Skip to content
AquaCensus

Grant County, Wisconsin — public water systems

At a glance

90 active public water systems are filed under Grant County, Wisconsin in EPA's SDWIS records, together reporting 41,674 people served. The largest is Platteville Waterworks, which reports serving 12,268 people. 28 are community water systems serving people where they live; the other 62 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

90

Population served

41.7K

Community systems

28

Groundwater share

100%

How does Grant County compare with other Wisconsin counties?

Grant County has the 50th-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 41,674 people served in total, the 28th-largest county figure in the state and 0.8% of the statewide total. The average system here reports serving 463 people, roughly in line with 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 Grant County's drinking water come from?

By primary water source, Grant County's active systems draw on groundwater (90, 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, Platteville Waterworks, draws primarily on groundwater.

What kinds of water systems operate in Grant County?

Grant County's active systems break down as 28 community systems (31%), 3 non-transient non-community systems (3.3%) and 59 transient non-community systems (66%). 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 (60%), local government (23%), state government (16%) and federal government (1.1%).

The 50 largest water systems in Grant County

🔒 Create a free account to export CSV
Active public water systems in Grant County, Wisconsin
#Water systemCountyPopulation servedTypeSource
1Platteville WaterworksGrant12,268CommunityGroundwater
2Lancaster WaterworksGrant3,907CommunityGroundwater
3Boscobel WaterworksGrant3,237CommunityGroundwater
4Fennimore WaterworksGrant2,507CommunityGroundwater
5Cuba City WaterworksGrant2,141CommunityGroundwater
6Muscoda WaterworksGrant1,453CommunityGroundwater
7Hazel Green WaterworksGrant1,193CommunityGroundwater
8Dickeyville WaterworksGrant1,069CommunityGroundwater
9Wi Dot Rest Area 106 JamestownGrant880Transient non-communityGroundwater
10Cassville WaterworksGrant777CommunityGroundwater
11Potosi WaterworksGrant718CommunityGroundwater
12Montfort WaterworksGrant718CommunityGroundwater
13Bloomington WaterworksGrant682CommunityGroundwater
14Livingston WaterworksGrant664CommunityGroundwater
15Wi Dnr Wyalusing Central Pump HouseGrant600Transient non-communityGroundwater
16Kieler Sd No 1Grant560CommunityGroundwater
17Blue River WaterworksGrant424CommunityGroundwater
18Boulder Creek CampgroundGrant368Transient non-communityGroundwater
19Tennyson WaterworksGrant367CommunityGroundwater
20Bagley WaterworksGrant353CommunityGroundwater
21Wi Historical Stonefield BarnGrant303Transient non-communityGroundwater
22Wi Historical Stonefield Ag MuseumGrant300Transient non-communityGroundwater
23Wi Dnr Wyalusing Visitors StationGrant254Transient non-communityGroundwater
24River of Lakes Riverfront Campground & ResortGrant250Transient non-communityGroundwater
25Platteville Golf & Cntry ClbGrant215Transient non-communityGroundwater
26Sinsinawa Dominicans Inc.Grant213CommunityGroundwater
27Hickory Grove Country ClubGrant210Transient non-communityGroundwater
28Crossroads Supper ClubGrant208Transient non-communityGroundwater
29Mount Hope WaterworksGrant181CommunityGroundwater
30Boscobel Bowling & BanquetGrant162Transient non-communityGroundwater
31Birchwood Golf Course ClubhouseGrant160Transient non-communityGroundwater
32Patch Grove WaterworksGrant160CommunityGroundwater
33Country Heights Supper ClubGrant153Transient non-communityGroundwater
34Whitetail Bluff Camp and Resort ExpansionGrant150Transient non-communityGroundwater
35Stitzer Sanitary Dist 1Grant150CommunityGroundwater
36St Marys Catholic ChurchGrant150Transient non-communityGroundwater
37Wisconsin Badger CampGrant140Transient non-communityGroundwater
38Three Mile HouseGrant135Transient non-communityGroundwater
39Village BarGrant129Transient non-communityGroundwater
40Wi Dnr Nelson Dewey Walnut Grove Group CampGrant125Transient non-communityGroundwater
41Coconut Cove ResortGrant108Transient non-communityGroundwater
42I Dont Care Pub & GrubGrant106Transient non-communityGroundwater
43Gulers CornersGrant106Transient non-communityGroundwater
44Whitetail Bluff Camp and ResortGrant103Transient non-communityGroundwater
45Calvary Baptist ChGrant101Transient non-communityGroundwater
46Motor Boatn Bar and GrillGrant101Transient non-communityGroundwater
47Wi Dnr Nelson Dewey Maple Grove OfficeGrant100Transient non-communityGroundwater
48St Joseph Catholic SchoolGrant100Non-transient non-communityGroundwater
49Grant River Recreation AreaGrant100Transient non-communityGroundwater
50Maryville Sd 2Grant100CommunityGroundwater

All other water systems in Grant County (40)

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

Grant County water systems: frequently asked questions

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

EPA's SDWIS records file 90 active public water systems under Grant County, Wisconsin: 28 community systems (31%), 3 non-transient non-community systems (3.3%) and 59 transient non-community systems (66%).

Who supplies drinking water in Grant County, WI?

The largest community water systems filed under Grant County are Platteville Waterworks (12,268 people served), Lancaster Waterworks (3,907 people served) and Boscobel Waterworks (3,237 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 Grant County's drinking water come from groundwater or surface water?

Of the 90 active public water systems in Grant County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, Platteville Waterworks, uses groundwater.

Where can I find a water quality report for Grant 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. 28 community systems are filed under Grant 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 Grant 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 Grant County, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/grant (data as of October 1, 2026).