Community Water System · PWSID ID4200032

City of Mountain Home

Serves 14,651 peopleGroundwaterOwner: Local GovernmentMountain Home, Idaho
1 open treatment violation.

Open for: Revised Total Coliform Rule. EPA counts treatment-technique violations as health-based: a required protective step was not done. It is not a measurement of contamination.

On record since 2013: 88 violations. 3 treatment lapses · 83 missed or late tests · 2 notices or reports. Most recent began 2025-08-01.

None of them is a measurement of contaminated water.

For this year's test results, ask the utility for its annual Consumer Confidence Report. Every community system must publish one.

0Over the limit
3Treatment lapse1 open
83Missed or late test2 open
2Notice or report1 open

More violations on record than 97% of active water systems in Idaho. Small systems with no staff chemist often rack up missed-test violations; big utilities rarely do.

The record, year by year

200520102013 · Notice or report: 12014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 292014 · Missed or late test: 2920152017 · Treatment lapse: 12018 · Missed or late test: 12020 · Missed or late test: 120202021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282021 · Missed or late test: 282024 · Treatment lapse: 12024 · Missed or late test: 242024 · Missed or late test: 242024 · Missed or late test: 242024 · Missed or late test: 242024 · Missed or late test: 242024 · Missed or late test: 242024 · Missed or late test: 242024 · Missed or late test: 242024 · Notice or report: 12025 · Treatment lapse: 12025
One square ≈ 3 violations (rounded up), by the year they began. Empty columns are years with nothing on EPA's record.
3% treatment lapse · 394% missed or late test · 832% notice or report · 2

Across Idaho, 80% of violations are missed or late tests and 5% are water over a limit.

What you can do

  • Total Coliform Bacteria: If your water system has coliform violations, consider boiling water or using bottled water until the system confirms the issue is resolved. Contact your water provider for their latest test results and any boil-water advisories.

Lead & copper at the tap

Utilities sample taps in homes most likely to have lead pipes, and report the 90th-percentile result: 9 in 10 homes sampled came in at or below this number. Above the red line (the action level) the utility must act. The action level is not a safe level; EPA's health goal for lead is zero. EPA's file does not date these results, so they are shown highest first.

Lead, 90th percentile 4 results on file · action level 15 ppb

0 ppb
0 ppb
0 ppb
0 ppb

Open now (4)

  1. 2025-08-01Revised Total Coliform RuleTTOpen
  2. 2024-09-30E. ColiMonitoring, Source Water (GWR)Open
  3. 2024-07-22E. ColiMonitoring, Source Water (GWR)Open
  4. 2013-10-05Public NoticePN Violation for NPDWR ViolationOpen

Every violation on record

  1. 2025-08-01Revised Total Coliform RuleTTOpen
  2. 2024-10-17Lead service line inventoryRPTBack in compliance
  3. 2024-10-17Lead service line inventoryTTBack in compliance
  4. 2024-09-30E. ColiMonitoring, Source Water (GWR)Open
  5. 2024-07-22E. ColiMonitoring, Source Water (GWR)Open
  6. 2024-06-01E. ColiFailure to Conduct Assessment MonitoringPeriod ended · no return to compliance on file
  7. 2024-01-01StyreneMonitoring, RegularPeriod ended · no return to compliance on file
  8. 2024-01-01EthylbenzeneMonitoring, RegularPeriod ended · no return to compliance on file
  9. 2024-01-01TolueneMonitoring, RegularPeriod ended · no return to compliance on file
  10. 2024-01-01BenzeneMonitoring, RegularPeriod ended · no return to compliance on file
  11. 2024-01-01ChlorobenzeneMonitoring, RegularPeriod ended · no return to compliance on file
  12. 2024-01-01TetrachloroethyleneMonitoring, RegularPeriod ended · no return to compliance on file
  13. 2024-01-011,1,2-TrichloroethaneMonitoring, RegularPeriod ended · no return to compliance on file
  14. 2024-01-01TrichloroethyleneMonitoring, RegularPeriod ended · no return to compliance on file
  15. 2024-01-011,2-DichloropropaneMonitoring, RegularPeriod ended · no return to compliance on file
  16. 2024-01-01Carbon tetrachlorideMonitoring, RegularPeriod ended · no return to compliance on file
  17. 2024-01-011,1,1-TrichloroethaneMonitoring, RegularPeriod ended · no return to compliance on file
  18. 2024-01-011,2-DichloroethaneMonitoring, RegularPeriod ended · no return to compliance on file
  19. 2024-01-01trans-1,2-DichloroethyleneMonitoring, RegularPeriod ended · no return to compliance on file
  20. 2024-01-011,1-DichloroethyleneMonitoring, RegularPeriod ended · no return to compliance on file
  21. 2024-01-01Vinyl chlorideMonitoring, RegularPeriod ended · no return to compliance on file
  22. 2024-01-01p-DichlorobenzeneMonitoring, RegularPeriod ended · no return to compliance on file
  23. 2024-01-01o-DichlorobenzeneMonitoring, RegularPeriod ended · no return to compliance on file
  24. 2024-01-01DichloromethaneMonitoring, RegularPeriod ended · no return to compliance on file
  25. 2024-01-01Xylenes, TotalMonitoring, RegularPeriod ended · no return to compliance on file
Show the other 63 entries
  1. 2024-01-01cis-1,2-DichloroethyleneMonitoring, RegularPeriod ended · no return to compliance on file
  2. 2024-01-011,2,4-TrichlorobenzeneMonitoring, RegularPeriod ended · no return to compliance on file
  3. 2021-10-01Combined UraniumMonitoring, RegularBack in compliance
  4. 2021-10-01Radium-228Monitoring, RegularBack in compliance
  5. 2021-10-01Radium-226Monitoring, RegularBack in compliance
  6. 2021-10-01Gross Alpha, Excl. Radon and UMonitoring, RegularBack in compliance
  7. 2021-10-01StyreneMonitoring, RegularBack in compliance
  8. 2021-10-01EthylbenzeneMonitoring, RegularBack in compliance
  9. 2021-10-01TolueneMonitoring, RegularBack in compliance
  10. 2021-10-01BenzeneMonitoring, RegularBack in compliance
  11. 2021-10-01ChlorobenzeneMonitoring, RegularBack in compliance
  12. 2021-10-01TetrachloroethyleneMonitoring, RegularBack in compliance
  13. 2021-10-011,1,2-TrichloroethaneMonitoring, RegularBack in compliance
  14. 2021-10-01TrichloroethyleneMonitoring, RegularBack in compliance
  15. 2021-10-011,2-DichloropropaneMonitoring, RegularBack in compliance
  16. 2021-10-01Carbon tetrachlorideMonitoring, RegularBack in compliance
  17. 2021-10-011,1,1-TrichloroethaneMonitoring, RegularBack in compliance
  18. 2021-10-011,2-DichloroethaneMonitoring, RegularBack in compliance
  19. 2021-10-01trans-1,2-DichloroethyleneMonitoring, RegularBack in compliance
  20. 2021-10-011,1-DichloroethyleneMonitoring, RegularBack in compliance
  21. 2021-10-01Vinyl chlorideMonitoring, RegularBack in compliance
  22. 2021-10-01p-DichlorobenzeneMonitoring, RegularBack in compliance
  23. 2021-10-01o-DichlorobenzeneMonitoring, RegularBack in compliance
  24. 2021-10-01DichloromethaneMonitoring, RegularBack in compliance
  25. 2021-10-01Xylenes, TotalMonitoring, RegularBack in compliance
  26. 2021-10-01cis-1,2-DichloroethyleneMonitoring, RegularBack in compliance
  27. 2021-10-011,2,4-TrichlorobenzeneMonitoring, RegularBack in compliance
  28. 2021-10-01DiquatMonitoring, RegularBack in compliance
  29. 2021-10-01EndothallMonitoring, RegularBack in compliance
  30. 2021-01-01NitrateMonitoring, RegularPeriod ended · no return to compliance on file
  31. 2020-10-01NitrateMonitoring, RegularBack in compliance
  32. 2018-09-01E. ColiFailure to Conduct Assessment MonitoringBack in compliance
  33. 2017-08-12Revised Total Coliform RuleTTBack in compliance
  34. 2014-01-01ChlordaneMonitoring, RegularBack in compliance
  35. 2014-01-01Ethylene DibromideMonitoring, RegularBack in compliance
  36. 2014-01-011, 2-Dibromo-3-ChloropropaneMonitoring, RegularBack in compliance
  37. 2014-01-01Total Polychlorinated Biphenyls (PCB)Monitoring, RegularBack in compliance
  38. 2014-01-01PentachlorophenolMonitoring, RegularBack in compliance
  39. 2014-01-01Benzo(a)pyreneMonitoring, RegularBack in compliance
  40. 2014-01-01HexachlorobenzeneMonitoring, RegularBack in compliance
  41. 2014-01-012, 4, 5-TpMonitoring, RegularBack in compliance
  42. 2014-01-012, 4-DMonitoring, RegularBack in compliance
  43. 2014-01-01Heptachlor epoxideMonitoring, RegularBack in compliance
  44. 2014-01-01HeptachlorMonitoring, RegularBack in compliance
  45. 2014-01-01LassoMonitoring, RegularBack in compliance
  46. 2014-01-01AtrazineMonitoring, RegularBack in compliance
  47. 2014-01-01CarbofuranMonitoring, RegularBack in compliance
  48. 2014-01-01HexachlorocyclopentadieneMonitoring, RegularBack in compliance
  49. 2014-01-01DinosebMonitoring, RegularBack in compliance
  50. 2014-01-01PicloramMonitoring, RegularBack in compliance
  51. 2014-01-01Di(2-ethylhexyl) phthalateMonitoring, RegularBack in compliance
  52. 2014-01-01SimazineMonitoring, RegularBack in compliance
  53. 2014-01-01OxamylMonitoring, RegularBack in compliance
  54. 2014-01-01Di(2-ethylhexyl) adipateMonitoring, RegularBack in compliance
  55. 2014-01-01GlyphosateMonitoring, RegularBack in compliance
  56. 2014-01-01EndothallMonitoring, RegularBack in compliance
  57. 2014-01-01DiquatMonitoring, RegularBack in compliance
  58. 2014-01-01DalaponMonitoring, RegularBack in compliance
  59. 2014-01-01ToxapheneMonitoring, RegularBack in compliance
  60. 2014-01-01MethoxychlorMonitoring, RegularBack in compliance
  61. 2014-01-01Bhc-GammaMonitoring, RegularBack in compliance
  62. 2014-01-01EndrinMonitoring, RegularBack in compliance
  63. 2013-10-05Public NoticePN Violation for NPDWR ViolationOpen

System details

Population served14,651
Service connections5,842
Water sourceGroundwater
System typeCommunity Water System
OwnerLocal Government
StatusActive
CityMountain Home
EPA ZIP on file83647

Areas served

  • Elmore County

Reading this record

City of Mountain Home is a community water system that draws from groundwater and serves about 14,651 people in Mountain Home, Idaho. Everything above comes from the EPA's Safe Drinking Water Information System (SDWIS), where states report every violation by every public water system.

Four kinds of violation. Only one is a measurement of the water: over the limit means a test came back above a legal maximum (an MCL). A treatment lapse means a required protective step was not done, such as disinfection, filtration, fixing a defect an inspector found, or filing a lead-pipe inventory. A missed or late test means a required test was skipped or never reported. That is the most common kind, and the most misread: it does not mean the water was bad, and it does not mean the water was fine. Notices and reports covers public notices and the annual Consumer Confidence Report.

Status. “Back in compliance” means the state recorded a return to compliance. “Period ended” means the violation's compliance period is over but no return to compliance was ever filed, which is common in older records. EPA's federal copy lags state records by months, so call the utility for anything current.