Despite the fact that MTBE hasn't been added to fuel in Iowa for several years, the Department of Natural Resources has found MTBE water and soil contamination throughout the state. According to the report, "Methyl tertiary-Butyl Ether (MTBE) Occurrence in Iowa," nearly 29 percent of the 2,569 groundwater samples taken had MTBE levels above the EPA Health Advisory Level (20 parts per billion). The highest MTBE concentration was 99,400 parts per billion, while the average was 200 parts per billion. Approximately 55 percent of the leaking underground storage tank sites had MTBE levels that may threaten public health.
The department expressed surprise and concern regarding the frequency of MTBE detection in soil. Approximately 60 percent of the 635 soil samples taken had MTBE levels above the quantification limit of 0.015 milligrams per kilogram. As a result of the report's findings, the department has recommended that the state regulate MTBE as a chemical of concern.
The report was completed as required by legislation enacted last year that restricted MTBE use to two percent by volume or less and required soil and water testing for MTBE. Some say that the law does not go far enough and that MTBE should be banned. Representative Mark Kuhn has introduced HF 2294 which would ban the sale or storage of MTBE in Iowa after December 31, 2000. U.S. Senator Chuck Grassley of Iowa explained in a letter to President Clinton and Vice President Gore that merely eliminating the oxygen requirement in federal reformulated gasoline will do little to protect the public from MTBE contamination. "Mere oxygenate waivers from the Clean Air Act will not protect the rest of America's water supply. To grant such a waiver would perpetuate a hoax that will leave the rest of the public vulnerable to MTBE water contamination," Grassley said.
The full report is at www.state.ia.us/government/dnr/organiza/epd/ust/gwprof/021500.htm
