Hollister, CA: 8 Health Violations — 64/100 (2026)
2 ZIP codes · 7 water systems · Updated 2026-06-03
For most households in Hollister, CA tap water is adequate — the middle-tier grade reflects gaps in specific service areas.
How Hollister Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Hollister Residents
- Your city's water systems recorded 16 violations in the past 5 years.
- Average lead level: 0.0023 mg/L.
- Estimated remediation: $2,200 per household.
- CDC health risk index: 10.93.
Hollister's Water Providers
3 water utilities share the residential service territory in Hollister, CA — out of 7 total systems in federal records.
Overview
We track water quality and home safety data for 2 ZIP codes in Hollister, California, covering 7 community water systems serving approximately 58,374 people.
2 of 2 ZIP codes (100%) have recorded EPA violations. 8 health-based violations documented.
Home Safety Score
Average Home Safety Score for Hollister: C (64/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Hollister water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0023 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 2 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Barium | Inorganic | 6 | 2 |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 6 | 2 |
| Stage 2 DBP Rule | Treatment Technique | 6 | 2 |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 3 | 2 |
| Lead and Copper Rule | Treatment Technique | 3 | 2 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 95023 | C | 8 | 4 | City of Hollister, |
| 95024 | C | 8 | 4 | City of Hollister, |
All ZIP Codes in Hollister
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
Updated daily.
Hollister Community Health Snapshot
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
What's in Hollister's Water?
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Remediation Costs Compare in Hollister
How much of a Hollister home's value does documented remediation represent? A small fraction — the equity share here is in the low tier, and from a household financial perspective, most property owners are considering a commitment that fits comfortably within standard planning rather than a decision that rises to the level of a material budget event or significant equity consideration.
Remediation costs in Hollister are relatively low compared to home values. The $1,100–$3,950 estimated range is a small fraction of median property value. Home values are 0% above the California average.
Hollister: Lead Risk & Vulnerable Populations
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Lead risk in Hollister appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Hollister: Flood History & Water Damage Risk
Hollister's flood exposure sits in the moderate range: 112 NFIP claims on record and 50% of ZIP codes within FEMA-designated flood zones. Residents with private wells or older infrastructure have reasonable grounds to factor flood timing into their water quality awareness.
Hollister has a moderate flood history with 112 FEMA claims averaging $32,401 per payout. 50% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,200</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Hollister
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. Filters rated for Barium can reduce the most common contaminant found in Hollister's water.
- Check your home's plumbing. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.
Deep Dive Reports
Detailed analysis for Hollister, CA