Lake County, Wisconsin — public water systems
At a glance
3 active public water systems are filed under Lake County, Wisconsin in EPA's SDWIS records, together reporting 1,550 people served. The largest is Millburn School Dist #24, which reports serving 650 people.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
3
Population served
1.6K
Community systems
—
Groundwater share
100%
How does Lake County compare with other Wisconsin counties?
Lake County has the 73rd-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 1,550 people served in total, the 72nd-largest county figure in the state and less than 0.1% of the statewide total. The average system here reports serving 517 people, about 10% 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 Lake County's drinking water come from?
By primary water source, Lake County's active systems draw on groundwater (3, 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, Millburn School Dist #24, draws primarily on groundwater.
What kinds of water systems operate in Lake County?
Lake County's active systems break down as 2 non-transient non-community systems (67%) and 1 transient non-community systems (33%). 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 (67%) and local government (33%).
Water systems in Lake County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Millburn School Dist #24 | Lake | 650 | Non-transient non-community | Groundwater |
| 2 | Supermart Shell | Lake | 500 | Transient non-community | Groundwater |
| 3 | Millburn School | Lake | 400 | Non-transient non-community | Groundwater |
Lake County water systems: frequently asked questions
How many public water systems are in Lake County, Wisconsin?
EPA's SDWIS records file 3 active public water systems under Lake County, Wisconsin: 2 non-transient non-community systems (67%) and 1 transient non-community systems (33%).
Does Lake County's drinking water come from groundwater or surface water?
Of the 3 active public water systems in Lake County, all draw mainly on groundwater and none on surface water, counting purchased supplies. The largest system, Millburn School Dist #24, uses groundwater.
Where can I find a water quality report for Lake 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.
How can I check violations for a water system in Lake 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 Lake County, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/lake (data as of October 1, 2026).