Public water system · SD4600060
ActiveJefferson
At a glance
Jefferson (PWSID SD4600060) is an active community water system in Union County, South Dakota. It reports serving 475 people through 235 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in February 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
475
Service connections
235
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Jefferson compare with other water systems in Union County?
By EPA's size categories, Jefferson is a very small system (500 people or fewer). Union County has 8 active public water systems. Its population served is well below the county average of 1,761 people per system, and accounts for 3.4% of the 14,087 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 Jefferson 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 Jefferson?
EPA lists Jefferson 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. 6 of the 8 active systems in Union County (75%) are also owned by a local government.
Does Jefferson have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in February 2014. The violations listed here began between July 1994 and February 2014. By type: 8 monitoring and reporting, 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) (3 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 |
|---|---|---|---|---|
| 2014-02-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2010-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-12-02 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2000-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1994-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Trichloroethylenecode 2984 | No | Resolved |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 1994-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | 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.
Jefferson: frequently asked questions
Who runs Jefferson?
Jefferson (PWSID SD4600060) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Jefferson serve?
Jefferson reports serving 475 people through 235 service connections in Union County, South Dakota.
Where does Jefferson 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 Jefferson 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 February 2014. 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 Jefferson'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 February 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Jefferson's water quality report?
As a community water system, Jefferson 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 Union County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Dakota Dunes Cid | Union | 3,700 | Community | Purchased groundwater under influence |
| North Sioux City | Union | 3,042 | Community | Groundwater |
| Beresford | Union | 2,359 | Community | Purchased groundwater |
| Elk Point | Union | 2,124 | Community | Groundwater |
| Clay Rws/South Union | Union | 1,447 | Community | Groundwater |
| Alcester | Union | 820 | 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, “Jefferson, PWSID SD4600060, South Dakota”, https://aquacensus.com/water-systems/south-dakota/jefferson-sd4600060 (data as of October 1, 2026).