Drinking water quality · 2024
· Verified
What's in Daly City, CA tap water
31 contaminants were measured in the Daly City, CA water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 31
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound detected in Daly City, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
Lithium
● Detected (no federal limit)below national p90 (76.59999999999991 mg/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
Daly City, CA's drinking water comes from ground water, drawn from 5 sources.
Source
- JEFFERSON WELL
- WESTLAKE WELL
- WELL 04 - STANDBY
- JUNIPERO SERRA WELL
- + 1 more
Treatment
- WESTLAKE PUMP STATION - BLENDED-TREATED
- CITRUS PUMP STATION - BLENDED - TREATED
Distribution
Also buys water from SAN FRANCISCO REGIONAL WATER SYSTEM, NORTH COAST COUNTY WATER DIST, and 4 more.
Historical readings · EPA Six-Year Review (2012–2019)
2 contaminants historically over EPA limits in Daly City, CA
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
NITRATE worst: 2014 | 38.4 mg/L 3.8× | 10 mg/L | '12'13'14'15'16'17'18'19 |
HAA5 worst: 2018 | 0.0638 mg/L 1.1× | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
TTHM worst: 2019 | 0.0688 mg/L 86% | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
GROSS BETA worst: 2019 | 1.27 mrem/yr within | 4 mrem/yr | '19 |
ARSENIC worst: 2013 | 0.003 mg/L within below national p90 | 0.01 mg/L | '13'15 |
CHROMIUM worst: 2013 | 0.025 mg/L within 2.5× the national p90 | 0.1 mg/L | '13'15'16'17'18'19 |
DIQUAT worst: 2013 | 0.0022 mg/L within | 0.02 mg/L | '13 |
FLUORIDE worst: 2015 | 0.24 mg/L within | 4 mg/L | '12'13'15'16'17 |
DBAA worst: 2013 | 0.0022 mg/L | — | '13'14'15'16'17 |
DCAA worst: 2012 | 0.0213 mg/L | — | '12'13'14'15'16'17'18'19 |
TCAA worst: 2012 | 0.0163 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2017 | 0.001 mg/L | — | '17 |
MCAA worst: 2016 | 0.004 mg/L | — | '16'17'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.00107 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.00183 mg/L | — | '12'13'14'15'16 |
CHLOROFORM worst: 2012 | 0.0299 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2013 | 0.00296 mg/L | — | '13'14'15'16'17'18'19 |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 2.82 mg/LAverageSystem-wide | 4 mg/LMRDL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 7.2 ug/L90th percentileAt the tap | 15 ug/LAction level | Within the limit |
| CopperA metal that enters water from corroding household plumbing. | 88 ug/L90th percentileAt the tap | 1300 ug/LAction level | Within the limit |
| BoronA naturally occurring element from rock and soil. | 41 ug/LAverageSystem-wide | 1000 ug/LMCL | Within the limit |
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | 0.1 ug/LAverageSystem-wide | 10 ug/LMCL | Within the limit |
| IronA naturally occurring metal common in groundwater. | 1.4 ug/LAverageSystem-wide | 300 ug/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | Not detected ug/LAverageSystem-wide | 200 ug/LMCL | Within the limit |
| ManganeseA naturally occurring metal from soil and rock. | Not detected ug/LAverageSystem-wide | 50 ug/LMCL | Within the limit |
| CalciumA naturally occurring mineral that contributes to water hardness. | 15 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 5.7 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| SilicaA naturally occurring compound from sand and rock. | 7.5 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 16 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| BromateA disinfection byproduct formed when bromide-containing water is treated with ozone. | 3 ug/LAverageSystem-wide | 10 ug/LMCL | Within the limit |
| ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade. | 144 ug/LAverageSystem-wide | 800 ug/LMCL | Within the limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 193AverageSystem-wide | 1600MCL | Within the limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 102 mg/LAverageSystem-wide | 1000 mg/LMCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.2 NTUAverageSystem-wide | 5 NTUMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 60 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 60 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 9.07AverageSystem-wide | None set | Detected — no federal limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.5 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 18 mg/LAverageSystem-wide | 500 mg/LMCL | Within the limit |
| ChlorideA naturally occurring salt compound. | 9.3 mg/LAverageSystem-wide | 500 mg/LMCL | Within the limit |
| BromideA naturally occurring salt found in source water. | Not detected ug/LAverageSystem-wide | None set | Detected — no federal limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0AverageSystem-wide | 0MCL | None detected |
| Giardia lamblia | 0.02AverageSystem-wide | None set | Detected — no federal limit |
People also ask about Daly City, CA's water
+Is Daly City, CA tap water safe to drink in 2024?
Every one of the 31 contaminants measured in Daly City, CA's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Daly City, CA tap water?
31 contaminants were measured in Daly City, CA's 2024 Consumer Confidence Report, spanning metals, physical & aggregate, and inorganic chemicals. 20 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Where does the data on this page come from?
Every value is transcribed from Daly City, CA's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Daly City, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.