OUR MISSION: To provide our customers with high-quality, efficient and reliable water, power and sewer services in a manner that values environmental and community interests and sustains the resources entrusted to our care.
CITY DISTRIBUTION DIVISION
1990 Newcomb Avenue
San Francisco, CA 94124
T 415.550.4900
DATE: September 15, 2022
TO: Commissioner Anson Moran, President
Commissioner Newsha Ajami, Vice President
Commissioner Sophie Maxwell
Commissioner Tim Paulson
THROUGH: Dennis Herrera, General Manager
Steven R. Ritchie, Assistant General Manager, Water
FROM: Bill Teahan, City Distribution Division Manager
Angela Cheung, Water Supply and Treatment Division Manager Andrew DeGraca, Water Quality Division Manager
SUBJECT: Water Pipeline Assessment: January 1, 2022 through June 30, 2022
Purpose
This memorandum captures the noteworthy maintenance and construction activities that the City Distribution, Water Supply & Treatment, and Water Quality Divisions performed to the linear assets during the period of January 1, 2022 through June 30, 2022.
I. Lead Occurrence/Pipeline Material
In 2016, the California Legislature enacted SB-1398 “Public Water Systems: Lead User Service Lines”1 which obligated water agencies to inventory and replace all user service line materials with confirmed or possible lead components by July 1, 2030. 2 In response to SB-1398, the SFPUC City Distribution and Water Quality Divisions created the Lead Service Line Replacement (LSLR) Program designed to implement strategies and tools to catalog, identify and compile user service line materials including a statistical analysis and field inventory of user service line materials, field verification and inspections, replacement of affected user service lines and water quality sampling for buildings and residents affected by the service line replacement.
In 2021, the United States Environmental Protection Agency (EPA) published the Lead and Copper Rule Revisions (LCRR), marking the first major update to its requirements since 1991 when the rule was first introduced. The EPA’s recently published LCRR aims to further reduce potential lead exposure to customers through additional actions such as requiring water agencies to identify locations most at risk to lead exposure, prioritize the locations for replacement, and perform water quality sampling.
1 A User Service Line is defined as that portion of a water line which extends from the water distribution main pipeline to the water meter. 2 In 1991, the United States Environmental Protection Agency (EPA) published the Lead and Copper Rules (LCR) to reduce exposure to lead in drinking water. The 2014 Flint Michigan tap water lead contamination crisis prompted the U.S. Congress to direct the EPA to obtain recommendations from the National Drinking Water Advisory Council (NDWAC) for LCR revisions. In 2015, the NDWAC published recommendations for LCR Revisions, most notably the recommendations requiring water agencies to create inventories of all lead service lines and replace all lead service lines by 2030.
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The LCRR also implemented further service line inventory requirements and service line replacement rules including 1) finalizing a service line inventory which includes the customer side of the water service by October 16, 2024, 2) make publicly available the service line inventory and field investigations, 3) providing water pitchers certified to remove lead and 4) collecting lead tap samples at locations serviced by the replaced line within 3 to 6 months after replacement.
Figure 1
Typical Water Service Line with Gooseneck/Lead Whip Diagram
A. Inventory of Service Line Materials
In the 1980s, the SFPUC proactively removed all pipes and water service lines that were known to have been fabricated with lead. Therefore, the majority, if not all, of the SFPUC’s Local Water System (LWS) user service lines consist primarily of copper, plastic, and iron.
However, out of the 176,028-retail customer user service lines within the City and County of San Francisco, SFPUC records indicated that 8,848 user service lines (5%) were of unknown material type (“unknown services”), and 4,434 (2.4%) user service lines were recorded as galvanized steel. Recently, the number of galvanized steel services were reduced from 4,434 to 4,292 because the services were discovered to be disconnected.
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Every unknown and galvanized steel service line is being field verified to confirm actual material type.
Field verified 2-inch and smaller galvanized steel service lines will be replaced with a copper service line since galvanized water service lines were commonly connected to water distribution pipes by a short flexible connection pipe made from lead, known as a goose neck or lead whip.
Gooseneck (Lead Whip) Water Line Connection
Lead whip from the water main to the water service line
As of June 2022, 7,587 (86%) of unknown user service lines and 3,662 (85%) of galvanized user service lines have been field inspected for a combined total of 11,249 conducted inspections. There are 1,891 services remaining that are expected to be field inspected by October 2022. Graph 1 charts the field investigation work completed to date while Tables 1 and 2 contain the field investigation results.
Lead Whip
Lead Whip
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Graph 1
Service Line Field Investigations
Table 1
Unknown Service Field Investigation Results
Field Identified
Material Quantity %
Galvanized 330 4%
Lead 0 0%
Other materials 7,257 96%
Total 7,587 100%
Table 2
Galvanized Service Field Investigation Results
Field Identified
Material Quantity %
Galvanized 856 23%
Lead 0 0%
Other materials 2,806 77%
Total 3,662 100%
0 2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
Actual Sampled Orignal Schedule At current rate
13,140 Total by October 2022
Current: 10,417
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1. EPA changes to the LCRR Inventory Requirements.
The newly expanded LCRR inventory obligations now include the customer owned portion of the service pipe that extends from the building outlet to the water meter.
Previously, the State inventory requirements only included the SFPUC owned portion of the service pipe. The expanded inventory requirements are to be completed by October 16, 2024.
As a result of this change, the LSLR Program will use a SFPUC Water Enterprise Professional Services Contract to focus its efforts on identifying strategies to inventory the customer side of the service, including utilizing predictive modeling and machine learning. The various strategies are necessary to surmount the challenges involved in field identifying and plan checking building plans and plumbing records to identify the service pipe material for approximately 176,000 customer side water service pipes.
The SFPUC has also begun investigating the customer-owned service pipe material while performing work for the user service line material field investigations. See Table 3 below.
Table 3
Customer Side Field Investigation Results
Field Identified
Material Quantity %
Galvanized 427 8%
Lead 0 0%
Other materials 4,774 92%
Total 5,201 100%
B. Service Line Replacement
As of June 2022, 1,186 service lines have been inspected and are confirmed to be a galvanized service. Of this total, 207 or 17% have been subsequently replaced with a copper service.
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Map 1
Galvanized Service Lines Replaced with a Copper Service
The rate of service line replacements has increased substantially through fiscal year FY21-22 due to an augmentation of resources, labor, and equipment.
Lead Whip Found (34)
No lead Whip Found (160)
School, No Lead Whip Found (13)
Supervisorial District
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The following photos provide a typical water line service replacement. A galvanized water service, located on Vincente Avenue, was replaced by a copper service on July 29, 2022.
Water Service Replacement on Vicente (between 34th Ave. and 35th Ave.)
Removal of a 3/4-inch galvanized service line Replacing the 3/4-inch galvanized service line with a 1-inch copper service line
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Graph 2
Galvanized Service Line Replacements by Fiscal Year
Of the 207 replaced galvanized service lines, 34 (16%), were connected to a lead whip while the remaining 173 were not connected to a lead whip.
To meet the EPA and SB-1398 requirements to remove all lead components from service lines within the water system by 2030, the SFPUC anticipates advertising Contract WD- 2889, “As-Needed Water Service Line Replacement Project” by September 2022. The work scope for this Contract will be to provide SFPUC all ancillary work associated with replacing water services such as permitting, earthwork, excavation, street restoration and traffic control. This will allow field crews and plumbers to focus on replacing the water service lines while the Contractor schedules, coordinates, and performs associated work.
The Engineering Estimate is $27 million and will support the work associated with replacing approximately 1,400 user service lines by FY27, thereby meeting the State target date of 2030.
In November 2021, the Federal Infrastructure Investment and Jobs Act (IIJA) was passed. This Act aims to modernize and improve various facets of public infrastructure including transportation, broadband, wastewater, and drinking water facilities. $15 billion is included under the IIJA for “lead service line replacement” that will be distributed by the EPA through the states. Money will be appropriated over multiple years, and in 2022, California will be receiving $250 million of the $15 billion through the State Water Resources Control Board (SWRCB). The SFPUC Water Enterprise submitted a General Application to the SWRCB Division of Financial Assistance for Lead Service Line Replacement Funding provided through the Federal IIJA on May 13, 2022. The applicable federal requirements to be eligible for the funding have been incorporated into the RFP for the As-Needed Water Service Line Replacement Project, WD-2889. The application is currently being reviewed by the SWRCB.
1 29
14 163
0 20
40 60
80 100
120
140
160
180
18-19 19-20 20-21 21-22
Total Service Replacements
Fiscal Year
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1. EPA Changes to the LCRR Service Line Replacement Requirements The LCRR service line replacement obligations have been expanded to include increased public information, outreach, and providing water pitchers and filters certified for lead removal to affected customers.
a. Make publicly available the service line inventory and field investigations The LCRR now requires water agencies to make publicly available all lead service line inventory findings. Therefore, the SFPUC has created and posted an interactive map that displays customers who have been identified to have either an unknown or galvanized water service. The map is updated every 6 months and can be accessed at: https://sfpuc.org/accounts-services/water-quality/lead . b. Provide a water pitcher and a 6-month supply of filters to all customers impacted by the service line replacement
The LSLR program provides notification, outreach and water pitcher delivery to customers before either the scheduled service line replacement date or within 24 hours of an emergency service replacement (e.g. a leak on a water service).
Additionally, 6 months of filters are provided to customers as well as LSLR program information and a SFPUC customer service contact in case there may be additional questions or concerns related to the service line replacement. c. Collect tap samples at locations served by the replaced line within 3 to 6 months after replacement
The SFPUC offers a 3-to-6-month follow-up tap sampling to customers for any lead component that has been identified and replaced. SFPUC is also offering a no cost follow-up tap sample after 30 days of lead component replacement to gather data. The data gathering will assist SFPUC in preparing for anticipated future regulations from the EPA or State requiring water agencies to increase filter distribution from 6 months to 18 months.
The EPA has introduced other changes to the LCRR replacement requirements such as a plan to oblige water agencies to adhere to a yearly replacement rate that will be calculated as a percentage of the total number of service lines that need replacement. The EPA strongly encourages water agencies to assist customers with replacing customer side of the service line as well as coordinating customer and agency service replacements for affected properties.
Although field crews have not encountered a leaded customer service line, the SFPUC pro-actively notifies all customers because the LCRR includes a provision that water agencies are required to notify all customers in case there may have previously been a galvanized customer service line that was downstream of a lead service line that the SFPUC removed in the 1980s.
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II. Pipeline Renewal and Replacement Program
A. Local Water Facilities
Capital improvement projects for the LWS pipelines have decreased throughout this reporting period due to 1) funding constraints attributable to a redirection of capital funds, 2) various construction delays on joint projects led by SFMTA and Public Works and 3) on-going nationwide material supply chain issues. However, the capital pipeline planning and design phases for pipeline rehabilitation projects continued including seismic improvements to the College Hill Reservoir system.
1. Replacement Rate for FY22 (Q3 and Q4)
At the beginning of FY22 (Q1), the anticipated mileage for distribution system pipeline replacement was projected to be 7.5 miles for the past fiscal year whereas the actual mileage during this period was 4.2 miles, 56% of the projected mileage from the beginning of FY22. 2.1 miles out of the 4.2 miles have been replaced during the second half of FY22 (Q3 and Q4). Projects under construction during Q3 and Q4 include: Casitas Avenue, Pierce Street, Castro Street, 17th Street, Baker Street, 19th Avenue, Vicente Street, College Hill Reservoir System, Prospect Avenue, and L-Taraval Street Segment B. During this same period, Diamond Street and Laidley Street have started the construction phase.
All other projects previously scheduled to begin construction during FY22 Q3 and Q4 have been delayed due to funding constraints. See Table 4.
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Table 4
Water Main Replacement Projects3
Ductile Iron Pipe (DIP) and Earthquake Resistant DIP (ERDIP)
Project Contract No. Miles
FY22 (Q1 – Q4)
8-Inch Ductile Iron Water Main Replacement on
Baker St. (Geary Blvd to Broadway St.), Sutter St.
(Divisadero St. to Presidio Ave)
WD-2616 0.70
Pavement Renovation, Sewer Replacement and
Water Main Replacement on Castro St. and 26th St. WD-2739 0.50 16-Inch & 36-Inch, and 8-Inch Ductile Iron Water
Mains at Various Locations on 19th Ave from
Holloway Ave to Lincoln Way
WD-2775 0.27
8-Inch Ductile Iron Water Main Replacement on
Casitas Ave (Lansdale Ave to Yerba Buena Ave)
and Dalewood Way (Lansdale to Sherwood Court)
WD-2842 0.92
Water Main Replacement for the Moscone
Expansion Project WD-2810.11 0.28
Geary Rapid East of Van Ness WD-2834
0.03 As-Needed Water Main Replacement at Various
Locations – No.2
WD-2819
0.35 36-inch Steel and 8-inch Ductile Iron Pipe Water
Main Installation on Vicente St. (19th to 25th Ave.)
WD-2806
0.51 8-inch and 16-inch Ductile Iron Water Main
Replacement 17th St. (Clayton St. to Douglass St.)
WD-2811
0.47 L-Taraval Improvement Project (Sunset Blvd. to
West Portal)
WD-2859R
0.13 Total 4.2 miles
3 New water mains installed to support the Moscone Center Expansion project have been added to this reporting period since they were mistakenly left out of the final mileage reporting from FY21 and are included to be actualized for the FY22 reporting period.
2. Unit Construction Costs
In FY22, the pipeline replacement program budget cost per mile to replace water distribution pipelines has increased 70% from $3.18 million to approximately $5.4 million. The updated cost per mile for streetscape, transit, or ERDIP-type projects is approximately $8 million, an increase of approximately $1 million.
The $3.18 million per mile was developed in 2011. The program previously focused on replacing smaller, less expensive water distribution mains. Since that time, design, construction, and material costs have increased. Additionally, the updated cost per mile for water main replacement projects have been affected by the following:
a. Projects have been including larger diameter pipe replacement for larger distribution mains as well as special earthquake-resistant pipe installation to increase seismic reliability of the City’s local water distribution. b. Ancillary costs have increased. Pavement restoration, ADA curb ramps, and permitting requirements within the City continue to increase pipe replacement project costs.
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Graph 3 identifies the targeted versus actual miles of pipeline installed over the last ten fiscal years.
Graph 3
Miles of Pipeline Installed
-
2.0 4.0
6.0 8.0
10.0 12.0
14.0 16.0
FY12 FY13 FY14 FY15 FY16 FY17 FY18 FY19 FY20 FY21 FY22
Linear Miles
Target Miles Actual Miles
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WD-2775 19th Avenue (Holloway Avenue to Lincoln Way)
8-inch water main Installation New 8-inch connection to an existing 6-inch water line
WD-2859 Taraval St. (21st to 22nd Avenue)
8-inch water main installation 8-inch water main cathodic protection
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3. Seismic Improvements
The College Hill Reservoir System Improvement Project (Phases 1 through 5) utilizes Kubota ERDIP pipe materials. Kubota ERDIP was evaluated and selected based on 1) a pipe’s ability to withstand large joint deflections 2) the pull-out resistance at joints and 3) the capacity and capability of each joint to expand and contract. Kubota ERDIP has demonstrated a high deflection and pull-out resistance performance as well as its capacity to expand and contract at joints.
Table 5
College Hill Reservoir System Improvement Project
Project Phase
Project Limits Miles Status
1 Various Streets in the vicinity of
SF General Hospital 0.6 Completed 2017
2 22nd St. (Valencia to Hampshire) 0.8 Completed 2019
3a College Hill Reservoir Outlet 0.2 Under Construction (NTP September 2021)
3b Prospect Ave. (Cortland to
Coso) 0.6 Under Construction (NTP Jan.
2022)
4 Precita Ave. (Coleridge to Cesar
Chavez) 0.7 Construction scheduled for FY23
Q2
5 Hampshire St. (Cesar Chavez to
18nd St.) 1.2 Construction scheduled for FY 22
Q3
Total Miles 4.1
Phases 1 and 2 were completed in 2017 and 2019, respectively. Phase 3a has been awarded to Ranger Pipelines Construction and Phase 3b has been awarded to Cratus Inc. Both Phases 3a and 3b are under construction. Final Phases 4 and 5 are currently in design and are scheduled to begin construction in FY23 and FY22, respectively.
WD-2718 Prospect Ave. (Cortland to Coso Avenue)
24-inch Earthquake Resistant Ductile Iron Pipe
Prospect Avenue North of Cortland
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Map 2
College Hill Reservoir System Improvement Project
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B. New Water Service Applications
New water service applications include new water services (typically two to six individually metered water connections per address for water, fire, and irrigation services); installation and/or relocation of fire hydrants; and new main connections for large private developments (Hunter’s Point, Mission Bay, Warriors Arena, Treasure Island, Potrero Hope SF, and Candlestick Point). During this reporting period, a total of 181 new single service installation requests were received. Graph 4 summarizes the number of new water service applications received during this reporting period as compared to previous periods.
Graph 4
New Water Service Applications
233
263
230
194
181 192 192 181
0 50
100
150
200
250
300
Jul-Dec
2018
Jan-Jun
2019
Jul-Dec
2019
Jan-Jun
2020
Jul-Dec
2020
Jan-Jun
2021
Jul-Dec
2021
Jan-Jun
2022
Number of Applications
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C. Emergency Firefighting Water System (EFWS) Infrastructure The SFPUC has the following EFWS projects under planning, design, and construction.
1. Planning and Design
a. Westside Potable EFWS Pipeline
New potable EFWS pipeline located within the Richmond and Sunset areas. Planning is currently in progress.
b. Fireboat Manifolds
a. Install a new fireboat manifold and pipelines within Fort Mason.
Planning is in progress. The geotechnical investigation will be taking place FY22 Q2, pending the application with the National Park Service (NPS).
b. Install a new fireboat manifold and pipelines near Pier 35.5.
Planning in progress.
c. Install a fireboat manifold and pipelines on Terry Francois Boulevard in the vicinity of the Warriors Stadium Ferry Landing.
Planning in progress.
2. Construction
a. 19th Avenue Pipeline
Install a new 20-inch EFWS pipeline on 19th Avenue from Irving Street to Kirkham Street, a crossing at Ulloa Street, and a new 36-inch diameter welded steel Potable Emergency Firefighting Water Systems (PEFWS) pipeline on 19th Avenue from Vicente Street to Sloat Blvd. as part of Public Works’ 19th Avenue Roadway Improvements, Contract 2652J. Construction completion expected September 2023.
b. Clarendon Supply
Provide new EFWS water supply and pipeline near the crest of Clarendon Avenue at Dellbrook Avenue. Construction continues. Construction completion expected April 2023.
c. Terry Francois Blvd./Mission Rock/Warriors Way Pipeline Installed new 20” AWSS pipe on Terry Francois Blvd from Mission Rock Street to Warriors Way as part of SFPUC contract DB-129.1. Construction completed May 2022.
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d. Pumping Station 2 Project
Improve the seismic performance of the Pump Station’s building structure.
Construction completion expected December 2022.
e. Vicente Pipeline
Install a new 36-inch diameter PEFWS pipeline on Vicente from 19 th Avenue to 25th Avenue. Constructed continues. Construction completion expected July 2024.
19th Avenue at Ulloa Street
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Clarendon Supply Project Terry Francois Blvd. Pipeline Project
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Pumping Station 2 Project
D. Regional Water Facilities
Capital improvement projects for the regional pipelines progressed steadily during this reporting period. Planning and design continued for several pipeline projects that will replace and rehabilitate deteriorated pipe segments.
1. Planning and Design
a. Crystal Springs Pipeline No. 2 (CSPL2) Reach 5 from K40 – K50 (approximately 3.9 miles)
CSPL2 is a 60-inch welded steel pipeline with coal tar lining. The scope of work for this project includes replacing coal tar lining with cement mortar lining, new manholes to improve access, a new in-line isolation valve, and appurtenance improvements to meet current water quality standards. The Alternatives Analysis Report was completed. Development of the Conceptual Engineering Report, site survey, and geotechnical study started in this reporting period.
b. Bay Division Pipeline (BDPL) Nos. 1, 2, 3 and 4
Planning phase continued for this lining repair project. The scope of the project is to repair lining defects that were identified from previous inspections and lining defects expected to be identified in future inspections.
When this contract is in place, maintenance inspections and lining repairs
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can be performed within the same shutdown, eliminating the need to perform a second shutdown for repairs.
The scope of work primarily consists of removing corrosion accumulation at pipe joints from spalled cement mortar lining, applying new cement mortar or dielectric lining, and cleaning debris and sediment found inside the pipe.
The Conceptual Engineering Report was completed. During this reporting period, AECOM was retained to support the design phase.
Safely isolating a pipeline for personnel entry must be considered during project planning and design. The Alternatives Analysis Report to ensure safe pipe isolation was finalized by Stantec. The report provided alternatives for design and a template to evaluate future alternatives. c. Town of Sunol Distribution Pipeline (creek crossing upgrades) The 12-inch pipeline, which crosses Arroyo de la Laguna in Sunol, was originally installed below the creek bed. This section of the pipeline feeds both the potable and firefighting water lines to the Town of Sunol. Over time, erosion has completely exposed the pipeline. This project will replace the pipeline where it crosses the creek. During this reporting period, the Conceptual Engineering Report was completed, and progress was made on the design and environmental permitting.
d. CSPL2 Reaches 2 and 3
CSPL2, from valves K10 to K30 (approximately 5.3 miles), is a 60-inch welded steel pipeline with coal tar lining. Some of it traverses through steep terrain with narrow access, making maintenance and repair difficult. This project will replace and realign 1.5 miles of the pipeline and make improvements to the appurtenances to meet current water quality standards. Site survey, geotechnical study, and development of the Conceptual Engineering Report continued during this reporting period. e. Bay Division Pipeline No. 4 (BDPL4)
Planning phase continued for the repair and replacement of targeted Prestressed Concrete Cylinder Pipe (PCCP) segments between Valves D50 and D68. In 2017, an inspection found numerous circumferential cracks in the last 1.5 miles that parallel Edgewood Road in Redwood City. These cracks were mostly small, with only a few as wide as 0.125-inch.
In March 2021, BDPL4 was shut down to repair leaks caused by the circumferential cracks. WEKO-seals were installed to seal the leaks.
Condition assessment findings and leaks confirmed that both the broken prestressed wires and circumferential cracks need to be addressed.
During this reporting period, consultant SGH was retained to perform failure risk analysis and repair prioritization for the distressed PCCP segments based on electromagnetic inspection results from May 2017 and wire continuity test results from 2008 and 2020. The recommendations from this study can better inform the repair approach and priority.
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f. Conditional blanket waiver approval for compliance with water main separation
In July 2021, the SFPUC received conditional approval from the SWRCB for compliance alternatives that were deemed to be equally protective of public health as the water main separation criteria in the California Waterworks Standards. This blanket waiver enables the SFPUC to implement a set of approved compliance alternatives when dealing with existing non-potable utility crossings in the Regional Water System. During this reporting period, internal Infrastructure procedures were updated to incorporate non-potable utility crossing mitigations.
2. Construction
a. Town of Sunol Potable and Raw Water Transmission Pipelines These pipelines conflict with Alameda County Transportation Commission’s (ACTC) project to widen freeway I-680. SFPUC staff worked closely with ACTC staff to develop the design to replace segments of the 12-inch potable and raw waterlines. In June 2021, ACTC started construction of their project, which includes installing the new Town of Sunol pipelines crossing I-680. During this reporting period, the potable and raw waterlines were installed under I-680 using the jack-and-bore method.
Town of Sunol Potable and Raw Water Transmission Pipelines Project
Town of Sunol Pipelines Replacement under I-680
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III. Pipeline Inspection Program
A. Local Water Facilities
In 2018, SFPUC implemented a pro-active leak detection pilot program to assess the effectiveness and benefits of installing acoustic based leak detection monitoring sensors procured from Echologics, a non-invasive acoustic technology for underground pipeline. The sound sensors proactively capture non-surfacing leaks and help the prevention of water loss as well as reduce the potential for property damage associated with catastrophic leaks.
The 2018 pilot program installed Phase 1 which consisted of 160 monitoring devices within the Diamond Heights Neighborhood. In September 2020, the SFPUC expanded the monitoring and pilot program to install Phase 2 which consisted of 150 monitoring devices in the Bernal Heights and Portola neighborhoods.
SFPUC is continuing to use acoustic based leak detection monitoring sensors in the Diamond Heights, Bernal Heights, and Portola neighborhoods. However, AT&T has discontinued their 3G services, affecting the Phase 1 Diamond Heights monitoring sensors. The feasibility to upgrade the 160 monitoring devices within the Diamond Heights neighborhood to Verizon’s 4G service is currently being evaluated. Phase 2 utilizes Verizon’s 4G service; therefore, a sensor upgrade to this phase will not be necessary.
For the current reporting period, 7 potential points of interest were identified. Of 7 locations, 3 were confirmed leaks, 2 need further investigation, 2 are pending investigation.
Table 6
Leak Sites Investigated and Repaired
No. Investigation
State Address
Field
Investigated
Date
Leak
Repair
Date
Leak Type
1 Leak Located
& Repaired
100 Block
of Maynard
St
2/29/2022 3/10/2022 Service
2 Leak Located
& Repaired
0-99 Block
of Newburg
St
5/23/2022 6/2/2022 Main
3 Leak Located &
Repair pending
300 Block
of Congdon
St.
7/7/2022 In
progress Service
4 Continued
Monitoring
0-99 Block
of Topaz
Way.
ongoing - -
5 Continued
Monitoring
2300 Block
of Castro St ongoing - -
6 Investigation
pending
400 Block
of Bosworth
St
- - -
7 Investigation
pending
1300 Block
of Douglass
St
- - -
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Map 3
B. Regional Water Facilities
Physical pipeline inspections were halted during the COVID-19 pandemic due to the lack of proper ventilation in confined spaces. Pipeline maintenance inspection will resume in FY23. No inspections were performed during this reporting period.
IV. Summary of Pipeline Failures
A. Local Water Facilities
1. Main Break Data
107 distribution main breaks occurred during this reporting period. Of this total, 91 (85%) were due to natural pipeline breaks and 16 (15%) were due to third-party contractors. Of the natural pipe failures, 82 (90%) occurred on cast iron pipes, 8 (9%) occurred on ductile iron pipe. Table 7 classifies the number of breaks based on material type and decade installed.
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Table 7
Natural Pipeline Failures FY 21/22 (Q3 &Q4)
Pipe
Material
Decade
Installed
No. Breaks Per Diameter (Inches) #
Breaks %
2 4 6 8 12 16 24
Cast Iron 1920 1 2 10 2 - - - 15 16.3%
1930 3 1 29 2 - - - 35 38%
1940 - - 4 6 1 - - 11 12%
1960 1 - 8 - 1 - - 10 10.9%
Other - 2 3 4 1 1 - 11 12.1%
Ductile Iron 1970 - - 1 1 - - - 2 2.2%
1980 1 - 1 - - - - 2 2.2%
1990 - - - 1 1 - - 2 2.2%
2000 - - 1 1 - - - 2 2.2%
Steel 1920 - - - - - - 1 1 1.1%
Total 91 100%
The number of miles of pipe replaced varies year to year; therefore, the failures were normalized to facilitate pipe break data comparisons. The break data for this reporting period reveals that pipelines installed in the 1920’s experienced the highest main break rate with 16 breaks per 100 miles of pipeline and pipelines installed in the 1930’s, 40’s, and 60’s experienced high break rates of 14, 13, and 10 breaks per 100 miles of pipeline. Pipelines installed in other decades experienced 6 breaks or less per 100 miles of pipe installed, which is more than a 50% decrease from the 1920’s. See Graph 5 displaying the number of breaks per 100 miles of pipe installation.
Graph 5
FY 22 Q3 & Q4 Nominalized Pipeline Failures
5 6
16 14
13 3
10 3 3 3
2 0
2 4
6 8
10 12
14 16
18 1890 1900 1920 1930 1940 1950 1960 1970 1980 1990 2000 No. Breaks per Mile of Pipe
Decade
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2. Main Break Repair Expenses
Two conventional repair methods were utilized for most main breaks including: 1) Installing a clamp to conceal and encompass the rupture or leak and 2) Replacing the affected pipe section.
For this reporting period, 47 breaks have been repaired with clamps and 44 have been repaired by replacing a section of the affected pipe. The total estimated expenses incurred for the two repair methods have been summarized in Table 8.
Table 8
Estimated Main Break Repair Costs FY 22 Q3 & Q4
Repair Type Labor Material Paving Cost Per
Repair
Total
No.
breaks
Total
Repair
Cost
Clamp $454,248 $12,519 $226,653 $14,754 47 $693,420
Pipe
Replacement
$496,350 $30,113 $462,381 $22,474 44 $988,844
Total $1,682,264
Table 9
Main Break Repair Cost Comparison
Repair Type
FY21
Q3 & Q4
FY22
Q1 & Q2
FY22
Q3 & Q4
Clamp $366,950 $368,100 $693,420
Pipe
Replacement $438,750 $515,600 $988,844
Total Cost $805,700 $883,700 $1,682,264
The total main break cost during this reporting period is $1,682,264, 91% higher than the previous 6-month reporting period. Of the 91 main breaks, 31 occurred within the College Hill System. The breaks could be attributed to pressure fluctuations due to the College Hill Outlet shut-down operations.
B. Regional Water Facilities
1. Four small leaks on pipeline appurtenances occurred in the Regional Water System during this reporting period. In June 2022, a small leak was reported at Service Connection No.122. The leak occurred inside the service connection vault for the City of Brisbane. It was caused by corrosion at the pipe spool and repaired by replacing the fitting.
2. In April 2022, a leak was found at the lower compression fitting of a water sampling station at Kilkare and West Foothill Road on the Town of Sunol’s fire suppression system. The leak was causing the fire pump to turn on frequently due to pressure loss. Staff repaired it by replacing the compression fitting.
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3. In February 2022, a leak
was reported on a 2-inch galvanized pipe on the Town of Sunol’s potable water distribution system. It was caused by corrosion and repaired with clamps.
4. In January 2022, a small leak was reported on a 1-inch tap located at the vault inside Pulgas Valve Lot. The tap is a sample line from BDPL1. It was caused by corrosion and repaired by replacing the fitting.
V. Summary
The City Distribution, Water Supply and Treatment, and Water Quality Division accomplished diverse and notable activities to linear assets during the period of January 1, 2022 through June 30, 2022. These 3 Divisions will continue to partner together to assess currently available maintenance solutions while remaining within budget constraints.