Is Stinson Beach, CA Tap Water Safe to Drink?
Graded A- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
86.1/100
waterverge.com Stinson Beach, CA — Water Quality Report
Stinson Beach's drinking water received a grade of A- (86.1 out of 100), indicating good water quality. The city's 1 water system serves approximately 583 residents using surface water.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 4 violations on record, including 2 health-based violations. 1 remains unresolved.
What to know about Stinson Beach's water
Stinson Beach ranks #245 out of 694 cities in California for water quality, placing it mid-range in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
As a small community water system, Stinson Beach may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Stinson Beach, CA water safe to drink?
Stinson Beach's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (86.1/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 583 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Stinson Beach
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Stinson Beach's water quality assessment. Grade: A- (86.1/100).
Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3591). Flood event — may have impacted local water infrastructure.
Contaminants: Arsenic.
1 health-based. Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Stinson Beach's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Stinson Beach's water system has 4 total violations on record, including 2 health-based violations. 1 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Marin 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 Corte Madera C A Ross, Redwood C A Hwy 1 Bridge A Muir Beach, Lagunitas C A Samuel P Taylor State Park, Olema C A Vedanta Bridge A Olema, Rodeo Lagoon W Bottom Nr Sausalito.
Where does Stinson Beach's water come from?
Stinson Beach's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 583 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Corte Madera C A Ross (river), Redwood C A Hwy 1 Bridge A Muir Beach (river), Lagunitas C A Samuel P Taylor State Park (river), Olema C A Vedanta Bridge A Olema (river), Rodeo Lagoon W Bottom Nr Sausalito (lake).
What Stinson Beach residents can do
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.
Stinson Beach'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 ↓Violation summary
Violations & advisories
Flood & disaster history
Marin 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 Stinson Beach'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. | 1.60 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Stinson Beach compares by contaminant
Explore where Stinson Beach ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Stinson Beach's water comes from
Stinson Beach's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 583 people through 1 water system.
Water bodies near Stinson Beach
Stinson Beach is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Stinson Beach
| System Name | PWSID | Population | Source |
|---|---|---|---|
| STINSON BEACH COUNTY WTR DIST | CA2110004 | 583 | SW |
How Stinson Beach compares
Full California rankings →Stinson Beach's score of 86.1/100 is above the average of 57/100 among major California cities. It outscores 8 of 10 nearby cities.
Nearby cities
View California rankings →About Stinson Beach, CA
Learn more about your water
Guides and resources related to Stinson Beach's water quality findings.
Explore water quality across Marin
Frequently asked questions
Is Stinson Beach, CA tap water safe to drink?
Stinson Beach's water quality earned a grade of A- (86.1/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #245 out of 694 cities tested in California.
What contaminants are in Stinson Beach's water?
Lead was measured at 0.0 ppb (90th percentile). 4 violations are on record.
How is Stinson Beach'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 Stinson Beach?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Stinson Beach's water come from?
Stinson Beach's water is sourced from Surface water. The city has 1 water system serving approximately 583 residents.
What health violations has Stinson Beach's water system had?
Stinson Beach has 2 health-based violations on record. The most recent violation was recorded in April 2021. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
How does Stinson Beach's water compare to other cities?
Stinson Beach ranks #245 out of 694 cities in California (better than 65% of state cities) and #4952 out of 15744 cities nationally (69th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Stinson Beach's small water system affect quality?
Stinson Beach's system serves approximately 583 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 4 violations on record.