Public water system · SD4600121
ActiveEureka
At a glance
Eureka (PWSID SD4600121) is an active community water system in McPherson County, South Dakota. It reports serving 813 people through 591 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 10 violations for this system; 4 are health-based, and the most recent began in October 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
813
Service connections
591
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Eureka compare with other water systems in McPherson County?
By EPA's size categories, Eureka is a small system (501 to 3,300 people). McPherson County has 2 active public water systems, and Eureka is the largest of them by population served. Its population served is about 30% above the county average of 624 people per system, and accounts for 65% of the 1,247 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 Eureka 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 surface water means the system buys surface water from another public water system rather than drawing its own. 142 South Dakota systems (20%) list purchased surface water as their primary source.
Who owns and regulates Eureka?
EPA lists Eureka 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. 2 of the 2 active systems in McPherson County (100%) are also owned by a local government.
Does Eureka have drinking water violations?
EPA's records list 10 violations for this system; 4 are health-based, and the most recent began in October 2023. The violations listed here began between July 1976 and October 2023. By type: 5 monitoring and reporting, 3 required treatment not met, 1 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 6 as resolved and 4 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 |
|---|---|---|---|---|
| 2023-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2018-01-26 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2013-02-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2010-02-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 1998-09-14 | Public notice, recordkeeping or otherNotification, Public · code 06 | Lead and Copper Rulecode 5000 | No | Archived |
| 1998-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1995-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1976-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Archived |
| 1976-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 10 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.
Eureka: frequently asked questions
Who runs Eureka?
Eureka (PWSID SD4600121) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Eureka serve?
Eureka reports serving 813 people through 591 service connections in McPherson County, South Dakota.
Where does Eureka get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Eureka have any drinking water violations?
EPA's records list 10 violations for this system; 4 are health-based, and the most recent began in October 2023. 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 Eureka'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 10 violations for this system; 4 are health-based, and the most recent began in October 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Eureka's water quality report?
As a community water system, Eureka 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 McPherson County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Leola | McPherson | 434 | Community | Purchased 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, “Eureka, PWSID SD4600121, South Dakota”, https://aquacensus.com/water-systems/south-dakota/eureka-sd4600121 (data as of October 1, 2026).