Community Water System · PWS IL0110700
Neponset
Operator location Neponset, Illinois - 55% of 1,195 violations are health-based (upper-third health share (> 23%)); groundwater source; 427 served per SDWIS.
- 427
- People served (this PWS)
- 1,195
- EPA violations (this PWS)
- 657
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Neponset standing, high SDWIS violation third
55% of 1,195 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 55% is upper-third health share (> 23%).
The verdict
Neponset sits in the upper third of the sitemap cohort by violation count (1,195), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (427; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 55% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- 1,195
- Total EPA violations on record
- 55%
- Health-based (MCL / treatment failure)
- 427
- 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
- Local
- Connections
- 200
- County
- Bureau
- School/Daycare
- No
- MCL Violations
- 655
- Monitoring Violations
- 275
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Combined Radium (-226 and -228) | MCL | 414 | 2013 |
| Gross Alpha, Excl. Radon and U | MCL | 229 | 2012 |
| Public Notice | Other | 187 | 2025 |
| Coliform (TCR) | MR | 55 | 2015 |
| Combined Radium (-226 and -228) | MR | 27 | 2010 |
| Consumer Confidence Rule | Other | 21 | 2025 |
| Gross Alpha, Excl. Radon and U | MR | 17 | 2004 |
| Coliform (TCR) | MCL | 12 | 2010 |
| Xylenes, Total | MR | 9 | 1993 |
| o-Dichlorobenzene | MR | 9 | 1993 |
| 1,1-Dichloroethylene | MR | 9 | 1993 |
| 1,1,1-Trichloroethane | MR | 9 | 1993 |
| Carbon tetrachloride | MR | 9 | 1993 |
| 1,2-Dichloropropane | MR | 9 | 1993 |
| Trichloroethylene | MR | 9 | 1993 |
| CHLOROBENZENE | MR | 9 | 1993 |
| Toluene | MR | 9 | 1993 |
| Ethylbenzene | MR | 9 | 1993 |
| trans-1,2-Dichloroethylene | MR | 9 | 1993 |
| Benzene | MR | 9 | 1993 |
| Combined Uranium | MR | 9 | 2010 |
| p-Dichlorobenzene | MR | 9 | 1993 |
| cis-1,2-Dichloroethylene | MR | 9 | 1993 |
| Tetrachloroethylene | MR | 9 | 1993 |
| Styrene | MR | 9 | 1993 |
| Lead and Copper Rule | MR | 8 | 2021 |
| 1,2-Dichloroethane | MR | 8 | 1993 |
| Chlorine | MR | 4 | 2015 |
| Fluoride | MR | 3 | 1999 |
| LEAD AND COPPER RULE REVISIONS | TT | 2 | 2024 |
Violation Count vs. the National Corpus
Neponset has 1,195 recorded EPA violations, 99% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 1% carry more. 55% of this system's own violations are health-based (657 of 1,195), 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)
1,195 Higher than most more violations than 99% 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
Health-based violations on Neponset
657 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for IL0110700.
Sources: EPA SDWIS · Illinois EPA, Bureau of Water
Nationwide peers
1,195 violations · 427 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 Neponset
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Illinois compares on the same EPA violation measures. Illinois 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.