Community Water System · PWS 090400394
Mishongnovi (Upper Sipaulovi/Upper Mishongnovi)
Operator location Second Mesa, EPA Region 9 — Tribal Water Systems - 27% of 454 violations are health-based (upper-third health share (> 23%)); groundwater source; 490 served per SDWIS.
- 490
- People served (this PWS) Smaller third of systems
- 454
- EPA violations (this PWS) Upper third of systems
- 121
- Health-based (this PWS) Upper third by health-based share
- Untested
- UCMR5 (this PWS) No UCMR5 result
Mishongnovi (Upper Sipaulovi/Upper Mishongnovi) standing, high SDWIS violation third
27% of 454 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 27% is upper-third health share (> 23%).
The verdict
Mishongnovi (Upper Sipaulovi/Upper Mishongnovi) sits in the upper third of the sitemap cohort by violation count (454), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (490; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 27% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- 454
- Total EPA violations on record
- 27%
- Health-based (MCL / treatment failure)
- 490
- People served by this PWS (SDWIS)
- N/A
- PFAS compounds detected (UCMR5)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 41
- School/Daycare
- No
- MCL Violations
- 121
- Monitoring Violations
- 237
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Arsenic | MCL | 121 | 2022 |
| Coliform (TCR) | MR | 43 | 2015 |
| Arsenic | MR | 18 | 2016 |
| Public Notice | Other | 12 | 2016 |
| Nitrate | MR | 7 | 2013 |
| Consumer Confidence Rule | Other | 7 | 2010 |
| Lead and Copper Rule | MR | 6 | 2014 |
| Fluoride | MR | 4 | 2004 |
| Barium | MR | 3 | 2001 |
| Cadmium | MR | 3 | 2001 |
| Chromium | MR | 3 | 2001 |
| Mercury | MR | 3 | 2001 |
| BHC-GAMMA | MR | 3 | 2001 |
| Methoxychlor | MR | 3 | 2001 |
| Toxaphene | MR | 3 | 2001 |
| Carbofuran | MR | 3 | 2001 |
| LASSO | MR | 3 | 2001 |
| 2,3,7,8-TCDD | MR | 3 | 2011 |
| Heptachlor | MR | 3 | 2001 |
| 2,4-D | MR | 3 | 2001 |
| 2,4,5-TP | MR | 3 | 2001 |
| Pentachlorophenol | MR | 3 | 2001 |
| 1,2,4-Trichlorobenzene | MR | 3 | 2001 |
| cis-1,2-Dichloroethylene | MR | 3 | 2001 |
| Total Polychlorinated Biphenyls (PCB) | MR | 3 | 2001 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 3 | 2001 |
| ETHYLENE DIBROMIDE | MR | 3 | 2001 |
| Chlordane | MR | 3 | 2001 |
| DICHLOROMETHANE | MR | 3 | 2001 |
| o-Dichlorobenzene | MR | 3 | 2001 |
Violation Count vs. the National Corpus
Mishongnovi (Upper Sipaulovi/Upper Mishongnovi) has 454 recorded EPA violations, 95% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 5% carry more. 27% of this system's own violations are health-based (121 of 454), and it ranks unranked by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
454 Higher than most more violations than 95% 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
How many violations vs. how serious, among peer systems
Mishongnovi (Upper Sipaulovi/Upper Mishongnovi) plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.
Violation volume vs. health-based share
Health-based violations on Mishongnovi (Upper Sipaulovi/Upper Mishongnovi)
121 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for 090400394.
Sources: EPA SDWIS
Nationwide peers
454 violations · 490 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.
What to do with Mishongnovi
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in EPA Region 9 — Tribal Water Systems compares on the same EPA violation measures. EPA Region 9 — Tribal Water Systems systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.