According to reports from the Environmental Protection Agency (EPA) and the New York Times, the drinking water of about 117 million Americans could be subjected to widespread pollution.

Yesterday, the New York Times reported that Supreme Court rulings over the last decade have caused an erosion of the 1972 Clean Water Act, leading thousands of businesses and corporations to declare that the law no longer applies to them.

As a result, at least 20 million acres of wetlands and as much as 60 percent of the nation’s small streams have been left unprotected, while effectively shutting down enforcement actions against developers who have been disturbing or plan to disturb these waters without a permit.

The situation stems from two decisions–Solid Waste Agency of Northern Cook County v. United States Army Corp of Engineers (2001) and Rapanos v. United States (2006)–which focus on the language authorizing the federal government to regulate various wetlands. At the center of the rulings is the term “navigable waters,” traditionally held by regulators to include large wetlands, estuaries and streams connected to major rivers.

The new rulings, however, suggested that waterways entirely in one state, creeks that sometimes go dry, and lakes unconnected to larger water systems may not be “navigable waters,” and are therefore excluded from the Clean Water Act. The result, according to EPA regulators, has been an increase in the discharge of pollution, including spilled oil, carcinogens, and dangerous bacteria.  EPA officials estimate that 45 percent of major polluters might be either outside the reach of the agency or in areas where proving jurisdiction is exceedingly difficult.

“We are, in essence, shutting down our Clean Water programs in some states,” Douglas F. Mundrick, an EPA lawyer in Atlanta, told the Times. “When companies figure out cops can’t operate, they start remembering how much cheaper it is to just dump stuff in a nearby creek.”

Adding to the confusion is the legal loophole left by the Supreme Court decisions. The Court did not define which waterways are regulated or what constituted a navigable waterway, and thus lower courts must decide on a case-by-case basis if the law applies to smaller waterways. The loophole has allowed companies to effectively claim they didn’t know dumping was illegal, not only creating an expensive and messy legal situation, but a safety hazard.

“This is a huge deal,” James M. Tierney, the New York State assistant commissioner for water resources, said of the rulings. “There are whole watersheds that feed into New York’s drinking water supply that are, as of now, unprotected.”

New York is not the only unprotected state. EPA officials said in a statement that internal studies show about 117 million Americans get their drinking water from sources fed by smaller waterways that are vulnerable to exclusion from the Clean Water Act, presenting a serious health hazard.

To help resolve the issue, some members of Congress have tried to restore the regulatory power of the EPA by introducing the Clean Water Restoration Act, but progress has been stunted by a broad coalition of lobbyists warning farmers and small-business owners of a government overreach.

“If you erase the word ‘navigable’ from the law, it erases any limitation of the federal government’s reach,” said Don Parrish, the American Farm Bureau Federation’s senior director of regulatory relations. “It could be a gutter, a roadside ditch or a rain puddle, but the federal government gets control of it.”

Legislators have dismissed these statements as scare tactics aimed at creating panic. But since its introduction in April 2009, the bill has stalled in the Senate. While some EPA officials believe EPA Administrator Lisa Jackson could exercise more authority, Mrs. Jackson has said it is up to Congress to resolve these issues.  

“I do believe in a legislative fix to clarify the distinction,” she told the House Committee on Transportation and Infrastructure during a hearing last October. “We know that about a third of the US population gets some or all of their drinking water from intermittent, ephemeral or headwater streams, many of which are the water bodies where jurisdiction is most in question. That lack of jurisdiction results in the one place where we probably get more natural capital return on our investment than any place else and we’re losing that at an alarming rate.”