Tap Water Quality Report
Tap water quality in DALY CITY, California
Tap water in DALY CITY, California receives a grade of D (61/100) from TapWaterSafety.org. It's served by CITY OF DALY CITY. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Chromium (hexavalent) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in DALY CITY's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving DALY CITY.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 23.6 ppb, 394x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.2 ppb, 362x above the EWG health guideline of 0.1 ppb.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 4.84 ppb, 242x above the EWG health guideline of 0.02 ppb.
Recommended filters for DALY CITY
Filters matched to the specific contaminants in DALY CITY's water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in DALY CITY's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
23.6 ppb | 0.06 | — | — | — | — | — | 394× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Chromium (hexavalent) Heavy metal |
4.84 ppb | 0.02 | — | — | — | — | — | 242× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
33.8 ppb | 0.15 | 80.0 | 100 | — | — | — | 226× over |
| Trichloroacetic acid Disinfection byproduct |
11.9 ppb | 0.1 | — | — | — | — | — | 119× over |
| Dichloroacetic acid Disinfection byproduct |
19.4 ppb | 0.2 | — | — | — | — | — | 97× over |
| Chloroform Disinfection byproduct |
31.5 ppb | 0.4 | — | — | — | — | — | 79× over |
| Bromodichloromethane Disinfection byproduct |
1.64 ppb | 0.06 | — | — | — | — | — | 27× over |
| Nitrate Inorganic |
3.08 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 22× over |
| Dibromochloromethane Disinfection byproduct |
0.692 ppb | 0.1 | — | — | — | — | — | 6.9× over |
| Dibromoacetic acid Disinfection byproduct |
0.103 ppb | 0.03 | — | — | — | — | — | 3.4× over |
| Chlorate Disinfection byproduct |
113.2 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.046 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | Below guideline |
| Vanadium Other |
2.03 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
4.35 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.144 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0884 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
4.06 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Lithium Other |
1.13 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from CITY OF DALY CITY.