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Transient Non-Community Water System · PWS MT0003267

Yaak Merc and Yaak River Tavern

Troy, Montana 59935 - drinking water served from groundwater sources to 81 people, tracked in EPA SDWIS and UCMR5.

81
People served
189
EPA violations
9
Health-based
Untested
UCMR5 result

The verdict

EPA records 189 drinking-water violations at Yaak Merc and Yaak River Tavern, 5% of them health-based - above the Montana per-system average.

189
Total EPA violations on record
5%
Health-based (MCL / treatment failure)
81
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Yaak Merc and Yaak River Tavern

Yaak Merc and Yaak River Tavern is a private-owned transient non-community water system that delivers drinking water to 81 residents in Troy, Montana (Lincoln County) through 1 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 189 total violations for this system , of which 9 (5%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 178 monitoring and reporting violations are on file. The most recent violation on record dates to 2021.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 125 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%).

Yaak Merc and Yaak River Tavern's 189 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
81
Total Violations
189
Health-Based Violations
9
Water Source
Groundwater

System Details

System Type
Transient Non-Community
Owner Type
Private
Connections
1
County
Lincoln
School/Daycare
No
MCL Violations
9
Monitoring Violations
178
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 125 2015
Revised Total Coliform Rule MON 30 2021
Nitrate-Nitrite MR 16 2019
Revised Total Coliform Rule MCL 5 2018
Coliform (TCR) MCL 4 2011
Nitrate MR 4 1998
E. COLI MR 3 2011

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 Yaak Merc and Yaak River Tavern.

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 MT0003267 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
2021 Revised Total Coliform Rule MON 30 SDWIS / MT0003267 / 8000
2019 Nitrate-Nitrite MR 16 SDWIS / MT0003267 / 1038
2018 Revised Total Coliform Rule MCL 5 SDWIS / MT0003267 / 8000
2015 Coliform (TCR) MR 125 SDWIS / MT0003267 / 3100
2011 Coliform (TCR) MCL 4 SDWIS / MT0003267 / 3100
2011 E. COLI MR 3 SDWIS / MT0003267 / 3014
1998 Nitrate MR 4 SDWIS / MT0003267 / 1040

How Yaak Merc and Yaak River Tavern Compares

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

Metric Yaak Merc and Yaak River Tavern Montana avg Federal benchmark
Total violations 189 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 9 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 81 492 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 Yaak Merc and Yaak River Tavern water safe to drink? ▼
Yaak Merc and Yaak River Tavern (PWS ID: MT0003267) has 189 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 81 people using Groundwater sources.
How many people does Yaak Merc and Yaak River Tavern serve? ▼
Yaak Merc and Yaak River Tavern serves 81 people in Troy, Montana. It is a Private-owned system using Groundwater water sources with 1 service connections.
What type of violations does Yaak Merc and Yaak River Tavern have? ▼
Yaak Merc and Yaak River Tavern has 189 total violations: 9 health-based violations (MCL exceedances or treatment failures), 178 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Yaak Merc and Yaak River Tavern water? ▼
No PFAS testing data is available for Yaak Merc and Yaak River Tavern under the EPA's UCMR5 monitoring program.
What water source does Yaak Merc and Yaak River Tavern use? ▼
Yaak Merc and Yaak River Tavern uses Groundwater as its primary water source. It is classified as a Transient Non-Community Water System, serving transient populations.
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.

Read our methodology - how this data is sourced, computed, and verified.

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.