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States → EPA Region 10 — Tribal Water Systems

Community Water System · PWS 101600010

Big Sky N. Subdivision

Pocatello, EPA Region 10 — Tribal Water Systems 83204 - drinking water served from groundwater sources to 300 people, tracked in EPA SDWIS and UCMR5.

300
People served
223
EPA violations
2
Health-based
Untested
UCMR5 result

The verdict

EPA records 223 drinking-water violations at Big Sky N. Subdivision, 1% of them health-based.

223
Total EPA violations on record
1%
Health-based (MCL / treatment failure)
300
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Big Sky N. Subdivision

Big Sky N. Subdivision is a private-owned community water system that delivers drinking water to 300 residents in Pocatello, EPA Region 10 — Tribal Water Systems through 212 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 223 total violations for this system , of which 2 (1%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 210 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 Coliform (TCR), recorded in 9 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

EPA Region 10 — Tribal Water Systems has thousands of regulated public water systems tracked by EPA under the Safe Drinking Water Act.

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
300
Total Violations
223
Health-Based Violations
2
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
212
School/Daycare
No
MCL Violations
2
Monitoring Violations
210
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 9 2016
Consumer Confidence Rule Other 8 2025
Lead and Copper Rule MR 7 2023
Nitrate MR 7 2022
Revised Total Coliform Rule MON 6 2021
Antimony, Total MR 5 2017
Selenium MR 5 2017
Barium MR 5 2017
Thallium, Total MR 5 2017
Nickel MR 5 2017
Mercury MR 5 2017
Cadmium MR 5 2017
Chromium MR 5 2017
Fluoride MR 5 2017
Beryllium, Total MR 5 2017
Combined Uranium MR 4 2017
Gross Alpha, Excl. Radon and U MR 4 2017
Combined Radium (-226 and -228) MR 4 2017
Arsenic MR 3 2017
Dalapon MR 3 2020
Endrin MR 3 2020
BHC-GAMMA MR 3 2020
Methoxychlor MR 3 2020
Toxaphene MR 3 2020
Diquat MR 3 2020
Di(2-ethylhexyl) phthalate MR 3 2020
Picloram MR 3 2020
Carbofuran MR 3 2020
LASSO MR 3 2020
Heptachlor MR 3 2020

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 Big Sky N. Subdivision.

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 101600010 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

EPA Region 10 — Tribal Water Systems Drinking Water Authority

EPA Region 10 — Tribal Water Systems'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 10 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 8 SDWIS / 101600010 / 7000
2023 Lead and Copper Rule MR 7 SDWIS / 101600010 / 5000
2022 Nitrate MR 7 SDWIS / 101600010 / 1040
2021 Revised Total Coliform Rule MON 6 SDWIS / 101600010 / 8000
2020 Dalapon MR 3 SDWIS / 101600010 / 2031
2020 Endrin MR 3 SDWIS / 101600010 / 2005
2020 BHC-GAMMA MR 3 SDWIS / 101600010 / 2010
2020 Methoxychlor MR 3 SDWIS / 101600010 / 2015
2020 Toxaphene MR 3 SDWIS / 101600010 / 2020
2020 Diquat MR 3 SDWIS / 101600010 / 2032
2020 Di(2-ethylhexyl) phthalate MR 3 SDWIS / 101600010 / 2039
2020 Picloram MR 3 SDWIS / 101600010 / 2040
2020 Carbofuran MR 3 SDWIS / 101600010 / 2046
2020 LASSO MR 3 SDWIS / 101600010 / 2051
2020 Heptachlor MR 3 SDWIS / 101600010 / 2065

How Big Sky N. Subdivision Compares

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

Metric Big Sky N. Subdivision EPA Region 10 — Tribal Water Systems avg Federal benchmark
Total violations 223 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 2 - Indicates a contaminant exceeded a federal MCL
PFAS detection None - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 300 - Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across all regulated public water systems in EPA Region 10 — Tribal Water Systems.

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 Big Sky N. Subdivision water safe to drink? ▼
Big Sky N. Subdivision (PWS ID: 101600010) has 223 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 300 people using Groundwater sources.
How many people does Big Sky N. Subdivision serve? ▼
Big Sky N. Subdivision serves 300 people in Pocatello, EPA Region 10 — Tribal Water Systems. It is a Private-owned system using Groundwater water sources with 212 service connections.
What type of violations does Big Sky N. Subdivision have? ▼
Big Sky N. Subdivision has 223 total violations: 2 health-based violations (MCL exceedances or treatment failures), 210 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Big Sky N. Subdivision water? ▼
No PFAS testing data is available for Big Sky N. Subdivision under the EPA's UCMR5 monitoring program.
What water source does Big Sky N. Subdivision use? ▼
Big Sky N. Subdivision 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.