Tud - Upper Basin Water System
EPA ID: CA5510012 · 13,280 people served · 3 ZIP codes
Past issues aside, Tud - Upper Basin Water System cleared all 1 violation and is compliant today, supplying 13,280 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Tud - Upper Basin Water System Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The Tud - Upper Basin Water System serves a community with a median household income of $85,956 and an estimated 32,843 residents across its service area. Approximately 74% 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 - Upper Basin 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 - Upper Basin Water System compares to EPA limits
What This Means For You
Consumer Confidence Report Rule at 1 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. 3 detections recorded.
Comparable Water Systems
Similar-sized systems in California
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 - Upper Basin Water System (EPA ID: CA5510012) is a community water system in California that serves approximately 13,280 people from surface water sources.
This system provides water to 3 ZIP codes across 3 communities.
Average Home Safety Score: B (70/100)
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 |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting Failure | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 95370 | 0.0081 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 - Upper Basin Water System (CA5510012) on EPA.gov.
Frequently Asked Questions
Is Tud - Upper Basin Water System water safe to drink?
Tud - Upper Basin Water System has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Tud - Upper Basin Water System serve?
Tud - Upper Basin Water System serves approximately 13,280 people across 3 ZIP codes in California.
Where does Tud - Upper Basin 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 - Upper Basin Water System (EPA ID: CA5510012) — request the latest Consumer Confidence Report or ask about specific contaminants.