Golden State Water Company - Simi Valley
EPA ID: CA5610059 · 45,128 people served · 6 ZIP codes
Although compliance varies widely among water utilities nationally, Golden State Water Company - Simi Valley stands out with zero EPA violations over five consecutive monitoring years, delivering safe tap water to 45,128 residents and showing no enforcement activity across the entire reporting span.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Golden State Water Company - Simi Valley Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Golden State Water Company - Simi Valley serves a community with a median household income of $118,962 and an estimated 204,296 residents across its service area. Approximately 50% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Golden State Water Company - Simi Valley'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 Ventura 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 65th percentile nationally for proximity to Superfund (NPL) sites.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 7 detections recorded. 3 exceed federal EPA limits (4 ppt for PFOA/PFOS). 2 exceed 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
Golden State Water Company - Simi Valley (EPA ID: CA5610059) is a community water system in California that serves approximately 45,128 people from surface water sources.
This system provides water to 6 ZIP codes across 3 communities.
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
Coverage: 3 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 3 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
- 93063 — Simi Valley
- 93064 — Brandeis
- 93065 — Simi Valley
- 95670 — Rancho Cordova
- 95741 — Rancho Cordova
- 95742 — Rancho Cordova
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Golden State Water Company - Simi Valley (CA5610059) on EPA.gov.
Frequently Asked Questions
Is Golden State Water Company - Simi Valley water safe to drink?
Based on EPA records, Golden State Water Company - Simi Valley has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Golden State Water Company - Simi Valley serve?
Golden State Water Company - Simi Valley serves approximately 45,128 people across 6 ZIP codes in California.
Where does Golden State Water Company - Simi Valley 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.