Water Quality Report · Updated May 12, 2026
CITY OF DAVIS
CITY OF DAVIS delivers tap water graded D (59/100) by TapWaterSafety.org. The utility serves approximately 67,457 residents in DAVIS, California using surface water (purchased). 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. For questions, the utility can be reached at 530-757-5686.
Is DAVIS tap water safe to drink?
CITY OF DAVIS delivers tap water that earns a grade of D (59/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including arsenic significantly above health guideline.
The utility serves 67,457 residents in DAVIS, drawing from surface water (purchased).
Public testing data identifies 8 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Chromium (hexavalent), Haloacetic acids (HAA9), Nitrate, Nitrate and nitrite, Radium, combined (-226 and -228), Uranium, Bromate*. 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 DAVIS 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 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.
Contact CITY OF DAVIS
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 DAVIS
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
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.
Score breakdown
This utility's overall score of 59/100 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 |
|---|---|---|---|---|---|---|---|---|
| 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
CITY OF DAVIS service area
This water system serves 1 community in Yolo County, California. Click any city for its dedicated tap water quality page.
Find the right filter for DAVIS water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.