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Libby, MT Tap Water Quality 2026

Water quality report for Libby, MT — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Libby's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Libby City Of PWSID: MT0000274 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 2.00 ppb, 13% of the action level and no violations are open. PFAS was sampled but not enough times for a compliance determination.

C

Libby earns a C for water quality

Graded on violations and lead, with state inspection findings. PFAS not tested.

Lead: 2.00 ppb — 13% of the federal action level
PFAS sampled, too few results to judge
29 violations since 2015, 7 health-based
No violations currently open
Libby's lead level vs. all Montana community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 2.00 ppb — 13% of the federal action level
✓ Lower lead than 67% of Montana utilities
Population Served
2452
~1957 connections
Water Source
Surface water
Drawn from surface water — SDWIS source code SW
Active Violations
0
29 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
13% of EPA action level
2.00 ppb
Action level: 15 ppb
Copper (Cu)
90th percentile of tap samples. SDWIS reports a copper figure only when a system exceeds the action level, so any value here is an exceedance.
107.7% of EPA action level
1,400 ppb
Action level: 1,300 ppb
The 90th-percentile lead result is 2.00 ppb, 13% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home. Copper reached the action level here; a copper figure appears in SDWIS only when a system triggers it.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2025 Resolved
Long Term 2 Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2022 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2022 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2021 Resolved
1,2,4-Trichlorobenzene MONITORING AND REPORTING — 0.07 mg/L 2021 Resolved
cis-1,2-Dichloroethylene MONITORING AND REPORTING — 0.07 mg/L 2021 Resolved
Xylenes, Total MONITORING AND REPORTING — 10 mg/L 2021 Resolved
DICHLOROMETHANE MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
o-Dichlorobenzene MONITORING AND REPORTING — 0.6 mg/L 2021 Resolved
p-Dichlorobenzene MONITORING AND REPORTING — 0.075 mg/L 2021 Resolved
Vinyl chloride MONITORING AND REPORTING — 0.002 mg/L 2021 Resolved
1,1-Dichloroethylene MONITORING AND REPORTING — 0.007 mg/L 2021 Resolved
trans-1,2-Dichloroethylene MONITORING AND REPORTING — 0.1 mg/L 2021 Resolved
1,2-Dichloroethane MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
1,1,1-Trichloroethane MONITORING AND REPORTING — 0.2 mg/L 2021 Resolved
Carbon tetrachloride MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
1,2-Dichloropropane MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
Trichloroethylene MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
1,1,2-Trichloroethane MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
Tetrachloroethylene MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
CHLOROBENZENE MONITORING AND REPORTING — 0.1 mg/L 2021 Resolved
Benzene MONITORING AND REPORTING — 0.005 mg/L 2021 Resolved
Toluene MONITORING AND REPORTING — 1 mg/L 2021 Resolved
Ethylbenzene MONITORING AND REPORTING — 0.7 mg/L 2021 Resolved
Styrene MONITORING AND REPORTING — 0.1 mg/L 2021 Resolved
Consumer Confidence Rule OTHER — — 2019 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2015 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2015 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2015 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

29 violations are on record since 2015, of which 7 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Libby City Of
PWSID MT0000274
Water source Surface water — Drawn from surface water — SDWIS source code SW
Population served 2,452
Service connections 1,957
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Libby tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 2.00 ppb, 13% of the action level.
Does Libby water have PFAS? ▼
It was sampled, but no sampling point had enough results for a compliance determination.
Who supplies water to Libby? ▼
Libby City Of (PWSID MT0000274). Surface water. Drawn from surface water — SDWIS source code SW
When was this system last inspected? ▼
It was last inspected on 2025-10-23. No significant deficiencies were recorded.

What Should Libby Residents Do?

1
Read your annual water report
Your supplier publishes a Consumer Confidence Report each July covering the prior year.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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