Tud - Sonora/jamestown Water System
EPA ID: CA5510001 · 11,054 people served · 3 ZIP codes
Not yet resolved: 2 EPA violations at Tud - Sonora/jamestown Water System, affecting about 11,054 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 3 (2021) to 2 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Tud - Sonora/jamestown Water System Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The Tud - Sonora/jamestown Water System serves a community with a median household income of $66,470 and an estimated 37,375 residents across its service area. Approximately 76% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Tud - Sonora/jamestown Water System's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 1% of homes in Tuolumne County, California rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Detected Contaminants
How Tud - Sonora/jamestown Water System compares to EPA limits
What This Means For You
Total Trihalomethanes (TTHM) at 3 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Stage 2 DBP Rule at 2 mg/L exceeds the EPA maximum of mg/L.
Consumer Confidence Report Rule at 2 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 5 detections recorded. 1 exceeds federal EPA limits (4 ppt for PFOA/PFOS).
Total Trihalomethanes (TTHM) was detected in this water system. granular activated carbon (GAC) filtration can reduce exposure.
Find a certified water filter →Comparable Water Systems
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Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Tud - Sonora/jamestown Water System (EPA ID: CA5510001) is a community water system in California that serves approximately 11,054 people from surface water sources.
This system provides water to 3 ZIP codes across 3 communities.
Average Home Safety Score: B (75/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| April 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| October 17, 2024 | Stage 2 DBP Rule | Monitoring | Unresolved |
| October 17, 2024 | Stage 2 DBP Rule | Health-based | Unresolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 3 | Yes |
| Stage 2 DBP Rule | Treatment Failure | 2 | Yes |
| Consumer Confidence Report Rule | Reporting Failure | 2 | Yes |
Health Risk Details
Total Trihalomethanes (TTHM) (EPA limit: 0.08 mg/L)
Bladder & rectal cancer risk; reproductive concerns At-risk groups: pregnant women, long-term consumers of chlorinated water, people who frequently shower in chlorinated water.
Removal methods: granular activated carbon (GAC), carbon block filter, point-of-entry aeration. Find the right filter →
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 95327 | 0.0013 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by CA or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Tud - Sonora/jamestown Water System (CA5510001) on EPA.gov.
Frequently Asked Questions
Is Tud - Sonora/jamestown Water System water safe to drink?
Tud - Sonora/jamestown Water System has recorded 5 health-based violations in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does Tud - Sonora/jamestown Water System serve?
Tud - Sonora/jamestown Water System serves approximately 11,054 people across 3 ZIP codes in California.
Where does Tud - Sonora/jamestown Water System get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: Tested Clean
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were detected.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Tud - Sonora/jamestown Water System (EPA ID: CA5510001) — request the latest Consumer Confidence Report or ask about specific contaminants.