Public water system · SD4600091
ActiveClark
At a glance
Clark (PWSID SD4600091) is an active community water system in Clark County, South Dakota. It reports serving 1,148 people through 635 service connections. Its primary water source is purchased groundwater, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in February 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,148
Service connections
635
Primary source
GWP
Purchased groundwater
System type
CWS
Community water system
System record
How does Clark compare with other water systems in Clark County?
By EPA's size categories, Clark is a small system (501 to 3,300 people). Clark County has 7 active public water systems, and Clark is the 2nd-largest of them by population served. Its population served is about twice the county average of 582 people per system, and accounts for 28% of the 4,073 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 Clark 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 Clark?
EPA lists Clark 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. 3 of the 7 active systems in Clark County (43%) are also owned by a local government.
Does Clark have drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in February 2016. The violations listed here began between July 1991 and February 2016. By type: 4 monitoring and reporting, 2 public notice, recordkeeping or other and 1 required treatment not met. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 4 as resolved and 3 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 |
|---|---|---|---|---|
| 2016-02-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2000-11-12 | Public notice, recordkeeping or otherNotification, Public · code 06 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 2000-09-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 1997-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1994-06-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1991-07-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 7 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.
Clark: frequently asked questions
Who runs Clark?
Clark (PWSID SD4600091) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Clark serve?
Clark reports serving 1,148 people through 635 service connections in Clark County, South Dakota.
Where does Clark 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 Clark have any drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in February 2016. 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 Clark'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. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in February 2016. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Clark's water quality report?
As a community water system, Clark 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 Clark County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Clark Rural Water System | Clark + 3 more | 2,325 | Community | Groundwater |
| Willow Lake | Clark | 255 | Community | Purchased groundwater |
| Fordham Colony | Clark | 142 | Community | Groundwater |
| Collins Colony | Clark | 95 | Community | Groundwater |
| Shamrock Colony | Clark | 75 | Community | Groundwater |
| Garden City | Clark | 33 | Community | Purchased 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, “Clark, PWSID SD4600091, South Dakota”, https://aquacensus.com/water-systems/south-dakota/clark-sd4600091 (data as of October 1, 2026).