Walnut Hills Mutual Water Company
EPA ID: CA4000670 · 486 people served · 2 ZIP codes
ZipCheckup's reading of EPA SDWIS for Walnut Hills Mutual Water Company (CA4000670): no EPA violations recorded in the last five years. From the earliest to the most recent cycle in the five-year EPA window, Walnut Hills Mutual Water Company has logged zero violations - no MCL exceedances, no health advisories, and no enforcement activity across the entire period for the 486 people in its service area, a record that stands up well against both state and national benchmarks.
Data: EPA SDWIS
Service Area Map
Coverage area for Walnut Hills Mutual Water Company Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Walnut Hills Mutual Water Company serves a community with a median household income of $107,678 and an estimated 56,107 residents across its service area.
💧 Where Does Your Water Come From?
Walnut Hills Mutual Water Company'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.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 9 detections recorded. 1 exceeds federal EPA limits (4 ppt for PFOA/PFOS). 1 exceeds state limits.
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
Walnut Hills Mutual Water Company (EPA ID: CA4000670) is a community water system in California that serves approximately 486 people from groundwater sources.
This system provides water to 2 ZIP codes across 2 communities.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0052 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
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 Walnut Hills Mutual Water Company (CA4000670) on EPA.gov.
Frequently Asked Questions
Is Walnut Hills Mutual Water Company water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Walnut Hills Mutual Water Company in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Walnut Hills Mutual Water Company serve?
Walnut Hills Mutual Water Company serves approximately 486 people across 2 ZIP codes in California.
Where does Walnut Hills Mutual Water Company get its water?
The primary water source is groundwater.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Walnut Hills Mutual Water Company Water Quality Report, CA. https://zipcheckup.com/water-system/ca4000670/
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