Environmental Protection Agency (EPA) officials refuse to explain why they let pollution fester at up to 302 highly-contaminated sites under their authority for years or even decades. They also won’t explain what they’re doing to protect people’s health.

The EPA doesn’t know what dangers exist at 191 sites, and humans face health risks at another 111, an investigation from The Daily Caller News Foundation revealed Monday. Pollution has threatened human health at up to 117 Superfund sites for more than 30 years.

EPA officials refused to explain why cleaning or even just assessing pollution risks has taken so long.

“I don’t think we will be providing anything further,” Associate Administrator Frank Benenati told TheDCNF after he was emailed the link to the investigation Monday. Benenati is also the EPA’s chief spokesman. The EPA ignored multiple DCNF requests regarding the Superfund investigation over a three-day period before Benenati ultimately responded just hours before deadline.

“Don’t think we’ll be able to make your deadline,” Benenati told TheDCNF in an email Friday.

The Superfund program was formed to decontaminate the nation’s most polluted sites.

TheDCNF provided the EPA with thorough details about the forthcoming report, which included substantial data points that would be incorporated. A reporter also detailed the rebuttals that would be used to counter explanations the agency provided months ago regarding why Superfund decontamination took so long. EPA ignored these details and failed to provide comment on any preventative or precautionary measures it had taken to avert human exposure to contaminants at these sites.

A 2007 Center for Public Integrity investigation (CPI) into Superfund revealed similar findings as TheDCNF. The CPI also had trouble acquiring public information.

“Yet, the EPA has resisted releasing information about cleanup plans or the sites’ danger to the public other than offering a list of the sites’ locations and a brief description about how people might become exposed — information buried so deep in the EPA’s website that it is difficult to find,” CPI wrote.

In fact, the EPA refused to answer CPI’s questions regarding Superfund’s secretive special accounts, which act like slush funds for the program. The EPA retaliated by later providing information to other reporters. The EPA has also withheld information from TheDCNF prior to the most recent Superfund investigation.

TheDCNF, for example, extended a deadline to give the EPA additional time to explain why a contractor received $2.7 million after causing the August 2015 Gold King Mine spill and how the funds were used. The agency internally crafted a response and a partial answer that was never sent to TheDCNF.

“It just slipped through the cracks,” EPA spokeswoman Melissa Harrison later told TheDCNF. “It was a mistake on our behalf.”

Follow Ethan on Twitter. Send tips to [email protected].

Copyright 2016 Daily Caller News Foundation