Community Water System · PWS OK2007102
Hollister
Operator location Hollister, Oklahoma - smaller served population (≤ 999) at 60 people served; 487 SDWIS violations on record from groundwater sources.
- 60
- People served (this PWS)
- 487
- EPA violations (this PWS)
- 44
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Hollister standing, high SDWIS violation third
60 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 9% is middle-third health share (≤ 23%).
The verdict
Hollister sits in the upper third of the sitemap cohort by violation count (487), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (60; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 9% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 487
- Total EPA violations on record
- 9%
- Health-based (MCL / treatment failure)
- 60
- 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
- 20
- County
- Tillman
- School/Daycare
- No
- MCL Violations
- 42
- Monitoring Violations
- 356
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| TTHM | MR | 102 | 2022 |
| Lead and Copper Rule | MR | 97 | 2019 |
| Total Haloacetic Acids (HAA5) | MR | 94 | 2022 |
| Coliform (TCR) | MR | 62 | 2013 |
| Public Notice | Other | 40 | 2019 |
| TTHM | MCL | 24 | 2007 |
| Consumer Confidence Rule | Other | 17 | 2017 |
| Nitrate-Nitrite | MCL | 8 | 2007 |
| Coliform (TCR) | MCL | 6 | 2006 |
| Combined Uranium | MCL | 4 | 2006 |
| LEAD AND COPPER RULE REVISIONS | RPT | 2 | 2024 |
| LEAD AND COPPER RULE REVISIONS | TT | 2 | 2024 |
| E. COLI | MR | 1 | 2013 |
Violation Count vs. the National Corpus
Hollister has 487 recorded EPA violations, 95% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 5% carry more. 9% of this system's own violations are health-based (44 of 487), 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)
487 Higher than most more violations than 95% 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
EPA SDWIS lists 60 people served and 20 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
487 violations · 60 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
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Oklahoma compares on the same EPA violation measures. Oklahoma 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.