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: March 7, 2023
TO: Commissioner Newsha Ajami, President
Commissioner Sophie Maxwell, Vice President
Commissioner Tim Paulson
Commissioner Anthony Rivera
Commissioner Kate Stacy
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: July 1, 2022 through December 31, 2022
Purpose
This memorandum covers the notable maintenance and construction activities that the City Distribution Division (CDD), Water Supply and Treatment Division (WSTD), and Water Quality Division (WQD) performed to the linear assets during the period July 1, 2022 through December 31, 2022. This report includes four sections with some notable activities identified below:
I. The Lead User Service Line Program
In this reporting period, 71 galvanized service lines were replaced with copper. Contract WD-2889, “As-Needed Water Service Line Replacement Project” has been awarded to JMB Construction Inc. for $26,663,850. This will allow us to increase the rate of service line replacements.
II. Pipeline Renewal and Replacement Program
3.4 miles of Local Water System distribution and transmission water pipelines have been replaced this reporting period.
New Town of Sunol potable and raw waterlines were installed, and the transfer of water service to the new pipelines is expected in the next reporting period.
III. Pipeline Inspection Program
The Regional Water System has added Syrinix Pipeminder-T, an acoustic leak detection system, to monitor high risk Prestressed Concrete Cylinder Pipe (PCCP).
IV. Summary of Pipeline Failures
There were 102 main breaks in the Local Water System during this reporting period, 92 were on older cast iron pipes. The total main break repair cost for the Local Water System was $2,218,000.
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I. Lead User Service Line Program
In 2016, the California Legislature enacted SB-1398 “Public Water Systems: Lead User Service Lines” 1 which compelled water agencies to inventory all service line materials and provide a replacement schedule for Lead User Service Lines (LUSL) and service lines with unknown material by July 1, 2030.
In 2021, the United States Environmental Protection Agency (EPA) published the Lead and Copper Rule Revisions (LCRR), the first major update to the Lead and Copper Rule that was established in 1991 2. The LCRR requires service line inventory for both publicly and privately owned service lines, lead water quality sampling, water filter distribution and lead testing in schools.
Therefore, CDD and WQD have developed the Lead Service Line Replacement (LSLR) Program to satisfy the State and Federal guidelines for the local water system (LWS), including preparing a water line service inventory, replacing water service lines affected by the regulations, and conducting water quality sampling.
A. Inventory of Service Line Materials
Originally, the State (SB-1398) and Federal (EPA LCRR) laws required California public water systems to identify all active service line materials and develop a service line inventory which encompassed only the SFPUC owned section of pipe that connects the water main to the water meter. This section of pipe is referred to as a “user service line”. However, the newly enacted LCRR have expanded this inventory to also include the privately owned section of pipe which connects the water meter to the building inlet. The State and Federal laws define this entire water service as a “service line”. The service line extends from the water main to the building inlet and includes both the private and publicly owned portion of the water service.
1 A User Service Line is defined as the 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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Typical Water Service Line with Gooseneck/Lead Whip Program
1. Publicly owned portion of water service line inventory The LWS encompasses approximately 176,000 active water service lines.
In the 1980’s, water service lines known to have been manufactured with lead or lead components were proactively removed; therefore, the majority, if not all, of the LWS water service lines consist primarily of copper, plastic, and iron.
However, SFPUC records have subsequently revealed that there are 8,848 (5%) identified as unknown material type (“unknown services”), and 4,434 (2.4%) identified as galvanized steel. The number of galvanized steel services have since been reduced from 4,434 to 4,292 because these services were later discovered to be disconnected.
Since the rules that govern the LSLR program require the identification and replacement of all user service lines that may contain lead, both unknown and galvanized services are being field investigated to confirm and verify the actual service line material.
Galvanized service lines have been found to be commonly connected to water distribution pipes with a short flexible connection pipe made from lead, known as a lead whip or gooseneck. Therefore, all field verified 2- inch and smaller galvanized service lines will be replaced with a copper service because the State considers service lines with lead whips as “lead user service lines”.
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Gooseneck (Lead Whip) Water line Connection
Main to Service
As of December 2022, 8,692 (98%) of unknown user service lines and 4,130 (96%) of galvanized user service lines have been field inspected for a combined total of 12,822 conducted inspections. Tables 1 and 2 show that the majority of unknown or galvanized services are made of copper or other non-lead materials.
There are 317 (2.4%) services that still need to be field verified and will require additional resources due to accessibility, obstruction, or other various issues. Table 3 identifies the remaining services. The investigative work is expected to be completed by June 2023, pending identification and coordination with other entities (e.g., parklet owners, basement owners).
Lead
Whip
Lead
Whip
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Table 1
Unknown Service Field Investigation Results
Field Identified Material Quantity %
Galvanized 373 4%
Lead 0 0%
Other Materials 8,319 96%
Total 8,692 100%
Table 2
Galvanized Service Field Investigation Results
Field Identified Material Quantity %
Galvanized 988 24%
Lead 0 0%
Other Materials 3,142 76%
Total 4,130 100%
Table 3
Remaining Services to be Field Investigated
Issue Quantity %
Inaccessible
e.g. meter in basement
142 45%
Obstruction
e.g. meter under parklet
45 15%
Other 130 40%
Total 317 100%
2. Customer Owned Service Line Material Inventory
Since the recently expanded LCRR inventory now includes the customer owned portion of the service pipe, the LSLR Program will employ a SFPUC Water Enterprise Professional Services Contract that will focus its work scope on identifying strategies to inventory customer owned service lines.
The work scope will include predictive modeling and machine learning to identify the service pipe material for approximately 176,000 customer owned water service lines in lieu of manually field identifying and plan checking building plans and plumbing records. The expanded inventory requirements are to be completed by October 16, 2024. After this initial inventory submittal to the State, if there are still unknown materials listed for customer owned portion of the service line, the effort will continue until the inventory is completed.
The SFPUC has also been field investigating the customer-owned service pipe material while conducting user service line material field investigations for the public owned portion of the service line. See Table 4 below.
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Table 4
Customer Side Field Investigation Results
Field Identified Material Quantity %
Galvanized 630 9%
Lead 0 0%
Other Materials 6,421 91%
Total 7,051 100%
The EPA LCRR require water agencies to make publicly available service line material findings. Therefore, the SFPUC has posted an interactive map displaying all customers that have been identified to have either an unknown or galvanized water service. The map is updated bi-annually and can be accessed at https://sfpuc.org/accounts-services/water-quality/lead .
B. Lead and Galvanized Service Line Replacements
1. State and Federal Requirements
The State and Federal Guidelines contain moderately different requirements for service line replacements.
Table 5
State and Federal Requirements for Service Line Replacements Rule State SB-1398 EPA LCRR
Public agency side of
a water service line
(water main to the
meter)
Provide inventory of
service line materials
Replace all service
lines made of lead and
service lines with lead
whips
Provide inventory of service line
materials
Replace all service lines made of lead
Replace all galvanized service lines
that is or ever has been downstream of
a lead service line (otherwise known as
Galvanized Requiring Replacement or
GRR)
Customer side of a
water service line
(meter to building
outlet)
None Inventory all lead and GRR lines
Water Quality Supply customers with
a 3-month water
pitcher filters
Supply customers with a water pitcher
and 6-month supply of filters.
Provide lead sampling for schools and
childcare facilities
Notification Provide the public with
an inventory of service
line materials and
replacement schedule
Notify all affected customers prior to a
scheduled replacement or within 24
hours of an unplanned replacement or
repair (e.g., due to an emergency
service leak).
Provide public with inventory of service
line materials
Provide outreach materials
2. Publicly Owned Galvanized Service Line Replacement Rate The State guidelines necessitate a service to be replaced if it is connected to a lead whip. Therefore, the SFPUC will replace all 2-inch and smaller services confirmed to be a galvanized service because galvanized services were commonly connected to the water main with a lead whip.
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As of December 2022, 1,361 service lines have been verified as galvanized and 281 have subsequently been replaced with a copper service. 50 (18%) of the 281 services were found to be connected to a lead whip.
Graph 1 shows the total number of galvanized service lines that have been replaced through this reporting period and Map 1 identifies the locations of the 281 galvanized services that have been replaced.
Graph 1
Galvanized Service Line Replacements
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Map 1
Galvanized Service Lines Replaced with a Copper Service
The photos below display a typical service line replacement on Vicente Avenue.
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Water Service Line Replacement on Vicente (34th Ave. to 35th Ave.)
Removal of a ¾-inch Galvanized Service Line
Replacing the ¾-inch Galvanized Service Line
with a 1-inch Copper Service Line
3. Galvanized Service Line Replacement Contract
State and Federal regulations compel water agencies to remove all lead components within the water system by 2030. As a result, CDD has been actively replacing galvanized service lines at a rate of 10-15 galvanized services per month. This work is integrated into the overall maintenance, rehabilitation, and repair work scheduled throughout the month. To meet the 2030 deadline however, the galvanized service line replacement rate would need to increase substantially, and the increased rate would then require additional staff, resources, and equipment.
To meet the timeframe and account for the limited resources, the SFPUC has designed and advertised WD-2889, “As-Needed Water Service Line Replacement Project”. The Contract work scope includes all ancillary work associated with replacing water services such as permitting, earthwork, excavation, street restoration, and traffic control. The work scope will allow CDD crews and plumbers to focus on service replacement piping while the Contractor schedules, coordinates with stakeholders, obtains permits and provides support work. The Contract is expected to replace approximately 1,400 user service lines by the end of 2026, well before the 2030 deadline.
As of December 2022, WD-2889 has been awarded to JMB Construction Inc. for $26,663,850.
4. IIJA Federal Funding
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. The IIJA contains $15 billion for “lead service line replacement” that will be distributed by the EPA through the states.
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Money will be appropriated over multiple years, and in 2022, California received $250 million of the $15 billion through the State Water Resources Control Board (SWRCB).
In May 2022, 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. The applicable federal funding requirements have already been incorporated into WD-2889 and the application is under SWRCB review.
C. Customer Side Service Line Data
Neither the State nor Federal requirements compel water agencies to replace customer owned Galvanized Requiring Replacement (GRR) lines. However, States that accept IIJA Federal funding will need to replace all customer owned GRR lines because it is a component of the funding mandates. SFPUC is contemplating the IIJA Federal funding requirements and will be deciding on the merits and disadvantages of accepting the IIJA funding.
D. Water Quality Sampling and Data Gathering
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. If lead results are above 5 parts per billion (ppb), a repeat sample will be offered along with a Water Service Inspector customer home visit to find sources of lead in house plumbing.
II. Pipeline Renewal and Replacement Program
A. Local Water Facilities
Capital improvement projects for the LWS pipelines have been decreasing over the past two fiscal years due to 1) a decrease in available funding, 2) costly coordination and joint project issues with Public Works and SFMTA and 3) universal nationwide material supply chain issues.
B. Replacement Rate for FY23 (Q1 and Q2)
At the beginning of FY23 (Q1), the annual mileage for distribution system pipeline replacement was projected to be 8.2 miles. During this reporting period, 3.4 miles have been constructed, which is 41% of the projected mileage during this 6-month period.
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Table 6
Water Main Replacement Contracts FY 23 (Q1 and Q2)
Project Contract No. Miles
8-inch Ductile Iron Pipe & 24-Inch Earthquake
Resistant Ductile Iron Pipe Water Main
Installation on Prospect, Fair and Coso Avenues
& Coleridge Street
WD-2718 0.42
16, 12, And 8-Inch Ductile Iron Water Main
Replacement on Diamond St (27th St To
Diamond Heights Blvd), 28th And Duncan St
(Douglass To Noe Sts.), Valley St (Diamond to
Noe Sts.), And Noe St (Duncan to Valley Sts.)
WD-2843 0.26
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 0.59
36-inch Steel and 8-inch Ductile Iron Pipe Water
Main Installation on Vicente St. (19th to 25th
Ave.)
WD-2806
1.10 L-Taraval Improvement Project (Sunset Blvd. to
West Portal) WD-2859R
0.03 8-inch and 16-inch Ductile Iron Water Main
Replacement 17th St. (Clayton St. to Douglass
St.)
WD-2811
0.23 8 & 12-inch Ductile Iron Pipe Water Main
Installation Project 16th (16th & Mission Sts.),
(16th & Guerrero Sts.)
WD-2857 0.77
Total 3.4 miles
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WD-2775 19th Avenue and Sloat Boulevard
Lowering 36-inch Steel Pipe into the trench
Welding the 36-inch Steel Pipe
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Aerial View
Asbestos Removal on the 54-inch Pipeline
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WD-2775 19th Ave and Sloat Blvd (Stern Grove)
Installation of a 54-inch by 36-inch Welded Steel Tee
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WD-2843 Various Locations Diamond Street
Diamond and 28th Streets
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WD-2843 Various Locations Diamond Street
Diamond and 28th Streets
Diamond and Beacon Streets Diamond and Duncan Streets
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WD-2859 Taraval Street
8-inch Water Main Installation at Taraval Street and 26th Avenue
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C. Unit Construction Costs
In FY23, the pipeline replacement program budget cost per mile to replace water distribution pipelines has increased 83% from $3.18 million to approximately $5.8 million. The updated cost per mile for streetscape, transit, or ERDIP-type projects is approximately $8.6 million, an increase of approximately $0.6 million from the prior fiscal year.
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. An analysis of financial data and construction pipeline miles will be performed in the next fiscal year to assess analyze the contributory factors towards escalating costs.
Graph 2 identifies the targeted versus actual miles of pipeline installed over the past decade.
Graph 2
Miles of Pipeline Installed
D. Water Main Replacement Project Study
CDD is responsible for approximately 1,200 miles of distribution and transmission pipelines. Prior to 2012, roughly 6 miles per year of pipelines were replaced or rehabilitated with cathodic protection or lining. The 6 miles represented 0.5% of annual system improvements whereas studies indicated that by 2040, 50% of the local water system’s distribution pipelines will exceed pipeline age criteria. Therefore, to determine a more appropriate rate of replacement for CDD’s Linear Asset Management Program (LAMP), CDD and AECOM completed a desktop study in 2012 that assessed existing pipeline conditions based upon pipe characteristics (e.g., age and material), corrosion potential, water main break data, and pipeline criticality. The study established a criticality ranking, reported as Total Risk Score to help prioritize pipelines for improvement and identified 320 miles of pipelines that were candidates to be replaced or rehabilitated. The LAMP program utilizes this information to plan, design, and construct pipeline replacement projects, including the projects discussed in this report.
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Since 2012, CDD has completed approximately 72 miles of replacement or rehabilitation projects. Within the next 50 years, a substantial percentage of the water system will exceed industry standard expected pipeline age criteria. This may increase unplanned outages due to water main leaks and breaks and create interruptions in water service. Therefore, CDD will be conducting a second study within the next year to build upon the findings from the 2011 report as well as develop future strategies to reduce or mitigate the effects of an aging water infrastructure. The study is expected to include:
Analysis of historical pipeline break information to assist with forecasting future breaks as well as understanding typical pipeline failure mechanisms.
Analysis and evaluation of useful expected pipeline lifespans and compare this evaluation with industry standards.
Evaluation of pipeline life extension strategies such as structural line, coating, and cathodic protection.
The LAMP study goals will assist CDD with developing a Linear Asset Management Master Plan to account for a necessary increase in CDD pipeline replacement miles.
E. Seismic Improvements
The College Hill Pressure System delivers water by gravity from College Hill Reservoir to customers in the mid-eastern strip of San Francisco including City Hall and San Francisco General Hospital (SFGH), the only Level I Trauma Center in the Bay Area that services 1.5 million residents of San Francisco and Northern San Mateo.
The College Hill Reservoir System Improvement Project (Phases 1 through 5) was developed and designed with Kubota Earthquake Resistant Ductile Iron Pipe (ERDIP). Kubota pipe was evaluated and selected based on 1) its ability to withstand large joint deflections 2) the pull-out resistance at the joints and 3) the capacity and capability of each joint to expand and contract.
Under Phases 1 and 2, 34% (1.4 out of the 4.1 miles) of the ERDIP have been constructed.
1. College Hill Reservoir System Improvement Project
Phase 1 was completed in 2017 and Phase 2 was completed in 2019. Phase 3a is under construction by Ranger Pipelines. Phase 3b construction has been completed by Cratus Inc. and is scheduled to be in service FY22-23 (March 2023).
Phase 4 is currently in design and the construction contract is expected to be advertised FY 22-23 Q4 (April 2023) and NTP will be FY23-24 Q1 (September 2023).
Phase 5 construction contract is scheduled to be awarded FY22-23 Q3 (February 2023) and NTP will be FY 22-23 Q4 (April 2023).
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Map 2
College Hill Reservoir System Improvement Project
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WD-2718 Prospect Avenue at Cortland Street
24-inch Earthquake Resistant Ductile Iron Pipe (ERDIP) Installation at Prospect Avenue, North of Cortland Avenue
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F. 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
A new potable EFWS pipeline is being planned within the Richmond and Sunset areas, and a draft Conceptual Engineering Report (CER) is under review by stakeholders.
b. Fireboat Manifolds
A new fireboat manifold and pipelines are being planned within Fort Mason. The geotechnical investigation will be taking place Fall 2023, pending the application with the National Park Service (NPS).
Installation of a new fireboat manifold and pipelines near Pier 35.5 are in the Planning stage.
Planning is in progress to install a fireboat manifold and pipelines on Terry Francois Boulevard in the vicinity of the Warriors Stadium Ferry Landing.
2. Construction
a. 19 th Avenue Pipeline
A new 20-inch EFWS pipeline (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 System (PEFWS) pipeline (19th Avenue from Vicente Street to Sloat Boulevard) are under construction as a part of the Public Works Department’s 19th Avenue Roadway Improvements, Contract 2652J.
Construction is expected to be completed July 2023.
b. Clarendon Supply
A new EFWS water supply and pipeline near the crest of Clarendon Avenue at Dellbrook Avenue is under construction and is expected to be completed June 2023.
c. Pumping Station 2 Project
The Pump Station 2 building is undergoing seismic performance improvements and construction is anticipated to be completed June 2023.
d. Vicente Pipeline
A new 36-inch diameter PEFWS pipeline on Vicente Street from 19th Avenue to 25th Avenue is under construction and expected to be completed July 2024.
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Installation of new 36-inch diameter Welded Steel Pipe (WSP) for Potable Emergency Firefighting Water System (PEFWS) Pipeline at 19th Avenue and Sloat Boulevard
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Clarendon Supply Project
Pumping Station 2 Project
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G. New Water Service Applications
During this period, a total of 158 new service applications have been received, a 16% decrease from the previous 6 months. A new water service application typically includes 2 to 6 individually metered water connections per address for water, fire, and irrigation services. Graph 3 summarizes the number of new water service applications received during this reporting period as compared to previous periods.
Graph 3
New Water Service Applications
H. Regional Water Facilities
Capital improvement projects for the regional water 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 Reach 5, located in Millbrae, San Bruno and South San Francisco, 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 to improve water quality and to extend the service life of the pipeline. Additional scope includes installing new manholes to improve access, new isolation valves for safe pipeline entry, and upgrading appurtenances to meet current water quality standards. A Conceptual Engineering Report (CER), which includes information from survey work and geotechnical studies, was presented and approved by the Technical Steering Committee in this reporting period.
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b. Bay Division Pipeline (BDPL) Nos. 1, 2, 3 and 4
The project will repair lining defects that were identified from previous inspections as well as lining defects expected to be identified in future inspections in the BDPL Nos. 1 – 4. When the construction contract is in place, maintenance inspections and lining repairs can be performed within the same shutdown, eliminating the need to perform subsequent shutdowns for repairs, since a new contractor will already be on board.
The scope of work consists primarily 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 (CER) was completed. However, an addendum to the CER is needed and in progress to address safe pipeline entry. An Alternatives Analysis Report (AAR), which studied various options to achieve safe pipeline entry, was completed and the selection of installing new isolation valves was the preferred option to move forward with design.
Identifying locations of new valves, geotechnical studies, and topographic surveys (which will be incorporated into the addendum) are in progress.
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 65% design milestone was completed, and progress was made to further the design toward 95%. Project team continues preparation of the CEQA Addendum and
environmental permitting. Real estate work is ongoing at the Sunol Glen School to obtain new permanent and temporary construction easements.
d. CSPL2 Reaches 2 and 3
CSPL2 Reaches 2 and 3, located in Hillsborough, San Mateo, and Burlingame, 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. This project will also replace
2.2 miles of coal tar lining with cement mortar lining to improve water quality and extend the service life of the pipeline. Additional scope includes installing new manholes to improve access, new isolation valves for safe pipeline entry, and upgrading appurtenances to meet current water quality standards. A Conceptual Engineering Report (CER), which includes information from survey work and geotechnical studies, was completed in this reporting period.
e. Bay Division Pipeline No. 4 (BDPL4)
In 2017, an inspection of BDPL4, constructed of Prestressed Concrete Cylinder Pipe (PCCP), from Valve D50 to D68, found narrow and wide circumferential cracks in 1.5 miles of the pipeline that parallels
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Edgewood Road in Redwood City. In 2021, temporary WEKO seals were installed at the wide cracks to repair active leaks. Concurrently, additional studies were performed, which concluded that high number of broken prestressed wires and circumferential cracks were a high priority. A Conceptual Engineering Report to replace approximately 650 feet of targeted segments of high priority PCCP will be prepared for an initial phase to address the segments with high number of broken prestressed wires. In addition, a Needs Assessment Report (NAR) studying the root cause of the circumferential cracks is being prepared and will determine the scope for a long-term repair project.
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 fully installed and hydrostatically tested at their tie-in locations.
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.
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, 1 new potential point of interest has been identified in the Phase 2 area. Monitoring for the 4 previously identified points within the Phase 1 Diamond Heights neighborhood has been placed on hold until the cell services issue in this phase is resolved.
Table 7
Leak Sites Investigated and Repaired
Phase Investigation State Address
Field
Investigated
Date
Leak Repair
Date Leak Type
2 Potential Leak 400 Block of
Campbell Ave in progress - -
1 On Hold 0-99 Block of
Topaz Wy - - -
1 On Hold 2300 Block of
Castro St. - - -
1 On Hold 400 Block of
Bosworth - - -
1 On Hold 1300 Block of
Douglass St - - -
Only one new potential point of interest has been identified in the Phase 2 Portola neighborhood and sensor information has become minimal and infrequent. This observation indicates that minimal below surface leaks are occurring within the Phase 2 area. Consequently, SFPUC is investigating the feasibility of moving the sensors to another neighborhood that may benefit from the monitoring program, such as the Bay View Neighborhood.
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B. Regional Water Facilities
Physical pipeline inspections resumed in FY23 beyond ROV/unmanned inspections employed during the COVID-19 pandemic. During this reporting period, the Water Supply and Treatment Division performed warranty inspection for the newly replaced segment of SAPL2. Also, a new inspection tool through Syrinix, was adopted to provide active monitoring of pressure and leakage on some PCCP pipelines.
1. San Andreas Pipeline No. 2 (SAPL2)
A warranty inspection was carried out in October 2022 to determine the condition of the internal lining of 6,500 feet of pipe that was replaced in 2020. Two locations of lining defects were identified, both at the transition joints between new and existing lining. The defects were repaired by the original contractor under warranty, and SAPL2 was returned to service in December 2022.
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SAPL2 Warranty Inspection – Failure at the Dielectric & Coal Tar Lining Transition
2. Bay Division Pipeline No. 4 (BDPL4) Transient Pressure and Leak Monitor
In 2017, an inspection of BDPL4, from Valve D50 to D68, found many narrow and wide circumferential cracks in the pipeline. In 2021, temporary WEKO seals were installed to repair active leaks. However, another leak developed post WEKO seal repairs in 2021. In lieu of another shutdown, the Division decided to monitor and divert the leak. With the objective of improving monitoring, Syrinix’s Pipeminder-T system was installed in
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November 2022. The monitoring system will stay in place until a long-term capital improvement project fully addresses the root cause.
BDPL4 Transient Pressure and Leak Monitoring System
IV. Summary of Pipeline Failures
A. Local Water Facilities
1. Main Break Data
102 distribution main breaks occurred during this reporting period. Of this total, 96 (94%) were due to natural pipeline breaks and 6 (6%) were due to third-party contractors. Of the natural pipe failures, 92 (96%) occurred on cast iron pipes, 3 (3%) occurred on ductile iron pipe and 1 (1%) occurred on steel pipe. Table 8 classifies the number of breaks based on material type and decade installed.
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Table 8
Natural Pipeline Failures FY 22-23 (Q1 & Q2)
Pipe
Material
Decade
Installed
No. Breaks Per Diameter (Inches) #
Breaks %
1.5 2 4 6 8 12 16 24
Cast Iron 1920 - 3 - 7 1 - - - 11 11
1930 - 3 5 21 6 1 1 - 37 39
1940 1 1 - 7 6 - - - 15 16
1960 - - 2 5 3 - 1 - 11 11
Other 1 - 1 4 9 2 1 - 18 19
Ductile Iron
1960 - - - 1 - - - - 1 1
2000 - - - - 1 - - - 1 1
2010 - - - - - - 1 - 1 1
Steel 1950 - - - - - - - 1 1 1
Total 96 100%
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 1880s experienced the highest main break rate with 20 breaks per 100 miles of pipeline and pipelines installed in the 1920’s, 30’s, 40’s, and 60’s experienced high break rates of 11, 14, 17, and 12 breaks per 100 miles of pipeline respectively. Pipelines installed in other decades experienced 9 breaks or less per 100 miles of pipe installed, which is more than a 50% decrease from the 1880’s. See Graph 4 identifying the number of breaks per 100 miles of pipe installation.
Graph 4
FY 23 Q1 & Q2 Normalized Pipeline Failures
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a. College Hill Pressure System
There were 19 main breaks within the College Hill pressure system concentrated within the last three months of 2022. This is a substantial increase in total breaks when compared to the same months in previous years.
The main breaks coincided with the College Hill Reservoir Outlet Phase 3a construction work, which disconnected the reservoir from the rest of the College Hill system. To maintain supply to the College Hill system, which is normally gravity-fed through the reservoir, additional water was directly drawn from the SA2 Pipeline to the College Hill system by activating two pressure regulators. The first regulator is located at Roanoke St & Arlington St and the second regulator is located at San Jose Ave & Dolores St. The first regulator is on-line while the second regulator is off- line. Furthermore, the reservoir normally acts as a mechanism to mitigate pressure spikes by allowing high pressure water to be released into the reservoir rather than continuing to circulate in the pipes. Consequently, the removal of the reservoir significantly impacted the system’s ability to mitigate pressure fluctuations because a closed piping system was created; rather than having the reservoir to help moderate pressure spikes, the high pressure would continue to circulate in the pipes until it reached a weak spot in the piping.
To address the high pressure, a divide gate on Woolsey St between the University Mound system and the College Hill system was opened to help control pressure fluctuations within the system.
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, 53 breaks have been repaired with clamps and 43 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 9.
Table 9
Estimated Main Break Repair Costs FY 23 Q1 & Q2
Repair Type Labor Material Paving Cost Per
Repair
Total No.
breaks
Total
Repair Cost
Clamp $509,724 $9,407 $267,919 $14,850 53 $787,050
Pipe
Replacement $805,495 $49,310 $576,118 $33,277 43 $1,430,923 Total $2,217,973
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Table 10
Main Break Repair Cost Comparison
Repair Type
FY22
Q1 & Q2
FY22
Q3 & Q4
FY23
Q1 & Q2
Clamp $368,100 $693,420 $787,050
Pipe Replacement $515,600 $988,844 $1,430,923
Total Cost $883,700 $1,682,264 $2,217,973
The total main break cost during this reporting period is $2,217,973, 32% higher than the previous 6-month reporting period.
B. Regional Water Facilities
Two pipeline leaks occurred in the Regional Water System during this reporting period.
1. In August 2022, a leak was reported on the Palo Alto Pipeline near El Camino Real and Middle Ave intersection in Palo Alto. The PAPL is located in public right-of-way, with shallow (9-inches) cover over the pipe.
The leak was caused by a combination of corrosion and abrasion of an electrical conduit that was sitting on top of the pipeline. The leak was repaired with a 1-inch plug.
2. In November 2022, a leak was reported on the Palo Alto Pipeline (PAPL), near El Camino Real and Stanford Ave in Palo Alto. There is a gas line that crosses perpendicularly to PAPL. The leak was caused by corrosion, most likely attributed to the nearby stray current from the gas pipeline’s cathodic protection system. The leak was repaired with a 2-inch plug.
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PAPL Leak at El Camino Real and Middle Avenue
V. Summary
The City Distribution, Water Supply and Treatment, and Water Quality Divisions have conducted several maintenance and construction activities to the linear assets during the period July 1, 2022 through December 31, 2022. The key highlights include:
Local Water System
The Lead Service Line Replacement Contract WD-2889, “As-Needed Water Service Line Replacement Project” has been awarded to JMB Construction Inc. for $26,663,850 and a General Application for funding provided through the Federal IIJA have been incorporated into WD-2889 and is currently under review by SWRCB.
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97 natural pipeline breaks were recorded during this reporting period. Of this total, 19 main breaks occurred within the College Hill pressure system. The total main break cost is $2,231,370, 33% higher than the previous 6-month reporting period.
3.4 miles of LWS distribution and transmission water pipelines have been replaced this reporting period, a 20% decrease from the prior reporting period.
A study will be conducted within the next year to develop future strategies to reduce or mitigate the effects of an aging water infrastructure. The study is expected to include an analysis of historical pipeline break information, and an evaluation of strategies to extend a pipeline’s useful expected lifespan.
Regional Water System
Physical pipeline inspections resumed in the current reporting period after the COVID-19 pandemic.
A new pipeline inspection tool, Syrinix Pipeminder-T acoustic leak detection, was adopted to monitor high risk PCCP.
The construction of the Town of Sunol Potable and Raw Pipelines across freeway I-680 has made significant progress. The transfer of water service to the new pipelines is expected in the next reporting period.