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Marathon County, Wisconsin — public water systems

At a glance

196 active public water systems are filed under Marathon County, Wisconsin in EPA's SDWIS records, together reporting 103,490 people served. The largest is Wausau Waterworks, which reports serving 39,994 people. 23 are community water systems serving people where they live; the other 173 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.

Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

196

Population served

103.5K

Community systems

23

Groundwater share

100%

How does Marathon County compare with other Wisconsin counties?

Marathon County has the 18th-most active public water systems among the 90 counties listed for active Wisconsin systems in EPA records; among the 74 with 3 or more systems, the median has 140. Its systems report 103,490 people served in total, the 12th-largest county figure in the state and 2% of the statewide total. The average system here reports serving 528 people, about 13% above the Wisconsin average of 469. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.

Where does Marathon County's drinking water come from?

By primary water source, Marathon County's active systems draw on groundwater (196, 100%). Overall, all rely mainly on groundwater (including purchased groundwater) and none on surface water, compared with 99% and 0.6% across Wisconsin. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Wausau Waterworks, draws primarily on groundwater.

What kinds of water systems operate in Marathon County?

Marathon County's active systems break down as 23 community systems (12%), 21 non-transient non-community systems (11%) and 152 transient non-community systems (78%). 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. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. 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. EPA lists their owner types as private (76%), local government (22%), state government (1%) and public/private partnership (1%).

The 50 largest water systems in Marathon County

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Active public water systems in Marathon County, Wisconsin
#Water systemCountyPopulation servedTypeSource
1Wausau WaterworksMarathon39,994CommunityGroundwater
2Weston Municipal UtilitiesMarathon16,000CommunityGroundwater
3Kronenwetter Water & Sewer UtilityMarathon6,931CommunityGroundwater
4Rib Mountain Water UtilityMarathon6,398CommunityGroundwater
5Mosinee WaterworksMarathon3,406CommunityGroundwater
6Rothschild WaterworksMarathon3,190CommunityGroundwater
7Abbotsford WaterworksMarathon2,502CommunityGroundwater
8Schofield WaterworksMarathon2,205CommunityGroundwater
9Spencer WaterworksMarathon1,848CommunityGroundwater
10Colby WaterworksMarathon1,829CommunityGroundwater
11Marathon City WaterworksMarathon1,695CommunityGroundwater
12Stratford WaterworksMarathon1,643CommunityGroundwater
13Edgar WaterworksMarathon1,491CommunityGroundwater
14Mosinee East SystemMarathon1,046CommunityGroundwater
15Athens WaterworksMarathon1,025CommunityGroundwater
16Holy Family Catholic ChurchMarathon800Transient non-communityGroundwater
17Riverside Elementary SchoolMarathon590Non-transient non-communityGroundwater
18Hatley WaterworksMarathon550CommunityGroundwater
19Land O Lakes Inc. Cheese DivMarathon350Non-transient non-communityGroundwater
20St LadislausMarathon300Transient non-communityGroundwater
21New Hope Community ChurchMarathon300Transient non-communityGroundwater
22Maine Water UtilityMarathon271CommunityGroundwater
23Maine Elementary SchoolMarathon255Non-transient non-communityGroundwater
24Stoney AcresMarathon254Transient non-communityGroundwater
25Ntc Ag CenterMarathon225Non-transient non-communityGroundwater
26St Thomas Catholic ChurchMarathon225Transient non-communityGroundwater
27Mullins Cheese FactoryMarathon200Non-transient non-communityGroundwater
28Red Granite BarMarathon175Transient non-communityGroundwater
29St. John Lutheran SchoolMarathon151Non-transient non-communityGroundwater
30Maizefield Mhc (Manufactured Home Community)Marathon145CommunityGroundwater
31Bethany Lutheran ChurchMarathon140Transient non-communityGroundwater
32Boardwalk Mhc LLCMarathon130CommunityGroundwater
33Belvedere Supper ClubMarathon125Transient non-communityGroundwater
34Deer Trail VillageMarathon120CommunityGroundwater
35Knowlton House DistilleryMarathon120Transient non-communityGroundwater
36Ntc Vet Tech LabMarathon115Non-transient non-communityGroundwater
37Obrien SteelMarathon108Non-transient non-communityGroundwater
38Mullins Cheese Retail StoreMarathon106Transient non-communityGroundwater
39Trappe River Golf ClubMarathon100Transient non-communityGroundwater
40Trails End LodgeMarathon100Transient non-communityGroundwater
41G S A Camp Del O ClaireMarathon100Transient non-communityGroundwater
42Mission EvangelicalMarathon100Transient non-communityGroundwater
43Maple Grove Charter SchoolMarathon100Non-transient non-communityGroundwater
44Lake Dubay ShoresMarathon100Transient non-communityGroundwater
45Pine Valley Golf CourseMarathon100Transient non-communityGroundwater
46Steve & Dianes Memories BallroomMarathon100Transient non-communityGroundwater
47Veritas Steel 1Marathon89Non-transient non-communityGroundwater
48Veritas Steel 2Marathon89Non-transient non-communityGroundwater
49Wild Steer DinerMarathon80Transient non-communityGroundwater
50Camp Sturtevant 1Marathon80Transient non-communityGroundwater

All other water systems in Marathon County (146)

The remaining active systems filed under Marathon County, largest first, with the population each reports serving.

Marathon County water systems: frequently asked questions

How many public water systems are in Marathon County, Wisconsin?

EPA's SDWIS records file 196 active public water systems under Marathon County, Wisconsin: 23 community systems (12%), 21 non-transient non-community systems (11%) and 152 transient non-community systems (78%).

Who supplies drinking water in Marathon County, WI?

The largest community water systems filed under Marathon County are Wausau Waterworks (39,994 people served), Weston Municipal Utilities (16,000 people served) and Kronenwetter Water & Sewer Utility (6,931 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.

Does Marathon County's drinking water come from groundwater or surface water?

Of the 196 active public water systems in Marathon County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, Wausau Waterworks, uses groundwater.

Where can I find a water quality report for Marathon County?

Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 23 community systems are filed under Marathon County, so the report to look for is the one from the system that supplies your address.

How can I check violations for a water system in Marathon County?

Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.

More Wisconsin water systems

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, “Public water systems in Marathon County, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/marathon (data as of October 1, 2026).