintenance activities require confined space entry. All confined space requirements must be strictly followed before entry into the system. In addition the following is recommended:
• Prepare the maintenance form by writing in the necessary information including project name, location, date & time, unit number and other info (see maintenance form). • Set up all appropriate safety and cleaning equipment. • Ensure traffic control is set up and properly positioned. • Prepare a pre-checks (OSHA, safety, confined space entry) are performed.
Maintenance Equipment
Following is a list of equipment required for maintenance of the MWS Linear:
• Modular Wetland Maintenance Form
• Manhole hook or appropriate tools to access hatches and covers • Protective clothing, flashlight and eye protection.
• 7/16" open or closed ended wrench.
• Vacuum assisted truck with pressure washer.
• Replacement BioMediaGREEN for Pre-Filter Cartridges if required (order from manufacturer). l\
L
www.modularwetlands.com
MODULAR
WETLANDS
Maintenance Steps
1. Pre-treatment Chamber (bottom of chamber)
A. Remove access hatch or manhole cover over pre-treatment chamber and position vacuum truck accordingly.
B. With a pressure washer spray down pollutants accumulated on walls and pre-filter cartridges.
C. Vacuum out Pre-Treatment Chamber and remove all accumulated pollutants including trash, debris and sediments. Be sure to vacuum the floor until pervious pavers are visible and clean.
D. If Pre-Filter Cartridges require media replacement move onto step 2. If not, replace access hatch or manhole cover.
Removal of access hatch to gain access below. Insertion of vacuum hose into separation chamber.
Removal of trash, sediment and debris. Fully cleaned separation chamber. www.modularwetlands.com
MODULAR
WETLANDS
2. Pre-Filter Cartridges (attached to wall of pre-treatment chamber) A. After finishing step 1 enter pre-treatment chamber.
B. Unscrew the two bolts holding the lid on each cartridge filter and remove lid.
Pre-filter cartridges with tops on.
Inside cartridges showing media filters ready for
replacement.
C. Place the vacuum hose over each individual media filter to suck out filter media.
Vacuuming out of media filters.
D. Once filter media has been sucked use a pressure washer to spray down inside of the cartridge and it's containing media cages. Remove cleaned media cages and place to the side. Once removed the vacuum hose can be inserted into the cartridge to vacuum out any remaining material near the bottom of the cartridge.
www.modularwetlands.com
MODULAR
WETLANDS
E. Reinstall media cages and fill with new media from manufacturer or outside supplier.
Manufacturer will provide specification of media and sources to purchase. Utilize the manufacture provided refilling trey and place on top of cartridge. Fill trey with new bulk media and shake down into place. Using your hands slightly compact media into each filter cage. Once cages are full removed refilling trey and replace cartridge top ensuring bolts are properly tightened.
Refilling trey for media replacement. Refilling trey on cartridge with bulk media.
F. Exit pre-treatment chamber. Replace access hatch or manhole cover.
3. Biofiltration Chamber (middle vegetated chamber)
A. In general, the biofiltration chamber is maintenance free with the exception of maintaining the vegetation. Using standard gardening tools properly trim back the vegetation to healthy levels. The MWS Linear utilizes vegetation similar to surrounding landscape areas therefore trim vegetation to match surrounding vegetation. If any plants have died replace plants with new ones:
www.modularwetlands.com
MODULAR
WETLANDS
Inspection Notes
1. Following maintenance and/or inspection, it is recommended the maintenance operator prepare a maintenance/inspection record. The record should include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanisms.
2. The owner should keep maintenance/inspection record(s) for a minimum of five years from the date of maintenance. These records should be made available to the governing municipality for inspection upon request at any time.
3. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements.
4. Entry into chambers may require confined space training based on state and local regulations.
5. No fertilizer shall be used in the Biofiltration Chamber.
6. Irrigation should be provided as recommended by manufacturer and/or landscape architect. Amount of irrigation required is dependent on plant species. Some plants may not require irrigation after initial establishment.
www.modularwetlands.com
Inspection Form
Cl
Modular Wetland System, Inc.
P. 760.433-7640
F. 760-433-3176
E. [email protected]
www.modularwetlands.com
MODULAR
WETLANDS
CLEAN. ENVPRONM£NTAL StltVrCES , INC .
Inspection Report
Modular Wetlands System MODULAII 1-
WETLANDS
Project Name
Project Address -----------------------------<-,.-ty) ____ c_) _____ _ - (Zip ode Owner I Management Company ___________________________________ _ Contact Phone ( ----------------------- Inspector Name ___________________ _ Date Time For Office Use Only
(Reviewed By)
(Date)
Office personnel to complete section to
the left.
AM/PM
Type of Inspection D Routine D FollowUp D Complaint D Storm Storm Event in Last 72-hours? D No D Yes Weather Condition __________________ Additional Notes
Inspection Checklist
Modular Wetland System Type (Curb, Grate or UG Vault): Size (22', 14' or etc.):
Structural Integrity: Yes No Comments
Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting pressure?
Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting pressure?
Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)? Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly? Working Condition:
Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging th1 unit?
Is there standing water in inappropriate areas after a dry period? Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system? Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes IDepth:
specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber.
Chamber.
Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber? Any signs of improper functioning in the discharge chamber? Note issues in comments section.
Other Inspection Items:
Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)? Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below.
Is there a septic or foul odor coming from inside the system? Waste: Yes No Recommended Maintenance Plant Information Sediment / Silt / Clay No Cleaning Needed Damaqe to Plants Trash / Bags/ Bottles Schedule Maintenance as Planned Plant Reolacement Green Waste / Leaves / Foliage Needs Immediate Maintenance Plant Trimming Additional Notes:
2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176 Maintenance Report
Modular Wetland System, Inc.
P. 760.433-7640
F. 760-433-3176
E. [email protected]
www.modularwetlands.com
MODULAR
WETLANDS
CLEAN. ENVIRONMENTAL SERVICES , INC.
Cleaning and Maintenance Report
Modular Wetlands System
-1_ MOD U LA !\
WETLANDS
Project Name ---------------------------------------- For Office Use Only ProjectAddress --------------------------------------- (city) (Zip Code) (Reviewed By) Owner I Management Company---------------------------------- Contact ---------------------- Inspector Name __________________ _ Type of Inspection D Routine D FollowUp D Complaint
Weather Condition
Site GPS Coordinates Manufacturer / Trash
Map# of Insert Description / Sizing Accumulation
Lat: MWS
Catch Basins
LonQ:
MWS
Sedimentation
Basin
Media Filter
Condition
Plant Condition
Drain Down Media
Condition
Discharge Chamber
Condition
Drain Down Pipe
Condition
Inlet and Outlet
Pipe Condition
Comments:
Phone (
Date
D Storm
Additional Notes
Foliage Sediment
Accumulation Accumulation
Time
(Uate)
Office personnel to complete section to
the left.
AM/PM -------
Storm Event in Last 72-hours? D No D Yes
Condition of Media Operational Per
Total Debris 25/50/75/100 Manufactures'
Accumulation (will be changed Specifications
@75%) (If not, why?)
2972 San Luis Rey Road, Oceanside, CA 92058 P. 760.433.7640 F. 760.433.3176 Yards at the Bay
Project Name/ ____________________ _
CCV BMP Manual
ATTACHMENT 4
Copy of Plan Sheets Showing
Permanent Storm Water BMPs
PDP SWQMP Template Date: March 2019 ~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Yards at the Bay
Project Name/ ______________________________ _
Use this checklist to ensure the required information has been included on the plans:
The plans must identify:
[j Structural BMP(s) with ID numbers matching Form 1-6 Summary of PDP Structural BMPs [j The grading and drainage design shown on the plans must be consistent with the delineation of DMAs shown on the DMA exhibit
Iii Details and specifications for construction of structural BMP(s) lil Signage indicating the location and boundary of structural BMP(s) as required by the City Engineer
Iii How to access the structural BMP(s) to inspect and perform maintenance lil Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds)
~ Manufacturer and part number for proprietary parts of structural BMP(s) when applicable lil Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP)
[j Recommended equipment to perform maintenance
Iii When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management Iii Include landscaping plan sheets showing vegetation requirements for vegetated structural BMP(s)
D All BMPs must be fully dimensioned on the plans
D When proprietary BMPs are used, site specific cross section with outflow, inflow and model number shall be provided. Broucher photocopies are not allowed.
CCV BMP Manual
PDP SWQMP Template Date: March 2019 ~Vt-
·•.: .. . -CllYOf
CHULA VISTA
Bio~ Clean
A Forterra Company
OVERVIEW
The Bio Clean Modular Wetlands® System Linear represents a pioneering breakthrough in stormwater technology as the only biofiltration system to utilize patented horizontal flow, allowing for a smaller footprint, higher treatment capacity, and a wide range of versatility. While most biofilters use little or no pretreatment, the Modular Wetlands® incorporates an advanced pretreatment chamber that includes separation and pre-filter cartridges. In this chamber, sediment and hydrocarbons are removed from runoff before entering the biofiltration chamber, reducing maintenance costs and improving performance.
Horizontal flow also gives the system the unique ability to adapt to the environment through a variety of configurations, bypass orientations, and diversion applications.
The Urban Impact
For hundreds of years, natural wetlands surrounding our shores have played an integral role as nature's stormwater treatment system.
But as cities grow and develop, our environment's natural filtration systems are blanketed with impervious roads, rooftops, and parking lots.
Bio Clean understands this loss and has spent
years re-establishing nature's presence in urban
areas, and rejuvenating waterways with the
Modular Wetlands® System Linear.
APPROVALS
The Modular Wetlands® System Linear has successfully met years of challenging technical reviews and testing from some of the most prestigious and demanding agencies in the nation and perhaps the world.
Here is a list of some of the most high-profile approvals, certifications, and verifications from around the country.
Washington State Department of Ecology TAPE Approved
The MWS Linear is approved for General Use Level Designation (GULD) for Basic, Enhanced, and Phosphorus treatment at 1 gpm/ft2 loading rate. The highest performing BMP on the market for all main pollutant categories.
California Water Resources Control Board, Full Capture Certification The Modular Wetlands® System is the first biofiltration system to receive certification as a full capture trash treatment control device.
Virginia Department of Environmental Quality, Assignment The Virginia Department of Environmental Quality assigned the MWS Linear the highest phosphorus removal rating for manufactured treatment devices to meet the new Virginia Stormwater Management Program (VSMP) regulation technical criteria.
Maryland Department of the Environment, Approved ESD
Granted Environmental Site Design (ESD) status for new construction, redevelopment, and retrofitting when designed in accordance with the design manual.
MASTEP Evaluation
The University of Massachusetts at Amherst - Water Resources Research Center issued a technical evaluation report noting removal rates up to 84% TSS, 70% total phosphorus,
68.5% total zinc, and more.
Rhode Island Department of Environmental Management, Approved BMP Approved as an authorized BMP and noted to achieve the following minimum removal efficiencies: 85% TSS, 60% pathogens, 30% total phosphorus, and 30% total nitrogen.
OPERATION
The Modular Wetlands® System Linear is the most efficient and versatile biofiltration system on the market, and it is the only system with horizontal flow which:
• Improves performance
• Reduces footprint
• Minimizes maintenance
Figure 1 & Figure 2 illustrate the invaluable benefits of horizontal flow and the multiple treatment stages. 0 PRETREATMENT
SEPARATION
• Trash, sediment, and debris are separated before
entering the pre-filter cartridges
• Designed for easy maintenance access
PRE-FILTER CARTRIDGES
• Over 25 sq. ft. of surface area per cartridge
• Utilizes BioMediaGREEN™ filter material
• Removes over 80% of TSS and 90% of hydrocarbons
• Prevents pollutants that cause clogging from migrating to the biofiltration chamber
Individual Media Filters
Cartridge Housing
Curb Inlet
Pre-filter Cartridge
BioMediaG REEN™
Vertical Underdrain
Manifold
WetlandMEDIA™
PERIMETER V
01D AREA
Draindown Line
Flow Control
Riser
2x to 3x more surface area than traditional downward flow bioretention systems. 0 BIOFILTRATION
HORIZONTAL FLOW
• Less clogging than downward flow biofilters
• Water flow is subsurface
• Improves biological filtration
PATENTED PERIMETER VOID AREA
• Vertically extends void area between the walls and
the WetlandMEDIA™ on all four sides
• Maximizes surface area of the media for higher
treatment capacity
WETLANDMEDIA
• Contains no organics and removes phosphorus
• Greater surface area and 48% void space
• Maximum evapotranspiration
• High ion exchange capacity and lightweight
Figure 1 0 DISCHARGE
Outlet Pipe
FLOW CONTROL
• Orifice plate controls flow of water
through WetlandMEDIA'M to a level lower
than the media's capacity
• Extends the life of the media and
improves performance
DRAINDOWN FILTER
• The draindown is an optional feature that
completely drains the pretreatment
chamber
• Water that drains from the pretreatment
chamber between storm events will be
treated
CONFIGURATIONS
The Modular Wetlands® System Linear is the preferred biofiltration system of civil engineers across the country due to its versatile design. This highly versatile system has available "pipe-in" options on most models, along with built-in curb or grated inlets for simple integration into your storm drain design.
CURB TYPE
The Curb Type configuration accepts sheet flow through a curb opening and is commonly used along roadways and parking lots. It can be used in sump or flow-by conditions. Length of curb opening varies based on model and size.
GRATE TYPE
The Grate Type configuration offers the same features and benefits as the Curb Type but with a grated/drop inlet above the systems pretreatment chamber. It has the added benefit of allowing pedestrian access over the inlet. ADA-compliant grates are available to assure easy and safe access.
The Grate Type can also be used in scenarios where runoff needs to be intercepted on both sides of landscape islands.
VAULT TYPE
The system's patented horizontal flow biofilter is able to accept inflow pipes directly into the pretreatment chamber, meaning the Modular Wetlands® can be used in end-of-the-line installations. This greatly improves feasibility over typical decentralized designs that are required with other biofiltration/ bioretention systems. Another benefit of the "pipe-in" design is the ability to install the system downstream of underground detention systems to meet water quality volume requirements.
DOWNSPOUT TYPE
The Downspout Type is a variation of the Vault Type and is designed to accept a vertical downspout pipe from rooftop and podium areas. Some models have the option of utilizing an internal bypass, simplifying the overall design. The system can be installed as a raised planter, and the exterior can be stuccoed or covered with other finishes to match the look of adjacent buildings.
ORIENTATIONS
SIDE-BY-SIDE
The Side-By-Side
orientation places the
pretreatment and
discharge chamber
adjacent to one
another with the
biofiltration chamber running
parallel on either side. This
minimizes the system length, providing a highly
compact footprint. It has been proven useful in
situations such as streets with directly adjacent
sidewalks, as half of the system can be placed
under that sidewalk. This orientation also offers
internal bypass options as discussed below.
BYPASS
INTERNAL BYPASS WEIR
(SIDE-BY-SIDE ONLY)
The Side-By-Side orientation places the
pretreatment and discharge chambers adjacent
to one another allowing for integration of internal
bypass. The wall between these chambers can act
as a bypass weir when flows exceed the system's
treatment capacity, thus allowing bypass from the
pretreatment chamber directly to the discharge
chamber.
EXTERNAL DIVERSION WEIR STRUCTURE
This traditional offline diversion method can be
used with the Modular Wetlands® in scenarios
where runoff is being piped to the system. These
simple and effective structures are generally
configured with two outflow pipes. The first is a
smaller pipe on the upstream side of the diversion
weir - to divert low flows over to the Modular
Wetlands® for treatment. The second is the main
pipe that receives water once the system has
exceeded treatment capacity and water flows over
the weir.
FLOW-BY-DESIGN
This method is one in which the system is placed
just upstream of a standard curb or grate inlet to
intercept the first flush. Higher flows simply pass
by the Modular Wetlands® and into the standard
inlet downstream.
END-TO-END
The End-To-End orientation
places the pretreatment and
discharge chambers
on opposite ends of the
biofiltration chamber,
therefore minimizing the width
of the system to 5 ft. (outside
dimension). This orientation is perfect
for linear projects and street retrofits
where existing utilities and sidewalks limit the
amount of space available for installation. One
limitation of this orientation is that bypass must
be external.
OVERT LOW FLOW DIVERSION
This simple yet innovative diversion trough can be
installed in existing or new curb and grate inlets
to divert the first flush to the Modular Wetlands®
via pipe. It works similar to a rain gutter and is
installed just below the opening into the inlet. It
captures the low flows and channels them over
to a connecting pipe exiting out the wall of the
inlet and leading to the MWS Linear. The OVERT
is perfect for retrofit and green street applications
that allow the Modular Wetlands® to be installed
anywhere space is available.
SPECIFICATIONS
FLOW-BASED DESIGNS
The Modular Wetlands® System Linear can be used in stand-alone applications to meet treatment flow requirements. Since the Modular Wetlands® is the only biofiltration system that can accept inflow pipes several feet below the surface, it can be used not only in decentralized design applications but also as a large central end-of-the-line application for maximum feasibility.
WETLANDMEDIA TREATMENT FLOW
MODEL# DIMENSIONS SURFACE AREA RATE
(sq. ft.) (cfs)
MWS-L-4-4 4'x4' 23 0.052
MWS-L-4-6 4' X 6' 32 0.073
MWS-L-4-8 4' X 8' 50 0.115
MWS-L-4-13 4' X 13' 63 0.144
MWS-L-4-15 4' X 15' 76 0.175
MWS-L-4-17 4' X 17' 90 0.206
MWS-L-4-19 4' X 79' 103 0.237
MWS-L-4-21 4' X 21' 117 0.268
MWS-L-6-8 7' X 9' 64 0.147
MWS-L-8-8 8' X 8' 100 0.230
MWS-L-8-12 8' X 12' 151 0.346
MWS-L-8-16 8' X 16' 201 0.462
MWS-L-8-20 9' X 21' 252 0.577
MWS-L-8-24 9' X 25' 302 0.693
MWS-L-10-20 10' X 20' 302 0.693
VOLUME-BASED DESIGNS
HORIZONTAL FLOW BIOFILTRATION ADVANTAGE
Modular Wetlands® with
Box Culvert Prestorage
The Modular Wetlands® System Linear offers a unique advantage in the world of biofiltration due to its exclusive horizontal flow design: Volume-Based Design. No other biofilter has the ability to be placed downstream of detention ponds, extended dry detention basins, underground storage systems and permeable paver reservoirs. The systems horizontal flow configuration and built-in orifice control allows it to be installed with just 6" of fall between inlet and outlet pipe for a simple connection to projects with shallow downstream tiein points. In the example above, the Modular Wetlands® is installed downstream of underground box culvert storage. Designed for the water quality volume, the Modular Wetlands® will treat and discharge the required volume within local draindown time requirements.
DESIGN SUPPORT
Modular Wetlands® with
Arch Plastic Chambers
Bio Clean engineers are trained to provide you with superior support for all volume sizing configurations throughout the country. Our vast knowledge of state and local regulations allow us to quickly and efficiently size a system to maximize feasibility. Volume control and hydromodification regulations are expanding the need to decrease the cost and size of your biofiltration system. Bio Clean will help you realize these cost savings with the Modular Wetlands®, the only biofilter than can be used downstream of storage BMPs.
ADVANTAGES
• LOWER COST THAN FLOW-BASED DESIGN • BUILT-IN ORIFICE CONTROL STRUCTURE • MEETS LID REQUIREMENTS • WORKS WITH DEEP INSTALLATIONS
APPLICATIONS
The Modular Wetlands® System Linear has been successfully used on numerous new construction and retrofit projects. The system's superior versatility makes it beneficial for a wide range of stormwater and waste water applications - treating rooftops, streetscapes, parking lots, and industrial sites.
INDUSTRIAL
Many states enforce strict regulations for discharges
from industrial sites. The Modular Wetlands® has
helped various sites meet difficult EPA-mandated
effluent limits for dissolved metals and other
pollutants.
STREETS
Street applications can be challenging due to limited
space. The Modular Wetlands® is very adaptable,
and it offers the smallest footprint to work around
the constraints of existing utilities on retrofit projects.
COMMERCIAL
Compared to bioretention systems, the Modular
Wetlands® can treat far more area in less space,
meeting treatment and volume control requirements.
RESIDENTIAL
Low to high density developments can benefit from
the versatile design of the Modular Wetlands®. The
system can be used in both decentralized LID design
and cost-effective end-of-the-line configurations.
PARKING LOTS
Parking lots are designed to maximize space and the
Modular Wetlands'® 4 ft. standard planter width
allows for easy integration into parking lot islands
and other landscape medians.
MIXED USE
The Modular Wetlands® can be installed as a raised
planter to treat runoff from rooftops or patios,
making it perfect for sustainable "live-work" spaces.
More applications include:
• Agriculture • Reuse • Low Impact Development • Waste Water
PLANT SELECTION
Abundant plants, trees, and grasses bring value and an aesthetic benefit to any urban setting, but those in the Modular Wetlands® System Linear do even more - they increase pollutant removal. What's not seen, but very important, is that below grade, the stormwater runoff/flow is being subjected to nature's secret weapon: a dynamic physical, chemical, and biological process working to break down and remove non-point source pollutants. The flow rate is controlled in the Modular Wetlands®, giving the plants more contact time so that pollutants are more successfully decomposed, volatilized, and incorporated into the biomass of the Modular Wetlands'® micro/macro flora and fauna.
A wide range of plants are suitable for use in the Modular Wetlands®, but selections vary by location and climate.
View suitable plants by visiting biocleanenvironmental.com/plants.
INSTALLATION
The Modular Wetlands® is simple, easy to install,
and has a space-efficient design that offers lower
excavation and installation costs compared to
traditional tree-box type systems. The structure of
the system resembles precast catch basin or utility
vaults and is installed in a similar fashion.
The system is delivered fully assembled for quick
installation. Generally, the structure can be unloaded
and set in place in 15 minutes. Our experienced
team of field technicians is available to supervise
installations and provide technical support.
MAINTENANCE
Reduce your maintenance costs, man hours, and
materials with the Modular Wetlands®. Unlike other
biofiltration systems that provide no pretreatment,
the Modular Wetlands® is a self-contained
treatment train which incorporates simple and
effective pretreatment.
Maintenance requirements for the biofilter itself are
almost completely eliminated, as the pretreatment
chamber removes and isolates trash, sediments, and
hydrocarbons. What's left is the simple maintenance
of an easily accessible pretreatment chamber that
can be cleaned by hand or with a standard vac
truck. Only periodic replacement of low-cost media
in the pre-filter cartridges is required for long-term
operation, and there is absolutely no need to replace
expensive biofiltration media.
A Forterra c'ompany
Yards at the Bay
Project Name/ ____________________________ _
ATTACHMENT 5
Drainage Report
Attach project's drainage report. Refer to the Subdivision Manual to determine the reporting requirements.
CCV BMP Manual
PDP SWQMP Template Date: March 2019 ~Vt-
-•.: .. .. . -CllYOf
CHULA VISTA
PRELIMINARY
DRAINAGE REPORT
YARDS AT THE BAY
City of Chula Vista, CA
City of Chula Vista Tentative Parcel Map and Coastal Development Permit ----
APN #: 571-330-36 Through 571-330-45
Project Address:
Marina Parkway and H Street,
Chula Vista, CA 91910
Prepared For:
WOHL Property Group
2251 San Diego A venue, Suite A24 7
San Diego, CA 92110
Prepared By:
PROJECT DESIGN
CONSULTANTS
701 B Street, Suite 800
San Diego, CA 92101
No. 71026
p. 06-30-
a Bowman company
619.235.6471
PDC Job No. 4508
Prepared by: Jonathan Teas, PE
Under the supervision of
Chelisa A. Pack, PE RCE 71026
Registration Expires 6/30/25
TABLE OF CONTENTS
1. INTRODUCTION .................................................................................................................. 1
2. EXISTING AND PROPOSED DRAINAGE PATTERNS AND IMPROVEMENTS .......... 2
2.1 Existing Drainage Patterns .............................................................................................. 2
2.2 Proposed Drainage Improvements .................................................................................. 3
3. HYDROLOGY CRITERIA, METHODOLOGY, AND RESULTS ...................................... 4
3.1 Hydrology Criteria .......................................................................................................... 4
3.2 Hydrologic Methodology ................................................................................................ 4
3.3 Description ofHydrologic Modeling Software .............................................................. 5
3.4 Hydrology Results .......................................................................................................... 6
4. HYDRAULIC CRITERIA, METHODOLOGY, AND RESULTS ....................................... 6
5. CONCLUSION ....................................................................................................................... 6 TABLES
Table 1: Hydrology Criteria ............................................................................................................ 4 Table 2: Hydrology Results ............................................................................................................ 6
APPENDICES
1 Supplemental Information (Intensity Duration Frequency Curve, Runoff Coefficients)
2 Existing Conditions Rational Method Computer Output
3 Proposed Conditions Rational Method Computer Output
4 Hydraulic Calculations
5 Drainage Exhibits
1. INTRODUCTION
This drainage report has been prepared in support of the preliminary design of the proposed storm drain improvements associated with the Yards at the Bay development project (Project) for a Tentative Parcel Map and Coastal Development Permit submittal. Total Project area is 35.91 acres and includes a development previously developed with two industrial buildings for manufacturing occupied by Rohr Aircraft Facility prior to 2020. The project is an active construction site for the demolition of the industrial buildings. The project is south of Sweetwater River, on the East side of Marina Parkway across from the Gaylord Resort development which is currently under construction. The project proposes commercial/light industrial uses with four large buildings, parking, and drive aisles. Fill will be imported in to the site to elevate the proposed buildings above existing grades. The additional fill will allow for additional protection against the effects of potential future sea level rise, as the site is close to the San Diego Bay. The southerly portion of the project consists of two undeveloped sloped pads which will not be developed with the project.
A future development of the pads will likely consist of commercial uses; thus, we have treated these pads as commercial development for flow calculations.
SAN DIEGO BA Y
NA TIONAL 'MLDLIFE
REFUGE
SAN DIEGO BAY
VICINITY MAP
NOT TO SCALE
Figure 1: Vicinity Map
1 P:14508\Engr\Rcports\Drainage-Prelim\ 4508 - Yanls at the Bay Drainage Rcport.docx At present the site land consists mostly of parking and building roofs. There is very little if any natural terrain existing on the site. There is a small amount of runon 0.3 acres at the north easterly comer of the site where an SDG&E substation exists, the run-on sheet flows through the site for a short distance and then enters G Street.
Presently the urban run-off is split north and south of the site. There are various roof drain collections and grate inlets which direct the flow, splitting the north and south sides of the site.
The proposed project will split the site in a similar way, however; minor grading adjustments will send more flow to the south, since the southerly storm drain has a higher capacity to handle the large flows conveyed on the site. One biofiltration basin and several Modular Wetland Units will be implemented to manage water. The proposed site's storm drain system will outlet into the existing storm drain facilities along the north and south end of the project respectively. Both north and south connections outlet to the San Diego Bay via pipe flow. For water quality management concerns refer to the Storm Water Quality Management Plan (SWQMP) prepared by Project Design Consultants for the proposed project treatment BMPs.
2. EXISTING AND PROPOSED DRAINAGE PATTERNS AND IMPROVEMENTS The following sections provide descriptions of the existing and proposed drainage patterns and improvements for the project.
2.1 Existing Drainage Patterns (Pre-demolition Conditions) There are on-site drainage facilities, including storm drain pipe with grate inlet and roof drain connections for the roofs and drive and parking aisles on the site which splits the site drainage between the North and South towards the San Diego Bay west of the site. The north system connects to an 36" RCP stub, and then outlets through an 54-inch RCP into a slough just northwest of the site. The slough is directly connect to the San Diego Bay. The south system connects to an 60" RCP stub, and then outlets through an 84-inch RCP that discharges into the San Diego Bay at the Chula Vista Marina. Refer to Exhibit A in Appendix 5 for the existing condition drainage map.
The Hydrologic Soil Group of the site consists of Soil Group D and an Unknown Soil Group. Per the NRCS Soil Map Survey, the easterly side of the site consists of HuC which is Soil Group D 2 P:\4508\Engr\Reports\Drainage-Prelim\ 4508 - Yards at the Bay Drainage Report.docx and a portion of the westerly side of the site consists of Md which is Made Land and is not a known Soil Group. The NRCS Soil Map Survey is included in Appendix 1.
2.2 Proposed Drainage Improvements
The site will remove the existing site storm drain facilities and replace with similar facilities to meet the project needs, trench drains, grate and curb inlets will be used to pick up flow, and storm drain pipes to convey the site flow. Roof flow will be directed to the drive aisles and picked up with grate inlets or hard tied directly to the storm drain. The project maintains similar patterns to the existing conditions, discharging to north and south. However; the project site's drainage plan directs more flow south because there is more capacity in the on-site storm drain stub on the south site. As described in Section 2.1, the north storm drain system connects to a 36" stub. In contrast, the south system connect to an 60" stub. Directing more flow to the South stub was necessary in the proposed conditions, so that the Northerly 36" stub capacity is not over-burdened. Refer to Exhibit B in Appendix 5 for the proposed condition drainage map.
Water quality requirements will be managed with one biofiltration basin and several modular wetland units.
3 P:\4508\Engr\Reports\Drainage-Prelim\ 4508 - Yards at the Bay Drainage Report.docx
3. HYDROLOGY CRITERIA, METHODOLOGY, AND RESULTS
Hydrologic modeling was performed per City of Chula Vista Subdivision Manual criteria to provide the design flows for storm drain design and improvements.
3.1 Hydrology Criteria
Table 1 summarizes the hydrology assumptions and criteria used for hydrologic modeling.
Table 1: Hydrology Criteria
Existing and Proposed 100-year storm frequency
Hydrology:
Soil Type: Hydrologic Soil Group D & Unknown
Land Use/ Runoff Coefficients: Based on criteria presented in the Revised 2012 City of Chula Vista Subdivision Manual Section 3-200
Hydrology/Drainage/Urban Runoff.
Rainfall intensity: Based on intensity duration frequency relationships presented in the 2017 Chula Vista Design Standards &
Revised 2012 Citv of Chula Vista Subdivision Manual
Section 3-200 Hydrology/Drainage/Urban Runoff, see
Appendix 1.
3.2 Hydrologic Methodology
The Rational Method was used to determine the onsite 100-year storm flow for the design of the Project storm drainpipe improvements. The goal of this analysis was to:
■ Determine the design flows for the sizing of any proposed storm drain improvements. ■ Determine the differences in the drainage conditions between existing and proposed conditions to confirm there are no significant downstream impacts.
The AES Modified Rational Method program was used to calculate onsite and offsite runoff for the 100-year storm event. For the existing conditions model, a runoff coefficient of 0.90 ("Paved Surface") was used, since the entire site is nearly 100% impervious. For the proposed condition model, a representative runoff coefficient was assigned for each subarea. Therefore, a runoff 4 P:\4508\Engr\Reports\Drainage-Prelim\ 4508 - Yards at the Bay Drainage Report.docx coefficient of0.90 ("Paved Surface") was used for areas that will be nearly 100% impervious, and other subareas were modeled as 0.85 runoff coefficient ("Commercial Areas") and 0.45 ("Flat Vegetated Slopes") was used only for the westerly large pervious area. For the two southerly undeveloped sloped pads on the project, a runoff coefficient of 0.85 ("Commercial Areas") was used, because a future project may develop these areas in the future. However, these pads are not proposed to be developed with this project, and thus until the pads are developed the actual runoff from these areas will be more similar to Flat Vegetated Slopes 0.45 runoff coefficient which will contribute less runoff thus making the modeling included in this report conservative.
3.3 Description of Hydrologic Modeling Software
The Modified Rational Method was used to determine the 100-year storm flow for the design of the storm system. The Advanced Engineering Software (AES) Rational Method Program was used to perform the hydrologic calculations. This section provides a brief explanation of the computational procedure used in the computer model.
The AES Modified Rational Method Hydrology Program is a computer-aided design program where the user develops a node link model of the watershed. Developing independent node link models for each interior watershed and linking these sub-models together at confluence points creates the node link model. The intensity-duration-frequency relationships are applied to each of the drainage areas in the model to get the peak flow rates at each point of interest. 5 P:\4508\Engr\Reports\Drainage-Prelim\ 4508 - Yards at the Bay Drainage Report.docx
3.4 Hydrology Results
The Rational Method as presented in the City of Chula Vista Subdivision Manual and County of San Diego Hydrology Manual was used to calculate the existing and proposed conditions peak storm flows. Table 2 below summarizes the Rational Method results for the comparison of the existing and proposed project site. The total peak 100-year flows under the post-prjoect condition are less than the pre-project condition peak flows. The peak flow to the south outlet increases slightly in the post-project condition, in order to alleviate downstream pipe capacity concerns for the north outlet, since the stub for the outlet has more pipe conveyance capacity that the storm drain stub for the north outlet.
Table 2: Hydrology Results
YARDS AT THE BAY HYDROLOGY SUMMARY
EXISTING CONDITIONS PROPOSED CONDITIONS
OUTFALL OF SYSTEM AREA TC Ql00 SYSTEM AREA TC Ql00
INTEREST {ac) {min) {cfs) {ac) {min) {cfs)
#1 (South) 100 18.6 6.5 102.7 100 23.2 7.18 109.1
#2 (North) 200 17.8 5.97 98.1 200 13.2 6.29 69.0
TOTAL 36.4 200.8 36.4 178.1
4. HYDRAULIC CRITERIA, METHODOLOGY, AND RESULTS
Hydraulic analyses shall be performed during final engineering will include grate and curb inlet sizing, and HGL determination.
5. CONCLUSION
This drainage report has been prepared in support of the preliminary design of the storm drain improvements for the Tentative Parcel Map and Coastal Development Permit for the Yards at the Bay project. The purpose of this report is to provide peak discharges for use in designing the private storm drain systems for the project and to address issues regarding comparing the postproject flows to the pre-project flows. Table 2 indicates that the proposed conditions discharge 6 P:14508\Engr\Rcports\Drainage-Prelim\ 4508 - Yanls at the Bay Drainage Rcport.docx slightly more runoff to the south, but the overall total post-project 100-year flow is less compared to the existing condition.
The storm drain system will be sufficient to satisfy City of Chula Vista criteria in the postdevelopment condition. 7 P:\4508\Engr\Reports\Drainage-Prelim\ 4508 - Yards at the Bay Drainage Report.docx APPENDIXl
Supplemental Information (Intensity Duration Frequency Curve, Runoff Coefficients)
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Directions for Application:
(1) From precipitation maps determine 6 hr and 24 hr amounts for the selected frequency. These maps are included in the County Hydrology Manual (10, 50, and 100 yr maps included in the Design and Procedure Manual).
(2) Adjust 6 hr precipitation (if necessary) so that it is within the range of 45% to 65% of the 24 hr precipitation (not applicaple to Desert).
(3) Plot 6 hr precipitation on the right side of the chart. (4) Draw a line through the point parallel to the plotted lines. (5) This line is the intensity-duration curve for the location being analyzed .
Application Form:
(a) Selected frequency ~ year
p
(b) P5 = --2.,Q_ in., P24 = _AA_ ' P 6 = 59.1 %<2l
24 (c) Adjusted P6<2l = __ in.
{d) Ix= ___ min.
(e) I= ___ in./hr.
Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965.
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P6 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 --·- Duration I I I I I I I I I I I I 5 2.63 3.95 5.27 6.59 7.90 9.22 1054 11.86 13.17 14.49 15.81 7 2.12 3.18 4.24 5.30 6.36 7.42 8.48 9.54 10.60 11 .66 12.72 10 1.68 2.53 3.37 4.21 5.05 5.90 6.74 7.58 8.42 9.27 10.11 15 1.30 1.95 2.59 3.24 3.89 4.54 5.19 5.84 6.49 7.13 7.78 20 1.08 1.62 2.15 2.69 3.23 3.77 4.31 4.85 5.39 5.93 6.46 - 25 0.93 1.40 1.87 2.33 2.80 3.27 3.73 4.20 4.67 5.13 5.60 30 0.83 1.24 1.66 2.07 2.49 2.90 3.32 '3.73 4.15 4.56 4.98 40 0.69 1.03 1.38 1.72 207 2.41 2.76 3.10 3.45 3T9" 4.13 50 0.60 0.90 1.19 1.49 1.79 2.09 2.39 2.69 2.98 3.28 3.58 60 0.53 0.80 1.06 1.33 1.59 1.86 2.12 2.39 2.65 2.92 3.18 90 0.41 0.61 0.82 1.02 1.23 1.43 1.63 1.84 2.04 - 2.25 2.45 120 0.34 0.51 0.68 0.85 1.02 1.19 1.36 1.53 1.70 1.87 2.04 150 0.29 0.44 0.59 0.73 0.88 1.03 1.18 1.32 1.47 1.62 1.76 180 0.26 0.39 0.52 0.65 0.78 0.91 1.04 1.18 1.31 1.44 1.57 240 0.22 0.33 0.43 0.54 0.65 0.76 0.87 0.98 1.08 1.19 1.30 300 0.19 0.28 0.38 0.47 0.56 0.66 0.75 0.85 0.94 1.03 1.13 360 0.17 0.25 0.33 0.42 0.50 0.58 0.67 0.75 0.84 0.92 1.00
SUBDIVISION MANUAL
SECTION 3: GENERAL DESIGN CRITERIA
Section 3-200 Page 5
Revised 03-13-2012
3-203 Hydrology
Developers draining to a river or stream will be required to use the latest adopted County Hydrology Manual to determine the flows expected at a given frequency (Q10, Q50 Q100, etc,) Infill developments will use the following Hydrology requirements. The City Engineer will determine which projects may be considered "infill" projects. 3-203.1 Previously Approved Reports
Runoff quantities; as set forth or derived from the report prepared by Lawrence, Fogg, Florer and Smith titled "A Special Study of Storm Drain Facilities" on file in the office of the City Engineer may be used in the design of drainage facilities in Chula Vista. A hydrologic study prepared and approved at General Development Plan (GDP) or Specific Planning Area (SPA) plan may be used as determined by the City Engineer.
3-203.2
For local drainage basins, storm discharge flow may be estimated based on the Rational Method or the Modified Rational Method. For all lateral and major drainage basins the SCS method, U.S. Army Corps of Engineers HEC-1 computer method or other tabular or computer method may be used upon City Engineer approval.
3-203.3 Rational and Modified Rational Methods
(1) The rational method equation relates storm rainfall intensity (I), a selected runoff coefficient (C) and drainage area (A) to the peak runoff rate (Q):
where:
Q = CIA (Empirical Units)
Q = Peak runoff in cubic feet per second
C = Runoff coefficient
I = lnten.sity, inches per hours
A = Drainage basin area in acres
Or
where:
Q=0.278CIA (Metric Units)
Q = Peak runoff in cubic meters per second
C = Runoff coefficient
I = Intensity in millimeters per second
A= Drainage area in square kilometers
(2) Coefficient of Runoff: Consider probable development. Use highest number of the following values:
a)
b)
c)
Paved Surface
Commercial Area
Dense Residential (R2, R3)
0.90 0.85
0.75 NOTES:
SUBDIVISION MANUAL
SECTION 3: GENERAL DESIGN CRITERIA
Section 3-200 Page 6
Revised 03-13-2012
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Normal Residential (R1)
Suburban Property (RE)
Barren Slopes Steep
Barren Slopes Hilly
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Vegetated Slopes Steep
II II Hilly
11 " Rolling 11 " Flat
Farm Land
Parks, Golf Courses
0.65 0.55
0.80 0.75
0.70 0.65
0.60 0.55
0.50 0.45
0.35 0.30
Steep, rugged terrain with average slopes generally above 30%.
Hilly terrain with average slopes of 10% to 30%.
Rolling terrain with average slopes of 5% to 10%.
Relatively flat land, with average slopes of 0% to 5%.
Where drainage areas are composed of parts having different runoff characteristics, a weighted coefficient for the total drainage area may be used.
The runoff coefficient for a basin should be a composite coefficient made of the many different runoff coefficients for the sub-areas of the basin per equation:
CA1 = C1A1+C~2+ ... CnAn
n
(3) Time of Concentration (tc = minutes) is the time required for runoff to flow from the most remote part of the watershed to the outlet point under consideration.
With exceptions for limited natural watersheds, the time of concentration shall be calculated as follows:
a) where:
ti = Initial time or overland flow time of concentration, the time required for runoff to flow to the first inlet or to the street gutter
tr= Travel time of concentration, the time required for runoff to flow within street gutters to inlets, with channels or within storm drain pipes.
b) ti may be calculated using the following natural watershed flow formula: •
L = Length of water shed (miles)
H = Difference in elevation from furthermost point to the design point (feet).
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ORIGINAL 01/02 ENGINEERING & CAPITAL PROJECTS
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I REVISION CVM C. SWANSON 11/02 STANDARD DRAWING WiLLIAMS Vf •~y " .. ln;IM•"' REVISION DPH W. VALLE 11/17 CITY ENGIN°EER
100-YEAR, 6-HOUR PRECIPITATION DRN-04
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Hydrology Manual
Rainfall lsopluvials
100 Year Rainfall Event- 24 Hours
lsopluvial (inches)
3 Miles
Hydrologic Soil Group-San Diego County Area, California 32° 38' O" N
32° 37' 33" N
400300 400400 400500 400700
Map Scale: 1:4,140 if printed on A portrait (8.5'' x 11") sheet.
N ----=====--------=======~Meters 0 50 100 200 ::ro
A ----====-------.-c========Feet
0 200 400 1200 In)
Map projection: Web Mercator Comer mordinates: WGS84 Edge tics: LJTM Zone llN WGS84 USDA Natural Resources
""' Conservation Service
Web Soil Survey
National Cooperative Soil Survey
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3 7/27/2023
32° 38' O" N
32° 37' 33" N
Hydrologic Soil Group-San Diego County Area, California
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
D Area of Interest (AOI)
Soils
Soil Rating Polygons
D A
D AID
DB
D BID
D C
□ CID
D D
D Not rated or not available
Soil Rating Lines
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....,,,. BID
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Soil Rating Points
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■ BID
USDA Natural Resources
= Conservation Service
□ C
CID
D
□ Not rated or not available
Water Features
Streams and Canals
Transportation
t+t Rails
.-., Interstate Highways
US Routes
Major Roads
Local Roads
Background
• Aerial Photography
Web Soil Survey
National Cooperative Soil Survey
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements .
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required .
This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.
Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 18, Sep 14, 2022
Soil map units are labeled (as space allows) for map scales 1 :50,000 or larger.
Date(s) aerial images were photographed: Mar 24, 2022-Apr 29,2022
The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.
7/27/2023