City of Hollister

ZipCheckup's reading of EPA SDWIS for City of Hollister (CA3510001): 1 past health-based violation, since resolved. While 3 violations did appear in City of Hollister's five-year monitoring record, none remain unresolved - the utility has returned to full compliance and continues to serve approximately 26,017 residents under all current EPA drinking water standards.

Data: EPA SDWIS

System Overview

City of Hollister, (EPA ID: CA3510001) is a community water system in California that serves approximately 26,017 people from surface water sources.

This system serves ZIP code 95023 in Hollister.

ZIP-Area Home Safety Context: C (60/100)

This is the average Home Safety Score for 1 of 1 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.

Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.

Violation History

Status breakdown for accepted records with record years 2021-2026: 1 resolved, 2 archived, 0 addressed, and 0 unaddressed. Under this source contract, current noncompliance is the sum of addressed and unaddressed records. Archived and resolved records are excluded from current noncompliance.

Recent Violations

Contaminants Detected

The following contaminants have been flagged in EPA records for this water system:

Health Risk Details

Haloacetic Acids (HAA5) (EPA limit: 0.06 mg/L)

Cancer risk; reproductive & developmental effects At-risk groups: pregnant women, infants, long-term consumers of chlorinated municipal water.

Removal methods: granular activated carbon (GAC), carbon block filter, reverse osmosis. Find the right filter →

Lead & Copper

EPA Lead and Copper Rule evidence attributed directly to this water system:

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

Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

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.

• 95023 - Hollister

Data Sources

This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Hollister (CA3510001) on EPA.gov.

Frequently Asked Questions

Is City of Hollister water safe to drink?

The accepted 2026Q2 ECHO snapshot shows no current noncompliance for City of Hollister; its 3 accepted 2021-2026 records are resolved or archived. Historical compliance status does not establish conditions at a specific tap.

How many people does City of Hollister serve?

City of Hollister serves approximately 26,017 people across 1 ZIP code in California.

Where does City of Hollister get its water?

The primary water source is surface water.

@misc{zipcheckup-water-system-ca3510001,
  author = {{ZipCheckup}},
  title  = {{City of Hollister (CA): 1 Health Violation}},
  year   = {n.d.},
  url    = {https://zipcheckup.com/water-system/ca3510001/}
}