Community Water System · PWS ID5420030
Hollister City Of
Operator location Hollister, Idaho - smaller served population (≤ 999) at 220 people served; 107 SDWIS violations on record from groundwater sources.
- 220
- People served (this PWS)
- 107
- EPA violations (this PWS)
- 14
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Hollister City Of standing, high SDWIS violation third
220 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 13% is middle-third health share (≤ 23%).
The verdict
Hollister City Of sits in the upper third of the sitemap cohort by violation count (107), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (220; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 13% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 107
- Total EPA violations on record
- 13%
- Health-based (MCL / treatment failure)
- 220
- People served by this PWS (SDWIS)
- N/A
- PFAS compounds detected (UCMR5)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 120
- County
- Twin Falls
- School/Daycare
- No
- MCL Violations
- 14
- Monitoring Violations
- 89
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Gross Alpha, Excl. Radon and U | MR | 27 | 2013 |
| Chlorine | MR | 23 | 2025 |
| Coliform (TCR) | MR | 19 | 2012 |
| Coliform (TCR) | MCL | 9 | 2014 |
| TTHM | MR | 6 | 2012 |
| Total Haloacetic Acids (HAA5) | MR | 6 | 2012 |
| Nitrate | MR | 4 | 2015 |
| Gross Alpha, Excl. Radon and U | MCL | 4 | 2008 |
| Radium-228 | MR | 2 | 2012 |
| Revised Total Coliform Rule | MON | 2 | 2025 |
| Consumer Confidence Rule | Other | 2 | 1999 |
| TTHM | MCL | 1 | 2005 |
| Public Notice | Other | 1 | 2011 |
Violation Count vs. the National Corpus
Hollister City Of has 107 recorded EPA violations, 75% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 25% carry more. 13% of this system's own violations are health-based (14 of 107), and it ranks unranked by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
107 Around the middle fewer violations than 25% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Population served record for Hollister City Of
EPA SDWIS lists 220 people served and 120 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
107 violations · 220 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
What to do with Hollister City Of
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Idaho compares on the same EPA violation measures. Idaho systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.