Golden State Water Company - Simi Valley
EPA ID: CA5610059 · 45,128 people served · 3 ZIP codes
ZipCheckup's reading of EPA records for Golden State Water Company - Simi Valley (CA5610059): no drinking-water violations recorded since 2021. Searching the federal compliance records for Golden State Water Company - Simi Valley turns up no EPA violations in any contaminant category the file covers; the utility's service area includes approximately 45,128 residents.
Data: EPA SDWIS
Service Area Map
Coverage area for Golden State Water Company - Simi Valley Source: EPA SDWIS service area boundaries.
Service area boundary
Demographics of ZIP Codes Served
The ZIP codes associated with Golden State Water Company - Simi Valley have a median household income of $118,962 and about 128,695 residents live in those ZIP codes (Census; not the number of people this system supplies). 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?
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.
Wastewater Proximity Note: This service area ranks in the 60th percentile nationally for proximity to wastewater discharge points. Surface water sources near wastewater outfalls may face additional treatment challenges.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in California
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 3 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 |
|---|---|---|
| Below the reporting limit | No | 2023-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
3 of 3 ZIP records with known zones are in EPA Radon Zone 1.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
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 available EPA compliance records 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?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Golden State Water Company - Simi Valley 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 Golden State Water Company - Simi Valley serve?
Golden State Water Company - Simi Valley serves approximately 45,128 people across 3 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: No PFAS Reported Above Reporting Levels
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were reported above UCMR5 minimum reporting levels.
EPA's April 2024 PFAS rule sets MCLs of 4 ppt for PFOA and PFOS and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX); water systems must comply from 2029. Other PFAS compounds have no individual federal MCL. A state standard is shown only where this system's state has its own enforceable PFAS limit. Detection results are EPA UCMR5 samples, not a measurement at your tap.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Golden State Water Company - Simi Valley: Serves 45K People. https://zipcheckup.com/water-system/ca5610059/
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