Rancho San Joaquin Water Sys
EPA ID: CA3900558 · 172 people served · 1 ZIP code
ZipCheckup's reading of EPA SDWIS for Rancho San Joaquin Water Sys (CA3900558): no EPA violations recorded in the last five years. Federal monitoring spanning five full years has produced zero violations at Rancho San Joaquin Water Sys - a clean record across every reporting cycle for a utility serving approximately 172 residents.
Data: EPA SDWIS
Service Area Map
Coverage area for Rancho San Joaquin Water Sys Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Rancho San Joaquin Water Sys serves a community with a median household income of $106,056 and an estimated 46,567 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.
Environmental Justice Note: 55% 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?
Rancho San Joaquin Water Sys'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.
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 Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 1 detection recorded. 1 exceeds federal EPA limits (4 ppt for PFOA/PFOS).
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
Rancho San Joaquin Water Sys (EPA ID: CA3900558) is a community water system in California that serves approximately 172 people from groundwater sources.
This system serves ZIP code 95209 in Stockton.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0 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.
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.
- 95209 - Stockton
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Rancho San Joaquin Water Sys (CA3900558) on EPA.gov.
Frequently Asked Questions
Is Rancho San Joaquin Water Sys water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Rancho San Joaquin Water Sys 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 Rancho San Joaquin Water Sys serve?
Rancho San Joaquin Water Sys serves approximately 172 people across 1 ZIP code in California.
Where does Rancho San Joaquin Water Sys get its water?
The primary water source is groundwater.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Rancho San Joaquin Water Sys Water Quality Report, CA. https://zipcheckup.com/water-system/ca3900558/
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title = {{Rancho San Joaquin Water Sys Water Quality Report, CA}},
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url = {https://zipcheckup.com/water-system/ca3900558/}
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