The US just finalized a major new policy to protect drinking water - but Trump already promised to kill it

The Interior Department announced on Monday that it had finalized a rule designed to protect water sources in the US from hazardous chemicals released by coal mining.

The Stream Protection Rule, as it is called, limits the impact mines are allowed to have on streams, rivers, groundwater, and forests in their surrounding areas. It will go into effect 30 days after its publication in the Federal Register, which is scheduled for Tuesday, December 20. That means the rule will become enforceable January 19, 2017 - one day before the start of the Trump administration.

That's significant, because Donald Trump's transition team has already promised to kill the rule.

A passage on the transition team website, GreatAgain.gov, says (emphasis added), "We will end the war on coal, and rescind the coal mining lease moratorium, the excessive Interior Department stream rule, and conduct a top-down review of all anti-coal regulations issued by the Obama Administration."

In states with heavy coal mining activity, like West Virginia, contaminants and runoff from coal mines can enter water sources that lead to the taps in people's homes, posing a risk to human safety as well as wildlife.

The rule would ban mining practices that permanently pollute streams and other sources of drinking water, increase flood risk, and threaten forests. Mines would also be required to measure the health of water in their surrounding areas before, during, and after extracting coal from the ground, restore mined land to its previous use, and replant native trees.

The rule has been perceived as anti-coal because it increases the cost of doing business for corporations that make their profits extracting coal from the ground, processing it, and selling it.

Donald Trump is expected to nominate Ryan Zinke, a Montana Republican, to lead the Interior Department.

It is uncertain what The Stream Rule's fate will be under his leadership. Typically, rules and regulations of this sort are somewhat more difficult to reverse that simple executive orders, because they have to go through a series of mandated procedures. But because they aren't the product of acts of Congress, the president doesn't need legislative approval to repeal them. And newer rules are more vulnerable.

Of course, Trump could always decide not to follow through on the transition team's promise. But given the Trump transition's stance on the issue, the Stream Protection Rule's future is up in the air.