Protecting groundwater

Excerpt

AFTER more than a decade and a half of often vigorous effort in the United States to protect the environment, it may be tempting to assume that pollution in its many forms has been addressed in law if not in fact. Yet contamination of groundwater supplies poses a major environmental threat that only now is beginning to attract the widespread attention it warrants.

This attention is long overdue. Though one of the least visible of environmental perils, groundwater contamination can be among the most insidious. Pollutants may take years to detect because they move so slowly through an aquifer. Cleaning contaminated groundwater is technologically difficult and extremely expensive, as experience with the federal Superfund program demonstrates.

Many sources of groundwater pollution are both mundane and ubiquitous. More than 16 million septic tanks receive an estimated 800 billion gallons of waste each year that eventually seeps into the ground. Gasoline stations account for more than 1 million underground storage tanks—perhaps a quarter of such tanks nationwide—most subject to corrosion, rupture, and leakage. The list of potential and actual contamination sources is lengthy, touching every …