Donald Trump’s decision to withdraw the US from the Paris climate deal may have followed months of anguished division amongst his closest advisers, but his administration has proceeded with quiet efficiency in its dismantling of other major environmental policies.

The White House, Congress and the Environmental Protection Agency have dovetailed to engineer a dizzying reversal of clean air and water regulations implemented by Barack Obama’s administration.

Unlike the travel ban or healthcare, Trump has faced few obstacles in sweeping away what he has called “job-killing” environmental rules that address problems such as climate change, water pollution and smoggy air.

“I’ve been very concerned by what I’ve seen – this is about people’s health,” said Christine Todd Whitman, a Republican who was the EPA administrator under George W Bush, and also served as governor of New Jersey. “They are undermining science and people’s respect for science. They don’t seem to care.”

Trump’s agenda has been enthusiastically spearheaded by Scott Pruitt, the administrator of the EPA, who promised in February that he would be rolling back regulations “in a very aggressive way”. Pruitt has repeatedly decried the economic cost of green strictures, especially on the coal industry, which he said was the target of a “war” from the Obama administration.

Pruitt, who previously sued the EPA more than a dozen times as attorney general of Oklahoma, and has had unusually close ties to the fossil fuel industry, has helped withdraw or postpone a raft of regulations and has steered the EPA away from climate change work.

While every new administration reviews or even reshapes inherited regulations – especially those enacted in the dying days of a prior presidency – the scale of the current rollback is unprecedented, according to Whitman.