Public water system · MN5850140
ActiveLock and Dam No. 7
At a glance
Lock and Dam No. 7 (PWSID MN5850140) is an active transient non-community water system in Winona County, Minnesota. It reports serving 600 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as owned by the federal government. EPA's records list one violation for this system; it is health-based, and the most recent began in January 1997.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
600
Service connections
2
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Lock and Dam No. 7 compare with other water systems in Winona County?
By EPA's size categories, Lock and Dam No. 7 is a small system (501 to 3,300 people). Winona County has 77 active public water systems. Its population served is roughly in line with the county average of 666 people per system, and accounts for 1.2% of the 51,279 people reported by systems filed under the county. Across Minnesota, the 6,465 active systems average 820 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Lock and Dam No. 7 is about 4.2 times that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. Minnesota has 5,008 active transient non-community water systems, 77% 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 Lock and Dam No. 7?
EPA lists Lock and Dam No. 7 as owned by the federal 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. 2 of the 77 active systems in Winona County (2.6%) are also owned by the federal government.
Does Lock and Dam No. 7 have drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in January 1997. By type: 1 contaminant level above the legal limit. The contaminant or rule involved is Total coliform bacteria (TCR). EPA lists 1 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 |
|---|---|---|---|---|
| 1997-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
The one violation in EPA's records.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.
Lock and Dam No. 7: frequently asked questions
Who runs Lock and Dam No. 7?
Lock and Dam No. 7 (PWSID MN5850140) is a transient non-community water system owned by the federal government. It is regulated by the MN state drinking water program.
How many people does Lock and Dam No. 7 serve?
Lock and Dam No. 7 reports serving 600 people through 2 service connections in Winona County, Minnesota.
Where does Lock and Dam No. 7 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 Lock and Dam No. 7 have any drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in January 1997. 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 Lock and Dam No. 7'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 one violation for this system; it is health-based, and the most recent began in January 1997. For current results, consult EPA ECHO, or the MN state drinking water program.
Where can I find Lock and Dam No. 7's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Lock and Dam No. 7 is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Winona County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Winona | Winona | 27,782 | Community | Groundwater |
| Goodview | Winona | 4,158 | Community | Groundwater |
| Saint Charles | Winona | 3,825 | Community | Groundwater |
| Kwik Trip No. 497 | Winona | 1,600 | Transient non-community | Groundwater |
| Lewiston | Winona | 1,512 | Community | Groundwater |
| Enterprise Rest Area Mndot | Winona | 1,220 | 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, “Lock and Dam No. 7, PWSID MN5850140, Minnesota”, https://aquacensus.com/water-systems/minnesota/lock-and-dam-no-7-mn5850140 (data as of October 1, 2026).