Illinois · population 2,300
Lead pipes in Thornton, IL
119 lead or galvanized lines to replace
Most of Thornton (population 2,300) gets its water from Thornton. That system reported 113 lead and 6 galvanized-requiring-replacement service lines out of 1,149, with 889 more of unknown material.
10% of Thornton's service lines are lead or galvanized requiring replacement, lower than the Illinois average (17%) and higher than the national average (3.1%).
- Lead 9.8%
- Galvanized (replace) 0.5%
- Unknown 77%
- Non-lead 12%
Latest lead test for Thornton (Jan 2026–Jun 2026): 2.8 ppb at the 90th percentile, against a 15 ppb federal action level. Full test history.
Compliance record: EPA lists 1 Lead and Copper Rule violation since 2015 for Thornton.
Water systems serving Thornton
| Water system | Lead | Galv. | Unknown | % lead |
|---|---|---|---|---|
| ThorntonMain system | 113 | 6 | 889 | 10% |
| South HollandServes nearby areas | 1,264 | 46 | 271 | 15% |
Matched from EPA water system service area boundaries and the cities each system reports serving. Edges of the city may be served by a neighboring system; your water bill names your utility.
Check your address in Thornton
The counts above cover the whole water system. To see whether your line is lead, look up your address on Thornton's official inventory. Utilities had to make these public by October 16, 2024.
No map yet? Do the 2-minute scratch and magnet test.
Protect your drinking water
If your line is lead, galvanized or unknown, use a filter certified to NSF/ANSI 53 for lead for drinking, cooking and baby formula, and use only cold water.
Choosing a lead-certified filter · Testing your water · Replacement cost
Nearby cities
- East Hazel Crestno lead reported
- South Holland1,310 lead + galv. lines
- Glenwoodno lead reported
- Homewood3,759 lead + galv. lines
- Phoenix322 lead + galv. lines
- Harvey190 lead + galv. lines
- Hazel Crest1,396 lead + galv. lines
- Dolton2,358 lead + galv. lines
Check another water system
Questions
Does Thornton, IL have lead pipes?
Yes. Thornton, which serves Thornton, reported 113 lead and 6 galvanized-requiring-replacement service lines, plus 889 of unknown material.
Who supplies water to Thornton?
EPA's service area maps place most of Thornton in Thornton's service area (PWSID IL0313090). South Holland also serves parts of the city or nearby areas.
How do I check whether my Thornton home has a lead service line?
Search your address on Thornton's service line inventory map. You can also scratch the pipe where water enters your home: lead is soft, dull gray, scratches to shiny silver and doesn't attract a magnet.
When will lead pipes in Thornton be replaced?
EPA's Lead and Copper Rule Improvements require most systems to replace lead and galvanized-requiring-replacement lines by December 31, 2037. Ask Thornton whether your street is scheduled and whether it covers the private side.