Water Quality in HAMILTON, MT (59840)

EPA violation data for public water systems serving ZIP code 59840.

525

Total Violations

21

Health-Based

504

Monitoring / Reporting

521

Resolved

What does this mean?

521 of 525 violations have been resolved. 21 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 504 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: 86 Population served: 16,592

Violations Detail (525 total)

ContaminantCategoryMCL LimitMeasuredDateStatusHealth Effects
E. COLIMonitoring0N/ANov 11, 2025ActiveSevere gastrointestinal illness; may be fatal in vulnerable populations
E. COLIMonitoring0N/ANov 11, 2025ActiveSevere gastrointestinal illness; may be fatal in vulnerable populations
Lead and Copper RuleMonitoringN/AN/ASep 30, 2025ActiveN/A
Lead and Copper RuleMonitoringN/AN/ASep 30, 2025ActiveN/A
Groundwater RuleHealth-BasedN/AN/ASep 30, 2025ResolvedN/A
Groundwater RuleHealth-BasedN/AN/ASep 30, 2025ResolvedN/A
Groundwater RuleHealth-BasedN/AN/ASep 30, 2025ResolvedN/A
Groundwater RuleMonitoringN/AN/AAug 31, 2025ResolvedN/A
Groundwater RuleMonitoringN/AN/AAug 31, 2025ResolvedN/A
Groundwater RuleMonitoringN/AN/AAug 31, 2025ResolvedN/A

Lead & Copper Levels

Violation Timeline

2025(24)

E. COLI

34

Nov 11Active

E. COLI

34

Nov 11Active

Lead and Copper Rule

52

Sep 30Active

Lead and Copper Rule

52

Sep 30Active

Groundwater Rule

41

Sep 30Resolved

Groundwater Rule

41

Sep 30Resolved

Groundwater Rule

41

Sep 30Resolved

Groundwater Rule

31

Aug 31Resolved

Groundwater Rule

31

Aug 31Resolved

Groundwater Rule

31

Aug 31Resolved

Groundwater Rule

31

Jul 31Resolved

Groundwater Rule

31

Jul 31Resolved

Groundwater Rule

31

Jul 31Resolved

Revised Total Coliform Rule

3A

Jun 30Resolved

Revised Total Coliform Rule

3A

Jun 30Resolved

Revised Total Coliform Rule

3A

Jun 30Resolved

Groundwater Rule

31

May 31Resolved

Groundwater Rule

31

May 31Resolved

Groundwater Rule

31

May 31Resolved

Groundwater Rule

31

Jan 31Resolved

Groundwater Rule

31

Jan 31Resolved

Groundwater Rule

31

Jan 31Resolved

Revised Total Coliform Rule

3A

Jan 31Resolved

Revised Total Coliform Rule

3A

Jan 31Resolved

2024(176)

Groundwater Rule

41

Dec 31Resolved

Groundwater Rule

41

Dec 31Resolved

Groundwater Rule

41

Dec 31Resolved

Groundwater Rule

31

Dec 31Resolved

Groundwater Rule

31

Dec 31Resolved

Groundwater Rule

31

Dec 31Resolved

Lead and Copper Rule

66

Dec 29Resolved

Lead and Copper Rule

66

Dec 29Resolved

Groundwater Rule

31

Nov 30Resolved

Groundwater Rule

31

Nov 30Resolved

Groundwater Rule

31

Nov 30Resolved

Groundwater Rule

31

Oct 31Resolved

Groundwater Rule

31

Oct 31Resolved

Groundwater Rule

31

Oct 31Resolved

Groundwater Rule

31

Oct 31Resolved

Groundwater Rule

31

Oct 31Resolved

Groundwater Rule

31

Oct 31Resolved

Groundwater Rule

31

Oct 31Resolved

Revised Total Coliform Rule

3A

Oct 31Resolved

Revised Total Coliform Rule

3A

Oct 31Resolved

Revised Total Coliform Rule

3A

Oct 31Resolved

Groundwater Rule

31

Sep 30Resolved

Groundwater Rule

31

Sep 30Resolved

Groundwater Rule

31

Sep 30Resolved

Consumer Confidence Rule

71

Jun 30Resolved

Consumer Confidence Rule

71

Jun 30Resolved

Atrazine

03

Jun 30Resolved

Atrazine

03

Jun 30Resolved

Methoxychlor

03

Jun 30Resolved

Methoxychlor

03

Jun 30Resolved

Methoxychlor

03

Jun 30Resolved

Atrazine

03

Jun 30Resolved

2,4,5-TP

03

Jun 30Resolved

2,4,5-TP

03

Jun 30Resolved

Di(2-ethylhexyl) phthalate

03

Jun 30Resolved

Di(2-ethylhexyl) phthalate

03

Jun 30Resolved

Di(2-ethylhexyl) phthalate

03

Jun 30Resolved

Dalapon

03

Jun 30Resolved

Dalapon

03

Jun 30Resolved

Di(2-ethylhexyl) adipate

03

Jun 30Resolved

Heptachlor

03

Jun 30Resolved

Heptachlor

03

Jun 30Resolved

Heptachlor

03

Jun 30Resolved

2,4-D

03

Jun 30Resolved

Simazine

03

Jun 30Resolved

Simazine

03

Jun 30Resolved

Simazine

03

Jun 30Resolved

Dinoseb

03

Jun 30Resolved

Dinoseb

03

Jun 30Resolved

Dinoseb

03

Jun 30Resolved

Carbofuran

03

Jun 30Resolved

Carbofuran

03

Jun 30Resolved

HEXACHLOROBENZENE

03

Jun 30Resolved

HEXACHLOROBENZENE

03

Jun 30Resolved

HEXACHLOROBENZENE

03

Jun 30Resolved

Di(2-ethylhexyl) adipate

03

Jun 30Resolved

Carbofuran

03

Jun 30Resolved

Heptachlor epoxide

03

Jun 30Resolved

Heptachlor epoxide

03

Jun 30Resolved

LASSO

03

Jun 30Resolved

LASSO

03

Jun 30Resolved

LASSO

03

Jun 30Resolved

Di(2-ethylhexyl) adipate

03

Jun 30Resolved

OXAMYL

03

Jun 30Resolved

Heptachlor epoxide

03

Jun 30Resolved

Hexachlorocyclopentadiene

03

Jun 30Resolved

Hexachlorocyclopentadiene

03

Jun 30Resolved

Hexachlorocyclopentadiene

03

Jun 30Resolved

OXAMYL

03

Jun 30Resolved

OXAMYL

03

Jun 30Resolved

Benzo(a)pyrene

03

Jun 30Resolved

Chlordane

03

Jun 30Resolved

Chlordane

03

Jun 30Resolved

Chlordane

03

Jun 30Resolved

Benzo(a)pyrene

03

Jun 30Resolved

Benzo(a)pyrene

03

Jun 30Resolved

Pentachlorophenol

03

Jun 30Resolved

Pentachlorophenol

03

Jun 30Resolved

Pentachlorophenol

03

Jun 30Resolved

2,4-D

03

Jun 30Resolved

2,4-D

03

Jun 30Resolved

Endrin

03

Jun 30Resolved

Endrin

03

Jun 30Resolved

Endrin

03

Jun 30Resolved

BHC-GAMMA

03

Jun 30Resolved

2,4,5-TP

03

Jun 30Resolved

BHC-GAMMA

03

Jun 30Resolved

BHC-GAMMA

03

Jun 30Resolved

Toxaphene

03

Jun 30Resolved

Toxaphene

03

Jun 30Resolved

Toxaphene

03

Jun 30Resolved

Dalapon

03

Jun 30Resolved

Picloram

03

Jun 30Resolved

Picloram

03

Jun 30Resolved

Picloram

03

Jun 30Resolved

Groundwater Rule

31

Jun 30Resolved

Groundwater Rule

31

Jun 30Resolved

Groundwater Rule

31

Jun 30Resolved

Revised Total Coliform Rule

3A

Apr 30Resolved

Revised Total Coliform Rule

3A

Apr 30Resolved

Revised Total Coliform Rule

3A

Apr 30Resolved

Nitrate-Nitrite

03

Mar 31Resolved

Nitrate-Nitrite

03

Mar 31Resolved

Nitrate-Nitrite

03

Mar 31Resolved

OXAMYL

03

Mar 31Resolved

Heptachlor

03

Mar 31Resolved

Heptachlor

03

Mar 31Resolved

Heptachlor

03

Mar 31Resolved

OXAMYL

03

Mar 31Resolved

LASSO

03

Mar 31Resolved

LASSO

03

Mar 31Resolved

LASSO

03

Mar 31Resolved

Benzo(a)pyrene

03

Mar 31Resolved

Benzo(a)pyrene

03

Mar 31Resolved

Benzo(a)pyrene

03

Mar 31Resolved

2,4-D

03

Mar 31Resolved

Pentachlorophenol

03

Mar 31Resolved

Pentachlorophenol

03

Mar 31Resolved

Pentachlorophenol

03

Mar 31Resolved

2,4-D

03

Mar 31Resolved

2,4-D

03

Mar 31Resolved

BHC-GAMMA

03

Mar 31Resolved

BHC-GAMMA

03

Mar 31Resolved

BHC-GAMMA

03

Mar 31Resolved

Simazine

03

Mar 31Resolved

Simazine

03

Mar 31Resolved

Simazine

03

Mar 31Resolved

Hexachlorocyclopentadiene

03

Mar 31Resolved

Hexachlorocyclopentadiene

03

Mar 31Resolved

Hexachlorocyclopentadiene

03

Mar 31Resolved

Endrin

03

Mar 31Resolved

HEXACHLOROBENZENE

03

Mar 31Resolved

Carbofuran

03

Mar 31Resolved

Carbofuran

03

Mar 31Resolved

Carbofuran

03

Mar 31Resolved

Endrin

03

Mar 31Resolved

Endrin

03

Mar 31Resolved

Methoxychlor

03

Mar 31Resolved

Toxaphene

03

Mar 31Resolved

Toxaphene

03

Mar 31Resolved

Dalapon

03

Mar 31Resolved

Dalapon

03

Mar 31Resolved

Dalapon

03

Mar 31Resolved

Di(2-ethylhexyl) adipate

03

Mar 31Resolved

Di(2-ethylhexyl) adipate

03

Mar 31Resolved

Di(2-ethylhexyl) adipate

03

Mar 31Resolved

Picloram

03

Mar 31Resolved

Picloram

03

Mar 31Resolved

Picloram

03

Mar 31Resolved

Dinoseb

03

Mar 31Resolved

Dinoseb

03

Mar 31Resolved

Dinoseb

03

Mar 31Resolved

Heptachlor epoxide

03

Mar 31Resolved

Heptachlor epoxide

03

Mar 31Resolved

Heptachlor epoxide

03

Mar 31Resolved

2,4,5-TP

03

Mar 31Resolved

Methoxychlor

03

Mar 31Resolved

Methoxychlor

03

Mar 31Resolved

2,4,5-TP

03

Mar 31Resolved

2,4,5-TP

03

Mar 31Resolved

Chlordane

03

Mar 31Resolved

Chlordane

03

Mar 31Resolved

Chlordane

03

Mar 31Resolved

Toxaphene

03

Mar 31Resolved

HEXACHLOROBENZENE

03

Mar 31Resolved

HEXACHLOROBENZENE

03

Mar 31Resolved

Di(2-ethylhexyl) phthalate

03

Mar 31Resolved

Di(2-ethylhexyl) phthalate

03

Mar 31Resolved

Di(2-ethylhexyl) phthalate

03

Mar 31Resolved

Atrazine

03

Mar 31Resolved

Atrazine

03

Mar 31Resolved

Atrazine

03

Mar 31Resolved

OXAMYL

03

Mar 31Resolved

Revised Total Coliform Rule

3A

Jan 31Resolved

Revised Total Coliform Rule

3A

Jan 31Resolved

Revised Total Coliform Rule

3A

Jan 31Resolved

How Does This Compare?

HAMILTON (59840) has 525 recorded violations, including 21 health-based. 4 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 →

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.

Nearby ZIP Codes

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