Gswc-south Arcadia
EPA ID: CA1910212 · 27,072 people served · 6 ZIP codes
ZipCheckup's reading of EPA records for Gswc-south Arcadia (CA1910212): a UCMR5 PFAS sample above the level of an EPA PFAS MCL, which takes effect in 2029; this is not a violation. Across the reporting cycles included in federal data, Gswc-south Arcadia has no EPA violation entries - the file covers a service population of approximately 27,072 residents and says nothing about individual household plumbing.
Data: EPA SDWIS
Service Area Map
Coverage area for Gswc-south Arcadia Source: EPA SDWIS service area boundaries.
Service area boundary
Demographics of ZIP Codes Served
The ZIP codes associated with Gswc-south Arcadia have a median household income of $98,872 and about 235,939 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 81% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: On average, 49% of census tracts in the counties mapped to this service area are designated disadvantaged by the federal Climate and Economic Justice Screening Tool (CEJST, 2022 version). 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-south Arcadia's water is classified in EPA records as a groundwater source. 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.
Superfund Proximity Note: This service area ranks in the 70th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
PFAS in ZIP Codes This System Serves
PFAS ("forever chemicals") have been reported in samples from water systems associated with the ZIP codes in this system's area. These results can come from other water systems serving the same ZIP codes; check the UCMR5 section for any results reported for this system. 28 detections recorded. 12 detections are above the level of a federal PFAS MCL (4 ppt for PFOA and PFOS), with compliance required from 2029.
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-south Arcadia (EPA ID: CA1910212) is a community water system in California that serves approximately 27,072 people from groundwater sources.
This system provides water to 6 ZIP codes across 6 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.
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: Ask your water utility whether running cold water for 2 minutes is enough to flush your plumbing before drinking.
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.
- 91006 - Arcadia
- 91010 - Duarte
- 91016 - Monrovia
- 91706 - Baldwin Park
- 91731 - El Monte
- 91780 - Temple City
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for Gswc-south Arcadia (CA1910212) on EPA.gov.
Frequently Asked Questions
Is Gswc-south Arcadia water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Gswc-south Arcadia 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-south Arcadia serve?
Gswc-south Arcadia serves approximately 27,072 people across 6 ZIP codes in California.
Where does Gswc-south Arcadia get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Sample Above an EPA MCL Value or State Standard
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). One or more PFAS measurements were above the level of the EPA MCL for that compound (April 2024 rule, which takes effect in 2029) or above an applicable state drinking-water standard; a monitoring result above that level is not by itself a violation.
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.). Gswc-south Arcadia, CA: Serves 27K People. https://zipcheckup.com/water-system/ca1910212/
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