Public water system · SD4600376

Active

Woonsocket

At a glance

Woonsocket (PWSID SD4600376) is an active community water system in Sanborn County, South Dakota. It reports serving 618 people through 330 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, 6 are health-based, and the most recent began in August 2024.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

618

Service connections

330

Primary source

Groundwater

System type

CWS

Community water system

System record

PWSIDSD4600376

System typeCommunity water system

Activity statusActive

Population served618

Service connections330

Primary water sourceGroundwater

Owner typeLocal government

Primacy agencySD state drinking water program

City servedWoonsocket

StateSouth Dakota

ZIP57385

CountySanborn County

How does Woonsocket compare with other water systems in Sanborn County?

By EPA's size categories, Woonsocket is a small system (501 to 3,300 people). Sanborn County has 5 active public water systems, and Woonsocket is the largest of them by population served. Its population served is about 172% above the county average of 227 people per system, and accounts for 54% of the 1,137 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 Woonsocket 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 Woonsocket?

EPA lists Woonsocket 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 5 active systems in Sanborn County (40%) are also owned by a local government.

Does Woonsocket have drinking water violations?

Of the 12 most recent violations in EPA's records, 6 are health-based, and the most recent began in August 2024. The violations listed here began between January 2009 and August 2024. By type: 6 monitoring and reporting, 5 required treatment not met 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 11 as resolved and 1 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.

Began	Violation	Contaminant or rule	Health-based	Status
2024-08-10	Monitoring and reportingMonitoring, Source Water (GWR) · code 34	E. colicode 3014	No	Unaddressed
2015-04-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2014-02-01	Required treatment not metTreatment Technique No Certif. Operator · code 12	Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400	Yes	Resolved
2013-08-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2011-10-04	Required treatment not metPublic Education · code 65	Lead and Copper Rulecode 5000	Yes	Resolved
2010-04-26	Required treatment not metPublic Education · code 65	Lead and Copper Rulecode 5000	Yes	Resolved
2010-04-01	Required treatment not metOCCT/SOWT Study/Recommendation · code 57	Lead and Copper Rulecode 5000	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
2009-01-01	Monitoring and reportingMonitoring, Regular · code 03	Styrenecode 2996	No	Resolved
2009-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Total trihalomethanes (TTHM)code 2950	No	Resolved
2009-01-01	Monitoring and reportingMonitoring, Regular · code 03	Chlorobenzenecode 2989	No	Resolved
2009-01-01	Monitoring and reportingMonitoring, Regular · code 03	Dichloromethanecode 2964	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.

Woonsocket: frequently asked questions

Who runs Woonsocket?

Woonsocket (PWSID SD4600376) is a community water system owned by a local government. It is regulated by the SD state drinking water program.

How many people does Woonsocket serve?

Woonsocket reports serving 618 people through 330 service connections in Sanborn County, South Dakota.

Where does Woonsocket 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 Woonsocket 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 August 2024. 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 Woonsocket'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 August 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the SD state drinking water program.

Where can I find Woonsocket's water quality report?

As a community water system, Woonsocket 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 Sanborn County

Water system	County	Population served	Type	Source
Upland Colony	Sanborn	198	Community	Groundwater
Letcher	Sanborn	159	Community	Purchased surface water
Sanborn Central School District	Sanborn	125	Non-transient non-community	Groundwater
Old Whites Drive in	Sanborn	37	Transient non-community	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, “Woonsocket, PWSID SD4600376, South Dakota”, https://aquacensus.com/water-systems/south-dakota/woonsocket-sd4600376 (data as of October 1, 2026).