Water Quality Report · Updated October 07, 2026
CITY OF ANTIOCH
CITY OF ANTIOCH delivers tap water graded B (75/100) by TapWaterSafety.org. The utility serves approximately 115,074 residents in ANTIOCH, California using surface water. The most significant water quality concerns are: Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Bromodichloromethane significantly above health guideline. For questions, the utility can be reached at 916-767-7536.
Is ANTIOCH tap water safe to drink?
CITY OF ANTIOCH delivers tap water that earns a grade of B (75/100) from TapWaterSafety.org — a good rating, with only minor concerns relative to health-based guidelines.
The utility serves 115,074 residents in ANTIOCH, drawing from surface water.
Public testing data identifies 11 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Bromodichloromethane, Haloacetic acids (HAA9), Dibromochloromethane, Dibromoacetic acid, Chloroform, Dichloroacetic acid, Trichloroacetic acid, Bromoform, 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.
EPA compliance record
Official U.S. EPA records for CITY OF ANTIOCH (system ID CA0710001) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for ANTIOCH 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 ANTIOCH.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 35.3 ppb, 353x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 48.2 ppb, 322x above the EWG health guideline of 0.15 ppb.
Bromodichloromethane significantly above health guideline
Moderate concernBromodichloromethane detected at 13.9 ppb, 232x above the EWG health guideline of 0.06 ppb.
Contact CITY OF ANTIOCH
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 ANTIOCH
Filters matched to the specific contaminants in this water supply.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
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 75/100 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 (HAA5) Disinfection byproduct |
35.3 ppb | 0.1 | 60.0 | 60 | — | — | — | 353× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
48.2 ppb | 0.15 | 80.0 | 100 | — | — | — | 322× over |
| Bromodichloromethane Disinfection byproduct |
13.9 ppb | 0.06 | — | — | — | — | — | 232× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
9.23 ppb | 0.06 | — | — | — | — | — | 154× over |
| Dibromochloromethane Disinfection byproduct |
13.1 ppb | 0.1 | — | — | — | — | — | 131× over |
| Dibromoacetic acid Disinfection byproduct |
1.28 ppb | 0.03 | — | — | — | — | — | 43× over |
| Chloroform Disinfection byproduct |
16.8 ppb | 0.4 | — | — | — | — | — | 42× over |
| Dichloroacetic acid Disinfection byproduct |
3.11 ppb | 0.2 | — | — | — | — | — | 16× over |
| Trichloroacetic acid Disinfection byproduct |
1.05 ppb | 0.1 | — | — | — | — | — | 11× over |
| Bromoform Disinfection byproduct |
4.23 ppb | 0.5 | — | — | — | — | — | 8.5× over |
| Chromium (hexavalent) Heavy metal |
0.0797 ppb | 0.02 | — | — | — | — | — | 4.0× over |
| Nitrate Inorganic |
0.11 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| Bromochloromethane Other |
0.0353 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Nitrate and nitrite Inorganic |
0.03 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | Below guideline |
| Vanadium Other |
2.55 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
13.6 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
0.95 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.899 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.215 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.0202 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.154 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Bromide Other |
180.0 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.545 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 ANTIOCH service area
This water system serves 1 community in Contra Costa County, California. Click any city for its dedicated tap water quality page.
Find the right filter for ANTIOCH water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.