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Community Water System · PWS OK2007102

Hollister

Hollister, Oklahoma 73551 - drinking water served from groundwater sources to 60 people, tracked in EPA SDWIS and UCMR5.

60
People served
487
EPA violations
44
Health-based
Untested
UCMR5 result

The verdict

EPA records 487 drinking-water violations at Hollister, 9% of them health-based - above the Oklahoma per-system average.

487
Total EPA violations on record
9%
Health-based (MCL / treatment failure)
60
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Hollister

Hollister is a local-owned community water system that delivers drinking water to 60 residents in Hollister, Oklahoma (Tillman County) through 20 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 487 total violations for this system , of which 44 (9%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 356 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is TTHM, recorded in 102 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Oklahoma, EPA tracks 1,262 public water systems serving 3,699,452 people, with 336,706 cumulative violations and 113,804 health-based violations on record. About 98% of systems in the state carry at least one violation, and state-wide the average per system is 266.8 violations. Statewide, 61 of 166 UCMR5-tested systems have reported PFAS detections (36.7%).

Hollister's 487 violations sit above the Oklahoma average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
60
Total Violations
487
Health-Based Violations
44
Water Source
Groundwater

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

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Hollister.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID OK2007102 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Oklahoma Drinking Water Authority

Oklahoma's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find OK regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2024 LEAD AND COPPER RULE REVISIONS RPT 2 SDWIS / OK2007102 / 5200
2024 LEAD AND COPPER RULE REVISIONS TT 2 SDWIS / OK2007102 / 5200
2022 TTHM MR 102 SDWIS / OK2007102 / 2950
2022 Total Haloacetic Acids (HAA5) MR 94 SDWIS / OK2007102 / 2456
2019 Lead and Copper Rule MR 97 SDWIS / OK2007102 / 5000
2019 Public Notice Other 40 SDWIS / OK2007102 / 7500
2017 Consumer Confidence Rule Other 17 SDWIS / OK2007102 / 7000
2013 Coliform (TCR) MR 62 SDWIS / OK2007102 / 3100
2013 E. COLI MR 1 SDWIS / OK2007102 / 3014
2007 TTHM MCL 24 SDWIS / OK2007102 / 2950
2007 Nitrate-Nitrite MCL 8 SDWIS / OK2007102 / 1038
2006 Coliform (TCR) MCL 6 SDWIS / OK2007102 / 3100
2006 Combined Uranium MCL 4 SDWIS / OK2007102 / 4006

How Hollister Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Hollister Oklahoma avg Federal benchmark
Total violations 487 266.8 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 44 90.2 Indicates a contaminant exceeded a federal MCL
PFAS detection None 36.7% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 60 2,931 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,262 regulated public water systems in Oklahoma.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Hollister water safe to drink? ▼
Hollister (PWS ID: OK2007102) has 487 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 60 people using Groundwater sources.
How many people does Hollister serve? ▼
Hollister serves 60 people in Hollister, Oklahoma. It is a Local-owned system using Groundwater water sources with 20 service connections.
What type of violations does Hollister have? ▼
Hollister has 487 total violations: 44 health-based violations (MCL exceedances or treatment failures), 356 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Hollister water? ▼
No PFAS testing data is available for Hollister under the EPA's UCMR5 monitoring program.
What water source does Hollister use? ▼
Hollister uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.