Public water system · 055294503
ActiveLower Sioux
At a glance
Lower Sioux (PWSID 055294503) is an active community water system in Minnesota. It reports serving 4,000 people through 195 service connections. Its primary water source is groundwater, and EPA lists it as Native American-owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in June 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,000
Service connections
195
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Lower Sioux compare with other water systems in Minnesota?
By EPA's size categories, Lower Sioux is a medium system (3,301 to 10,000 people). Across Minnesota, the 6,465 active systems average 820 people each. Nationally, the average active community water system reports serving 6,703 people, so Lower Sioux is about 40% 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. Minnesota has 987 active community water systems, 15% of the state's 6,465 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,261 Minnesota systems (97%) list groundwater as their primary source.
Who owns and regulates Lower Sioux?
EPA lists Lower Sioux as Native American-owned. The EPA Region 05 is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act.
Does Lower Sioux have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in June 2025. The violations listed here began between January 2017 and June 2025. By type: 7 monitoring and reporting, 3 reporting and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Revised Total Coliform Rule (3 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 |
|---|---|---|---|---|
| 2025-06-26 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-07-02 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-05-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-05-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2023-10-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-08-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2019-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Endothallcode 2033 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbofurancode 2046 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toxaphenecode 2020 | 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.
Lower Sioux: frequently asked questions
Who runs Lower Sioux?
Lower Sioux (PWSID 055294503) is a community water system Native American-owned. It is regulated by the EPA Region 05.
How many people does Lower Sioux serve?
Lower Sioux reports serving 4,000 people through 195 service connections in Minnesota.
Where does Lower Sioux 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 Lower Sioux have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in June 2025. 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 Lower Sioux'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, none is health-based, and the most recent began in June 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the EPA Region 05.
Where can I find Lower Sioux's water quality report?
As a community water system, Lower Sioux 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 Minnesota
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Minneapolis | Hennepin | 425,300 | Community | Surface water |
| Saint Paul Regional Water Services | Ramsey | 392,529 | Community | Surface water |
| Rochester | Olmsted | 123,624 | Community | Groundwater |
| Bloomington | Hennepin | 91,300 | Community | Purchased surface water |
| Brooklyn Park | Hennepin | 89,995 | Community | Groundwater |
| Duluth | St. Louis | 86,859 | Community | 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, “Lower Sioux, PWSID 055294503, Minnesota”, https://aquacensus.com/water-systems/minnesota/lower-sioux-055294503 (data as of October 1, 2026).