Water Quality Report · Updated May 12, 2026
SANTA ROSA, CITY OF
SANTA ROSA, CITY OF delivers tap water graded C (68/100) by TapWaterSafety.org. The utility serves approximately 175,396 residents in SANTA ROSA, California using groundwater. The most significant water quality concerns are: Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline. For questions, the utility can be reached at 707-543-3975.
Is SANTA ROSA tap water safe to drink?
SANTA ROSA, CITY OF delivers tap water that earns a grade of C (68/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 175,396 residents in SANTA ROSA, drawing from groundwater.
Public testing data identifies 11 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Haloacetic acids (HAA9), Bromodichloromethane, Dibromoacetic acid, Dibromochloromethane, Chloroform, Trichloroacetic acid, Dichloroacetic acid, Chromium (hexavalent), Bromoform. 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 SANTA ROSA residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for SANTA ROSA, CITY OF.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.2 ppb, 362x above the EWG health guideline of 0.1 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 28.2 ppb, 188x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 10.2 ppb, 169x above the EWG health guideline of 0.06 ppb.
Contact SANTA ROSA, CITY OF
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 SANTA ROSA
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.
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 68/100 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 |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
28.2 ppb | 0.15 | 80.0 | 100 | — | — | — | 188× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
10.2 ppb | 0.06 | — | — | — | — | — | 169× over |
| Bromodichloromethane Disinfection byproduct |
8.45 ppb | 0.06 | — | — | — | — | — | 141× over |
| Dibromoacetic acid Disinfection byproduct |
2.1 ppb | 0.03 | — | — | — | — | — | 70× over |
| Dibromochloromethane Disinfection byproduct |
6.46 ppb | 0.1 | — | — | — | — | — | 65× over |
| Chloroform Disinfection byproduct |
11.9 ppb | 0.4 | — | — | — | — | — | 30× over |
| Trichloroacetic acid Disinfection byproduct |
2.47 ppb | 0.1 | — | — | — | — | — | 25× over |
| Dichloroacetic acid Disinfection byproduct |
4.48 ppb | 0.2 | — | — | — | — | — | 22× over |
| Chromium (hexavalent) Heavy metal |
0.291 ppb | 0.02 | — | — | — | — | — | 15× over |
| Bromoform Disinfection byproduct |
1.27 ppb | 0.5 | — | — | — | — | — | 2.5× over |
| Chlorate Disinfection byproduct |
51.8 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Chloromethane Other |
0.25 ppb | 2.69 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
3.78 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Vanadium Other |
0.575 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
0.613 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.164 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Bromomethane Other |
0.1 ppb | — | — | — | — | — | — | Below guideline |
| Germanium Other |
1.43 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
48.0 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.
SANTA ROSA, CITY OF service area
This water system serves 1 community in Sonoma County, California. Click any city for its dedicated tap water quality page.
Find the right filter for SANTA ROSA water
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