Just a few years ago, the EPA and environmentalists were heralding an additive used in gasoline for drastically reducing air toxics emissions. Now, the chemical, methyl tertiary butyl ether, or M-T-B-E, is being blamed for contaminating groundwater all over the country. And Congress is scrambling to write legislation to ban it. In the first of a two part series, the Great Lakes Radio Consortium’s Julie Halpert takes a look back into the history of this controversial chemical: