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| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Platteville Waterworks | Grant | 12,268 | Community | Groundwater |
| 2 | Lancaster Waterworks | Grant | 3,907 | Community | Groundwater |
| 3 | Boscobel Waterworks | Grant | 3,237 | Community | Groundwater |
| 4 | Fennimore Waterworks | Grant | 2,507 | Community | Groundwater |
| 5 | Cuba City Waterworks | Grant | 2,141 | Community | Groundwater |
| 6 | Muscoda Waterworks | Grant | 1,453 | Community | Groundwater |
| 7 | Hazel Green Waterworks | Grant | 1,193 | Community | Groundwater |
| 8 | Dickeyville Waterworks | Grant | 1,069 | Community | Groundwater |
| 9 | Wi Dot Rest Area 106 Jamestown | Grant | 880 | Transient non-community | Groundwater |
| 10 | Cassville Waterworks | Grant | 777 | Community | Groundwater |
| 11 | Potosi Waterworks | Grant | 718 | Community | Groundwater |
| 12 | Montfort Waterworks | Grant | 718 | Community | Groundwater |
| 13 | Bloomington Waterworks | Grant | 682 | Community | Groundwater |
| 14 | Livingston Waterworks | Grant | 664 | Community | Groundwater |
| 15 | Wi Dnr Wyalusing Central Pump House | Grant | 600 | Transient non-community | Groundwater |
| 16 | Kieler Sd No 1 | Grant | 560 | Community | Groundwater |
| 17 | Blue River Waterworks | Grant | 424 | Community | Groundwater |
| 18 | Boulder Creek Campground | Grant | 368 | Transient non-community | Groundwater |
| 19 | Tennyson Waterworks | Grant | 367 | Community | Groundwater |
| 20 | Bagley Waterworks | Grant | 353 | Community | Groundwater |
| 21 | Wi Historical Stonefield Barn | Grant | 303 | Transient non-community | Groundwater |
| 22 | Wi Historical Stonefield Ag Museum | Grant | 300 | Transient non-community | Groundwater |
| 23 | Wi Dnr Wyalusing Visitors Station | Grant | 254 | Transient non-community | Groundwater |
| 24 | River of Lakes Riverfront Campground & Resort | Grant | 250 | Transient non-community | Groundwater |
| 25 | Platteville Golf & Cntry Clb | Grant | 215 | Transient non-community | Groundwater |
| 26 | Sinsinawa Dominicans Inc. | Grant | 213 | Community | Groundwater |
| 27 | Hickory Grove Country Club | Grant | 210 | Transient non-community | Groundwater |
| 28 | Crossroads Supper Club | Grant | 208 | Transient non-community | Groundwater |
| 29 | Mount Hope Waterworks | Grant | 181 | Community | Groundwater |
| 30 | Boscobel Bowling & Banquet | Grant | 162 | Transient non-community | Groundwater |
| 31 | Birchwood Golf Course Clubhouse | Grant | 160 | Transient non-community | Groundwater |
| 32 | Patch Grove Waterworks | Grant | 160 | Community | Groundwater |
| 33 | Country Heights Supper Club | Grant | 153 | Transient non-community | Groundwater |
| 34 | Whitetail Bluff Camp and Resort Expansion | Grant | 150 | Transient non-community | Groundwater |
| 35 | Stitzer Sanitary Dist 1 | Grant | 150 | Community | Groundwater |
| 36 | St Marys Catholic Church | Grant | 150 | Transient non-community | Groundwater |
| 37 | Wisconsin Badger Camp | Grant | 140 | Transient non-community | Groundwater |
| 38 | Three Mile House | Grant | 135 | Transient non-community | Groundwater |
| 39 | Village Bar | Grant | 129 | Transient non-community | Groundwater |
| 40 | Wi Dnr Nelson Dewey Walnut Grove Group Camp | Grant | 125 | Transient non-community | Groundwater |
| 41 | Coconut Cove Resort | Grant | 108 | Transient non-community | Groundwater |
| 42 | I Dont Care Pub & Grub | Grant | 106 | Transient non-community | Groundwater |
| 43 | Gulers Corners | Grant | 106 | Transient non-community | Groundwater |
| 44 | Whitetail Bluff Camp and Resort | Grant | 103 | Transient non-community | Groundwater |
| 45 | Calvary Baptist Ch | Grant | 101 | Transient non-community | Groundwater |
| 46 | Motor Boatn Bar and Grill | Grant | 101 | Transient non-community | Groundwater |
| 47 | Wi Dnr Nelson Dewey Maple Grove Office | Grant | 100 | Transient non-community | Groundwater |
| 48 | St Joseph Catholic School | Grant | 100 | Non-transient non-community | Groundwater |
| 49 | Grant River Recreation Area | Grant | 100 | Transient non-community | Groundwater |
| 50 | Maryville Sd 2 | Grant | 100 | Community | Groundwater |
All other water systems in Grant County (40)
The remaining active systems filed under Grant County, largest first, with the population each reports serving.
- Oak Park Community90
- Castle Rock Inn85
- Cozy Acres MHP80
- Patriot Park80
- Dew Drop Inn76
- Happy Hooves LLC75
- Wi Dnr Wyalusing Indoor Group Camp75
- Big H Campground75
- Biddick Inc.75
- Wi Dnr Wilson State Nursery Shop70
- Ritchie Implement65
- Beetown Assembly60
- Fenmore Hills Motel & Apartments58
- Up the Street56
- Sandy Hook Tavern55
- Yoders Rockville Bar53
- Mccartney Corners52
- Burton Tavern51
- Country Care Childrens Center48
- Lyghthouse LLC47
- Milk Specialties Global Company Dba Actus Nutrition45
- Midwest Motor Sports43
- Potosi Community Bible Church40
- Gracies Point40
- Bluffside Court40
- Wi Dnr Nelson Dewey Campground40
- Stateline Mobile Home Park37
- Wi Dnr Wyalusing Homestead Campground35
- Wi Dnr Wyalusing Wi Ridge Shower Building35
- Valley Pub34
- Gerg LLC34
- Ellenboro Saloon34
- River of Lakes Resort Office33
- River Vista Estates LLC30
- Wi Dnr Wyalusing Shop & Residence30
- Midway Pub30
- Yesterdaze Ii29
- Denlinger Orthodontic28
- Wi Historical Stonefield Confectionary27
- Cottonwood Sports Bar & Banquet25
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).