DEPARTMENT
Water Quality Division
AGENDA NO.
7 MEETING DATE
September 9, 2025
AGENDA ITEM
Public Utilities Commission
City and County of San Francisco
Calendar: Regular Calendar
Project Manager: Andrew DeGraca
Public Hearing on the San Francisco Water System 2025 Public Health Goal Report
Summary of Proposed
Commission Action:
Public hearing on the San Francisco Water System 2025 Public Health Goal Report for the purpose of accepting and responding to public comment and directing the San Francisco Public Utilities Commission General Manager or the General Manager’s designee to submit a letter to the State Water Resources Control Board documenting that such a hearing has been held.
Background: The San Francisco Public Utilities Commission (SFPUC) delivers drinking water to the City and County of San Francisco and must comply with federal and state regulation for water quality . Public Health Goals (PHGs) are numeric health protection goals developed by the California Office of Environmental Health Hazard Assessment for the levels of chemical contaminants in drinking water that do not pose a significant risk to health. PHGs are established solely based on health risk information with no considerati on of technical and economic feasibility. Maximum Contaminant Level Goals (MCLGs), developed by the U.S. Environmental Protection Agency (USEPA), are considered the federal equivalent of PHGs. The PHGs and MCLGs are not enforceable but are used to support the development of enforceable drinking water standards such as Maximum Contaminant Levels (MCLs) by the State Water Resources Control Board (SWRCB) and USEPA, respectively. MCLs are set as close to the health goals as is economically and technologically feasible.
Section 116470 of California Health and Safety Code requires that a public water system with more than 10,000 service connections compare its drinking water quality primarily with the PHGs and submit a report to its governing board presenting the comparison every three years should monitoring results exceed the applicable PHGs. If a PHG has not been adopted for a regulated contaminant, the public water system must use an existing MCLG for comparison. For a public water utility like the
SFPUC, the report must be presented at a public
meeting. The governing board (i.e., the Commission) must respond to any public comments received. After the public meeting is held, the SFPUC must submit a letter to the SWRCB documenting that the Agenda Title: The San Francisco Water System 2025 Public Health Goal Report Commission Meeting Date: September 9, 2025
San Francisco Water System (SFWS) has complied with these legal requirements. This is the tenth triennial P ublic Health Goals Report (Report) and hearing that the SFPUC has held since 1998.
On June 18, 2025, in advance of the June 24, 2025 meeting of this Commission, SFPUC staff submitted the Report as a published communication item. The Report includes a comparison of SFWS water quality with the list of contaminants that have drinking water standards and applicable PHGs between 2022 and 2024 (the Reporting Period). The drinking water standards may be expressed as either Maximum Contaminant Levels (MCLs), Action Levels (ALs), or Treatment Techniques (TT). San Francisco water met all enforceable drinking water standards but exceeded the non- enforceable PHGs for bromate, hexavalent chromium, and lead.
In general, t he PHG evaluation follows recommendations and guidelines published by the Association of California Water Agencies, as the SWRCB does not provide any guidance. Although the law does not mandate actions by water systems to meet the health goals, it requires utilities to provide information about any best available technology (BAT) commercially available and a cost estimate to reduce the contaminant to the PHG level.
Key findings of the PHG report and evaluation of applicable BATs for the abovementioned contaminants are as follows:
Bromate
In our drinking water, bromate is a disinfection byproduct formed during ozone treatment of the raw water in which naturally occurring bromide is present. Bromate is identified as a human carcinogen, and it can also cause hyperplasia - enlargement of an organ or tissue.
During the monthly compliance monitoring in the Reporting Period, bromate was detected above the PHG of 0.1 ppb but below the MCL of 10 ppb in the treated water from the Harry Tracy Water Treatment Plant (HTWTP). T he USEPA and SWRCB indicate that optimized controls of the ozone treatment process is the BAT for reducing bromate formation. Although t he current ozone treatment at the HTWTP is continuously optimized, the amount of bromate may still be affected by the variability of bromide levels in the source water. As an additional measure, s taff prepared an updated evaluation of commercially available BAT and cost est
imates for bromate
treatment. The evaluation concluded that even if HTWTP
implemented expensive treatment methods, there would still be no guarantee that the PHG level would be attained. As such, the report recommends continuing current practices of optimization of ozone dosage with routine raw water bromide monitoring.
Hexavalent Chromium (Cr-6)
The SWRCB adopted a MCL of 10 ppb in late 2024. The PHG of 0.02 Agenda Title: The San Francisco Water System 2025 Public Health Goal Report Commission Meeting Date: September 9, 2025
ppb was developed based on toxic effects from both oral and inhalation exposures to Cr -6 that may be present in drinking water.
This contaminant may occur naturally in groundwater and surface water or may be due to human activities such as industrial sources and discharges. In the Reporting Period, Cr-6 was detected at or above the PHG in both non- Hetch Hetchy surface water sources and local groundwater sources. However, all results in the drinking water delivered to SFWS customers were below the MCL, as a result of blending. The SWRCB has identified BATs in its MCL regulation, but none of them is intended to reduce the Cr-6 to a level below or at the PHG. Staff also prepared an updated evaluation of select BATs and the associated annualized costs as part of this Report. The evaluation concluded that since no human sources of Cr-6 have been identified in our watersheds and the current levels in the drinking water delivered to customers are well below the MCL, additional treatment of this naturally occurring contaminant beyond blending would not be necessary or cost-effective.
Lead
Lead is toxic and has multiple chronic health effects including negative neurobehaviors in children and hypertension in adults. It also has the potential to cause kidney disease and cancer. Lead enters drinking water primarily through leaching of lead- containing materials in household plumbing and some service lines between water mains and houses.
Our 2024 monitoring of the water supplied to the SFWS
showed there is no detectable lead. In conjunction with the SFWS supply monitoring, our latest triennial cus tomer tap monitoring demonstrates continued regulatory compliance. All results of the tap monitoring were below the regulatory Action Level of 15 ppb, although the calculated 90th percentile (used for Action Level compliance) value at 4.9 ppb and some individual results were above the PHG of 0.2 ppb.
Neither the USEPA nor the SWRCB specifies any technology as a BAT; thus, staff has not prepared any cost estimates for treatment of this contaminant. H owever, a combination of regulatory actions by utilities is recognized by these agencies as necessary to abate the lead in drinking water . These actions include, but are not limited to, corrosion control optimization, replacement of identified lead service lines by the regulatory deadline, monitoring of lead at select customer taps and appropriate water quality parameters in the distribution system, and proactive public outreach to educate customers. In addition to performing these regulatory activities, the SFWS will continue the following voluntary actions to help customer s
reduce lead exposure
from drinking water:
• Replace meters and curb stop valves with lead-free units, if found. • Offer low-cost lead tests for City customers and free lead tests for enrollees of the Woman, Infants, and Children Program.
Agenda Title: The San Francisco Water System 2025 Public Health Goal Report Commission Meeting Date: September 9, 2025
• Provide analytical services in support of lead reduction efforts by San Francisco Department of Public Health.
Additionally, new measures will be implemented to comply with the upcoming requirements of USEPA’s new Lead and Copper Rule Improvements. These include:
• Updating the material inventory and associated location map for utility-side and customer-side service lines.
• Collaborating with K -12 schools and childcare facilities to conduct lead testing.
• Identifying new Tier 3 single-family premises to recruit volunteers for future lead and copper monitoring. These are homes that had a lead utility service line previously removed and have a galvanized customer service line.
• Evaluating potential methods to facilitate replacement of the customer-side galvanized service lines requiring replacement.
Attachments: 1. The San Francisco Water System 2025 Public Health Goal Report
2. June 2025 Memorandum to Commission
PUBLIC UTILITIES COMMISSION
City and County of San Francisco
RESOLUTION NO.
WHEREAS, The San Francisco Public Utilities Commission (SFPUC) delivers drinking water to the City and County of San Francisco and complies with federal and state regulation for drinking water quality. Section 116470 of California Health and Safety Code requires a public water system serving more than 10,000 service connections to compare drinking water quality with the applicable Public Health Goal (PHG) and submit a report (PHG Report) to its governing body for public hearing every three years; and
WHEREAS, The Public Utilities Commission has held PHG report h earings triennially since 1998; and
WHEREAS, SFPUC staff prepared a PHG Report that covers the Reporting Period between 2022 and 2024, and submitted it to the Commission on June 18, 2025, a copy of which has been made available to the public and is on file with the Director of Commission Affairs; and
WHEREAS, During the Reporting Period, the drinking water supplied by the San Francisco Water System to the City and County of San Francisco met all enforceable drinking water standards that are expressed as Maximum Contaminant Levels (MCLs) , Action Levels (ALs), or treatment technique, but exceeded the non-enforceable PHGs for three contaminants, including bromate, hexavalent chromium, and lead; and
WHEREAS, Bromate, a carcinogen that is produced as a disinfection byproduct during the ozone treatment of raw water containing bromide , was detected above the PHG of 0.1 ppb in monthly treated water samples from Harry Tracy Water Treatment Plant; and
WHEREAS, The SFPUC has been implementing watershed protection programs, optimization of ozone dosage, and monitoring bromide in raw water; and
WHEREAS, Hexavalent Chromium , a carcinogen based on studies re lated to a irborne inhalation and oral injection, was detected at or above the PHG of 0.02 ppb in SFWS’s raw groundwater supplies and treated local, non-Hetch Hetchy surface water, but was not detected in the blended groundwater water supplies and surface water entry points at BADEN Valve Lot during the Reporting Period; and
WHEREAS, The California Division of Drinking Water of State Water Resources Control Board (SWRCB) has previously approved the use of blending to meet the MCL of hexavalent chromium for the SFWS’s groundwater supply; and
WHEREAS, Lead, which has multiple toxic effects on the human body, was not detected in the water supplied to the distribution system but the latest round of triennial Lead and Copper Rule customer tap monitoring had a calculated 90
th percentile value of 4.9 ppb and some individual
results being above the PHG of 0.2 ppb; and
WHEREAS, Sources of lead in drinking water are typically originated from leaching of household plumbing and lead-laden service lines; and
WHEREAS, In August 2006, the SWRCB confirmed that the SFPUC’s pH adjustment is the optimized corrosion control treatment; and
WHEREAS, In 2020, the SFWS submitted to the SWRCB a 10-year replacement schedule accompanying a reported inventory of 8,848 unknown material s and 4,434 galvanized steel user service lines, of which 1,578 might have short lengths of lead connectors; and
WHEREAS, As of May 1, 2025, the SFWS updated the number of galvanized steel user service lines to 1,423 through field inspections, and 1,156 of them were subsequently replaced with the remaining 267 to be replaced by mid-2026 (four years ahead of the regulatory deadline of 2030); and
WHEREAS, In October 2024, the SFWS submitted to the SWRCB an inventory of lead- status service lines documenting that there are no lead service lines, 653 service lines that are galvanized requiring replacement (GRR), and 407 unknown material service lines on the customer side; and
WHEREAS, As of May 1, 2025, the total number of GRRs and unknown material service lines on the customer side were updated to 675 and 241, respectively, through site inspections; and
WHEREAS, An interactive map is publicly access ible through the SFPUC website and enables users to verify if an address has a utility- or customer-side galvanized service line; and
WHEREAS, The SFPUC is working on several programs including the development of a schedule to start lead sampling at public and private K-12 schools and licensed childcare facilities by 2028, i dentification of new Tier 3 single -family premises to recruit additional volunteers for future Lead and Copper Monitoring under the USEPA’s 2024 Lead and Copper Rule Improvements, and evaluation of potential methods to facilitate GRR replacement program for customer-side service lines; and
WHEREAS, The SFPUC policy is to replace discovered utility service lines that have lead connectors and to educate customers about lead reduction efforts; and
WHEREAS, On September 9, 2025, the Commission held a public hearing for the purpose of addressing any public comments received on the PHG Report; now, therefore, be it
RESOLVED, The Commission directs the General Manager or the General Manager’s designee to issue a letter to the SWRCB documenting that the 2025 PHG Report was prepared and that a public hearing was held for the purpose of accepting and responding to public comments on the 2025 Report.
I hereby certify that the foregoing resolution was adopted by the San Francisco Public Utilities Commission at its meeting of September 9, 2025.
Director of Commission Affairs
San Francisco Public Utilities Commission