Claiming to promote cleaner air, in the early 1990s the Environmental Protection Agency began requiring the nation’s oil refiners to blend oxygenated additives into their gasoline, and a substance called MTBE soon became the dominant additive at gas pumps. Now we’re learning that MTBE, which is seeping into much of the nation’s water supply, is itself a dangerous pollutant. Hoover media fellow Deroy Murdock on another fine mess the EPA has gotten us into.