Environmentalists have been rightly focused on the fact that climate deniers Scott Pruitt, Trump’s pick to run the Environmental Protection Agency, and Cathy McMorris Rodgers, whom he is expected to nominate for the Department of the Interior, could devastate the Clean Power Plan, the Paris Accord and, through them, national and even global progress on climate change. But Trump’s picks could permanently damage the country’s waters, too.

Both have a record of wide-ranging hostility toward the environment. As Attorney General of Oklahoma, Pruitt repeatedly (and often unsuccessfully) sued the EPA to stop the agency from doing its job. McMorris Rodgers, a conservative member of the House from Washington who has received almost a half-million dollars in campaign contributions from oil and gas companies, earned a zero rating from the League of Conservation Voters. Both have already made the dismantling of water protections a particular priority.

If appointed, these two foes of the earth will likely usher in dark days for our nation’s lakes, streams, and rivers. Our waterways are already in serious peril, according to an EPA evaluation of U.S. lakes released Friday. According to the report, 30 percent of lakes now contain the pesticide atrazine.

Water contamination will almost certainly increase if Pruitt declines to issue penalties to polluters and cuts the budgets of divisions responsible for enforcement, as his record and rhetoric has indicated he will.

“A lot of how much protection we get has to do with whether the agency chooses to buddy up to the industry or really hold them accountable for the violation of the laws,” said Maya van Rossum, the Delaware Riverkeeper. Van Rossum is currently involved in fighting fracking and more than a dozen pipeline projects and fears the threats to the river basin will only increase.

“Under a Pruitt EPA, we’re going to have a whole agency that’s about turning a blind eye, rather than holding industries accountable and protecting the people,” said van Rossum.

While it will take years to feel the full effects of some environmental disasters, the impact of not enforcing water laws will be felt more quickly. “The scary thing about water is there’s no wiggle room,” said Lisa Garcia, vice president of litigation for healthy communities at Earthjustice. “Once you discharge contamination into our drinking water, that’s an immediate impact. This could turn into real impacts to human health. It’s not something you want to play around with.”

Yet Pruitt and McMorris Rodgers already have. Both nominees have vocally opposed the Waters of the United States Rule, which would extend federal protection to thousands of lakes, rivers, and streams and allow the EPA to use the Clean Water Act to prosecute people who pollute them. Last year, Pruitt sued the EPA over the rule because it would harm the “property rights of the average American.”

Though a court is currently reviewing the rule, as EPA head Pruitt could decide not to defend it or even withdraw it. Other water protections in the works that he could snuff out include a tightening of the rules on lead and copper piping. If finalized, those rules could help prevent another Flint.

“We’re really concerned about lead and copper,” said David Goldston, director of government affairs for the Natural Resources Defense Council. “But really it’s everything.”

The fact that Trump has already surrounded himself with so many enemies of the environment makes the threat all the worse. “An entire constellation of anti-environmental people would clearly put in place policies that are counter to the public interest,” said Goldston.

Now environmental groups are turning their energies to fighting the appointments. Some have noted that only a few Republicans would need to break ranks to block Pruitt’s path in the Senate. And the opposition to McMorris Rodgers has already begun. Just hours after Trump’s choice was reported, Wenonah Hauter, executive director of Food & Water Watch, called on any senator “with a concern for future generations of Americans” to oppose her: “Rep. McMorris Rodgers poses a clear and present danger to our treasured public lands.”