San Joaquin County - Colonial Heights
EPA ID: CA3910002 · 1,841 people served · 20 ZIP codes
Even as other utilities in the region logged violations, San Joaquin County - Colonial Heights kept a clean EPA record — five years, no issues, 1,841 people served.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Stable · Risk tier: High · 91% chance of violation in next 12 months
Violations went from 20 (2022) to 80 (2023). Violation counts have remained relatively steady.
Service Area Map
Coverage area for San Joaquin County - Colonial Heights Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The San Joaquin County - Colonial Heights serves a community with a median household income of $68,767 and an estimated 388,283 residents across its service area. Approximately 66% 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?
San Joaquin County - Colonial Heights'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 San Joaquin 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 70th 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. 12 detections recorded. 12 exceed 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
San Joaquin County - Colonial Heights (EPA ID: CA3910002) is a community water system in California that serves approximately 1,841 people from surface water sources.
This system provides water to 20 ZIP codes across 1 community.
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: 1 ZIP code confirmed via EPA Community Water System Service Area Boundaries v3 plus 19 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.
- 95201 — Stockton
- 95202 — Stockton
- 95203 — Stockton
- 95204 — Stockton
- 95205 — Stockton
- 95206 — Stockton
- 95207 — Stockton
- 95208 — Stockton
- 95209 — Stockton
- 95210 — Stockton
- 95211 — Stockton
- 95212 — Stockton
- 95213 — Stockton
- 95214 — Stockton
- 95215 — Stockton
- 95219 — Stockton
- 95267 — Stockton
- 95269 — Stockton
- 95296 — Stockton
- 95297 — Stockton
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for San Joaquin County - Colonial Heights (CA3910002) on EPA.gov.
Frequently Asked Questions
Is San Joaquin County - Colonial Heights water safe to drink?
Based on EPA records, San Joaquin County - Colonial Heights has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does San Joaquin County - Colonial Heights serve?
San Joaquin County - Colonial Heights serves approximately 1,841 people across 20 ZIP codes in California.
Where does San Joaquin County - Colonial Heights get its water?
The primary water source is surface water.
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.