Green River Mutual Water Company
EPA ID: CA4000554 · 350 people served · 2 ZIP codes
Water monitoring for Green River Mutual Water Company: clean, five years, 350 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Stable · Risk tier: High · 94% chance of violation in next 12 months
Violations went from 2 (2021) to 4 (2024). Violation counts have remained relatively steady.
Service Area Map
Coverage area for Green River Mutual Water Company Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Green River Mutual Water Company serves a community with a median household income of $94,512 and an estimated 45,859 residents across its service area. Approximately 46% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Green River 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.
About 1% of homes in San Luis Obispo 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
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 7 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
Green River Mutual Water Company (EPA ID: CA4000554) is a community water system in California that serves approximately 350 people from groundwater sources.
This system provides water to 2 ZIP codes across 1 community.
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
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Green River Mutual Water Company (CA4000554) on EPA.gov.
Frequently Asked Questions
Is Green River Mutual Water Company water safe to drink?
Based on EPA records, Green River Mutual Water Company has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Green River Mutual Water Company serve?
Green River Mutual Water Company serves approximately 350 people across 2 ZIP codes in California.
Where does Green River Mutual Water Company 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:
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.