Community Water System · PWS IL0111050
Tiskilwa
Operator location Tiskilwa, Illinois - smaller served population (≤ 999) at 740 people served; 41 SDWIS violations on record from groundwater sources.
- 740
- People served (this PWS)
- 41
- EPA violations (this PWS)
- 8
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Tiskilwa standing, mid SDWIS violation third
740 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 20% is middle-third health share (≤ 23%). Population rank #23,644 of 29,740 among systems serving 500+.
The verdict
Tiskilwa lands in the middle third by violation volume (41), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (740; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 20% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #23,644 of 29,740
- Population · /systems
- #1,061 of 1,310
- Population · IL
- 41
- Total EPA violations on record
- 20%
- 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
- Local
- Connections
- 360
- County
- Bureau
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 29
- Treatment Tech Violations
- 8
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 13 | 2000 |
| Lead and Copper Rule | MR | 7 | 2000 |
| Lead and Copper Rule | TT | 5 | 2008 |
| Diquat | MR | 4 | 2020 |
| Endothall | MR | 4 | 2020 |
| LEAD AND COPPER RULE REVISIONS | TT | 3 | 2024 |
| Consumer Confidence Rule | Other | 2 | 2003 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1977 |
Violation Count vs. the National Corpus
Tiskilwa has 41 recorded EPA violations, 51% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 48% carry more. 20% of this system's own violations are health-based (8 of 41), and it ranks #23,644 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)
41 Around the middle fewer violations than 48% 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 Tiskilwa
EPA SDWIS lists 740 people served and 360 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS · Illinois EPA, Bureau of Water
Nationwide peers
41 violations · 740 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with smaller service footprints
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Tiskilwa
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.