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Community Water System · PWS MT0004249

Clarks Lookout

Dillon, Montana 59725 - drinking water served from groundwater sources to 62 people, tracked in EPA SDWIS and UCMR5.

62
People served
281
EPA violations
139
Health-based
Untested
UCMR5 result

The verdict

EPA records 281 drinking-water violations at Clarks Lookout, 49% of them health-based - above the Montana per-system average.

281
Total EPA violations on record
49%
Health-based (MCL / treatment failure)
62
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Clarks Lookout

Clarks Lookout is a private-owned community water system that delivers drinking water to 62 residents in Dillon, Montana (Beaverhead County) through 43 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 281 total violations for this system , of which 139 (49%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 126 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Arsenic, recorded in 139 violations (MCL, health-based). 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%).

Clarks Lookout's 281 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
62
Total Violations
281
Health-Based Violations
139
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
43
County
Beaverhead
School/Daycare
No
MCL Violations
139
Monitoring Violations
126
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Arsenic MCL 139 2019
Consumer Confidence Rule Other 16 2025
Lead and Copper Rule MR 7 2012
Di(2-ethylhexyl) adipate MR 4 2012
Dinoseb MR 4 2012
Hexachlorocyclopentadiene MR 4 2012
Aldicarb MR 4 2012
Atrazine MR 4 2012
LASSO MR 4 2012
Endrin MR 4 2012
2,4-D MR 4 2012
2,4,5-TP MR 4 2012
HEXACHLOROBENZENE MR 4 2012
Benzo(a)pyrene MR 4 2012
Chlordane MR 4 2012
Gross Alpha, Excl. Radon and U MR 4 2012
Arsenic MR 4 2012
Dalapon MR 4 2012
Heptachlor MR 4 2012
Di(2-ethylhexyl) phthalate MR 4 2012
Pentachlorophenol MR 4 2012
BHC-GAMMA MR 4 2012
Combined Radium (-226 and -228) MR 4 2012
Toxaphene MR 4 2012
Picloram MR 4 2012
Heptachlor epoxide MR 4 2012
Aldicarb sulfoxide MR 4 2012
Aldicarb sulfone MR 4 2012
Simazine MR 4 2012
Carbofuran MR 4 2012

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 Clarks Lookout.

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 MT0004249 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
2025 Consumer Confidence Rule Other 16 SDWIS / MT0004249 / 7000
2019 Arsenic MCL 139 SDWIS / MT0004249 / 1005
2012 Lead and Copper Rule MR 7 SDWIS / MT0004249 / 5000
2012 Di(2-ethylhexyl) adipate MR 4 SDWIS / MT0004249 / 2035
2012 Dinoseb MR 4 SDWIS / MT0004249 / 2041
2012 Hexachlorocyclopentadiene MR 4 SDWIS / MT0004249 / 2042
2012 Aldicarb MR 4 SDWIS / MT0004249 / 2047
2012 Atrazine MR 4 SDWIS / MT0004249 / 2050
2012 LASSO MR 4 SDWIS / MT0004249 / 2051
2012 Endrin MR 4 SDWIS / MT0004249 / 2005
2012 2,4-D MR 4 SDWIS / MT0004249 / 2105
2012 2,4,5-TP MR 4 SDWIS / MT0004249 / 2110
2012 HEXACHLOROBENZENE MR 4 SDWIS / MT0004249 / 2274
2012 Benzo(a)pyrene MR 4 SDWIS / MT0004249 / 2306
2012 Chlordane MR 4 SDWIS / MT0004249 / 2959

How Clarks Lookout Compares

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

Metric Clarks Lookout Montana avg Federal benchmark
Total violations 281 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 139 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 62 492 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 Clarks Lookout water safe to drink? ▼
Clarks Lookout (PWS ID: MT0004249) has 281 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 62 people using Groundwater sources.
How many people does Clarks Lookout serve? ▼
Clarks Lookout serves 62 people in Dillon, Montana. It is a Private-owned system using Groundwater water sources with 43 service connections.
What type of violations does Clarks Lookout have? ▼
Clarks Lookout has 281 total violations: 139 health-based violations (MCL exceedances or treatment failures), 126 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Clarks Lookout water? ▼
No PFAS testing data is available for Clarks Lookout under the EPA's UCMR5 monitoring program.
What water source does Clarks Lookout use? ▼
Clarks Lookout 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.

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.