Water Quality Report · Updated May 12, 2026
CITY OF HAYWARD
CITY OF HAYWARD delivers tap water graded C (65/100) by TapWaterSafety.org. The utility serves approximately 162,954 residents in HAYWARD, California using surface water (purchased). 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. For questions, the utility can be reached at 510-583-4701.
Is HAYWARD tap water safe to drink?
CITY OF HAYWARD delivers tap water that earns a grade of C (65/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 162,954 residents in HAYWARD, drawing from surface water (purchased).
Public testing data identifies 14 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA9), Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Trichloroacetic acid, Chloroform, Dichloroacetic acid, Bromodichloromethane, Nitrate*, Nitrate and nitrite*, Arsenic*, Bromate, Dibromochloromethane*, Dibromoacetic acid, Chromium (hexavalent). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for HAYWARD residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for CITY OF 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.
Contact CITY OF HAYWARD
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for HAYWARD
Filters matched to the specific contaminants in this 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.
Score breakdown
This utility's overall score of 65/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
CITY OF HAYWARD service area
This water system serves 1 community in Alameda County, California. Click any city for its dedicated tap water quality page.
Find the right filter for HAYWARD water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.