Public water system · MN1550036
ActiveOronoco
At a glance
Oronoco (PWSID MN1550036) is an active community water system in Olmsted County, Minnesota. It reports serving 2,040 people through 656 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 2 violations for this system; none is health-based, and the most recent began in July 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,040
Service connections
656
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Oronoco compare with other water systems in Olmsted County?
By EPA's size categories, Oronoco is a small system (501 to 3,300 people). Olmsted County has 81 active public water systems, and Oronoco is the 5th-largest of them by population served. Its population served is about 12% above the county average of 1,816 people per system, and accounts for 1.4% of the 147,054 people reported by systems filed under the county. Across Minnesota, the 6,465 active systems average 820 people each. Nationally, the average active community water system reports serving 6,703 people, so Oronoco 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. 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 Oronoco?
EPA lists Oronoco as owned by a local government. The MN state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 9 of the 81 active systems in Olmsted County (11%) are also owned by a local government.
Does Oronoco have drinking water violations?
EPA's records list 2 violations for this system; none is health-based, and the most recent began in July 2021. The violations listed here began between July 2021 and July 2021. By type: 2 monitoring and reporting. The contaminants or rules involved are Haloacetic acids (HAA5) and Total trihalomethanes (TTHM). EPA lists 2 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 |
|---|---|---|---|---|
| 2021-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2021-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
All 2 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.
Oronoco: frequently asked questions
Who runs Oronoco?
Oronoco (PWSID MN1550036) is a community water system owned by a local government. It is regulated by the MN state drinking water program.
How many people does Oronoco serve?
Oronoco reports serving 2,040 people through 656 service connections in Olmsted County, Minnesota.
Where does Oronoco 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 Oronoco have any drinking water violations?
EPA's records list 2 violations for this system; none is health-based, and the most recent began in July 2021. 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 Oronoco'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 2 violations for this system; none is health-based, and the most recent began in July 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the MN state drinking water program.
Where can I find Oronoco's water quality report?
As a community water system, Oronoco 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 Olmsted County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Rochester | Olmsted | 123,624 | Community | Groundwater |
| Stewartville | Olmsted | 6,850 | Community | Groundwater |
| Byron | Olmsted | 6,809 | Community | Groundwater |
| Eyota | Olmsted | 2,043 | Community | Groundwater |
| Dover | Olmsted | 792 | Community | Groundwater |
| Crosswinds Church | Olmsted | 400 | 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, “Oronoco, PWSID MN1550036, Minnesota”, https://aquacensus.com/water-systems/minnesota/oronoco-mn1550036 (data as of October 1, 2026).