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Community Water System · PWS 083090075

Rocky Boy's Rural Water

Operator location Box Elder, EPA Region 8 — Tribal Water Systems - upper-third violation load (> 74 violations) with 130 EPA violations; groundwater source; 2,000 served (PWS-level, not municipal population).

2,000
People served (this PWS)
130
EPA violations (this PWS)
23
Health-based (this PWS)
Untested
UCMR5 (this PWS)
Follow published updates (RSS)

Rocky Boy's Rural Water standing, high SDWIS violation third

130 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 18% is middle-third health share (≤ 23%). Population rank #13,528 of 29,740 among systems serving 500+.

The verdict

Rocky Boy's Rural Water sits in the upper third of the sitemap cohort by violation count (130), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 2,000 (mid served population (≤ 3,309)). Health-based share is 18% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.

#13,528 of 29,740
Population · /systems
#23 of 55
Population · 08
130
Total EPA violations on record
18%
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
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

Violation Count vs. the National Corpus

Rocky Boy's Rural Water has 130 recorded EPA violations, 78% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 21% carry more. 18% of this system's own violations are health-based (23 of 130), and it ranks #13,528 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)

130 Higher than most more violations than 78% 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's Rural Water

130 violations on record for 083090075; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.

Sources: EPA SDWIS

Nationwide peers

130 violations · 2,000 served: nearest cross-state SDWIS matches.

What to do with Rocky Boy's Rural Water

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