Water Quality Report · Updated May 12, 2026
PETALUMA, CITY OF
PETALUMA, CITY OF delivers tap water graded D (63/100) by TapWaterSafety.org. The utility serves approximately 60,781 residents in PETALUMA, California using groundwater. The most significant water quality concerns are: Arsenic significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. For questions, the utility can be reached at 707-364-5592.
Is PETALUMA tap water safe to drink?
PETALUMA, CITY OF delivers tap water that earns a grade of D (63/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including arsenic significantly above health guideline.
The utility serves 60,781 residents in PETALUMA, drawing from groundwater. Despite being legal under US EPA standards, this water would fail the European Union's Drinking Water Directive, primarily due to arsenic significantly above health guideline.
Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Haloacetic acids (HAA5), Total trihalomethanes (TTHMs), Haloacetic acids (HAA9), Bromodichloromethane, Dibromochloromethane, Trichloroacetic acid, Dichloroacetic acid, Chloroform, Dibromoacetic acid, Chromium (hexavalent), Nitrate. 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 PETALUMA residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for PETALUMA, CITY OF.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 3.0 ppb, 750x above the EWG health guideline of 0.004 ppb.
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 25.4 ppb, 170x above the EWG health guideline of 0.15 ppb.
Contact PETALUMA, 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 PETALUMA
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 63/100 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 |
3.0 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 750× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
25.4 ppb | 0.15 | 80.0 | 100 | — | — | — | 170× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
9.47 ppb | 0.06 | — | — | — | — | — | 158× over |
| Bromodichloromethane Disinfection byproduct |
7.5 ppb | 0.06 | — | — | — | — | — | 125× over |
| Dibromochloromethane Disinfection byproduct |
5.02 ppb | 0.1 | — | — | — | — | — | 50× over |
| Trichloroacetic acid Disinfection byproduct |
4.1 ppb | 0.1 | — | — | — | — | — | 41× over |
| Dichloroacetic acid Disinfection byproduct |
6.61 ppb | 0.2 | — | — | — | — | — | 33× over |
| Chloroform Disinfection byproduct |
12.5 ppb | 0.4 | — | — | — | — | — | 31× over |
| Dibromoacetic acid Disinfection byproduct |
0.875 ppb | 0.03 | — | — | — | — | — | 29× over |
| Chromium (hexavalent) Heavy metal |
0.338 ppb | 0.02 | — | — | — | — | — | 17× over |
| Nitrate Inorganic |
0.289 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.1× over |
| Bromoform Disinfection byproduct |
0.4 ppb | 0.5 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
54.4 ppb | 100.0 | — | 50 | 80 | — | — | Fails EU |
| Vanadium Other |
2.39 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
58.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
1.07 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Dichloromethane (methylene chloride) Volatile organic compound |
0.0646 ppb | 4.0 | 5.0 | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
5.3 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Chlorate Disinfection byproduct |
1.13 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.29 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.106 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.0321 ppb | — | — | — | — | — | — | Below guideline |
| o-toluidine Other |
0.01 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.
PETALUMA, 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 PETALUMA water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.