Lead In Drinking Water In Illinois
What residents of Illinois need to know about lead in drinking water — including how it enters water, which utilities have documented violations, and what steps to take.
Source: EPA SDWIS, Illinois Environmental Protection Agency (Illinois EPA), CDC · Last reviewed: 2025-01-01
Quick Answer
Is lead in drinking water a real concern in Illinois?
Yes — Chicago is believed to have more lead service lines than any other U.S. city, and Illinois has a dense inventory of pre-1986 housing with lead plumbing materials.
Is this mostly a public-water issue, a private-well issue, or both?
Primarily public water service lines; Chicago's city-wide lead service line infrastructure is the defining concern in this state.
What is the main reason residents should care?
Chicago historically required lead service lines by ordinance on private property, resulting in an estimated 380,000+ lead service lines — more than any other U.S. city. Illinois EPA oversees the Lead and Copper Rule, and Illinois enacted Public Act 101-0175 requiring lead service line inventories.
Key Facts
| Chicago lead service lines | Estimated 380,000+ — highest of any U.S. city |
| Historical ordinance | Chicago required lead service lines by city code until 1986 |
| Federal MCLG | Zero — no safe level of lead has been established |
| State law | Illinois Public Act 101-0175 requires statewide lead service line inventories |
| State oversight | Illinois Environmental Protection Agency (Illinois EPA) |
Why This Matters in Illinois
Chicago is in a category of its own when it comes to lead in drinking water infrastructure. For decades, Chicago city ordinance required that service lines connecting homes to the water main be made of lead — a requirement that remained in place until 1986. The result is an estimated 380,000 or more lead service lines across the city. These lines can leach lead into drinking water, particularly after disturbances (like repairs or replacement of nearby lines), which can dislodge scale that was previously containing the lead. Chicago began a systematic lead service line replacement program in 2021. Illinois law (Public Act 101-0175) requires all community water supplies to submit a lead service line inventory.
Historical Context
Chicago required lead service lines by ordinance until 1986. The city is now in a multi-year replacement program targeting its estimated 380,000+ lead service lines. Research has shown that lead service line replacements — if only partial — can temporarily increase lead levels at the tap.
Illinois Utilities With Lead Violation Records
The utilities listed below have at least one lead violation on record in EPA's SDWIS database. Violations may be open or resolved — see individual utility pages for current status and risk level.
Chicago
Chicago · 2,746,388 served
Aurora
Aurora · 183,000 served
Joliet
Joliet · 160,000 served
Il American-peoria
Peoria · 137,575 served
Il American-east St Louis
East St Louis · 131,368 served
Elgin
Elgin · 114,797 served
Waukegan
Waukegan · 87,149 served
Cicero
Cicero · 83,000 served
Aqua Illinois-kankakee
Kankakee · 80,000 served
Bloomington
Bloomington · 77,610 served
How Lead Gets Into Drinking Water
Lead service lines
The pipe connecting a home to the water main may be made of lead, especially in pre-1986 construction. Water sitting in these lines can accumulate lead before it reaches the tap.
Lead solder
Lead solder at pipe joints was banned for potable water systems in 1986. Homes built before that date — including significant portions of older Illinois cities — may still have lead solder throughout their plumbing.
Older brass fixtures
Faucets, valves, and fixtures with high lead content were common before the 2014 revision of 'lead-free' standards. Replacing older fixtures at kitchen and drinking taps can meaningfully reduce exposure.
Corrosive water chemistry
Soft, acidic, or low-alkalinity water dissolves lead from plumbing more readily. Utilities use orthophosphate and other corrosion control treatments, but household plumbing after the meter is not within their control.
Who Should Pay Closest Attention
Chicago residents on the city's South Side, West Side, and older North Side neighborhoods are most likely to have lead service lines. Families with young children and pregnant residents in these areas should consider a certified water filter regardless of recent test results.
Families with children under six
Pregnant residents
Households in homes built before 1986
Renters who cannot inspect building plumbing
Residents on a confirmed lead service line
Households that had plumbing work done recently (disturbances dislodge protective scale)
How to Check Your Situation in Illinois
- 1
Identify your water utility. Use the ZIP lookup below or browse the Illinois utility directory on this site.
- 2
Read your utility's page on this site to see its current risk level and any open lead violations.
- 3
Contact your utility and ask for your address-level service line material status. Under the federal Lead and Copper Rule Revisions (LCRR), utilities must maintain and provide this information.
- 4
Review your utility's most recent Consumer Confidence Report (CCR) — mailed annually or available on the utility's website.
- 5
Consider testing your tap water at a Illinois Environmental Protection Agency (Illinois EPA)-certified lab. Your state health department or Illinois Environmental Protection Agency (Illinois EPA) maintains a list of certified labs.
- 6
If you have young children or are pregnant, install a certified NSF/ANSI 53 or 58 filter at the kitchen tap as a precautionary measure.
Treatment Options
Boiling does not remove lead. Use a certified filter for drinking and cooking water.
NSF/ANSI Standard 53 — Activated Carbon Block
Under-sink or pitcher filters certified to Standard 53 are independently verified to reduce lead. Replace filters on the manufacturer's schedule — an overdue filter may not perform as certified.
NSF/ANSI Standard 58 — Reverse Osmosis
RO systems certified to Standard 58 remove 95–99% of lead and a broad range of contaminants. Requires under-sink installation. More comprehensive than Standard 53 for households with multiple contaminant concerns.
Flushing — temporary mitigation only
EPA recommends flushing the cold tap for 30 seconds to 2 minutes if water has sat in pipes for 6+ hours. Not a substitute for certified filtration or service line replacement.
Frequently Asked Questions
Related Pages
Lead — National Overview
All U.S. utilities with lead records
Illinois State Overview
All utilities and water quality data
Nitrate in Drinking Water
A separate but common concern
Reverse Osmosis Guide
Removes 95–99% of lead
Activated Carbon Filter Guide
NSF/ANSI 53 certified options
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
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Illinois Environmental Protection Agency (Illinois EPA) ↗