National Drinking Water Database
Illinois
1,765 systems serving 13,084,369 people
This drinking water quality report shows results of tests conducted by water utilities in Illinois, provided to the Environmental Working Group (EWG) by the Illinois Environmental Protection Agency. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results from 45 states and the District of Columbia. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources in protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes drinking water quality for this state.
Chemicals |
Water Utilities |
Population Served |
|
|---|---|---|---|
| Detected Chemicals | 101 |
1,765 |
13,083,669 |
Exceed health guidelines* | 63 |
1,756 |
13,082,056 |
Exceed Legal Limits* | 38 |
816 |
4,474,868 |
Unregulated chemicals detected | 23 |
491 |
6,374,140 |
| * Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance. | |||
63 Contaminants Exceeding Health Based Limits
Contaminants detected in Illinois drinking water above health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities
| Contaminant | Population |
Number of Systems |
||
|---|---|---|---|---|
| At Any Level | Above Health Limits | At Any Level | Above Health Limits | |
| Total haloacetic acids (HAAs) | 12,319,906 | 12,319,906 | 1,345 | 1,345 |
| Bromodichloromethane | 12,229,020 | 12,229,020 | 1,195 | 1,195 |
| Dibromochloromethane | 11,896,659 | 11,883,519 | 1,114 | 1,112 |
| Total trihalomethanes (TTHMs) | 12,650,186 | 11,847,956 | 1,476 | 1,031 |
| Dichloroacetic acid | 11,715,567 | 11,715,567 | 1,169 | 1,169 |
| Chloroform | 12,493,882 | 11,399,380 | 1,391 | 872 |
| Lead (total) | 11,228,655 | 11,228,655 | 1,196 | 1,196 |
| Radium-226 | 8,033,465 | 8,033,465 | 894 | 894 |
| Radium-228 | 7,960,993 | 7,960,993 | 871 | 871 |
| Combined Radium (-226 & -228) | 7,893,389 | 7,893,389 | 918 | 918 |
Water Utilities in Illinois Reporting Chemicals Exceeding Health Guidelines
Water utilities in Illinois reporting chemicals exceeding health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities, include:
| System | Population |
Chemicals tested |
Chemicals found |
Chemicals exceeding health guidelines |
|---|---|---|---|---|
| Rockford | 155,000 | 114 | 36 | 20 |
| Frankfort | 21,501 | 109 | 33 | 19 |
| Lakewood | 1,245 | 101 | 29 | 19 |
| Crystal Lake | 40,634 | 107 | 26 | 19 |
| Dixon | 16,100 | 108 | 27 | 19 |
| Lindenhurst | 14,632 | 114 | 26 | 19 |
| Farina | 600 | 96 | 26 | 19 |
| St Rose Pwd | 1,800 | 96 | 24 | 19 |
| Loves Park | 22,476 | 103 | 26 | 18 |
| IL American-Peoria | 136,000 | 145 | 32 | 18 |
| East Alton | 6,695 | 95 | 31 | 18 |
| IL American-Terra Cotta | 684 | 89 | 21 | 18 |
| Batavia | 26,348 | 97 | 28 | 18 |
| Aurora | 171,000 | 101 | 30 | 18 |
| South Elgin | 14,668 | 99 | 28 | 18 |
| Iola | 172 | 103 | 27 | 18 |
| North Park Pwd | 32,000 | 103 | 30 | 17 |
| Silvis | 6,000 | 101 | 27 | 17 |
| South Jacksonville | 3,645 | 95 | 25 | 17 |
| Cary | 18,713 | 103 | 22 | 17 |
Sources of Illinois Drinking Water Contaminants
The contaminants identified in Illinois drinking water come from a wide variety of sources, including agriculture, industry, water treatment plants, and polluted storm runoff from urban areas.
Testing Summary for Illinois
The federal government has set standards for some of the pollutants found in tap water supplies.
| Contaminants reported as tested by water suppliers in Illinois | 226 | |
| Contaminants tested due to federal law: | 95 | |
| Contaminants tested in addition to those required by federal law: | 131 | |
Violation Summary for Illinois
Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Illinois since 2004
| Violation Type | Number of Violations |
|---|---|
| Failure to monitor regularly | 2,157 |
| Over maximum contaminant level, Average | 1,891 |
| Monitoring and Reporting Disinfection Byproduct Rule | 741 |
| Public Notification Violation for National Primary Drinking Water Regulations | 505 |
| Failure to monitor, Routine Major (Coliform bacteria) | 439 |
| Other Non-National Primary Drinking Water Regulations Potential Health Risks | 416 |
| Inadequate reporting of information to the public | 290 |
| Treatment Technique (Surface Water Treatment Rule) | 232 |
| Maximum contaminant level, Monthly (Coliform bacteria) | 207 |
| Failure to report information to the public or state agency in the Consumer Confidence Report | 205 |
| Failure to monitor, Routine Minor (Coliform bacteria) | 178 |
| Initial Water Quality Parameter Monitoring and Reporting | 128 |
| Failure to monitor, Repeat Major (Coliform bacteria) | 110 |
| Follow-up and Routine Tap Sampling | 79 |
| Failure to monitor, Repeat Minor (Coliform bacteria) | 49 |
| Excess Turbidity at 0.3 NTU | 49 |
| Treatment Technique Precursor Removal | 41 |
| Public Education | 22 |
| Excess Turbidity at 1 NTU | 20 |
| Initial Tap Sampling for Lead and Copper | 18 |
| Maximum contaminant level, Acute (Coliform bacteria) | 15 |
| Optimal Corrosion Control Treatment Study Recommendation | 15 |
| Water Quality Program Entry Point Non-Compliance | 10 |
| Filter Turbidity Reporting | 7 |
| Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) | 5 |
| Non-Acute maximum residual disinfectant level | 3 |
| Optimal Corrosion Control Treatment Installation/Demonstration | 3 |
| Over maximum contaminant level, Single Sample | 2 |
| Initial, Follow-up, or Routine Source Water Treatment Monitoring and Reporting | 2 |
| Treatment Technique w/o State Prior Approval | 2 |
