Public water system · SD4602180
ActiveHermosa Water Users Association
At a glance
Hermosa Water Users Association (PWSID SD4602180) is an active community water system in Custer County, South Dakota. It reports serving 108 people through 49 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, 5 are health-based, and the most recent began in July 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
108
Service connections
49
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Hermosa Water Users Association compare with other water systems in Custer County?
By EPA's size categories, Hermosa Water Users Association is a very small system (500 people or fewer). Custer County has 49 active public water systems. Its population served is about 61% below the county average of 274 people per system, and accounts for 0.8% 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 Hermosa Water Users Association 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 Hermosa Water Users Association?
EPA lists Hermosa Water Users Association 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 Hermosa Water Users Association have drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in July 2021. The violations listed here began between January 2000 and July 2021. By type: 4 monitoring and reporting, 4 contaminant level above the legal limit, 2 public notice, recordkeeping or other, 1 required treatment not met and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 11 as resolved 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. 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 |
|---|---|---|---|---|
| 2021-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2020-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2019-10-05 | Required treatment not metTreatment Technique, Level 1 Assessment (RTCR) · code 2A | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2019-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2017-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, E. coli (RTCR) · code 1A | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2013-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2005-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2001-11-13 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2001-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2001-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2000-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2000-01-17 | Public notice, recordkeeping or otherNotification, Public · code 06 | Total coliform bacteria (TCR)code 3100 | No | Archived |
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.
Hermosa Water Users Association: frequently asked questions
Who runs Hermosa Water Users Association?
Hermosa Water Users Association (PWSID SD4602180) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Hermosa Water Users Association serve?
Hermosa Water Users Association reports serving 108 people through 49 service connections in Custer County, South Dakota.
Where does Hermosa Water Users Association 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 Hermosa Water Users Association have any drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in July 2021. 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 Hermosa Water Users Association'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, 5 are health-based, and the most recent began in July 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Hermosa Water Users Association's water quality report?
As a community water system, Hermosa Water Users Association 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, “Hermosa Water Users Association, PWSID SD4602180, South Dakota”, https://aquacensus.com/water-systems/south-dakota/hermosa-water-users-association-sd4602180 (data as of October 1, 2026).