083090047 · Montana
MNIHNAPA WATER SYSTEM
Federal fiscal 2026Q3 · EPA violation and follow-up records
- Violation records shown
- 16
- EPA health-based flag
- 0
- Health-based records unresolved in this snapshot
- 0
- Monitoring and reporting records
- 16
Find the utility’s annual water quality report. For current advisories, check the utility or local drinking-water authority.
Violations and what followed
Among 11 resolved records with both dates, the median interval from recorded noncompliance start to EPA’s return-to-compliance date was 91 days. The interval uses the reporting periods and dates on file.
Monitoring or reporting · Resolved
Monitoring, RegularViolation 3679 · Radium-228 · Radionuclides and Revised Rad RuleNoncompliance period start January 1, 2021 · period end March 31, 2021 · first reported June 17, 2021 · EPA return-to-compliance field March 31, 2021
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 639 May 7, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3678 · Radium-226 · Radionuclides and Revised Rad RuleNoncompliance period start January 1, 2021 · period end March 31, 2021 · first reported June 17, 2021 · EPA return-to-compliance field March 31, 2021
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 639 May 7, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3677 · Combined Radium (-226 and -228) · Radionuclides and Revised Rad RuleNoncompliance period start January 1, 2021 · period end March 31, 2021 · first reported June 17, 2021 · EPA return-to-compliance field March 31, 2021
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 639 May 7, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3676 · Combined Uranium · Radionuclides and Revised Rad RuleNoncompliance period start January 1, 2021 · period end March 31, 2021 · first reported June 17, 2021 · EPA return-to-compliance field March 31, 2021
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 639 May 7, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3675 · Gross Alpha, Excl. Radon and U · Radionuclides and Revised Rad RuleNoncompliance period start January 1, 2021 · period end March 31, 2021 · first reported June 17, 2021 · EPA return-to-compliance field March 31, 2021
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 639 May 7, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3668 · Radium-228 · Radionuclides and Revised Rad RuleNoncompliance period start October 1, 2020 · period end December 31, 2020 · first reported March 31, 2021 · EPA return-to-compliance field December 31, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 633 February 18, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3667 · Radium-226 · Radionuclides and Revised Rad RuleNoncompliance period start October 1, 2020 · period end December 31, 2020 · first reported March 31, 2021 · EPA return-to-compliance field December 31, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 633 February 18, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3666 · Combined Radium (-226 and -228) · Radionuclides and Revised Rad RuleNoncompliance period start October 1, 2020 · period end December 31, 2020 · first reported March 31, 2021 · EPA return-to-compliance field December 31, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 633 February 18, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3665 · Combined Uranium · Radionuclides and Revised Rad RuleNoncompliance period start October 1, 2020 · period end December 31, 2020 · first reported March 31, 2021 · EPA return-to-compliance field December 31, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 633 February 18, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3664 · Gross Alpha, Excl. Radon and U · Radionuclides and Revised Rad RuleNoncompliance period start October 1, 2020 · period end December 31, 2020 · first reported March 31, 2021 · EPA return-to-compliance field December 31, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 633 February 18, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Follow-up Or Routine LCR Tap M/RViolation 3648 · Lead and Copper Rule · Lead and Copper RuleNoncompliance period start July 1, 2020 · period end December 15, 2021 · first reported September 23, 2020 · EPA return-to-compliance field December 15, 2021
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 640 December 15, 2021 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3674 · Radium-228 · Radionuclides and Revised Rad RuleNoncompliance period start April 1, 2020 · period end February 27, 2020 · first reported March 31, 2021 · EPA return-to-compliance field February 27, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 636 February 27, 2020 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3673 · Radium-226 · Radionuclides and Revised Rad RuleNoncompliance period start April 1, 2020 · period end February 27, 2020 · first reported March 31, 2021 · EPA return-to-compliance field February 27, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 636 February 27, 2020 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3672 · Combined Radium (-226 and -228) · Radionuclides and Revised Rad RuleNoncompliance period start April 1, 2020 · period end February 27, 2020 · first reported March 31, 2021 · EPA return-to-compliance field February 27, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 636 February 27, 2020 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3671 · Combined Uranium · Radionuclides and Revised Rad RuleNoncompliance period start April 1, 2020 · period end February 27, 2020 · first reported March 31, 2021 · EPA return-to-compliance field February 27, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 636 February 27, 2020 Resolving State Compliance achieved Monitoring or reporting · Resolved
Monitoring, RegularViolation 3670 · Gross Alpha, Excl. Radon and U · Radionuclides and Revised Rad RuleNoncompliance period start April 1, 2020 · period end February 27, 2020 · first reported March 31, 2021 · EPA return-to-compliance field February 27, 2020
1 linked action
Enforcement and resolution records linked by EPA Action ID Date Category EPA action type 636 February 27, 2020 Resolving State Compliance achieved
EPA data and scope
How to read the records
The enforcement snapshot is federal fiscal 2026Q3. The EPA archive labels its violation file October 13, 2026. EPA says federal reporting can lag by several months. For current advisories, check your utility or local drinking-water authority.
- We matched active community water systems by public water system ID between EPA’s system search and SDWIS inventory. We show violations with a recorded noncompliance, initial reporting or return-to-compliance date from 2021 onward, plus earlier records listed as Addressed or Unaddressed.
- EPA’s health-based flag identifies violations of contaminant or disinfectant limits or treatment requirements. Monitoring and reporting violations describe required tests or reports. Neither category measures household exposure.
- Addressed means EPA records formal enforcement on a violation that remains unresolved in the snapshot. Unaddressed means no formal action is recorded for an unresolved violation. Resolved can mean compliance was restored, the rule ceased to apply, or further action was unnecessary. Archived is a separate status.
- We count a violation once per water system and group its distinct linked actions. Conflicting records are set aside. Places are EPA-listed search locations and can include mailing locations. Use the provider name and system ID to identify your service.
EPA data dictionary and files · EPA reporting and enforcement FAQ · Find an annual water quality report · How to get the report from your utility