Nearly half a million dollars had already been spent when the study was halted, the Interior Department's inspector general found.
Revision has long been sought by conservative allies of President Trump.
Millions of people who breathe polluted air around the world will die of heart attacks and respiratory illnesses that are preventable.
Administrator Scott Pruitt wants partial excavation — a middle-ground remedy — of the West Lake Landfill. It is expected to cost the two companies responsible for the site about $236 million.
The culprit appears to be small particles released by combustion, researchers say.
The Trump administration will delay an Obama-era rule limiting methane emissions.
The Obama administration said its clean power plan could save thousands of lives annually. The Trump team's draft analysis moved that figure higher.
Andrew Wheeler changed his tune once Trump articulated an energy and environmental platform — and once it became increasingly clear Trump would win the GOP nomination.
Arkema is not the only chemical plant to suffer damage in the storm.
EPA Administrator Scott Pruitt has reversed a decision to put off the Oct. 1 implementation of an Obama-era ozone rule a day after 16 states sued over the delay.