Water quality in more than two-thirds of the 419 units of the National Park System already is "impaired," according to the National Parks Conservation Association, and President Trump's rollback of clean water regulations will only heighten the problems, the park advocacy group says.

Environmental Protection Agency Administrator Andrew Wheeler and Assistant Secretary of the Army for Civil Works R.D. James on Thursday announced what was promoted as "a new, clear definition for waters of the United States.”

The Navigable Waters Protection Rule is seen as a way to protect the nation’s navigable waters from pollution and will result in economic growth across the country, an EPA release said.

The Navigable Waters Protection Rule ends decades of uncertainty over where federal jurisdiction begins and ends. For the first time, EPA and the Army are recognizing the difference between federally protected wetlands and state protected wetlands. It adheres to the statutory limits of the agencies’ authority. It also ensures that America’s water protections – among the best in the world – remain strong, while giving our states and tribes the certainty to manage their waters in ways that best protect their natural resources and local economies.

But according to NPCA, failing to protect the small streams and wetlands covered in the original rule will contribute to the potential pollution washing downstream. The trickle-down effect on water quality could be dramatic with potential impacts on drinking water, swimming, paddling and camping, not to mention wildlife habitat in our parks, the group said.

“The administration’s rollback of clean water protections is a devasting blow to our national parks and surrounding communities. With two-thirds of national park waters impaired and many communities living with unsafe drinking water, we need more protections for our waterways, not less," said NPCA President and CEO Theresa Pierno.

“In just two weeks, the administration has dismantled two of our nation’s most fundamental environmental laws. These bipartisan laws were put in place to protect human health and our environment, including the waterways we use for drinking, swimming and fishing," she added. "Today’s action erases decades of progress in our efforts to clean up America’s waters, paving the way for more pollution that threatens our national park waterways from trout streams in Yellowstone to wetlands in the Everglades. NPCA will continue to fight to ensure the protection of our waterways for our health, our communities, our parks and all who rely on them.”

At the Izaak Walton League, officials said the new policy fundamentally weakens Clean Water Act protections for drinking water, streams, and wetlands nationwide. 

“Striping away Clean Water Act protections for streams and wetlands runs counter to science, the law, and common sense,” said Jared Mott, conservation director for the League. “With its focus on one arbitrary criteria – continuous flow of water – rather than protecting water quality, the administration is jeopardizing public health and the $887 billion outdoor recreation economy.”

The Clean Water Act was passed to improve and protect water quality by limiting pollution discharges into the nation’s streams, rivers, and other waterbodies and to stem the dramatic loss of wetlands by regulating when they could be drained or filled. Beginning in the 1970s, EPA regulations relied on science-based standards to identify the specific types of waterbodies protected by the law. The overwhelming body of science proves that water quality in rivers and lakes, for example, is directly affected by waters that directly and indirectly flow into them. Because the purpose of the Clean Water Act is to improve and restore water quality nationwide, EPA regulations protected streams that flow periodically because pollution dumped into these streams adversely affects the health of larger waters. -- Izaak Walton League

The League said the new policy "stands the Clean Water Act on its head."

"Under this policy, a stream that flows for a few months due to melting snow would be included in the definition, but a stream that flows only after it rains or following a snowstorm would be excluded," the organization said in a release. "Both flow periodically and both can carry pollution to other waters and affect water quality downstream, which demonstrates how blatantly arbitrary the new policy is. According the EPA’s own analysis, about 117 million Americans – more than one-third of the total U.S. population – get some or all of their drinking water from public drinking water systems that are supplied, at least in part, by the very streams that are now at risk of pollution."

"Nearly 50 years after passage of the Clean Water Act, we see the signs of water pollution all around us, from algal blooms in the Great Lakes to red tides in the Gulf of Mexico,” said Scott Kovarovics, the League's executive director. “We know that pollution doesn’t just start in the biggest rivers – it starts in the smallest streams, too. Today, the administration retreated from the nation’s fight for clean water, jeopardizing our drinking water, fish and wildlife, and outdoor recreation economy.”