Does Helena, MT tap water have any EPA-reported violations?

As of June 2026, EPA SDWIS records show 837 violation(s) across the community water systems serving Helena, of which 80 are classified by the EPA as health-based. Most older violations have returned to compliance; see the per-system list.

Where does Helena, MT tap water come from?

Helena is served by 39 active community water system(s). Their primary sources, per EPA records, are: surface water, groundwater.

MT / Helena

MT · Tap water records

Helena tap water, in plain English

Here is what the EPA's own data shows about tap water in Helena. According to EPA SDWIS data retrieved June 2026, Helena is served by 39 active community water systems, together reported to serve about 39,636 people.

As of June 2026, EPA records show 837 violations across the community water system(s) serving Helena, going back to the earliest EPA record. 80 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.

39

Community water systems
~39,636

People served (EPA-reported)
June 2026

EPA records reviewed through

What the EPA has on record, by system

Helena Water System

32,091 served · surface water · PWSID MT0000241

Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 12 times between July 2022 and January 2023. The EPA record lists a level of 0.066 MG/L; the limit (MCL) is 0.06 MG/L. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2011. All have since returned to compliance, per EPA records.
Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2008. EPA records do not show all of these as returned to compliance.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2001 and October 2007. All have since returned to compliance, per EPA records.

Helena Leisure Llc

1,200 served · groundwater · PWSID MT0000590

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2010 and December 2024. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in March 2023. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2008 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Gross Alpha, Excl. Radon and U: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2021. All have since returned to compliance, per EPA records.
Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2020 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2021. All have since returned to compliance, per EPA records.
Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring CYANIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring Total Polychlorinated Biphenyls (PCB): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,2-DIBROMO-3-CHLOROPROPANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in June 2015. All have since returned to compliance, per EPA records.

Jefferson Hills Wua

780 served · groundwater · PWSID MT0002978

Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in June 2023. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between October 2007 and December 2024. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2022 and July 2023. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2020. All have since returned to compliance, per EPA records.
Monitoring CYANIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Diquat: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Endothall: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Glyphosate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Total Polychlorinated Biphenyls (PCB): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring 1,2-DIBROMO-3-CHLOROPROPANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring ETHYLENE DIBROMIDE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.

Ten Mile And Pleasant Valley Wua

750 served · groundwater · PWSID MT0002005

Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times in April 2024. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between July 2005 and January 2026. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 11 times between July 2007 and October 2023. All have since returned to compliance, per EPA records.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2021 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in June 2021. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2014. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2014. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between September 2011 and May 2014. All have since returned to compliance, per EPA records.

North Star Pud

715 served · groundwater · PWSID MT0004264

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2005 and October 2025. All have since returned to compliance, per EPA records.
Monitoring Manganese: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2024. EPA records do not show all of these as returned to compliance.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in April 2016. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2007. All have since returned to compliance, per EPA records.

Treasure State Acres Wua

483 served · groundwater · PWSID MT0002390

Monitoring Barium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Cadmium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Chromium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Fluoride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Selenium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2004 and January 2014. All have since returned to compliance, per EPA records.

Ncmrwa North Shelby

300 served · groundwater · PWSID MT0005064

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between September 2021 and April 2025. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between January 2021 and January 2022. EPA records do not show all of these as returned to compliance.
Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between June 2021 and July 2021. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in March 2021. All have since returned to compliance, per EPA records.

Ranchview Estates Wua

250 served · groundwater · PWSID MT0003782

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between October 2002 and December 2024. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2007 and July 2022. All have since returned to compliance, per EPA records.

Ryan Dam Water System

230 served · groundwater · PWSID MT0000046

Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in May 2023. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in April 2023. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2008 and July 2019. All have since returned to compliance, per EPA records.
Monitoring Groundwater Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2018 and July 2019. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 1993 and October 2012. All have since returned to compliance, per EPA records.
Monitoring Gross Alpha, Excl. Radon and U: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2008. All have since returned to compliance, per EPA records.
Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2008. All have since returned to compliance, per EPA records.

Holmberg Village Estates

225 served · groundwater · PWSID MT0004190

Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in October 2025. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2007. All have since returned to compliance, per EPA records.

Glacier Point Ho And Wua

210 served · groundwater · PWSID MT0004559

Health-based Revised Total Coliform Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in August 2020. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between October 2022 and September 2023. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2011 and July 2014. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2010. All have since returned to compliance, per EPA records.

Ncmrwa Tiber Service Area

200 served · surface water · PWSID MT0004719

Health-based Total Haloacetic Acids (HAA5): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 28 times between April 2019 and July 2024. The EPA record lists a level of 90 UG/L; the limit (MCL) is 60 UG/L. EPA records do not show all of these as returned to compliance.
Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in January 2020. The EPA record lists a level of 83 UG/L; the limit (MCL) is 80 UG/L. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between October 2015 and January 2017. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between October 2015 and January 2017. All have since returned to compliance, per EPA records.

Town View Estates Wua Inc

175 served · groundwater · PWSID MT0002172

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2022. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between July 2006 and July 2022. All have since returned to compliance, per EPA records.

Mountain Heritage Water System

175 served · groundwater · PWSID MT0002873

Monitoring Barium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Cadmium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Chromium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Fluoride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Selenium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2020. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between July 1993 and April 2019. All have since returned to compliance, per EPA records.

Prairie Mobile Village

163 served · groundwater · PWSID MT0000600

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2024. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between April 2016 and November 2023. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2008. All have since returned to compliance, per EPA records.

Ncmrwa Pondera Co Service Area

144 served · surface water · PWSID MT0004834

Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2025. EPA records do not show all of these as returned to compliance.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2025. EPA records do not show all of these as returned to compliance.

Bryant No 3 Subdivision

100 served · groundwater · PWSID MT0004489

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2010 and December 2024. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2018. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2018. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2011 and October 2011. All have since returned to compliance, per EPA records.

Shade Tree Mobile Park

100 served · surface water · PWSID MT0004685

Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in December 2023. EPA records do not show all of these as returned to compliance.

North Forestvale Homeowners

98 served · groundwater · PWSID MT0001793

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between January 2010 and October 2023. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2019. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2005 and July 2013. All have since returned to compliance, per EPA records.
Monitoring Gross Alpha, Excl. Radon and U: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2008. EPA records do not show all of these as returned to compliance.
Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2008. EPA records do not show all of these as returned to compliance.

Camel Mountain Hoa

96 served · groundwater · PWSID MT0000572

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2017. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in April 2017. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2002 and July 2006. All have since returned to compliance, per EPA records.

Camelot Hoa

96 served · groundwater · PWSID MT0000615

Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2018. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between July 2003 and July 2009. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 1997 and October 2004. All have since returned to compliance, per EPA records.

Piegan Border Station

94 served · surface water · PWSID MT0003334

Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 2013. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2025 and December 2025. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between April 2012 and October 2025. EPA records do not show all of these as returned to compliance.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2025. EPA records do not show all of these as returned to compliance.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2025. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between July 2012 and July 2022. All have since returned to compliance, per EPA records.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Arsenic: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.

Ncmrwa North Havre Cwd Leg

90 served · surface water · PWSID MT0004720

Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in October 2024. EPA records do not show all of these as returned to compliance.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2024. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2024. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2015. All have since returned to compliance, per EPA records.

Applegate Village

85 served · groundwater · PWSID MT0004144

Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2007 and July 2020. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2010 and October 2017. All have since returned to compliance, per EPA records.
Monitoring Gross Alpha, Excl. Radon and U: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2017. All have since returned to compliance, per EPA records.

South Forestvale Hoa

82 served · groundwater · PWSID MT0003881

Health-based Coliform (TCR): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in March 2016. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 1997 and December 2021. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2020. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between November 2013 and October 2019. All have since returned to compliance, per EPA records.
Monitoring Coliform (TCR): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2016 and February 2016. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2006 and October 2013. All have since returned to compliance, per EPA records.

Mitchell Court Apartments

80 served · surface water · PWSID MT0005190

Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2026. All have since returned to compliance, per EPA records.

Rivers Edge Mobile Home Park Grt Fls

75 served · surface water · PWSID MT0004687

Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in December 2023. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between July 2010 and July 2014. All have since returned to compliance, per EPA records.

Barnett Water Users System

70 served · groundwater · PWSID MT0003183

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times between October 2004 and December 2024. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between July 2006 and July 2023. All have since returned to compliance, per EPA records.
Monitoring Barium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Cadmium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Chromium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Fluoride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Selenium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2014 and January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Arsenic: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in October 2022. All have since returned to compliance, per EPA records.

Ncmrwa Shelby To Ethridge

70 served · groundwater · PWSID MT0004936

Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2017. All have since returned to compliance, per EPA records.

Blue Cloud Subdivision

60 served · groundwater · PWSID MT0004288

Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 26 times between April 2011 and July 2017. The EPA record lists a level of 0.015 MG/L; the limit (MCL) is 0.01 MG/L. All have since returned to compliance, per EPA records.
Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in January 2021. EPA records do not show all of these as returned to compliance.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in January 2021. EPA records do not show all of these as returned to compliance.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2008 and July 2019. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2018. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in June 2018. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2003 and December 2015. All have since returned to compliance, per EPA records.

Big Stack Estates

60 served · surface water · PWSID MT0004682

Monitoring Long Term 2 Enhanced Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in December 2023. EPA records do not show all of these as returned to compliance.

Beacon Trailer Court Helena

55 served · groundwater · PWSID MT0000596

Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in November 2007. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2022. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 1997 and December 2017. All have since returned to compliance, per EPA records.
Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2016. All have since returned to compliance, per EPA records.

Grand Valley Estates Subdivision

50 served · groundwater · PWSID MT0004474

Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in July 2022. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2015 and October 2021. All have since returned to compliance, per EPA records.
Monitoring Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2019. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.

Moonlight Estates Hoa

44 served · groundwater · PWSID MT0004872

Monitoring E. COLI: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2025. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2021. All have since returned to compliance, per EPA records.
Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2018. All have since returned to compliance, per EPA records.

Trails End Tr Park Helena

35 served · groundwater · PWSID MT0000605

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between January 1997 and October 2021. All have since returned to compliance, per EPA records.
Monitoring Nitrate-Nitrite: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2019. All have since returned to compliance, per EPA records.
Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in September 2018. All have since returned to compliance, per EPA records.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Nickel: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Antimony, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Beryllium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Thallium, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Endrin: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring BHC-GAMMA: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Methoxychlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Toxaphene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Dalapon: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) adipate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring OXAMYL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Simazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Di(2-ethylhexyl) phthalate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Picloram: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Dinoseb: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Hexachlorocyclopentadiene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Carbofuran: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Atrazine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring LASSO: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Heptachlor: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Heptachlor epoxide: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 2,4-D: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring 2,4,5-TP: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring HEXACHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Benzo(a)pyrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Pentachlorophenol: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2017. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2006 and July 2007. All have since returned to compliance, per EPA records.

Rosemarys Addition

30 served · groundwater · PWSID MT0002743

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2004 and October 2014. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in February 2007. All have since returned to compliance, per EPA records.

Western Skies Mobile Ct

25 served · groundwater · PWSID MT0000519

Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between September 2018 and November 2019. All have since returned to compliance, per EPA records.
Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between July 2007 and October 2019. All have since returned to compliance, per EPA records.
Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 1993 and January 2012. All have since returned to compliance, per EPA records.

Ncmrwa Etheridge To Cutbank

25 served · groundwater · PWSID MT0004993

Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in December 2024. All have since returned to compliance, per EPA records.

Southern Cross Pud

25 served · groundwater · PWSID MT0005157

As of June 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.

What this means

A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.

This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.

Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.