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Fergus County, Montana — public water systems

At a glance

21 active public water systems are filed under Fergus County, Montana in EPA's SDWIS records, together reporting 11,187 people served. The largest is City of Lewistown, which reports serving 5,923 people. 11 are community water systems serving people where they live; the other 10 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

21

Population served

11.2K

Community systems

11

Groundwater share

95.2%

How does Fergus County compare with other Montana counties?

Fergus County has the 22nd-most active public water systems among the 76 counties listed for active Montana systems in EPA records; among the 55 with 3 or more systems, the median has 16. Its systems report 11,187 people served in total, the 15th-largest county figure in the state and 1% of the statewide total. The average system here reports serving 533 people, roughly in line with the Montana average of 489. 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 Fergus County's drinking water come from?

By primary water source, Fergus County's active systems draw on groundwater (17, 81%), purchased groundwater (3, 14%) and surface water (1, 4.8%). Overall, 95% rely mainly on groundwater (including purchased groundwater) and 4.8% on surface water, compared with 89% and 11% across Montana. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of Lewistown, draws primarily on groundwater.

What kinds of water systems operate in Fergus County?

Fergus County's active systems break down as 11 community systems (52%), 2 non-transient non-community systems (9.5%) and 8 transient non-community systems (38%). 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 (71%) and local government (29%).

Water systems in Fergus County

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Active public water systems in Fergus County, Montana
#Water systemCountyPopulation servedTypeSource
1Lewistown City ofFergus5,923CommunityGroundwater
2Lehrkinds Big Spring WaterFergus2,575Non-transient non-communityPurchased groundwater
3Eddies CornerFergus503Transient non-communityGroundwater
4K-M Scout Ranch Water SystemFergus325Transient non-communityGroundwater
5Mountain Acres Mb Hm PkFergus320CommunityPurchased groundwater
6Winifred Town ofFergus274CommunityGroundwater
7Denton Town ofFergus255CommunitySurface water
8Moore Town ofFergus186CommunityGroundwater
9Pine Meadows Golf Course Elks 456 theFergus130Transient non-communityGroundwater
10Roy Water and Sewer DistrictFergus110CommunityGroundwater
11Grass Range Town ofFergus102CommunityGroundwater
12Big Sky Grocery UnapprovedFergus90Transient non-communityGroundwater
13Hi Heat Industries Inc.Fergus75Non-transient non-communityGroundwater
14Ayers Hutterite ColonyFergus58CommunityGroundwater
15King Ranch ColonyFergus56CommunityGroundwater
16Deerfield Hutterite ColonyFergus51CommunityGroundwater
17Spring Creek Colony LewistownFergus48CommunityGroundwater
18Judith Mountain Lodge UnapprovedFergus30Transient non-communityGroundwater
19The HideawayFergus26Transient non-communityGroundwater
20Judith Shadows Golf CourseFergus25Transient non-communityGroundwater
21Town & Country LewistownFergus25Transient non-communityPurchased groundwater

Fergus County water systems: frequently asked questions

How many public water systems are in Fergus County, Montana?

EPA's SDWIS records file 21 active public water systems under Fergus County, Montana: 11 community systems (52%), 2 non-transient non-community systems (9.5%) and 8 transient non-community systems (38%).

Who supplies drinking water in Fergus County, MT?

The largest community water systems filed under Fergus County are City of Lewistown (5,923 people served), Mountain Acres Mb Hm Pk (320 people served) and Town of Winifred (274 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 Fergus County's drinking water come from groundwater or surface water?

Of the 21 active public water systems in Fergus County, 95% draw mainly on groundwater and 4.8% on surface water, counting purchased supplies. The largest system, City of Lewistown, uses groundwater.

Where can I find a water quality report for Fergus 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. 11 community systems are filed under Fergus 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 Fergus 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 Montana 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 Fergus County, Montana”, https://aquacensus.com/water-systems/montana/fergus (data as of October 1, 2026).