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Community Water System · PWS MT0003556

North Shore Estates HOA

Thompson Falls, Montana 59873 - drinking water served from groundwater sources to 65 people, tracked in EPA SDWIS and UCMR5.

65
People served
124
EPA violations
82
Health-based
Untested
UCMR5 result

The verdict

EPA records 124 drinking-water violations at North Shore Estates HOA, 66% of them health-based - below the Montana per-system average.

124
Total EPA violations on record
66%
Health-based (MCL / treatment failure)
65
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: North Shore Estates HOA

North Shore Estates HOA is a private-owned community water system that delivers drinking water to 65 residents in Thompson Falls, Montana (Sanders County) through 31 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 124 total violations for this system , of which 82 (66%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 34 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 Arsenic, recorded in 53 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%).

North Shore Estates HOA's 124 violations sit below 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
65
Total Violations
124
Health-Based Violations
82
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
31
County
Sanders
School/Daycare
No
MCL Violations
82
Monitoring Violations
34
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Arsenic MCL 53 2011
Coliform (TCR) MCL 29 2011
Coliform (TCR) MR 18 2012
Lead and Copper Rule MR 10 2001
Consumer Confidence Rule Other 8 2021
Nitrate-Nitrite MR 4 2002
Nitrate MR 2 1997

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 North Shore Estates HOA.

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 MT0003556 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 Consumer Confidence Rule Other 8 SDWIS / MT0003556 / 7000
2012 Coliform (TCR) MR 18 SDWIS / MT0003556 / 3100
2011 Arsenic MCL 53 SDWIS / MT0003556 / 1005
2011 Coliform (TCR) MCL 29 SDWIS / MT0003556 / 3100
2002 Nitrate-Nitrite MR 4 SDWIS / MT0003556 / 1038
2001 Lead and Copper Rule MR 10 SDWIS / MT0003556 / 5000
1997 Nitrate MR 2 SDWIS / MT0003556 / 1040

How North Shore Estates HOA Compares

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

Metric North Shore Estates HOA Montana avg Federal benchmark
Total violations 124 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 82 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 65 492 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 North Shore Estates HOA water safe to drink? ▼
North Shore Estates HOA (PWS ID: MT0003556) has 124 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 65 people using Groundwater sources.
How many people does North Shore Estates HOA serve? ▼
North Shore Estates HOA serves 65 people in Thompson Falls, Montana. It is a Private-owned system using Groundwater water sources with 31 service connections.
What type of violations does North Shore Estates HOA have? ▼
North Shore Estates HOA has 124 total violations: 82 health-based violations (MCL exceedances or treatment failures), 34 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in North Shore Estates HOA water? ▼
No PFAS testing data is available for North Shore Estates HOA under the EPA's UCMR5 monitoring program.
What water source does North Shore Estates HOA use? ▼
North Shore Estates HOA 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.