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Public water system · OK2007102

Active

Hollister

At a glance

Hollister (PWSID OK2007102) is an active community water system in Tillman County, Oklahoma. It reports serving 60 people through 20 service connections. Its primary water source is purchased groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2024.

Dataset updated . Source: EPA SDWIS/ECHO public records.

Population served

60

Service connections

20

Primary source

GWP

Purchased groundwater

System type

CWS

Community water system

System record

PWSIDOK2007102
System typeCommunity water system
Activity statusActive
Population served60
Service connections20
Primary water sourcePurchased groundwater
Owner typeLocal government
Primacy agencyOK state drinking water program
City served—
StateOklahoma
ZIP—
CountyTillman County

How does Hollister compare with other water systems in Tillman County?

By EPA's size categories, Hollister is a very small system (500 people or fewer). Tillman County has 7 active public water systems. Its population served is well below the county average of 1,168 people per system, and accounts for 0.7% of the 8,179 people reported by systems filed under the county. Across Oklahoma, the 1,254 active systems average 2,907 people each. Nationally, the average active community water system reports serving 6,703 people, so Hollister is well below that figure.

What does “community water system” mean?

A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Oklahoma has 864 active community water systems, 69% of the state's 1,254 active systems. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own. 67 Oklahoma systems (5.3%) list purchased groundwater as their primary source.

Who owns and regulates Hollister?

EPA lists Hollister as owned by a local government. The OK state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 7 of the 7 active systems in Tillman County (100%) are also owned by a local government.

Does Hollister have drinking water violations?

Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2024. The violations listed here began between April 2019 and October 2024. By type: 8 monitoring and reporting, 2 public notice, recordkeeping or other, 1 required treatment not met and 1 reporting. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (4 of them). EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.

BeganViolationContaminant or ruleHealth-basedStatus
2024-10-17Required treatment not metLSL Inventory · code 2ELead and Copper Rule Revisionscode 5200YesResolved
2024-10-17ReportingLSL Reporting · code 4GLead and Copper Rule Revisionscode 5200NoResolved
2022-10-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoResolved
2022-10-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Haloacetic acids (HAA5)code 2456NoResolved
2021-10-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoResolved
2021-10-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Haloacetic acids (HAA5)code 2456NoResolved
2019-08-19Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75Public Noticecode 7500NoResolved
2019-07-01Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52Lead and Copper Rulecode 5000NoResolved
2019-07-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Haloacetic acids (HAA5)code 2456NoResolved
2019-07-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoResolved
2019-06-15Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75Public Noticecode 7500NoResolved
2019-04-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoResolved

The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.

Hollister: frequently asked questions

Who runs Hollister?

Hollister (PWSID OK2007102) is a community water system owned by a local government. It is regulated by the OK state drinking water program.

How many people does Hollister serve?

Hollister reports serving 60 people through 20 service connections in Tillman County, Oklahoma.

Where does Hollister get its water?

EPA SDWIS lists this system's primary water source as purchased groundwater. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own.

Does Hollister have any drinking water violations?

Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2024. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.

Is Hollister's water safe to drink?

AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the OK state drinking water program.

Where can I find Hollister's water quality report?

As a community water system, Hollister must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.

Other water systems in Tillman County

Water systemCountyPopulation servedTypeSource
FrederickTillman3,940CommunitySurface water
Tillman Co Rwd #1Tillman1,500CommunityPurchased surface water
GrandfieldTillman1,110CommunityPurchased surface water
TiptonTillman916CommunityPurchased surface water
DavidsonTillman375CommunityPurchased surface water
ManitouTillman278CommunityPurchased surface water

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About this data

Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.

Cite as: AquaCensus, “Hollister, PWSID OK2007102, Oklahoma”, https://aquacensus.com/water-systems/oklahoma/hollister-ok2007102 (data as of October 1, 2026).