Public water system · SD4600269
ActiveHidden Valley Water Association Inc.
At a glance
Hidden Valley Water Association Inc. (PWSID SD4600269) is an active community water system in Pennington County, South Dakota. It reports serving 27 people through 15 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
27
Service connections
15
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Hidden Valley Water Association Inc. compare with other water systems in Pennington County?
By EPA's size categories, Hidden Valley Water Association Inc. is a very small system (500 people or fewer). Pennington County has 150 active public water systems. Its population served is well below the county average of 930 people per system, and accounts for less than 0.1% of the 139,467 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 Hidden Valley Water Association Inc. 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 Hidden Valley Water Association Inc.?
EPA lists Hidden Valley Water Association Inc. as privately owned. 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. 134 of the 150 active systems in Pennington County (89%) are also privately owned.
Does Hidden Valley Water Association Inc. have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in October 2024. The violations listed here began between February 1997 and October 2024. By type: 6 monitoring and reporting, 2 monitoring, 2 required treatment not met and 2 contaminant level above the legal limit. 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 |
|---|---|---|---|---|
| 2024-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2017-10-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2016-02-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2015-12-22 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2015-12-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2015-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2012-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 1999-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1998-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1997-02-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | 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.
Hidden Valley Water Association Inc.: frequently asked questions
Who runs Hidden Valley Water Association Inc.?
Hidden Valley Water Association Inc. (PWSID SD4600269) is a community water system privately owned. It is regulated by the SD state drinking water program.
How many people does Hidden Valley Water Association Inc. serve?
Hidden Valley Water Association Inc. reports serving 27 people through 15 service connections in Pennington County, South Dakota.
Where does Hidden Valley Water Association Inc. 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 Hidden Valley Water Association Inc. have any drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are 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 Hidden Valley Water Association Inc.'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, 4 are 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 SD state drinking water program.
Where can I find Hidden Valley Water Association Inc.'s water quality report?
As a community water system, Hidden Valley Water Association Inc. 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 Pennington County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Rapid City | Pennington | 72,009 | Community | Surface water |
| Box Elder | Pennington | 14,000 | Community | Groundwater |
| Rapid Valley Sanitary District | Pennington | 11,408 | Community | Surface water |
| Ellsworth Afb | Pennington | 9,100 | Community | Purchased surface water |
| Nps-Mount Rushmore National Memorial | Pennington | 4,100 | Non-transient non-community | Groundwater |
| Colonial Pine Hills Sanitary Distric | Pennington | 1,200 | 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, “Hidden Valley Water Association Inc., PWSID SD4600269, South Dakota”, https://aquacensus.com/water-systems/south-dakota/hidden-valley-water-association-inc-sd4600269 (data as of October 1, 2026).