Public water system · 084690458
ActiveOld Agency Water System
At a glance
Old Agency Water System (PWSID 084690458) is an active community water system in South Dakota. It reports serving 1,180 people through 236 service connections. Its primary water source is purchased groundwater, and EPA lists it as Native American-owned. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,180
Service connections
236
Primary source
GWP
Purchased groundwater
System type
CWS
Community water system
System record
How does Old Agency Water System compare with other water systems in South Dakota?
By EPA's size categories, Old Agency Water System is a small system (501 to 3,300 people). 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 Old Agency Water System 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. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own. 100 South Dakota systems (14%) list purchased groundwater as their primary source.
Who owns and regulates Old Agency Water System?
EPA lists Old Agency Water System as Native American-owned. The EPA Region 08 is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act.
Does Old Agency Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in January 2026. The violations listed here began between May 1998 and January 2026. By type: 9 monitoring and reporting, 2 monitoring and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (7 of them). EPA lists 10 as resolved and 2 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 |
|---|---|---|---|---|
| 2026-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2017-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2017-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2016-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2014-11-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2014-04-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2013-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2013-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2009-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2001-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1998-05-01 | 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.
Old Agency Water System: frequently asked questions
Who runs Old Agency Water System?
Old Agency Water System (PWSID 084690458) is a community water system Native American-owned. It is regulated by the EPA Region 08.
How many people does Old Agency Water System serve?
Old Agency Water System reports serving 1,180 people through 236 service connections in South Dakota.
Where does Old Agency Water System 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 Old Agency Water System 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 January 2026. 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 Old Agency Water System'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 January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the EPA Region 08.
Where can I find Old Agency Water System's water quality report?
As a community water system, Old Agency Water System 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 South Dakota
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Sioux Falls | Minnehaha | 216,462 | Community | Surface water |
| Rapid City | Pennington | 72,009 | Community | Surface water |
| Aberdeen | Brown | 27,989 | Community | Surface water |
| Brookings Municipal Utilities | Brookings | 23,377 | Community | Groundwater |
| Watertown Municipal Utilities | Codington | 23,230 | Community | Groundwater |
| Web Water Development Association | Walworth + 9 more | 20,750 | Community | 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, “Old Agency Water System, PWSID 084690458, South Dakota”, https://aquacensus.com/water-systems/south-dakota/old-agency-water-system-084690458 (data as of October 1, 2026).