Water Quality in GREAT FALLS, MT (59404)

EPA violation data for public water systems serving ZIP code 59404.

295

Total Violations

Health-Based

287

Monitoring / Reporting

276

Resolved

What does this mean?

276 of 295 violations have been resolved. 8 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 287 are monitoring or reporting violations (missed testing deadlines or late paperwork — not necessarily a water quality issue). Not all violations mean your water is unsafe. The EPA requires reporting even for minor administrative issues.

Water systems: 29 Population served: 7,478

Violations Detail (295 total)

Contaminant	Category	MCL Limit	Measured	Date	Status	Health Effects
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2025	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2025	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2025	Resolved	N/A
E. COLI	Monitoring	0	N/A	Jul 21, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Jul 21, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Jul 21, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2025	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2025	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 29, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 29, 2024	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 29, 2024	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Oct 4, 2024	Active	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Oct 4, 2024	Active	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2024	Active	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Active	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2024	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Atrazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Cardiovascular system or reproductive problems
Atrazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Cardiovascular system or reproductive problems
Atrazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Cardiovascular system or reproductive problems
Atrazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Cardiovascular system or reproductive problems
Atrazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Cardiovascular system or reproductive problems
Atrazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Cardiovascular system or reproductive problems
Endrin	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Endrin	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Endrin	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
OXAMYL	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
OXAMYL	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
OXAMYL	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Carbofuran	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Carbofuran	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Carbofuran	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4,5-TP	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Endrin	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Endrin	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Endrin	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
BHC-GAMMA	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Toxaphene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
OXAMYL	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
OXAMYL	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
OXAMYL	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dinoseb	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4-D	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4-D	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4-D	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
HEXACHLOROBENZENE	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Pentachlorophenol	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Chlordane	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Dalapon	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) phthalate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Picloram	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Picloram	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Picloram	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Hexachlorocyclopentadiene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor epoxide	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Di(2-ethylhexyl) adipate	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Picloram	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Picloram	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Picloram	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
LASSO	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Heptachlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Benzo(a)pyrene	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Carbofuran	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Carbofuran	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Carbofuran	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4-D	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4-D	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
2,4-D	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Methoxychlor	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Simazine	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Arsenic	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Arsenic	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Arsenic	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2024	Resolved	N/A
Combined Radium (-226 and -228)	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
Combined Radium (-226 and -228)	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
Combined Radium (-226 and -228)	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
Gross Alpha, Excl. Radon and U	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
Gross Alpha, Excl. Radon and U	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
Gross Alpha, Excl. Radon and U	Monitoring	N/A	N/A	Mar 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 29, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 29, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 29, 2024	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Active	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Active	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2023	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Aug 3, 2023	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Aug 3, 2023	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Aug 3, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Active	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Active	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2023	Active	N/A
E. COLI	Monitoring	0	N/A	Jun 20, 2023	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Jun 20, 2023	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Jun 20, 2023	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	N/A
Arsenic	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Arsenic	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Arsenic	Monitoring	N/A	N/A	Mar 31, 2023	Resolved	Skin damage; circulatory system problems; increased risk of cancer
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2023	Resolved	N/A
TTHM	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
TTHM	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
Fluoride	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Bone disease (pain and tenderness of the bones); children may get mottled teeth
Fluoride	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Bone disease (pain and tenderness of the bones); children may get mottled teeth
Fluoride	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Bone disease (pain and tenderness of the bones); children may get mottled teeth
Fluoride	Monitoring	N/A	N/A	Dec 31, 2022	Resolved	Bone disease (pain and tenderness of the bones); children may get mottled teeth
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2022	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2022	Active	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2022	Active	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2022	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Mar 24, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Mar 24, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Mar 24, 2022	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 29, 2021	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 29, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2021	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
E. COLI	Monitoring	0	N/A	Sep 7, 2021	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Sep 7, 2021	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Sep 7, 2021	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Consumer Confidence Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A

Lead & Copper Levels

Violation Timeline

2025(26)

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Lead and Copper Rule

Sep 30Resolved

Lead and Copper Rule

Sep 30Resolved

Lead and Copper Rule

Sep 30Resolved

Revised Total Coliform Rule

Sep 30Resolved

Revised Total Coliform Rule

Sep 30Resolved

Revised Total Coliform Rule

Aug 31Resolved

Revised Total Coliform Rule

Aug 31Resolved

Revised Total Coliform Rule

Aug 31Resolved

Revised Total Coliform Rule

Aug 31Resolved

Revised Total Coliform Rule

Aug 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

E. COLI

Jul 21Resolved

E. COLI

Jul 21Resolved

E. COLI

Jul 21Resolved

Revised Total Coliform Rule

May 31Resolved

Revised Total Coliform Rule

May 31Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Jan 31Resolved

Revised Total Coliform Rule

Jan 31Resolved

Revised Total Coliform Rule

Jan 31Resolved

2024(172)

Lead and Copper Rule

Dec 29Resolved

Lead and Copper Rule

Dec 29Resolved

Lead and Copper Rule

Dec 29Active

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 4Active

Revised Total Coliform Rule

Oct 4Active

Consumer Confidence Rule

Sep 30Active

Lead and Copper Rule

Sep 30Active

Lead and Copper Rule

Sep 30Active

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Consumer Confidence Rule

Jun 30Resolved

Consumer Confidence Rule

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

Atrazine

Jun 30Resolved

Atrazine

Jun 30Resolved

Atrazine

Jun 30Resolved

Atrazine

Jun 30Resolved

Atrazine

Jun 30Resolved

Atrazine

Jun 30Resolved

Endrin

Jun 30Resolved

Endrin

Jun 30Resolved

Endrin

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

Toxaphene

Jun 30Resolved

Toxaphene

Jun 30Resolved

Toxaphene

Jun 30Resolved

OXAMYL

Jun 30Resolved

OXAMYL

Jun 30Resolved

OXAMYL

Jun 30Resolved

Dinoseb

Jun 30Resolved

Dinoseb

Jun 30Resolved

Dinoseb

Jun 30Resolved

Carbofuran

Jun 30Resolved

Carbofuran

Jun 30Resolved

Carbofuran

Jun 30Resolved

LASSO

Jun 30Resolved

LASSO

Jun 30Resolved

LASSO

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

2,4,5-TP

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Chlordane

Jun 30Resolved

Chlordane

Jun 30Resolved

Chlordane

Jun 30Resolved

Endrin

Jun 30Resolved

Endrin

Jun 30Resolved

Endrin

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

BHC-GAMMA

Jun 30Resolved

Toxaphene

Jun 30Resolved

Toxaphene

Jun 30Resolved

Toxaphene

Jun 30Resolved

Dalapon

Jun 30Resolved

Dalapon

Jun 30Resolved

Dalapon

Jun 30Resolved

OXAMYL

Jun 30Resolved

OXAMYL

Jun 30Resolved

OXAMYL

Jun 30Resolved

Dinoseb

Jun 30Resolved

Dinoseb

Jun 30Resolved

Dinoseb

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

2,4-D

Jun 30Resolved

2,4-D

Jun 30Resolved

2,4-D

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

HEXACHLOROBENZENE

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Pentachlorophenol

Jun 30Resolved

Chlordane

Jun 30Resolved

Chlordane

Jun 30Resolved

Chlordane

Jun 30Resolved

Heptachlor

Jun 30Resolved

Heptachlor

Jun 30Resolved

Heptachlor

Jun 30Resolved

Dalapon

Jun 30Resolved

Dalapon

Jun 30Resolved

Dalapon

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Di(2-ethylhexyl) phthalate

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Picloram

Jun 30Resolved

Picloram

Jun 30Resolved

Picloram

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

Hexachlorocyclopentadiene

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

Heptachlor epoxide

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Di(2-ethylhexyl) adipate

Jun 30Resolved

Picloram

Jun 30Resolved

Picloram

Jun 30Resolved

Picloram

Jun 30Resolved

Simazine

Jun 30Resolved

Simazine

Jun 30Resolved

Simazine

Jun 30Resolved

LASSO

Jun 30Resolved

LASSO

Jun 30Resolved

LASSO

Jun 30Resolved

Heptachlor

Jun 30Resolved

Heptachlor

Jun 30Resolved

Heptachlor

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

Benzo(a)pyrene

Jun 30Resolved

Carbofuran

Jun 30Resolved

Carbofuran

Jun 30Resolved

Carbofuran

Jun 30Resolved

2,4-D

Jun 30Resolved

2,4-D

Jun 30Resolved

2,4-D

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Methoxychlor

Jun 30Resolved

Simazine

Jun 30Resolved

Simazine

Jun 30Resolved

Simazine

Jun 30Resolved

Arsenic

Jun 30Resolved

Arsenic

Jun 30Resolved

Arsenic

Jun 30Resolved

Revised Total Coliform Rule

Jun 30Resolved

Revised Total Coliform Rule

Jun 30Resolved

Revised Total Coliform Rule

Jun 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Combined Radium (-226 and -228)

Mar 31Resolved

Combined Radium (-226 and -228)

Mar 31Resolved

Combined Radium (-226 and -228)

Mar 31Resolved

Gross Alpha, Excl. Radon and U

Mar 31Resolved

Gross Alpha, Excl. Radon and U

Mar 31Resolved

Gross Alpha, Excl. Radon and U

Mar 31Resolved

Revised Total Coliform Rule

Feb 29Resolved

Revised Total Coliform Rule

Feb 29Resolved

Revised Total Coliform Rule

Feb 29Resolved

How Does This Compare?

GREAT FALLS (59404) has 295 recorded violations, including 8 health-based. 19 remain unresolved. Consider testing your tap water independently for added peace of mind.

Recommended Water Filters

Based on the contaminants detected in your area, these filter types may help improve your water quality.

Reverse Osmosis System

Highly effective at removing heavy metals, dissolved solids, and a wide range of contaminants. Recommended for homes with lead or arsenic concerns.

Targets:Lead, Copper, Arsenic, Mercury, Cadmium

Look for:NSF/ANSI 58 certified

NSF Certified Products → EPA Safe Drinking Water Guide →

Activated Carbon Filter

Excellent for removing chlorine, chloramine, and disinfection byproducts like THMs and HAAs. Available as pitcher filters, countertop, or under-sink units.

Targets:THMs, HAAs, Chlorine, Chloramine, Taste & Odor

Look for:NSF/ANSI 42 & 53 certified

NSF Certified Products → EPA Safe Drinking Water Guide →

UV Water Purifier

Uses ultraviolet light to neutralize bacteria, viruses, and parasites without chemicals. Ideal for homes with microbial contamination concerns.

Targets:E. coli, Coliform, Giardia, Cryptosporidium

Look for:NSF/ANSI 55 (Class A) certified

NSF Certified Products → EPA Safe Drinking Water Guide →

Always look for filters certified by NSF International for the specific contaminants you want to remove.

Water Quality in GREAT FALLS, MT (59404)

What does this mean?

Violations Detail (295 total)

Lead & Copper Levels

Violation Timeline

2025(26)

2024(172)

2023(46)

2022(39)

2021(12)

How Does This Compare?

Recommended Water Filters

Reverse Osmosis System

Activated Carbon Filter

UV Water Purifier

Nearby ZIP Codes

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