Is Jamestown, CA Tap Water Safe to Drink?
Graded C+ — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
69.3/100
waterverge.com Jamestown, CA — Water Quality Report
Jamestown's drinking water received a grade of C+ (69.3 out of 100), indicating fair water quality. The city's 4 water systems serve approximately 4,119 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 54 violations on record, including 25 health-based violations. 8 remain unresolved.
What to know about Jamestown's water
Jamestown ranks #517 out of 694 cities in California for water quality, placing it below average 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.
The system has seen 8 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Jamestown, CA water safe to drink?
Jamestown's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (69.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 4,119 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Jamestown
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Jamestown's water quality assessment. Grade: C+ (69.3/100).
Contaminants: Revised Total Coliform Rule.
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.
2 health-based. Contaminants: Revised Total Coliform Rule, Total Haloacetic Acids (HAA5).
Key contaminant findings
Based on the most recent EPA sampling data for Jamestown'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
Jamestown's water system has 54 total violations on record, including 25 health-based violations. 8 remain unresolved. 8 violations were issued in the last 5 years.
Flood & environmental risk
Tuolumne County has experienced 8 federally declared disasters since 1964. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Jamestown's water come from?
Jamestown's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 4 water systems serving approximately 4,119 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.
What Jamestown residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Jamestown'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.
Jamestown'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
Top industrial polluters within 10 miles of Jamestown
Industrial polluters nearby
Reported releases to surface water by facilities near Jamestown, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
SPI SONORA DIV SONORA, CA95370 | — | — | 4.7 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Tuolumne County has experienced 8 federally declared disasters since 1964. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Jamestown'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. | 2.10 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 2.100 mg/L (2004)
EPA action level: 1.3 mg/L
See how Jamestown compares by contaminant
Explore where Jamestown ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Jamestown's water comes from
Jamestown'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 state ownership and serves approximately 4,119 people through 4 water systems.
Water systems serving Jamestown
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CDCR - SIERRA CONSERVATION CENTER | CA5510851 | 3,571 | SW |
| RAWHIDE MUTUAL WATER COMPANY | CA5500071 | 269 | GW |
| CAL FIRE BASELINE CONSERVATION CAMP | CA5510852 | 150 | SW |
| SIERRA TWAIN HARTE MHP | CA5500096 | 129 | GW |
How Jamestown compares
Full California rankings →Jamestown's score of 69.3/100 is above the average of 57/100 among major California cities. It outscores 6 of 10 nearby cities.
Nearby cities
View California rankings →About Jamestown, CA
Wikipedia →Jamestown is an unincorporated community in Tuolumne County, California, United States. Formerly a California Gold Rush town, Jamestown was designated a California Historical Landmark on March 16, 1949. It is the home of Railtown 1897 State Historic Park and the Sierra Railway, which operates steam passenger trains. For statistical purposes, the United States Census Bureau has defined the community as a census-designated place (CDP). The population was 3,478 at the 2020 census, up from 3,433 at the 2010 census.
Learn more about your water
Guides and resources related to Jamestown's water quality findings.
Explore water quality across Tuolumne
Frequently asked questions
Is Jamestown, CA tap water safe to drink?
Jamestown's water quality earned a grade of C+ (69.3/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #517 out of 694 cities tested in California.
What contaminants are in Jamestown's water?
Lead was measured at 0.0 ppb (90th percentile). 54 violations are on record.
How is Jamestown'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 Jamestown?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Jamestown's water come from?
Jamestown's water is sourced from Surface water. The city has 4 water systems serving approximately 4,119 residents.
What health violations has Jamestown's water system had?
Jamestown has 25 health-based violations on record. The most recent violation was recorded in April 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 8 violations remain unresolved.
How does Jamestown's water compare to other cities?
Jamestown ranks #517 out of 694 cities in California (better than 26% of state cities) and #10939 out of 15744 cities nationally (31th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.