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States → EPA Region 8 — Tribal Water Systems

Community Water System · PWS 083090075

Rocky Boy's Rural Water

Box Elder, EPA Region 8 — Tribal Water Systems 59521 - drinking water served from groundwater sources to 2,000 people, tracked in EPA SDWIS and UCMR5.

2,000
People served
130
EPA violations
23
Health-based
Untested
UCMR5 result

The verdict

EPA records 130 drinking-water violations at Rocky Boy's Rural Water, 18% of them health-based.

130
Total EPA violations on record
18%
Health-based (MCL / treatment failure)
2,000
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Rocky Boy's Rural Water

Rocky Boy's Rural Water is a native american-owned community water system that delivers drinking water to 2,000 residents in Box Elder, EPA Region 8 — Tribal Water Systems through 477 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 130 total violations for this system , of which 23 (18%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 99 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 21 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.

EPA Region 8 — 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
2,000
Total Violations
130
Health-Based Violations
23
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
477
School/Daycare
No
MCL Violations
21
Monitoring Violations
99
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 21 2009
Coliform (TCR) MR 13 2003
Asbestos MR 4 2021
Diquat MR 2 2017
Endothall MR 2 2017
Glyphosate MR 2 2017
Cadmium MR 2 2014
Consumer Confidence Rule Other 2 2014
Antimony, Total MR 2 2014
Chromium MR 2 2014
Thallium, Total MR 2 2014
Nickel MR 2 2014
Barium MR 2 2014
Groundwater Rule TT 2 2017
Arsenic MR 2 2014
Selenium MR 2 2014
Mercury MR 2 2014
Beryllium, Total MR 2 2014
Lead and Copper Rule MR 2 2011
Endrin MR 1 2014
Toxaphene MR 1 2014
OXAMYL MR 1 2014
Simazine MR 1 2014
Picloram MR 1 2014
Dinoseb MR 1 2014
Carbofuran MR 1 2014
LASSO MR 1 2014
2,3,7,8-TCDD MR 1 2014
Heptachlor epoxide MR 1 2014
2,4-D MR 1 2014

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 Rocky Boy's Rural Water.

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 083090075 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

EPA Region 8 — Tribal Water Systems Drinking Water Authority

EPA Region 8 — 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 08 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 Nitrite MR 1 SDWIS / 083090075 / 1041
2021 Asbestos MR 4 SDWIS / 083090075 / 1094
2017 Diquat MR 2 SDWIS / 083090075 / 2032
2017 Endothall MR 2 SDWIS / 083090075 / 2033
2017 Glyphosate MR 2 SDWIS / 083090075 / 2034
2017 Groundwater Rule TT 2 SDWIS / 083090075 / 0700
2017 Nitrate-Nitrite MR 1 SDWIS / 083090075 / 1038
2014 Cadmium MR 2 SDWIS / 083090075 / 1015
2014 Consumer Confidence Rule Other 2 SDWIS / 083090075 / 7000
2014 Antimony, Total MR 2 SDWIS / 083090075 / 1074
2014 Chromium MR 2 SDWIS / 083090075 / 1020
2014 Thallium, Total MR 2 SDWIS / 083090075 / 1085
2014 Nickel MR 2 SDWIS / 083090075 / 1036
2014 Barium MR 2 SDWIS / 083090075 / 1010
2014 Arsenic MR 2 SDWIS / 083090075 / 1005

How Rocky Boy's Rural Water Compares

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

Metric Rocky Boy's Rural Water EPA Region 8 — Tribal Water Systems avg Federal benchmark
Total violations 130 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 23 - Indicates a contaminant exceeded a federal MCL
PFAS detection None - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 2,000 - 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 8 — 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 Rocky Boy's Rural Water water safe to drink? ▼
Rocky Boy's Rural Water (PWS ID: 083090075) has 130 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 2,000 people using Groundwater sources.
How many people does Rocky Boy's Rural Water serve? ▼
Rocky Boy's Rural Water serves 2,000 people in Box Elder, EPA Region 8 — Tribal Water Systems. It is a Native American-owned system using Groundwater water sources with 477 service connections.
What type of violations does Rocky Boy's Rural Water have? ▼
Rocky Boy's Rural Water has 130 total violations: 23 health-based violations (MCL exceedances or treatment failures), 99 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Rocky Boy's Rural Water water? ▼
No PFAS testing data is available for Rocky Boy's Rural Water under the EPA's UCMR5 monitoring program.
What water source does Rocky Boy's Rural Water use? ▼
Rocky Boy's Rural Water 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.