Sierra Twain Harte Mhp
EPA ID: CA5500096 · 129 people served · 1 ZIP code
Federal monitoring records confirm Sierra Twain Harte Mhp has operated without any EPA violations for the full five-year window — covering every contaminant category and reporting cycle across a service area of approximately 129 residents, with no gaps in the compliance record.
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 (2024). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Sierra Twain Harte Mhp Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Sierra Twain Harte Mhp serves a community with a median household income of $60,506 and an estimated 8,799 residents across its service area. Approximately 66% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Sierra Twain Harte Mhp's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
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
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
Sierra Twain Harte Mhp (EPA ID: CA5500096) is a community water system in California that serves approximately 129 people from groundwater sources.
This system serves ZIP code 95327 in Jamestown.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
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
- 95327 — Jamestown
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Sierra Twain Harte Mhp (CA5500096) on EPA.gov.
Frequently Asked Questions
Is Sierra Twain Harte Mhp water safe to drink?
Based on EPA records, Sierra Twain Harte Mhp has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Sierra Twain Harte Mhp serve?
Sierra Twain Harte Mhp serves approximately 129 people across 1 ZIP code in California.
Where does Sierra Twain Harte Mhp get its water?
The primary water source is groundwater.
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.