Zone 7 Water Agency
EPA ID: CA0110010 · 40 people served · 14 ZIP codes
Zone 7 Water Agency carries zero EPA violations in five years — a spotless record for a utility serving 40 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 94% chance of violation in next 12 months
Violations went from 2 (2022) to 4 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Zone 7 Water Agency Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Zone 7 Water Agency serves a community with a median household income of $187,145 and an estimated 524,763 residents across its service area. Approximately 45% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Zone 7 Water Agency'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 Contra Costa County, California rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 33 detections recorded. 10 exceed federal EPA limits (4 ppt for PFOA/PFOS). 4 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
Zone 7 Water Agency (EPA ID: CA0110010) is a community water system in California that serves approximately 40 people from surface water sources.
This system provides water to 14 ZIP codes across 11 communities.
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: 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.
- 94506 — Danville
- 94539 — Fremont
- 94542 — Hayward
- 94550 — Livermore
- 94551 — Livermore
- 94552 — Castro Valley
- 94566 — Pleasanton
- 94568 — Dublin
- 94582 — San Ramon
- 94586 — Sunol
- 94587 — Union City
- 94588 — Pleasanton
- 95377 — Tracy
- 95391 — Tracy
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Zone 7 Water Agency (CA0110010) on EPA.gov.
Frequently Asked Questions
Is Zone 7 Water Agency water safe to drink?
Based on EPA records, Zone 7 Water Agency has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Zone 7 Water Agency serve?
Zone 7 Water Agency serves approximately 40 people across 14 ZIP codes in California.
Where does Zone 7 Water Agency 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.