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Community Water System · PWS 083090079

Rocky Boy Agency Water System

Operator location Box Elder, EPA Region 8 — Tribal Water Systems - upper-third violation load (> 74 violations) with 109 EPA violations; groundwater source; 1,442 served (PWS-level, not municipal population).

1,442
People served (this PWS)
109
EPA violations (this PWS)
15
Health-based (this PWS)
Untested
UCMR5 (this PWS)
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Rocky Boy Agency Water System standing, high SDWIS violation third

109 EPA SDWIS violations on record - upper-third violation load (> 74 violations). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 14% is middle-third health share (≤ 23%). Population rank #16,328 of 29,740 among systems serving 500+.

The verdict

Rocky Boy Agency Water System sits in the upper third of the sitemap cohort by violation count (109), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 1,442 (mid served population (≤ 3,309)). Health-based share is 14% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.

#16,328 of 29,740
Population · /systems
#32 of 55
Population · 08
109
Total EPA violations on record
14%
Health-based (MCL / treatment failure)

Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.

System Details

System Type
Community
Owner Type
Native American
Connections
150
School/Daycare
Yes
MCL Violations
14
Monitoring Violations
86
Treatment Tech Violations
1

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 28 2009
Coliform (TCR) MCL 14 2005
Groundwater Rule Other 5 2012
Asbestos MR 3 2023
Consumer Confidence Rule Other 2 2014
Xylenes, Total MR 2 2020
Toluene MR 2 2020
1,2,4-Trichlorobenzene MR 1 2014
p-Dichlorobenzene MR 1 2014
Vinyl chloride MR 1 2014
1,2-Dichloroethane MR 1 2014
1,2-Dichloropropane MR 1 2014
Benzene MR 1 2014
Styrene MR 1 2014
Endrin MR 1 2014
BHC-GAMMA MR 1 2014
Methoxychlor MR 1 2014
Toxaphene MR 1 2014
Diquat MR 1 2014
Endothall MR 1 2014
Di(2-ethylhexyl) adipate MR 1 2014
OXAMYL MR 1 2014
Simazine MR 1 2014
Hexachlorocyclopentadiene MR 1 2014
Carbofuran MR 1 2014
Atrazine MR 1 2014
2,3,7,8-TCDD MR 1 2014
Heptachlor MR 1 2014
2,4-D MR 1 2014
2,4,5-TP MR 1 2014

Violation Count vs. the National Corpus

Rocky Boy Agency Water System has 109 recorded EPA violations, 75% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 25% carry more. 14% of this system's own violations are health-based (15 of 109), and it ranks #16,328 of 29,740 by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

109 Around the middle fewer violations than 25% of 29,740 water systems

the national water-system corpus, bucketed by value

Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source EPA SDWIS · 2026-05-15

SDWIS compliance record for Rocky Boy Agency Water System

109 violations on record for 083090079; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.

Sources: EPA SDWIS

Nationwide peers

109 violations · 1,442 served: nearest cross-state SDWIS matches.

Cross-state systems with comparable violation load

Nearest cross-state community systems (500+ served) by total SDWIS violations on record.

4 peers

Cross-state systems near this population served

Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).

4 peers

What to do with Rocky Boy Agency Water System

Use this system's EPA-reported record as a starting filter, not a final verdict.

EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater