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Tap Water Quality Report

Tap water quality in SANTA ROSA, California

Served by SANTA ROSA, CITY OF. 175,396 residents.

Average score 78/100
Utilities 1
Population 175,396
Quick answer

Tap water in SANTA ROSA, California receives a grade of C (78/100) from TapWaterSafety.org. It's served by SANTA ROSA, CITY OF. 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. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.

Data sources for this grade: utilities.csv EWG Tap Water Database ⓘ How did we get this rating?

What's in SANTA ROSA's tap water

Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving SANTA ROSA.

Haloacetic acids (HAA5) significantly above health guideline

Moderate concern

Haloacetic 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 concern

Total 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 concern

Haloacetic acids (HAA9) detected at 10.2 ppb, 169x above the EWG health guideline of 0.06 ppb.

EPA compliance record

Official U.S. EPA records for SANTA ROSA, CITY OF (system ID CA4910009) for the last 3 years. Checked 2026-10-07.

No EPA violations in the last 3 years.
0 of 12quarters with a violation
Nolead above EPA action level
10/17/2023last state inspection

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 SANTA ROSA

Filters matched to the specific contaminants in SANTA ROSA's water supply.

Carbon filter certified for VOCs (NSF/ANSI 53)

$180-$599

Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.

Aquasana AQ-5300 Under-Sink Filter
$180-$240 NSF 42, 53, 401, 372
Editorial pick · affiliate link coming soon
AquaTru Countertop Reverse Osmosis
$449-$599 NSF 42, 53, 58, 401, 372
Editorial pick · affiliate link coming soon
Aquasana OptimH2O Reverse Osmosis + Claryum
$429-$549 NSF 42, 53, 58, 401
Editorial pick · affiliate link coming soon

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 SANTA ROSA'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
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, 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 SANTA ROSA, CITY OF.

Treatment Plant

FacilityTREATMENT PLNT-FARMERS LN WELLS 01&02

ZIP codes served

SANTA ROSA's public water systems serve the following ZIP codes: