Public water system · SD4600199
ActiveMadison
At a glance
Madison (PWSID SD4600199) is an active community water system in Lake County, South Dakota. It reports serving 6,191 people through 2,687 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, 9 are health-based, and the most recent began in April 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
6,191
Service connections
2,687
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Madison compare with other water systems in Lake County?
By EPA's size categories, Madison is a medium system (3,301 to 10,000 people). Lake County has 5 active public water systems, and Madison is the largest of them by population served. Its population served is about 3.2 times the county average of 1,956 people per system, and accounts for 63% of the 9,782 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 Madison is roughly in line with 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 Madison?
EPA lists Madison 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. 4 of the 5 active systems in Lake County (80%) are also owned by a local government.
Does Madison have drinking water violations?
Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in April 2013. The violations listed here began between July 1996 and April 2013. By type: 9 contaminant level above the legal limit, 2 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (9 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 |
|---|---|---|---|---|
| 2013-04-15 | Public notice, recordkeeping or otherSanitary Survey (TCR) · code 28 | Not reported | No | Resolved |
| 2013-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2012-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2011-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2011-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2011-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2011-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 1996-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | 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.
Madison: frequently asked questions
Who runs Madison?
Madison (PWSID SD4600199) is a community water system owned by a local government. It is regulated by the SD state drinking water program.
How many people does Madison serve?
Madison reports serving 6,191 people through 2,687 service connections in Lake County, South Dakota.
Where does Madison 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 Madison have any drinking water violations?
Of the 12 most recent violations in EPA's records, 9 are health-based, and the most recent began in April 2013. 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 Madison'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, 9 are health-based, and the most recent began in April 2013. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.
Where can I find Madison's water quality report?
As a community water system, Madison 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 Lake County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Kingbrook Iii Rural Water System | Lake | 2,888 | Community | Groundwater |
| Chester Sanitary District | Lake | 363 | Community | Purchased groundwater |
| Wentworth | Lake | 181 | Community | Purchased groundwater |
| Ramona | Lake | 159 | 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, “Madison, PWSID SD4600199, South Dakota”, https://aquacensus.com/water-systems/south-dakota/madison-sd4600199 (data as of October 1, 2026).