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Community Water System · PWS MT0000195

Darby Town Of

Darby, Montana 59829 - drinking water served from groundwater sources to 850 people, tracked in EPA SDWIS and UCMR5.

850
People served
639
EPA violations
58
Health-based
Untested
UCMR5 result

The verdict

EPA records 639 drinking-water violations at Darby Town Of, 9% of them health-based - above the Montana per-system average.

639
Total EPA violations on record
9%
Health-based (MCL / treatment failure)
850
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Darby Town Of

Darby Town Of is a local-owned community water system that delivers drinking water to 850 residents in Darby, Montana (Ravalli County) through 494 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 639 total violations for this system , of which 58 (9%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 576 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 201 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Montana, EPA tracks 2,263 public water systems serving 1,112,267 people, with 297,270 cumulative violations and 25,922 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 131.4 violations. Statewide, 28 of 45 UCMR5-tested systems have reported PFAS detections (62.2%).

Darby Town Of's 639 violations sit above the Montana average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
850
Total Violations
639
Health-Based Violations
58
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
494
County
Ravalli
School/Daycare
No
MCL Violations
54
Monitoring Violations
576
Treatment Tech Violations
4

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 201 2006
Coliform (TCR) MCL 54 2005
Coliform (TCR) MR 8 2004
1,2,4-Trichlorobenzene MR 6 1999
Xylenes, Total MR 6 1999
Vinyl chloride MR 6 1999
1,1-Dichloroethylene MR 6 1999
trans-1,2-Dichloroethylene MR 6 1999
1,1,1-Trichloroethane MR 6 1999
1,2-Dichloropropane MR 6 1999
1,1,2-Trichloroethane MR 6 1999
Tetrachloroethylene MR 6 1999
CHLOROBENZENE MR 6 1999
Toluene MR 6 1999
Styrene MR 6 1999
DICHLOROMETHANE MR 6 1999
o-Dichlorobenzene MR 6 1999
1,2-Dichloroethane MR 6 1999
Carbon tetrachloride MR 6 1999
Trichloroethylene MR 6 1999
Endrin MR 6 1999
Methoxychlor MR 6 1999
Toxaphene MR 6 1999
Diquat MR 6 1999
Endothall MR 6 1999
Glyphosate MR 6 1999
Di(2-ethylhexyl) adipate MR 6 1999
OXAMYL MR 6 1999
Di(2-ethylhexyl) phthalate MR 6 1999
Picloram MR 6 1999

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Darby Town Of.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID MT0000195 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Montana Drinking Water Authority

Montana's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find MT regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2024 Lead and Copper Rule TT 4 SDWIS / MT0000195 / 5000
2023 Revised Total Coliform Rule MON 3 SDWIS / MT0000195 / 8000
2021 Consumer Confidence Rule Other 4 SDWIS / MT0000195 / 7000
2010 Gross Alpha, Excl. Radon and U MR 3 SDWIS / MT0000195 / 4000
2010 Combined Radium (-226 and -228) MR 3 SDWIS / MT0000195 / 4010
2006 Lead and Copper Rule MR 201 SDWIS / MT0000195 / 5000
2005 Coliform (TCR) MCL 54 SDWIS / MT0000195 / 3100
2004 Coliform (TCR) MR 8 SDWIS / MT0000195 / 3100
1999 1,2,4-Trichlorobenzene MR 6 SDWIS / MT0000195 / 2378
1999 Xylenes, Total MR 6 SDWIS / MT0000195 / 2955
1999 Vinyl chloride MR 6 SDWIS / MT0000195 / 2976
1999 1,1-Dichloroethylene MR 6 SDWIS / MT0000195 / 2977
1999 trans-1,2-Dichloroethylene MR 6 SDWIS / MT0000195 / 2979
1999 1,1,1-Trichloroethane MR 6 SDWIS / MT0000195 / 2981
1999 1,2-Dichloropropane MR 6 SDWIS / MT0000195 / 2983

How Darby Town Of Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Darby Town Of Montana avg Federal benchmark
Total violations 639 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 58 11.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 62.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 850 492 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,263 regulated public water systems in Montana.

Federal MCL reference, Safe Drinking Water Act thresholds
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Darby Town Of water safe to drink?
Darby Town Of (PWS ID: MT0000195) has 639 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 850 people using Groundwater sources.
How many people does Darby Town Of serve?
Darby Town Of serves 850 people in Darby, Montana. It is a Local-owned system using Groundwater water sources with 494 service connections.
What type of violations does Darby Town Of have?
Darby Town Of has 639 total violations: 58 health-based violations (MCL exceedances or treatment failures), 576 monitoring/reporting violations, and 4 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Darby Town Of water?
No PFAS testing data is available for Darby Town Of under the EPA's UCMR5 monitoring program.
What water source does Darby Town Of use?
Darby Town Of uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from?
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.