Gswc - Claremont
EPA ID: CA1910024 · 39,730 people served · 4 ZIP codes
ZipCheckup's reading of EPA SDWIS for Gswc - Claremont (CA1910024): PFAS sampling above the current EPA limit (UCMR5). Gswc - Claremont carries zero EPA violations in five years - a spotless record for a utility serving 39,730 residents.
Data: EPA SDWIS
Service Area Map
Coverage area for Gswc - Claremont Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Gswc - Claremont serves a community with a median household income of $111,789 and an estimated 121,403 residents across its service area. Approximately 79% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 50% 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?
Gswc - Claremont'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.
Superfund Proximity Note: This service area ranks in the 68th 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. 8 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
Gswc - Claremont (EPA ID: CA1910024) is a community water system in California that serves approximately 39,730 people from surface water sources.
This system provides water to 4 ZIP codes across 4 communities.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0057 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.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
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 Gswc - Claremont (CA1910024) on EPA.gov.
Frequently Asked Questions
Is Gswc - Claremont water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Gswc - Claremont 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 Gswc - Claremont serve?
Gswc - Claremont serves approximately 39,730 people across 4 ZIP codes in California.
Where does Gswc - Claremont get its water?
The primary water source is surface water.
Federal UCMR5 PFAS Monitoring: Above Current MCL
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). One or more PFAS compounds were measured above the current state-enforceable MCL.
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 →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Gswc - Claremont, CA: Serves 40K People. https://zipcheckup.com/water-system/ca1910024/
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