Public water system · SD4600112
ActiveTri-County Rural Water System
At a glance
Tri-County Rural Water System (PWSID SD4600112) is an active community water system serving Dewey, Meade and Ziebach counties, South Dakota. It reports serving 2,190 people through 876 service connections. Its primary water source is surface water, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 6 are health-based, and the most recent began in December 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,190
Service connections
876
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Tri-County Rural Water System compare with other water systems in South Dakota?
By EPA's size categories, Tri-County Rural 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 Tri-County Rural 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 24 South Dakota systems (3.4%) list surface water as their primary source.
Who owns and regulates Tri-County Rural Water System?
EPA lists Tri-County Rural Water System 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.
Does Tri-County Rural Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, 6 are health-based, and the most recent began in December 2022. The violations listed here began between October 2005 and December 2022. By type: 4 public notice, recordkeeping or other, 3 required treatment not met, 3 contaminant level above the legal limit, 1 monitoring and 1 monitoring and reporting. The contaminant or rule involved most often is Interim Enhanced Surface Water Treatment Rule (3 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2022-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2013-05-19 | Public notice, recordkeeping or otherSanitary Survey (TCR) · code 28 | Not reported | No | Resolved |
| 2009-03-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2008-12-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2006-11-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2006-04-10 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2006-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2006-01-10 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2006-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2005-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2005-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | 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.
Tri-County Rural Water System: frequently asked questions
Who runs Tri-County Rural Water System?
Tri-County Rural Water System (PWSID SD4600112) is a community water system privately owned. It is regulated by the SD state drinking water program.
How many people does Tri-County Rural Water System serve?
Tri-County Rural Water System reports serving 2,190 people through 876 service connections in Dewey, Meade and Ziebach counties, South Dakota.
Where does Tri-County Rural Water System get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Tri-County Rural Water System have any drinking water violations?
Of the 12 most recent violations in EPA's records, 6 are health-based, and the most recent began in December 2022. 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 Tri-County Rural 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, 6 are health-based, and the most recent began in December 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Tri-County Rural Water System's water quality report?
As a community water system, Tri-County Rural 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 Dewey County(the first county EPA lists for this system)
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Eagle Butte | Dewey | 4,000 | Community | Purchased surface water |
| Timber Lake | Dewey | 499 | Community | Groundwater |
| T C & G Rural Water System | Dewey | 166 | Community | Groundwater |
| Isabel | Dewey | 145 | Community | Purchased surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Tri-County Rural Water System, PWSID SD4600112, South Dakota”, https://aquacensus.com/water-systems/south-dakota/tri-county-rural-water-system-sd4600112 (data as of October 1, 2026).