The EPA and National Park Service found harmful nitrogen pollution was 38 percent higher than the 2017 target level.
Environmental Protection Agency (EPA)
State officials said this approach lets companies determine how much a site will likely pollute, so regulators can take that into account when they issue air pollution permits later.
Sunnyside Gold Corp. has been resisting attempts made by the Environmental Protection Agency to get the company to pitch in money for the cleanup.
Many mines pose the chronic problem of relentless pollution.
PFAs are found in some non-stick coatings, including from a firefighting foam used by the Peterson Air Force Base.
An Associated Press investigation found there could be more premature deaths, greenhouse gas emissions and other impacts.
The documents may have evidence of residual plutonium contamination and other ongoing environmental dangers.
A new study from the Environmental Protection Agency found fish and other aquatic life in the are are not suffering severe or long-lasting damage.
President Trump has said he will roll back an Obama-era rule that would've matched federal emissions standards with California standards.
The EPA wants to roll back a 2016 Obama-era rule that required energy companies to step up detection and elimination of methane leaks.