Community Water System · PWS IL0430010
York Township Water System
Operator location Darien, Illinois - upper-third violation load (> 74 violations) with 172 EPA violations; surface water source; 1,423 served (PWS-level, not municipal population).
- 1,423
- People served (this PWS)
- 172
- EPA violations (this PWS)
- 24
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
York Township Water System standing, high SDWIS violation third
172 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 14% is middle-third health share (≤ 23%). Population rank #16,421 of 29,740 among systems serving 500+.
The verdict
York Township Water System sits in the upper third of the sitemap cohort by violation count (172), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 1,423 (mid served population (≤ 3,309)). Health-based share is 14% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #16,421 of 29,740
- Population · /systems
- #719 of 1,310
- Population · IL
- 172
- Total EPA violations on record
- 14%
- 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
- Private
- Connections
- 480
- County
- DuPage
- School/Daycare
- No
- MCL Violations
- 18
- Monitoring Violations
- 133
- Treatment Tech Violations
- 6
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 27 | 2000 |
| Coliform (TCR) | MCL | 18 | 2007 |
| Consumer Confidence Rule | Other | 10 | 2025 |
| Lead and Copper Rule | MR | 9 | 2012 |
| Lead and Copper Rule | TT | 6 | 2009 |
| Public Notice | Other | 4 | 2008 |
| Nitrate | MR | 4 | 2011 |
| BHC-GAMMA | MR | 3 | 1994 |
| Toxaphene | MR | 3 | 1994 |
| Carbofuran | MR | 3 | 1994 |
| Atrazine | MR | 3 | 1994 |
| Heptachlor epoxide | MR | 3 | 1994 |
| 2,4-D | MR | 3 | 1994 |
| Pentachlorophenol | MR | 3 | 1994 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 3 | 1994 |
| Chlordane | MR | 3 | 1994 |
| Endothall | MR | 3 | 1994 |
| Di(2-ethylhexyl) adipate | MR | 3 | 1994 |
| Di(2-ethylhexyl) phthalate | MR | 3 | 1994 |
| Picloram | MR | 3 | 1994 |
| Aldicarb sulfoxide | MR | 3 | 1994 |
| Aldicarb sulfone | MR | 3 | 1994 |
| Aldicarb | MR | 3 | 1994 |
| Hexachlorocyclopentadiene | MR | 3 | 1994 |
| Total Polychlorinated Biphenyls (PCB) | MR | 3 | 1994 |
| Dalapon | MR | 3 | 1994 |
| ETHYLENE DIBROMIDE | MR | 3 | 1994 |
| Benzo(a)pyrene | MR | 3 | 1994 |
| Diquat | MR | 3 | 1994 |
| Heptachlor | MR | 3 | 1994 |
Violation Count vs. the National Corpus
York Township Water System has 172 recorded EPA violations, 83% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 17% carry more. 14% of this system's own violations are health-based (24 of 172), and it ranks #16,421 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)
172 Higher than most more violations than 83% 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 York Township Water System
172 violations on record for IL0430010; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.
Sources: EPA SDWIS · Illinois EPA, Bureau of Water
Nationwide peers
172 violations · 1,423 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 near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with York Township Water System
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.