Community Water System · PWS AK2260040
Koliganek Water System
Operator location Koliganek, Alaska - smaller served population (≤ 999) at 170 people served; 492 SDWIS violations on record from groundwater sources.
- 170
- People served (this PWS)
- 492
- EPA violations (this PWS)
- 10
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Koliganek Water System standing, high SDWIS violation third
170 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 2% is middle-third health share (≤ 23%).
The verdict
Koliganek Water System sits in the upper third of the sitemap cohort by violation count (492), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (170; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 2% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- 492
- Total EPA violations on record
- 2%
- Health-based (MCL / treatment failure)
- 170
- 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.
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 40
- County
- Dillingham Census Area
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 349
- Treatment Tech Violations
- 10
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 43 | 2016 |
| Lead and Copper Rule | MR | 23 | 2024 |
| Chlorine | MR | 22 | 2005 |
| Nitrate | MR | 18 | 2024 |
| Groundwater Rule | TT | 10 | 2018 |
| Consumer Confidence Rule | Other | 9 | 2021 |
| p-Dichlorobenzene | MR | 6 | 2014 |
| Carbon tetrachloride | MR | 6 | 2014 |
| Trichloroethylene | MR | 6 | 2014 |
| Benzene | MR | 6 | 2014 |
| Revised Total Coliform Rule | MON | 6 | 2019 |
| Vinyl chloride | MR | 6 | 2014 |
| 1,2-Dichloroethane | MR | 6 | 2014 |
| 1,1-Dichloroethylene | MR | 6 | 2014 |
| 1,1,1-Trichloroethane | MR | 6 | 2014 |
| Arsenic | MR | 5 | 2014 |
| Endrin | MR | 4 | 2010 |
| BHC-GAMMA | MR | 4 | 2010 |
| Toxaphene | MR | 4 | 2010 |
| Dalapon | MR | 4 | 2010 |
| Endothall | MR | 4 | 2010 |
| Glyphosate | MR | 4 | 2010 |
| OXAMYL | MR | 4 | 2010 |
| Simazine | MR | 4 | 2010 |
| Di(2-ethylhexyl) phthalate | MR | 4 | 2010 |
| Picloram | MR | 4 | 2010 |
| Hexachlorocyclopentadiene | MR | 4 | 2010 |
| Carbofuran | MR | 4 | 2010 |
| Atrazine | MR | 4 | 2010 |
| LASSO | MR | 4 | 2010 |
Violation Count vs. the National Corpus
Koliganek Water System has 492 recorded EPA violations, 95% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 5% carry more. 2% of this system's own violations are health-based (10 of 492), 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)
492 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
Population served record for Koliganek Water System
EPA SDWIS lists 170 people served and 40 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
492 violations · 170 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 Koliganek Water System
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Alaska compares on the same EPA violation measures. Alaska 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.