Is Santa Rosa, CA Tap Water Safe to Drink?
Graded F — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
43.1/100
waterverge.com Santa Rosa, CA — Water Quality Report
Santa Rosa's drinking water received a grade of F (43.1 out of 100), indicating failing water quality. The city's 40 water systems serve approximately 186,173 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.
The system has 820 violations on record, including 177 health-based violations. 96 remain unresolved.
What to know about Santa Rosa's water
Santa Rosa ranks #656 out of 694 cities in California for water quality, placing it among the lowest-rated in the state.
Santa Rosa relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.
Hexavalent chromium (chromium-6) was detected at 0.48 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
The system has seen 105 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Santa Rosa, CA water safe to drink?
Santa Rosa's drinking water has significant quality concerns based on EPA testing data. With a grade of F (43.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 40 water systems serve approximately 186,173 residents using groundwater (wells).
Recent water quality updates for Santa Rosa
A timeline of significant water quality events, violations, and data updates.
Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.
Latest EPA compliance and testing data incorporated into Santa Rosa's water quality assessment. Grade: F (43.1/100).
Contaminants: LEAD AND COPPER RULE REVISIONS.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Santa Rosa's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.
Violation history
Santa Rosa's water system has 820 total violations on record, including 177 health-based violations. 96 remain unresolved. 105 violations were issued in the last 5 years.
Flood & environmental risk
Sonoma County has experienced 10 federally declared disasters since 1969. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Dry C Nr Mouth Nr Healdsburg, Copeland C A Rohnert Park, Laguna De Santa Rosa A Stony Pt Rd Nr Cotati, Colgan C Nr Santa Rosa, Colgan C Nr Sebastopol.
Where does Santa Rosa's water come from?
Santa Rosa's drinking water comes from groundwater (wells), supplied by 40 water systems serving approximately 186,173 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Dry C Nr Mouth Nr Healdsburg (river), Copeland C A Rohnert Park (river), Laguna De Santa Rosa A Stony Pt Rd Nr Cotati (river), Colgan C Nr Santa Rosa (river), Colgan C Nr Sebastopol (river).
What Santa Rosa residents can do
Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Santa Rosa's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Santa Rosa's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Santa Rosa
Industrial polluters nearby
Reported releases to surface water by facilities near Santa Rosa, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
PARKER HANNIFIN CORP EMN NA ROHNERT PARK, CA94928 | — | — | 6.2 mi |
ITT CANNON LLC DBA BIW CONNECTOR SYSTEMS SANTA ROSA, CA95401 | — | — | 1.6 mi |
KEYSIGHT TECHNOLOGIES INC SANTA ROSA, CA95403 | — | — | 2.6 mi |
BODEAN CO INC SANTA ROSA, CA95401 | — | — | 1.3 mi |
GENERAL HYDROPONICS SANTA ROSA, CA95407 | — | — | 3.2 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Sonoma County has experienced 10 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Santa Rosa's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 4.19 | 1.3 | mg/L | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | 96.000 | HI | µg/L | PFAS | Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | ND | HI | µg/L | PFAS | Not Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | ND | HI | µg/L | PFAS | Not Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | ND | HI | µg/L | PFAS | Not Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | ND | HI | µg/L | PFAS | Not Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Santa Rosa compares by contaminant
Explore where Santa Rosa ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Santa Rosa's water comes from
Santa Rosa's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 186,173 people through 40 water systems.
Water bodies near Santa Rosa
Santa Rosa is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Santa Rosa
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SANTA ROSA, CITY OF | CA4910009 | 175,396 | GW |
| PENNGROVE WATER COMPANY (PUC) | CA4910003 | 1,742 | GWP |
| SONOMA COUNTY CSA 41-FITCH MOUNTAIN | CA4910010 | 1,265 | GWP |
| KENWOOD VILLAGE WATER COMPANY (PUC) | CA4910025 | 1,029 | GW |
| CANON MANOR WATER SYSTEM | CA4910022 | 805 | GW |
| WILLOWSIDE MUTUAL WATER COMPANY | CA4900561 | 448 | GW |
| BENNETT RIDGE MUTUAL WATER COMPANY | CA4900585 | 439 | GW |
| SONOMA COUNTY CSA 41-SALMON CREEK | CA4900543 | 427 | SW |
| LEISURE MOBILE HOME PARK | CA4900832 | 410 | GW |
| SONOMA COUNTY CSA 41-JENNER | CA4900532 | 406 | SW |
| BRANGER MUTUAL WATER COMPANY, INC. | CA4900545 | 300 | GW |
| HOLLAND HEIGHTS MUTUAL WATER COMPANY | CA4900548 | 300 | GW |
| SONOMA COUNTY CSA 41-FREESTONE | CA4900549 | 290 | SW |
| NORTH STAR MOBILE HOME PARK | CA4900797 | 221 | GW |
| MOBILE HOME ESTATES | CA4900720 | 210 | GW |
| JAMES COURT WATER SYSTEM | CA4901445 | 208 | GW |
| RANDAL'S RANCHETTE MUTUAL WATER COMPANY | CA4900599 | 200 | GW |
| YULUPA MUTUAL WATER COMPANY | CA4900660 | 200 | GW |
| EL PORTAL MOBILE ESTATES | CA4900799 | 200 | GW |
| CASPAR SOUTH SERVICE COMPANY | CA2300610 | 188 | GU |
| SHAMROCK MOBILE HOME PARK | CA4900723 | 188 | GW |
| SONOMA MOUNTAIN COUNTY WATER DISTRICT | CA4900580 | 181 | GW |
| Kashia | 090600135 | 153 | SW |
| SUNSET PARK COMMUNITY | CA4900794 | 141 | GW |
| END-O-VALLEY MUTUAL WATER COMPANY | CA4900547 | 129 | GW |
| PARK ROYAL MUTUAL WATER COMPANY | CA4900553 | 75 | GW |
| WILSHIRE HEIGHTS MUTUAL WATER COMPANY | CA4900573 | 70 | GW |
| BLUE LAKES VILLAGE | CA1700596 | 65 | GW |
| MELITA HEIGHTS MUTUAL WATER COMPANY | CA4900551 | 64 | GW |
| MARK WEST ACRES MWC | CA4900605 | 61 | GW |
| DELORES LANE WATER SYSTEM | CA4901346 | 59 | GW |
| ATHENA TERRACE MUTUAL WATER COMPANY | CA4900673 | 50 | GW |
| SUMMIT VIEW RANCH MUTUAL WATER CO. | CA4900892 | 45 | GW |
| INDIAN CREEK TRAILER PARK | CA5303002 | 43 | SW |
| WEST WATER COMPANY (PUC) | CA4900893 | 40 | GW |
| CRYSTALS | CA4901595 | 40 | GW |
| EVERGREEN RETREAT MHP | WA5324164 | 39 | GW |
| LOCH HAVEN MUTUAL WATER COMPANY | CA4900575 | 26 | GW |
| MARK WEST MEADOWS MUTUAL WATER | CA4900905 | 20 | GW |
| SONOMA COUNTY WATER AGENCY | CA4910020 | — | GW |
How Santa Rosa compares
Full California rankings →Santa Rosa's score of 43.1/100 is below the average of 57/100 among major California cities. It outscores 5 of 10 nearby cities.
Nearby cities
View California rankings →ZIP codes served by Santa Rosa
The water systems serving Santa Rosa cover 1 ZIP code. Select any ZIP to see which water systems serve that area.
About Santa Rosa, CA
Wikipedia →Santa Rosa is a city in and the county seat of Sonoma County, in the North Bay region of the Bay Area in California. Its population as of the 2020 census was 178,127. It is the largest city in California's Wine Country and Redwood Coast. It is the fifth most populous city in the Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 27th-most populous city in California.
Learn more about your water
Guides and resources related to Santa Rosa's water quality findings.
Explore water quality across Sonoma
Frequently asked questions
Is Santa Rosa, CA tap water safe to drink?
Santa Rosa's water quality earned a grade of F (43.1/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #656 out of 694 cities tested in California.
What contaminants are in Santa Rosa's water?
Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 820 violations are on record.
How is Santa Rosa's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Santa Rosa?
PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.
Where does Santa Rosa's water come from?
Santa Rosa's water is sourced from Groundwater. The city has 40 water systems serving approximately 186,173 residents.
What health violations has Santa Rosa's water system had?
Santa Rosa has 177 health-based violations on record. The most recent violation was recorded in September 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 96 violations remain unresolved.
Is Santa Rosa's groundwater at risk of contamination?
Santa Rosa uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 820 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Santa Rosa's water compare to other cities?
Santa Rosa ranks #656 out of 694 cities in California (better than 5% of state cities) and #14630 out of 15744 cities nationally (7th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.