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Boneau, MT Tap Water Quality 2026

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

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

Main Utility: Rocky Boy's Rural Water PWSID: 083090075 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 1.00 ppb, 7% of the action level and no violations are open. PFAS has never been sampled at this system.

B

Boneau earns a B for water quality

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

Lead: 1.00 ppb — 7% of the federal action level
PFAS never sampled at this system
31 violations since 2015, 1 health-based
No violations currently open
Boneau's lead level vs. all Montana community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 1.00 ppb — 7% of the federal action level
✓ Lower lead than 99% of Montana utilities
Population Served
335
~477 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
31 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
7% of EPA action level
1.00 ppb
Action level: 15 ppb
The 90th-percentile lead result is 1.00 ppb, 7% 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.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
1,2,4-Trichlorobenzene MONITORING AND REPORTING — 0.07 mg/L 2025 Resolved
cis-1,2-Dichloroethylene MONITORING AND REPORTING — 0.07 mg/L 2025 Resolved
Xylenes, Total MONITORING AND REPORTING — 10 mg/L 2025 Resolved
DICHLOROMETHANE MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
o-Dichlorobenzene MONITORING AND REPORTING — 0.6 mg/L 2025 Resolved
p-Dichlorobenzene MONITORING AND REPORTING — 0.075 mg/L 2025 Resolved
Vinyl chloride MONITORING AND REPORTING — 0.002 mg/L 2025 Resolved
1,1-Dichloroethylene MONITORING AND REPORTING — 0.007 mg/L 2025 Resolved
trans-1,2-Dichloroethylene MONITORING AND REPORTING — 0.1 mg/L 2025 Resolved
1,2-Dichloroethane MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
1,1,1-Trichloroethane MONITORING AND REPORTING — 0.2 mg/L 2025 Resolved
Carbon tetrachloride MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
1,2-Dichloropropane MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
Trichloroethylene MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
1,1,2-Trichloroethane MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
Tetrachloroethylene MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
CHLOROBENZENE MONITORING AND REPORTING — 0.1 mg/L 2025 Resolved
Benzene MONITORING AND REPORTING — 0.005 mg/L 2025 Resolved
Toluene MONITORING AND REPORTING — 1 mg/L 2025 Resolved
Ethylbenzene MONITORING AND REPORTING — 0.7 mg/L 2025 Resolved
Styrene MONITORING AND REPORTING — 0.1 mg/L 2025 Resolved
Nitrite MONITORING AND REPORTING — 1 mg/L 2025 Archived
Asbestos MONITORING AND REPORTING — 7 MFL 2021 Resolved
Asbestos MONITORING AND REPORTING — 7 MFL 2021 Resolved
Asbestos MONITORING AND REPORTING — 7 MFL 2017 Resolved
Groundwater Rule TREATMENT TECHNIQUE — — 2017 Resolved
Asbestos MONITORING AND REPORTING — 7 MFL 2017 Resolved
Glyphosate MONITORING AND REPORTING — 0.7 mg/L 2017 Resolved
Endothall MONITORING AND REPORTING — 0.1 mg/L 2017 Resolved
Diquat MONITORING AND REPORTING — 0.02 mg/L 2017 Resolved
Nitrate-Nitrite MONITORING AND REPORTING — — 2017 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

31 violations are on record since 2015, of which 1 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Rocky Boy's Rural Water
PWSID 083090075
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 335
Service connections 477
Systems serving this area 1
Regulator US EPA (tribal primacy)
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Boneau tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 1.00 ppb, 7% of the action level.
Does Boneau water have PFAS? ▼
This system has never been sampled for PFAS. EPA's national monitoring covered systems serving 3,300 people or more, so no results exist — which is not evidence that none is present.
Who supplies water to Boneau? ▼
Rocky Boy's Rural Water (PWSID 083090075). Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2022-08-12. No significant deficiencies were recorded.

What Should Boneau 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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