Tap Water Quality Report
Tap water quality in HAYWARD, California
Tap water in HAYWARD, California receives a grade of D (65/100) from TapWaterSafety.org. It's served by CITY OF HAYWARD. The most significant water quality concerns are: Haloacetic acids (HAA9) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Arsenic detected. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in HAYWARD's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving HAYWARD.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 31.4 ppb, 523x above the EWG health guideline of 0.06 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.0 ppb, 360x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 40.2 ppb, 268x above the EWG health guideline of 0.15 ppb.
Arsenic detected
Moderate concernArsenic detected at 0.0788 ppb.
Recommended filters for HAYWARD
Filters matched to the specific contaminants in HAYWARD's water supply.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
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 HAYWARD'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 |
31.4 ppb | 0.06 | — | — | — | — | — | 523× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.0 ppb | 0.1 | 60.0 | 60 | — | — | — | 360× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
40.2 ppb | 0.15 | 80.0 | 100 | — | — | — | 268× over |
| Trichloroacetic acid Disinfection byproduct |
12.3 ppb | 0.1 | — | — | — | — | — | 123× over |
| Chloroform Disinfection byproduct |
38.6 ppb | 0.4 | — | — | — | — | — | 96× over |
| Dichloroacetic acid Disinfection byproduct |
17.7 ppb | 0.2 | — | — | — | — | — | 88× over |
| Bromodichloromethane Disinfection byproduct |
1.55 ppb | 0.06 | — | — | — | — | — | 26× over |
| Nitrate* Inorganic |
3.28 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 23× over |
| Nitrate and nitrite* Inorganic |
2.95 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 21× over |
| Arsenic* Heavy metal |
0.0788 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 20× over |
| Bromate Disinfection byproduct |
1.7 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 17× over |
| Dibromochloromethane* Disinfection byproduct |
0.791 ppb | 0.1 | — | — | — | — | — | 7.9× over |
| Dibromoacetic acid Disinfection byproduct |
0.0709 ppb | 0.03 | — | — | — | — | — | 2.4× over |
| Chromium (hexavalent) Heavy metal |
0.04 ppb | 0.02 | — | — | — | — | — | 2.0× over |
| Uranium* Radiological |
0.21 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | Below guideline |
| Chlorate Disinfection byproduct |
80.7 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Perchlorate* Disinfection byproduct |
0.332 ppb | 1.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
2.1 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Aluminum* Heavy metal |
9.16 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Vanadium Other |
0.1 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium* Heavy metal |
2.34 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.166 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0286 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Bromide* Other |
9.28 ppb | — | — | — | — | — | — | Below guideline |
| Chromium (total)* Heavy metal |
3.03 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride* Inorganic |
0.272 ppm | — | 4.0 | 1.5 | 1.5 | — | — | 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 HAYWARD.