Treasure Island
EPA ID: CA3810702 · 3,864 people served · 2 ZIP codes
ZipCheckup's reading of EPA records for Treasure Island (CA3810702): a lead 90th-percentile reading above the EPA action level. Water monitoring for Treasure Island: no violations on record, 3,864 residents.
Data: EPA SDWIS
Service Area Map
Coverage area for Treasure Island Source: EPA SDWIS service area boundaries.
Service area boundary
Demographics of ZIP Codes Served
The ZIP codes associated with Treasure Island have a median household income of $105,625 and about 66,346 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 91% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Treasure Island'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 65th percentile nationally for proximity to Superfund (NPL) sites.
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. 1 detection recorded.
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
Treasure Island (EPA ID: CA3810702) is a community water system in California that serves approximately 3,864 people from surface water sources.
This system provides water to 2 ZIP codes across 2 communities.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.1 mg/L | Yes | 2024-12-31 |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
2 of 2 ZIP records with known zones are in EPA Radon Zone 2.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
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 available EPA compliance records for Treasure Island (CA3810702) on EPA.gov.
Frequently Asked Questions
Is Treasure Island water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Treasure Island 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 Treasure Island serve?
Treasure Island serves approximately 3,864 people across 2 ZIP codes in California.
Where does Treasure Island get its water?
The primary water source is surface water.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Treasure Island Water Quality Report, CA. https://zipcheckup.com/water-system/ca3810702/
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author = {{ZipCheckup}},
title = {{Treasure Island Water Quality Report, CA}},
year = {n.d.},
url = {https://zipcheckup.com/water-system/ca3810702/}
}