Community Water System · PWS IL1570100
Chester
Operator location Chester, Illinois - 27% of 113 violations are health-based (upper-third health share (> 23%)); surface water source; 8,407 served per SDWIS.
- 8,407
- People served (this PWS)
- 113
- EPA violations (this PWS)
- 30
- Health-based (this PWS)
- 3 PFAS
- UCMR5 (this PWS)
Chester standing, high SDWIS violation third
27% of 113 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%). UCMR5: middle-third PFAS panel (≤ 4 compounds). Population rank #5,410 of 29,740 among systems serving 500+.
The verdict
Chester sits in the upper third of the sitemap cohort by violation count (113), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (8,407; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 27% - most of this ledger is MCL or treatment-technique exceedance. UCMR5 detected 3 PFAS compounds (middle-third PFAS panel (≤ 4 compounds)).
- #5,410 of 29,740
- Population · /systems
- #260 of 1,310
- Population · IL
- 113
- Total EPA violations on record
- 27%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
3 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 2,826
- County
- Randolph
- School/Daycare
- No
- MCL Violations
- 7
- Monitoring Violations
- 63
- Treatment Tech Violations
- 23
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Surface Water Treatment Rule | MR | 46 | 2000 |
| Surface Water Treatment Rule | TT | 12 | 2008 |
| Coliform (TCR) | MR | 10 | 2012 |
| Coliform (TCR) | MCL | 7 | 2003 |
| Chlorine | MR | 6 | 2012 |
| Public Notice | Other | 6 | 2013 |
| CARBON, TOTAL | TT | 5 | 2012 |
| Interim Enhanced Surface Water Treatment Rule | TT | 5 | 2013 |
| Lead and Copper Rule | TT | 1 | 1992 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1977 |
Violation Count vs. the National Corpus
Chester has 113 recorded EPA violations, 76% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 24% carry more. 27% of this system's own violations are health-based (30 of 113), and it ranks #5,410 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)
113 Higher than most more violations than 76% 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
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 6 of 116 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFDA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 9/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxS | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 9/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDoA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 9/10/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/10/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 9/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| NMeFOSAA | 9/10/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFOS | 9/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBA | 9/10/2024 | 11.00 ppt | 5.00 ppt | Detected |
| PFHpS | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NEtFOSAA | 9/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 9/10/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFTA | 9/10/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFPeS | 9/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFEESA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 9/10/2024 | 3.10 ppt | 3.00 ppt | Detected |
| PFMPA | 9/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 9/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 9/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 9/10/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| 4:2 FTS | 9/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 6/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 6/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 6/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 6/10/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 6/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpS | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTrDA | 6/10/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFBA | 6/10/2024 | 5.00 ppt | 5.00 ppt | Detected |
| NEtFOSAA | 6/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 6/10/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFTA | 6/10/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFNA | 6/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| HFPO-DA | 6/10/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 6/10/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 6/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 6/10/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
Health-based violations on Chester
30 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for IL1570100.
Sources: EPA SDWIS · Illinois EPA, Bureau of Water
Nationwide peers
113 violations · 8,407 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.
Cross-state systems with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Chester
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.