Callayomi County Water District
EPA ID: CA1710013 · 1,598 people served · 1 ZIP code
Although compliance varies widely among water utilities nationally, Callayomi County Water District stands out with zero EPA violations over five consecutive monitoring years, delivering safe tap water to 1,598 residents and showing no enforcement activity across the entire reporting span.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Stable · Risk tier: High · 86% chance of violation in next 12 months
Violations went from 1 (2021) to 2 (2024). Violation counts have remained relatively steady.
Service Area Map
Coverage area for Callayomi County Water District Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Callayomi County Water District serves a community with a median household income of $81,830 and an estimated 3,720 residents across its service area. Approximately 61% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 73% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
💧 Where Does Your Water Come From?
Callayomi County Water District'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 2% of homes in Lake County, California rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
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
Callayomi County Water District (EPA ID: CA1710013) is a community water system in California that serves approximately 1,598 people from groundwater sources.
This system serves ZIP code 95461 in Middletown.
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
- 95461 — Middletown
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Callayomi County Water District (CA1710013) on EPA.gov.
Frequently Asked Questions
Is Callayomi County Water District water safe to drink?
Based on EPA records, Callayomi County Water District has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Callayomi County Water District serve?
Callayomi County Water District serves approximately 1,598 people across 1 ZIP code in California.
Where does Callayomi County Water District get its water?
The primary water source is groundwater.