Public water system · WI7370462
ActiveMarks Bar
At a glance
Marks Bar (PWSID WI7370462) is an active transient non-community water system in Marathon County, Wisconsin. It reports serving 50 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in June 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
50
Service connections
1
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Marks Bar compare with other water systems in Marathon County?
By EPA's size categories, Marks Bar is a very small system (500 people or fewer). Marathon County has 196 active public water systems. Its population served is well below the county average of 528 people per system, and accounts for less than 0.1% of the 103,490 people reported by systems filed under the county. Across Wisconsin, the 11,056 active systems average 469 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Marks Bar is about 65% below 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. Wisconsin has 9,112 active transient non-community water systems, 82% of the state's 11,056 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 10,978 Wisconsin systems (99%) list groundwater as their primary source.
Who owns and regulates Marks Bar?
EPA lists Marks Bar as privately owned. The WI state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 149 of the 196 active systems in Marathon County (76%) are also privately owned.
Does Marks Bar have drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in June 2022. The violations listed here began between January 1999 and June 2022. By type: 5 contaminant level above the legal limit, 4 public notice, recordkeeping or other and 3 monitoring and reporting. The contaminant or rule involved most often is Nitrate (8 of them). EPA lists 11 as resolved and 1 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2022-06-17 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2022-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
| 2022-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
| 2017-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
| 2004-11-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2004-10-01 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Nitratecode 1040 | No | Resolved |
| 2004-10-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2004-09-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2004-09-01 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Nitratecode 1040 | No | Resolved |
| 2004-07-30 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Nitratecode 1040 | No | Resolved |
| 2004-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 1999-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | 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.
Marks Bar: frequently asked questions
Who runs Marks Bar?
Marks Bar (PWSID WI7370462) is a transient non-community water system privately owned. It is regulated by the WI state drinking water program.
How many people does Marks Bar serve?
Marks Bar reports serving 50 people through 1 service connection in Marathon County, Wisconsin.
Where does Marks Bar 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 Marks Bar have any drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in June 2022. 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 Marks Bar'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, 5 are health-based, and the most recent began in June 2022. For current results, consult EPA ECHO, or the WI state drinking water program.
Where can I find Marks Bar's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Marks Bar 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 Marathon County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Wausau Waterworks | Marathon | 39,994 | Community | Groundwater |
| Weston Municipal Utilities | Marathon | 16,000 | Community | Groundwater |
| Kronenwetter Water & Sewer Utility | Marathon | 6,931 | Community | Groundwater |
| Rib Mountain Water Utility | Marathon | 6,398 | Community | Groundwater |
| Mosinee Waterworks | Marathon | 3,406 | Community | Groundwater |
| Rothschild Waterworks | Marathon | 3,190 | Community | Groundwater |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Marks Bar, PWSID WI7370462, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/marks-bar-wi7370462 (data as of October 1, 2026).