Tap Water Quality Report
Tap water quality in DAVIS, California
Tap water in DAVIS, California receives a grade of C (71/100) from TapWaterSafety.org. It's served by CITY OF DAVIS. The most significant water quality concerns are: Arsenic significantly above health guideline; Chromium (hexavalent) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in DAVIS's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving DAVIS.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 5.27 ppb, 1318x above the EWG health guideline of 0.004 ppb.
Chromium (hexavalent) significantly above health guideline
Moderate concernChromium (hexavalent) detected at 12.1 ppb, 607x above the EWG health guideline of 0.02 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 9.38 ppb, 156x above the EWG health guideline of 0.06 ppb.
EPA compliance record
Official U.S. EPA records for CITY OF DAVIS (system ID CA5710001) 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.
Recommended filters for DAVIS
Filters matched to the specific contaminants in DAVIS's water supply.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
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.
All contaminants detected in DAVIS'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 |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
5.27 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 1318× over |
| Chromium (hexavalent) Heavy metal |
12.1 ppb | 0.02 | — | — | — | — | — | 607× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
9.38 ppb | 0.06 | — | — | — | — | — | 156× over |
| Nitrate Inorganic |
3.81 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 27× over |
| Nitrate and nitrite Inorganic |
2.17 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 16× over |
| Radium, combined (-226 and -228) Radiological |
0.32 pCi/L | 0.05 | 5.0 | — | — | — | — | 6.5× over |
| Uranium Radiological |
1.24 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 2.9× over |
| Bromate* Disinfection byproduct |
0.259 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 2.6× over |
| Chlorate Disinfection byproduct |
156.3 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
9.41 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
10.7 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Manganese Heavy metal |
9.01 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Barium Heavy metal |
61.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
2.34 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Chloromethane Other |
0.0393 ppb | 2.69 | — | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
2.87 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Strontium Radiological |
0.544 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
18.0 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.193 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
15.7 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 DAVIS.