Florida's aquifer needs special protection from being overpumped, the Sierra Club contends in a petition sent to the U.S. Environmental Protection Agency. The club's Florida chapter has filed the petition asking the EPA to declare it a "sole source aquifer," a tool to protect drinking water supplies in areas where there are few or no alternative sources. Such a declaration, carried out only after a public hearing, would require the federal government to give it greater protection and also offer grants and other financial assistance for avoiding pollution. The aquifer, which is the primary source of water for Florida's 19 million residents, is "threatened by ...over-pumping, pollution and waste," said Tom Larson, Sierra Club Florida chapter conservation chair.