The Power of Information

National Drinking Water Database

MTBE in Illinois

MTBE (methyl tert-butyl ether) is a fuel additive that had been used as an octane enhancer in unleaded gasoline; it contaminates groundwater due to spillage or leakage at gas stations, and has been banned or scheduled for phaseout in most states.

The Most Polluted Communities in Illinois

24 water utilities reported detecting MTBE in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average MTBE level

RankSystem Population Served Positive test results of total reported tests Average Level
Roanoke, IL
2,00023 of 253.02 ppb
(0 to 8.6 ppb)
2Utl Inc-Lake Marian Water Corporation
Northbrook, IL
1,12015 of 212.6 ppb
(0 to 7.5 ppb)
Fairmount, IL
6905 of 51.95 ppb
(1 to 2.5 ppb)
Nokomis, IL
2,3703 of 31.92 ppb
(1.3 to 2.8 ppb)
Bethalto, IL
17,5003 of 41.24 ppb
(0 to 2 ppb)
Carpentersville, IL
30,5862 of 50.6 ppb
(0 to 1.89 ppb)
7Island Lake
Island Lake, IL
8,3208 of 180.49 ppb
(0 to 2.92 ppb)
8Crystal Lake
Crystal Lake, IL
40,63419 of 230.47 ppb
(0 to 0.8 ppb)
9Fox Lake
Fox Lake, IL
8,66211 of 190.42 ppb
(0 to 1 ppb)
Stonington, IL
9601 of 30.33 ppb
(0 to 1 ppb)

Health Based Limits for MTBE

California Public Health GoalsDefined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.13 ppb

Violation Summary for MTBE in Illinois

There are no violations reported for this contaminant in Illinois