Water Quality in MISSOULA, MT (59804)

EPA violation data for public water systems serving ZIP code 59804.

163

Total Violations

Health-Based

150

Monitoring / Reporting

141

Resolved

What does this mean?

141 of 163 violations have been resolved. 13 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 150 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: 35 Population served: 6,432

Violations Detail (163 total)

Contaminant	Category	MCL Limit	Measured	Date	Status	Health Effects
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2025	Active	N/A
E. COLI	Monitoring	0	N/A	Oct 16, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Oct 16, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Oct 16, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2025	Active	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Sep 30, 2025	Active	N/A
E. COLI	Monitoring	0	N/A	Sep 17, 2025	Active	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Sep 17, 2025	Active	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Aug 7, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Aug 7, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Aug 7, 2025	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
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
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	Dec 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Dec 31, 2024	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Dec 31, 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	Resolved	N/A
Lead and Copper Rule	Monitoring	N/A	N/A	Dec 29, 2024	Active	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	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	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	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
E. COLI	Monitoring	0	N/A	Oct 22, 2024	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Oct 22, 2024	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Oct 22, 2024	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Sep 22, 2024	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Sep 22, 2024	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
E. COLI	Monitoring	0	N/A	Sep 22, 2024	Resolved	Severe gastrointestinal illness; may be fatal in vulnerable populations
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 12, 2024	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 12, 2024	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Sep 12, 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
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 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
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2023	Resolved	N/A
Groundwater Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Groundwater Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Groundwater Rule	Monitoring	N/A	N/A	Jun 30, 2023	Resolved	N/A
Groundwater 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
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
TTHM	Monitoring	N/A	N/A	Dec 31, 2022	Active	N/A
TTHM	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
Total Haloacetic Acids (HAA5)	Monitoring	N/A	N/A	Dec 31, 2022	Active	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
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	Nov 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 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
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	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	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
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2022	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Jul 31, 2022	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Jul 31, 2022	Resolved	N/A
Groundwater Rule	Health-Based	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
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Apr 1, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Apr 1, 2022	Resolved	N/A
Revised Total Coliform Rule	Health-Based	N/A	N/A	Apr 1, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2022	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jan 31, 2022	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Nitrate-Nitrite	Monitoring	N/A	N/A	Dec 31, 2021	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Nov 30, 2021	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Nov 30, 2021	Resolved	N/A
Groundwater Rule	Health-Based	N/A	N/A	Nov 30, 2021	Resolved	N/A
Groundwater Rule	Health-Based	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
Revised Total Coliform Rule	Monitoring	N/A	N/A	Nov 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Oct 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Revised Total Coliform 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
Consumer Confidence Rule	Monitoring	N/A	N/A	Sep 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Aug 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jul 31, 2021	Resolved	N/A
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
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Jun 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	May 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Apr 30, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Mar 31, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2021	Resolved	N/A
Revised Total Coliform Rule	Monitoring	N/A	N/A	Feb 28, 2021	Resolved	N/A

Lead & Copper Levels

Violation Timeline

2025(24)

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

Revised Total Coliform Rule

Oct 31Active

E. COLI

Oct 16Resolved

E. COLI

Oct 16Resolved

E. COLI

Oct 16Resolved

Lead and Copper Rule

Sep 30Active

Lead and Copper Rule

Sep 30Active

E. COLI

Sep 17Active

E. COLI

Sep 17Active

E. COLI

Aug 7Resolved

E. COLI

Aug 7Resolved

E. COLI

Aug 7Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

May 31Resolved

Revised Total Coliform Rule

May 31Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

2024(34)

Revised Total Coliform Rule

Dec 31Resolved

Revised Total Coliform Rule

Dec 31Resolved

Revised Total Coliform Rule

Dec 31Resolved

Lead and Copper Rule

Dec 29Resolved

Lead and Copper Rule

Dec 29Resolved

Lead and Copper Rule

Dec 29Active

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 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

Revised Total Coliform Rule

Oct 31Resolved

E. COLI

Oct 22Resolved

E. COLI

Oct 22Resolved

E. COLI

Oct 22Resolved

E. COLI

Sep 22Resolved

E. COLI

Sep 22Resolved

E. COLI

Sep 22Resolved

Revised Total Coliform Rule

Sep 12Resolved

Revised Total Coliform Rule

Sep 12Resolved

Revised Total Coliform Rule

Sep 12Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Jul 31Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

Revised Total Coliform Rule

Apr 30Resolved

How Does This Compare?

MISSOULA (59804) has 163 recorded violations, including 13 health-based. 22 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 MISSOULA, MT (59804)

What does this mean?

Violations Detail (163 total)

Lead & Copper Levels

Violation Timeline

2025(24)

2024(34)

2023(19)

2022(41)

2021(45)

How Does This Compare?

Recommended Water Filters

Reverse Osmosis System

Activated Carbon Filter

UV Water Purifier

Nearby ZIP Codes

Check Another ZIP Code