Public water system · SD4600077

Active

Buffalo Gap

At a glance

Buffalo Gap (PWSID SD4600077) is an active community water system in Custer County, South Dakota. It reports serving 126 people through 93 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2025.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

126

Service connections

Primary source

Groundwater

System type

CWS

Community water system

System record

PWSIDSD4600077

System typeCommunity water system

Activity statusActive

Population served126

Service connections93

Primary water sourceGroundwater

Owner typeLocal government

Primacy agencySD state drinking water program

City servedBuffalo Gap

StateSouth Dakota

ZIP57722

CountyCuster County

How does Buffalo Gap compare with other water systems in Custer County?

By EPA's size categories, Buffalo Gap is a very small system (500 people or fewer). Custer County has 49 active public water systems. Its population served is about half of the county average of 274 people per system, and accounts for 0.9% of the 13,414 people reported by systems filed under the county. Across South Dakota, the 699 active systems average 1,387 people each. Nationally, the average active community water system reports serving 6,703 people, so Buffalo Gap 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. South Dakota has 510 active community water systems, 73% of the state's 699 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 431 South Dakota systems (62%) list groundwater as their primary source.

Who owns and regulates Buffalo Gap?

EPA lists Buffalo Gap as owned by a local government. The SD 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 49 active systems in Custer County (14%) are also owned by a local government.

Does Buffalo Gap have drinking water violations?

Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2025. The violations listed here began between January 2018 and July 2025. By type: 6 monitoring and reporting, 3 required treatment not met and 3 monitoring. The contaminant or rule involved most often is Chlorine (5 of them). EPA lists 10 as resolved, 1 as unaddressed and 1 as archived. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.

Began	Violation	Contaminant or rule	Health-based	Status
2025-07-07	Required treatment not metTreatment Technique No Certif. Operator · code 12	Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400	Yes	Unaddressed
2025-07-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Archived
2024-05-21	Required treatment not metTreatment Technique No Certif. Operator · code 12	Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400	Yes	Resolved
2023-12-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2023-10-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2023-10-01	Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52	Lead and Copper Rulecode 5000	No	Resolved
2023-04-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2023-04-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2023-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2018-07-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2018-04-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2018-01-01	Required treatment not metTreatment Technique No Certif. Operator · code 12	Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400	Yes	Resolved

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.

Buffalo Gap: frequently asked questions

Who runs Buffalo Gap?

Buffalo Gap (PWSID SD4600077) is a community water system owned by a local government. It is regulated by the SD state drinking water program.

How many people does Buffalo Gap serve?

Buffalo Gap reports serving 126 people through 93 service connections in Custer County, South Dakota.

Where does Buffalo Gap get its water?

EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.

Does Buffalo Gap have any drinking water violations?

Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2025. 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 Buffalo Gap'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, 3 are health-based, and the most recent began in July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.

Where can I find Buffalo Gap's water quality report?

As a community water system, Buffalo Gap 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 Custer County

Water system	County	Population served	Type	Source
Laughing Water Restaurant at Crazy H	Custer	2,055	Non-transient non-community	Groundwater
Custer	Custer	1,919	Community	Groundwater
Nps-Wind Cave National Park	Custer	1,404	Non-transient non-community	Groundwater
Southern Black Hills Water	Custer + 1 more	947	Community	Groundwater
Csp-Sylvan Lake	Custer	799	Transient non-community	Groundwater
Csp-Game Lodge	Custer	541	Transient non-community	Groundwater

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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, “Buffalo Gap, PWSID SD4600077, South Dakota”, https://aquacensus.com/water-systems/south-dakota/buffalo-gap-sd4600077 (data as of October 1, 2026).