In current tracking cycles, San Quentin records above-average water quality outcomes for CA; compliance history over recent years shows few departures from federal standards and no systemic failures across its water systems.

Data: EPA SDWIS

Overview

We track home safety data for 2 ZIP codes in San Quentin, California (population ~2,115), covering 1 community water system serving approximately 186,895 people region-wide. The EPA snapshots used for this build directly map water systems to 1 of 2 ZIP codes.

The available EPA record reports 0 violations for 1 ZIP code with a reported violation count.

Home Safety Score

Average Home Safety Score for San Quentin: A (100/100)

Model 4.0.0 uses four measured components across three equally weighted domains. If a required domain is unavailable, no score is published:

Factor	What It Measures
Water Quality	EPA violations and compliance history
PFAS MCL Screen	UCMR 5 testing against the covered federal MCLs
Radon Risk	EPA radon zone classification
Annual AQI	EPA AirData county-year median with at least 90 observed days

Water Sources

San Quentin water systems draw from: Surface water.

Lead & Copper

• Average lead level (90th percentile): 0.0000 mg/L (EPA action level: 0.015 mg/L)
• 0 of 1 ZIP code with known status exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 3 (Low Risk)

• Zone 1 (High): 0 ZIP codes
• Zone 2 (Moderate): 0 ZIP codes
• Zone 3 (Low): 2 ZIP codes

Areas with No Violations

All ZIP Codes in San Quentin

• 94964 [A]
• 94974

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Radon: EPA Map of Radon Zones

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.