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2,202 Illinois water systems have inventoried 3,875,591 service lines for EPA. 615,181 (16%) are confirmed lead and 530,644 (14%) are still of unknown material. Below: every large or city-linked Illinois utility ranked by lead lines.
Illinois water systems reported 615,181 lead service lines and 57,081 galvanized lines requiring replacement as of Q2 2026 — 16% of the 3,875,591 lines inventoried and 28% of the national lead total, ranking #1 of 51. CHICAGO reports the most in the state (350,531).
CHICAGO (350,531), AURORA (16,799), ROCKFORD (14,240) lead the list; 329 Illinois systems report at least one lead line in total.
Find your utility in the table below, then check its published service line inventory (most utilities post an address-lookup map) or call the number on your water bill. Utilities must notify customers whose line is lead, galvanized-requiring-replacement or unknown. You can also test the pipe entering your home: lead is soft, dull gray, non-magnetic and turns shiny when scratched.
Under EPA's Lead and Copper Rule Improvements, systems must replace lead and galvanized-requiring-replacement lines within 10 years starting in 2027; systems with very high counts can receive longer deadlines. Ask your utility for its replacement plan and whether it covers the homeowner-owned portion.
Use a filter certified to NSF/ANSI 53 for lead for drinking and cooking, flush the tap after water has sat for hours, never use hot tap water for drinking or infant formula, and confirm your actual level with a certified lab test.
Source: EPA SDWIS Service Line Inventory, Q2 2026 snapshot (updated 2026-08-18). Counts are service lines, not people.
2,047 of the 2,202 Illinois systems in EPA's Q2 2026 report have filed line counts. The 615,181 confirmed lead lines and 57,081 galvanized lines requiring replacement come from 329 systems — 16% of those reporting — so roughly one Illinois system in 6 reports at least one lead line. 530,644 lines (14%) are still of unknown material, below the national share of 22%.
Why unknown lines matter: Under EPA's Lead and Copper Rule Revisions (LCRR), every community water system had to submit an initial service line inventory by October 16, 2024, and lines whose material could not be documented were reported as unknown. The Lead and Copper Rule Improvements (LCRI), finalized in October 2024, require systems to keep identifying those lines, to notify customers served by a lead, galvanized-requiring-replacement or unknown line, and to replace lead and galvanized-requiring-replacement lines — generally within 10 years of the rule's November 1, 2027 compliance date. The LCRI also lowers the lead action level from 15 to 10 ppb. For Illinois, that makes the 530,644 unknown lines (14%) the pool from which future confirmed-lead counts will be drawn.
Among the 56 Illinois utilities linked to a city report on this site, 43 report at least one lead or galvanized-requiring-replacement line and 13 report no lead with most lines verified. The largest — CHICAGO (2,721,308 served), AURORA (183,000 served), and JOLIET (160,000 served) — report 350,531 lead + 10,326 GRR, 16,799 lead + 138 GRR, and 299 lead + 8 GRR respectively.
To check your own line, start with your utility: most Illinois systems publish their inventory as an address-lookup map or table, and the annual Consumer Confidence Report (CCR) names the system and its lead results. If your address shows lead, galvanized or unknown, the utility is required to have notified you; if you cannot find it, ask for the service line material on record. You can also inspect the pipe where it enters the house — lead is dull gray, soft enough to scratch shiny with a coin, and does not attract a magnet.
EPA's rule text and timelines are on its Lead and Copper Rule Improvements page. While your line is unverified, our best water filters for lead guide covers NSF/ANSI 53-certified options, and the lead in drinking water guide explains testing and health thresholds.
EPA SDWIS Service Line Inventory, Q2 2026 snapshot (updated 2026-08-18); regulatory dates from EPA's LCRR/LCRI pages.
Community systems serving 50,000+ people plus systems linked to a city report on this site (59 shown). State totals above include every reporting system.
| # | Water system | Status | Lead | GRR | Unknown | Total lines | City report |
|---|---|---|---|---|---|---|---|
| 1 | CHICAGO IL0316000 · 2,721,308 served | Lead service lines present | 350,531 | 10,326 | 39,427 | 486,450 | Chicago → |
| 2 | AURORA IL0894070 · 183,000 served | Lead service lines present | 16,799 | 138 | 93 | 50,058 | Aurora → |
| 3 | ROCKFORD IL2010300 · 147,051 served | Lead service lines present | 14,240 | 1,088 | 28,598 | 55,377 | Rockford → |
| 4 | CICERO IL0310510 · 83,000 served | Lead service lines present | 13,059 | 0 | 940 | 14,666 | Cicero → |
| 5 | IL AMERICAN-PEORIA IL1435030 · 137,575 served | Lead service lines present | 11,000 | 442 | 24,303 | 64,085 | Peoria → |
| 6 | BERWYN IL0310210 · 57,250 served | Lead service lines present | 10,863 | 291 | 4 | 13,423 | Berwyn → |
| 7 | EVANSTON IL0310810 · 74,486 served | Lead service lines present | 10,017 | 243 | 0 | 14,654 | Evanston → |
| 8 | ELGIN IL0894380 · 114,797 served | Lead service lines present | 9,248 | 1 | 1,507 | 34,503 | Elgin → |
| 9 | WAUKEGAN IL0971900 · 87,149 served | Lead service lines present | 7,260 | 62 | 686 | 21,060 | Waukegan → |
| 10 | OAK PARK IL0312250 · 54,583 served | Lead service lines present | 6,935 | 714 | 1,222 | 12,549 | Oak Park → |
| 11 | BLOOMINGTON IL1130200 · 77,610 served | Lead service lines present | 5,734 | 27 | 6,034 | 32,091 | Bloomington → |
| 12 | QUINCY IL0010650 · 42,000 served | Lead service lines present | 5,223 | 33 | 70 | 18,249 | Quincy → |
| 13 | SKOKIE IL0312880 · 66,422 served | Lead service lines present | 4,672 | 186 | 11,065 | 17,645 | Skokie → |
| 14 | CALUMET CITY IL0310390 · 37,000 served | Lead service lines present | 4,121 | 0 | 1,226 | 9,728 | Calumet City → |
| 15 | MOLINE IL1610450 · 44,500 served | Lead service lines present | 3,859 | 873 | 2,416 | 17,193 | Moline → |
| 16 | ARLINGTON HEIGHTS IL0314030 · 73,320 served | Lead service lines present | 3,677 | 1 | 80 | 20,303 | Arlington Heights → |
| 17 | ST CHARLES IL0894830 · 33,103 served | Lead service lines present | 3,222 | 95 | 26 | 12,959 | St. Charles → |
| 18 | PARK RIDGE IL0312460 · 39,800 served | Lead service lines present | 3,121 | 0 | 5,530 | 12,648 | Park Ridge → |
| 19 | GLENVIEW IL0311020 · 47,856 served | Lead service lines present | 2,217 | 0 | 1,983 | 18,209 | Glenview → |
| 20 | OAK LAWN IL0312220 · 58,362 served | Lead service lines present | 2,209 | 497 | 47 | 17,012 | Oak Lawn → |
| 21 | DES PLAINES IL0310630 · 60,675 served | Lead service lines present | 1,607 | 1,824 | 6,835 | 16,665 | Des Plaines → |
| 22 | LOMBARD IL0430600 · 44,476 served | Lead service lines present | 1,335 | 877 | 0 | 15,270 | Lombard → |
| 23 | ELMHURST IL0430350 · 45,000 served | Lead service lines present | 1,224 | 4 | 0 | 15,101 | Elmhurst → |
| 24 | NORTH CHICAGO IL0971250 · 16,813 served | Lead service lines present | 849 | 0 | 4,804 | 5,653 | North Chicago → |
| 25 | DOWNERS GROVE IL0430300 · 49,425 served | Lead service lines present | 802 | 146 | 2,173 | 17,048 | Downers Grove → |
| 26 | IL AMERICAN-EAST ST LOUIS IL1635040 · 131,368 served | Lead service lines present | 749 | 351 | 34,431 | 71,163 | |
| 27 | MOUNT PROSPECT IL0311980 · 41,000 served | Lead service lines present | 700 | 27 | 65 | 11,654 | Mount Prospect → |
| 28 | IL AMERICAN-GRANITE CITY IL1195030 · 33,572 served | Lead service lines present | 697 | 130 | 12,306 | 21,217 | Granite City → |
| 29 | SPRINGFIELD IL1671200 · 117,444 served | Lead service lines present | 652 | 1,130 | 8,481 | 55,138 | Springfield → |
| 30 | CRYSTAL LAKE IL1110150 · 40,661 served | Lead service lines present | 517 | 43 | 1,109 | 13,787 | Crystal Lake → |
| 31 | AQUA ILLINOIS-KANKAKEE IL0915030 · 80,000 served | Lead service lines present | 311 | 1,895 | 4,304 | 32,550 | |
| 32 | JOLIET IL1970450 · 160,000 served | Lead service lines present | 299 | 8 | 6,188 | 47,852 | Joliet → |
| 33 | PALATINE IL0312340 · 70,875 served | Lead service lines present | 280 | 261 | 7 | 19,776 | Palatine → |
| 34 | NAPERVILLE IL0434670 · 156,406 served | Lead service lines present | 265 | 28 | 29 | 47,379 | Naperville → |
| 35 | ROCK ISLAND IL1610650 · 39,018 served | Lead service lines present | 207 | 0 | 9,258 | 12,082 | Rock Island → |
| 36 | DEKALB IL0370100 · 40,290 served | Lead service lines present | 192 | 0 | 0 | 10,815 | DeKalb → |
| 37 | WHEATON IL0431050 · 53,970 served | Lead service lines present | 180 | 0 | 525 | 16,699 | Wheaton → |
| 38 | PLAINFIELD IL1970800 · 50,000 served | Lead service lines present | 107 | 23 | 21 | 14,532 | Plainfield → |
| 39 | BARTLETT IL0314120 · 41,500 served | Lead service lines present | 57 | 14 | 462 | 14,498 | Bartlett → |
| 40 | CARPENTERSVILLE IL0890200 · 37,983 served | Lead service lines present | 47 | 0 | 0 | 10,849 | Carpentersville → |
| 41 | ADDISON IL0430050 · 38,017 served | Lead service lines present | 16 | 0 | 325 | 10,830 | Addison → |
| 42 | IL AMERICAN-CHAMPAIGN IL0195300 · 150,000 served | Lead service lines present | 5 | 1,723 | 14,962 | 60,751 | Champaign → |
| 43 | ORLAND PARK IL0312310 · 58,020 served | Lead service lines present | 4 | 14 | 0 | 24,274 | Orland Park → |
| 44 | NORMAL IL1130900 · 52,736 served | Lead service lines present | 2 | 28 | 4 | 18,145 | Normal → |
| 45 | DECATUR IL1150150 · 76,122 served | Lead service lines present | 0 | 6,558 | 12 | 30,098 | Decatur → |
| 46 | SCHAUMBURG IL0314890 · 75,750 served | No lead service lines reported | 0 | 0 | 0 | 26,526 | Schaumburg → |
| 47 | IL AMERICAN-WEST SUBURBAN IL1974151 · 73,978 served | No lead service lines reported | 0 | 0 | 0 | 24,705 | |
| 48 | TINLEY PARK IL0314910 · 56,703 served | No lead service lines reported | 0 | 0 | 0 | 20,435 | Tinley Park → |
| 49 | ROMEOVILLE IL1970900 · 50,458 served | No lead service lines reported | 0 | 0 | 0 | 16,743 | Romeoville → |
| 50 | HOFFMAN ESTATES IL0311290 · 50,179 served | No lead service lines reported | 0 | 0 | 0 | 15,042 | Hoffman Estates → |
| 51 | BUFFALO GROVE IL0314180 · 43,212 served | No lead service lines reported | 0 | 0 | 0 | 12,148 | Buffalo Grove → |
| 52 | CAROL STREAM IL0430200 · 39,854 served | No lead service lines reported | 0 | 0 | 0 | 11,100 | Carol Stream → |
| 53 | WHEELING IL0314970 · 39,725 served | No lead service lines reported | 0 | 0 | 0 | 8,181 | Wheeling → |
| 54 | STREAMWOOD IL0313060 · 39,577 served | No lead service lines reported | 0 | 0 | 0 | 13,706 | Streamwood → |
| 55 | OSWEGO IL0930150 · 38,169 served | No lead service lines reported | 0 | 0 | 0 | 12,051 | Oswego → |
| 56 | HANOVER PARK IL0314480 · 37,470 served | No lead service lines reported | 0 | 0 | 0 | 1,096 | Hanover Park → |
| 57 | GALESBURG IL0950200 · 31,620 served | No lead service lines reported | 0 | 0 | 0 | 12,366 | Galesburg → |
| 58 | ALGONQUIN IL1110050 · 30,700 served | No lead service lines reported | 0 | 0 | 0 | 11,840 | Algonquin → |
| 59 | GURNEE IL0970350 · 30,193 served | No lead service lines reported | 0 | 0 | 0 | 9,648 | Gurnee → |
A lead or unknown service line means lead can enter water after it leaves the treatment plant, so city-level test results understate what reaches your tap. Filter drinking and cooking water with an NSF/ANSI 53 lead-certified system, and see the lead in drinking water guide or Illinois city water reports.
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