Lead pipes by county in Illinois
Lead, galvanized and unknown service lines reported by the water systems serving each Illinois county.
| County | Lead | Galv. | Unknown | Systems |
|---|
| Adams County | 5,223 | 33 | 70 | 6 |
| Alexander County | 0 | 34 | 2,742 | 5 |
| Bond County | 0 | 0 | 285 | 3 |
| Boone County | 456 | 630 | 3,350 | 6 |
| Brown County | 0 | 0 | 0 | 2 |
| Bureau County | 614 | 287 | 2,060 | 14 |
| Calhoun County | 0 | 6 | 337 | 2 |
| Carroll County | 170 | 253 | 332 | 6 |
| Cass County | 0 | 156 | 0 | 3 |
| Champaign County | 19 | 1,781 | 16,380 | 12 |
| Christian County | 1,558 | 653 | 832 | 7 |
| Clark County | 0 | 184 | 846 | 6 |
| Clay County | 0 | 196 | 36 | 3 |
| Clinton County | 25 | 0 | 0 | 13 |
| Coles County | 0 | 1,268 | 7,708 | 6 |
| Cook County | 493,077 | 15,966 | 137,187 | 136 |
| Crawford County | 5 | 1 | 477 | 6 |
| Cumberland County | 0 | 117 | 676 | 3 |
| De Witt County | 27 | 31 | 192 | 3 |
| Dekalb County | 436 | 241 | 368 | 14 |
| Douglas County | 13 | 29 | 214 | 5 |
| Dupage County | 6,550 | 1,790 | 13,972 | 40 |
| Edgar County | 0 | 0 | 3,532 | 2 |
| Edwards County | 0 | 0 | 0 | 2 |
| Effingham County | 0 | 22 | 0 | 6 |
| Fayette County | 1 | 177 | 2,286 | 3 |
| Ford County | 9 | 194 | 1,974 | 5 |
| Franklin County | 0 | 2 | 5,139 | 11 |
| Fulton County | 922 | 190 | 2,443 | 9 |
| Gallatin County | 0 | 0 | 0 | 2 |
| Greene County | 83 | 765 | 1,244 | 6 |
| Grundy County | 1,862 | 12 | 342 | 7 |
| Hamilton County | 0 | 1 | 1,096 | 2 |
| Hancock County | 84 | 234 | 812 | 8 |
| Hardin County | 0 | 16 | 455 | 2 |
| Henderson County | 0 | 0 | 0 | 2 |
| Henry County | 2,864 | 236 | 3,417 | 11 |
| Iroquois County | 220 | 49 | 1,055 | 11 |
| Jackson County | 0 | 1 | 3,463 | 12 |
| Jasper County | 0 | 0 | 144 | 3 |
| Jefferson County | 46 | 762 | 31 | 8 |
| Jersey County | 2 | 34 | 1,760 | 2 |
| Jo Daviess County | 73 | 58 | 907 | 7 |
| Johnson County | 0 | 0 | 0 | 4 |
| Kane County | 26,809 | 329 | 7,137 | 27 |
| Kankakee County | 336 | 1,897 | 5,842 | 7 |
| Kendall County | 0 | 0 | 5 | 5 |
| Knox County | 0 | 0 | 129 | 7 |
| Lake County | 13,863 | 181 | 10,662 | 57 |
| Lasalle County | 826 | 305 | 19,265 | 17 |
| Lawrence County | 134 | 310 | 4 | 6 |
| Lee County | 123 | 484 | 554 | 9 |
| Livingston County | 213 | 653 | 3,508 | 10 |
| Logan County | 5 | 354 | 2,937 | 9 |
| Macon County | 2 | 6,550 | 509 | 9 |
| Macoupin County | 333 | 112 | 1,071 | 16 |
| Madison County | 853 | 888 | 27,327 | 31 |
| Marion County | 42 | 20 | 3,571 | 10 |
| Marshall County | 302 | 444 | 1,150 | 7 |
| Mason County | 835 | 9 | 371 | 3 |
| Massac County | 16 | 1,997 | 1,800 | 3 |
| McDonough County | 715 | 38 | 1,743 | 5 |
| McHenry County | 2,592 | 877 | 5,988 | 26 |
| McLean County | 5,605 | 36 | 6,300 | 15 |
| Menard County | 2 | 41 | 508 | 6 |
| Mercer County | 56 | 0 | 339 | 4 |
| Monroe County | 0 | 83 | 0 | 4 |
| Montgomery County | 137 | 1,089 | 1,443 | 10 |
| Morgan County | 4,215 | 535 | 93 | 8 |
| Moultrie County | 0 | 16 | 0 | 5 |
| Ogle County | 59 | 573 | 695 | 13 |
| Peoria County | 11,238 | 627 | 25,877 | 11 |
| Perry County | 1,228 | 0 | 2,907 | 4 |
| Piatt County | 1 | 0 | 736 | 4 |
| Pike County | 1 | 10 | 2,324 | 5 |
| Pope County | 0 | 0 | 0 | 1 |
| Pulaski County | 0 | 0 | 959 | 2 |
| Putnam County | 11 | 43 | 182 | 5 |
| Randolph County | 46 | 0 | 161 | 9 |
| Richland County | 0 | 0 | 100 | 2 |
| Rock Island County | 4,811 | 1,093 | 17,543 | 13 |
| Saline County | 0 | 0 | 3,408 | 10 |
| Sangamon County | 1,036 | 1,266 | 11,213 | 18 |
| Schuyler County | 0 | 116 | 1,520 | 3 |
| Scott County | 0 | 0 | 0 | 1 |
| Shelby County | 273 | 349 | 193 | 6 |
| St. Clair County | 751 | 408 | 36,311 | 15 |
| Stark County | 218 | 17 | 48 | 3 |
| Stephenson County | 41 | 72 | 1,089 | 6 |
| Tazewell County | 249 | 2,613 | 5,942 | 16 |
| Union County | 1,218 | 0 | 222 | 6 |
| Vermilion County | 174 | 238 | 18,461 | 10 |
| Wabash County | 2 | 53 | 3,631 | 2 |
| Warren County | 520 | 35 | 2,865 | 4 |
| Washington County | 0 | 0 | 0 | 5 |
| Wayne County | 0 | 0 | 100 | 6 |
| White County | 0 | 494 | 39 | 6 |
| Whiteside County | 33 | 1,088 | 5,071 | 9 |
| Will County | 1,089 | 3,080 | 14,480 | 32 |
| Williamson County | 311 | 71 | 5,273 | 17 |
| Winnebago County | 14,280 | 1,414 | 31,962 | 15 |
| Woodford County | 2 | 88 | 674 | 8 |
Systems serving several counties are counted in each. Source: EPA SDWIS service line inventory, 2026 Q3.