Central Florida’s main source of drinking water is being contaminated by a toxic leak from one of the nation’s oldest Superfund sites, according to federal authorities. Ten years ago, the U.S. EPA ended the cleanup of a Tower Chemical plant that manufactured pesticides for the citrus industry; now, an unidentified pesticide-related chemical has seeped from a sinkhole below the plant’s former wastewater pond and into the Floridan Aquifer, 90 feet underground. EPA officials don’t know how far the chemical could spread (so far, it seems to have remained within 200 feet of the sinkhole) or how dangerous it may be. In light of the contamination, which was discovered during routine checks of wells on the Tower property, the EPA could decide to resume the terminated, $6 million cleanup of the area.