Elmore County, Idaho — public water systems
At a glance
44 active public water systems are filed under Elmore County, Idaho in EPA's SDWIS records, together reporting 26,726 people served. The largest is City of Mountain Home, which reports serving 14,651 people. 24 are community water systems serving people where they live; the other 20 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
44
Population served
26.7K
Community systems
24
Groundwater share
95.5%
How does Elmore County compare with other Idaho counties?
Elmore County has the 16th-most active public water systems among the 64 counties listed for active Idaho systems in EPA records; among the 47 with 3 or more systems, the median has 27. Its systems report 26,726 people served in total, the 12th-largest county figure in the state and 1.5% of the statewide total. The average system here reports serving 607 people, about 32% below the Idaho average of 899. 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 Elmore County's drinking water come from?
By primary water source, Elmore County's active systems draw on groundwater (40, 91%), surface water (2, 4.5%), groundwater under influence of surface water (1, 2.3%) and purchased groundwater (1, 2.3%). Overall, 95% rely mainly on groundwater (including purchased groundwater) and 4.5% on surface water, compared with 96% and 4.1% across Idaho. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of Mountain Home, draws primarily on groundwater.
What kinds of water systems operate in Elmore County?
Elmore County's active systems break down as 24 community systems (55%), 2 non-transient non-community systems (4.5%) and 18 transient non-community systems (41%). 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 (89%), local government (6.8%) and federal government (4.5%).
Water systems in Elmore County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Mountain Home, City of | Elmore | 14,651 | Community | Groundwater |
| 2 | Mountain Home Air Force Base | Elmore | 7,500 | Community | Groundwater |
| 3 | Glenns Ferry City of | Elmore | 1,282 | Community | Surface water |
| 4 | Trinity Estates Water Users Assn | Elmore | 250 | Community | Groundwater |
| 5 | Mellen Subd Water Dist | Elmore | 250 | Community | Purchased groundwater |
| 6 | Canyon Creek Mobile Home Park | Elmore | 243 | Community | Groundwater |
| 7 | Summerwind Water Users | Elmore | 192 | Community | Groundwater |
| 8 | Sawtooth Estates Water Users | Elmore | 175 | Community | Groundwater |
| 9 | LDS Church Mountain Home Airbase | Elmore | 150 | Transient non-community | Groundwater |
| 10 | Blue Sage Subdivision | Elmore | 112 | Community | Groundwater |
| 11 | Elk Valley Resort | Elmore | 100 | Transient non-community | Groundwater |
| 12 | Simplot Livestock Company Grandview | Elmore | 100 | Community | Groundwater |
| 13 | Hamilton Place | Elmore | 97 | Community | Groundwater |
| 14 | Atlanta Water Assn | Elmore | 91 | Community | Surface water |
| 15 | Splendid Acres Water Assn | Elmore | 91 | Community | Groundwater |
| 16 | Trinity View Resort | Elmore | 90 | Transient non-community | Groundwater |
| 17 | King Hill Domestic Water and Sewer | Elmore | 87 | Community | Groundwater |
| 18 | Town and Country Water Users Assn | Elmore | 86 | Community | Groundwater |
| 19 | Pleasant Acres Mobile Home Park | Elmore | 85 | Community | Groundwater |
| 20 | New Horizons Water Inc. | Elmore | 85 | Community | Groundwater |
| 21 | Mountain Home Migrant Head Start | Elmore | 78 | Non-transient non-community | Groundwater |
| 22 | Tlk | Elmore | 75 | Non-transient non-community | Groundwater |
| 23 | Oakleaf Subdivision | Elmore | 71 | Community | Groundwater |
| 24 | Mountain Sage | Elmore | 65 | Community | Groundwater |
| 25 | Hammett Haven Apartments | Elmore | 64 | Community | Groundwater |
| 26 | Featherville Townsite Water Corp | Elmore | 60 | Community | Groundwater under influence of surface water |
| 27 | Danskin Properties Association Inc. | Elmore | 52 | Community | Groundwater |
| 28 | Desert Winds Chevron | Elmore | 50 | Transient non-community | Groundwater |
| 29 | Key Mart Corner | Elmore | 50 | Transient non-community | Groundwater |
| 30 | Camas Estates Water Users | Elmore | 50 | Community | Groundwater |
| 31 | Riverview Subd Water Assn | Elmore | 45 | Transient non-community | Groundwater |
| 32 | Paradise Homeowners Assn Inc. | Elmore | 43 | Transient non-community | Groundwater |
| 33 | Silver Sage Real Property Owners Assn | Elmore | 30 | Community | Groundwater |
| 34 | Shiok | Elmore | 26 | Transient non-community | Groundwater |
| 35 | Pine Resort | Elmore | 26 | Transient non-community | Groundwater |
| 36 | Nitz' Pine Store | Elmore | 25 | Transient non-community | Groundwater |
| 37 | Y-Stop General Store | Elmore | 25 | Transient non-community | Groundwater |
| 38 | Mountain Home Afb Cj Strike Dam Rec Ctr | Elmore | 25 | Transient non-community | Groundwater |
| 39 | South Fork Senior Center | Elmore | 25 | Transient non-community | Groundwater |
| 40 | Mcguires Subd | Elmore | 25 | Transient non-community | Groundwater |
| 41 | Fall Creek Recreational Retreat | Elmore | 25 | Transient non-community | Groundwater |
| 42 | Bakers Acres Association Inc. | Elmore | 25 | Transient non-community | Groundwater |
| 43 | Cj Strike North Park | Elmore | 25 | Transient non-community | Groundwater |
| 44 | Ballantyne Camp Subd 1 | Elmore | 24 | Transient non-community | Groundwater |
Elmore County water systems: frequently asked questions
How many public water systems are in Elmore County, Idaho?
EPA's SDWIS records file 44 active public water systems under Elmore County, Idaho: 24 community systems (55%), 2 non-transient non-community systems (4.5%) and 18 transient non-community systems (41%).
Who supplies drinking water in Elmore County, ID?
The largest community water systems filed under Elmore County are City of Mountain Home (14,651 people served), Mountain Home Air Force Base (7,500 people served) and City of Glenns Ferry (1,282 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 Elmore County's drinking water come from groundwater or surface water?
Of the 44 active public water systems in Elmore County, 95% draw mainly on groundwater and 4.5% on surface water, counting purchased supplies. The largest system, City of Mountain Home, uses groundwater.
Where can I find a water quality report for Elmore 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. 24 community systems are filed under Elmore 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 Elmore 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 Idaho 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 Elmore County, Idaho”, https://aquacensus.com/water-systems/idaho/elmore (data as of October 1, 2026).