Three environmental groups are objecting to a permit granted to a proposed natural gas plant meant to power a massive data center at the site of the former Homer City coal-fired power plant.

The proposed 4.4 gigawatt gas-fired plant would generate enough power for more than 3 million homes and emit more greenhouse gases each year than all the cars on Pennsylvania’s roads, according to the groups appealing the permit.

Clean Air Council, PennFuture, and the Sierra Club said the state Department of Environmental Protection made several errors by granting the permit, including failure to follow its own environmental justice policy by not adequately engaging with the surrounding community and accepting flawed methodology for the amount of emissions the plant will create.

They also say letting this plant go forward is a violation of the state’s Environmental Rights Amendment, which guarantees the right to a healthy environment for Pennsylvanians today and into the future.

Lawrence Hafetz, legal director for Clean Air Council, said public health will suffer if the plant is allowed to be built as proposed. He said the added pollution could especially harm vulnerable groups and people with respiratory conditions, such as asthma.

The appeal also said the applicant, Homer City Generation, failed to show the benefits of the project would “significantly outweigh the environmental and social costs.”

“ Most of that power will likely go to the data center, which is a private company as opposed to that power going to the public grid,” said Sarah Gordon, a staff attorney at Clean Air Council. “And so there’s a really different calculation in the cost benefit analysis of that pollution.”

Hafetz was critical of what he said is the DEP’s piecemeal approach to permitting. He said the power plant is only one part of the planned 3,200-acre data center campus.

“ You can’t look at the environmental impacts of a project unless you look at the totality of the project,” Hafetz said.

Gordon said they believe it’s DEP’s duty under the Environmental Rights Amendment to do a comprehensive review of the entire project, including water use and noise pollution.

Hafetz said it appears the DEP prioritized speed over accuracy in reviewing the permit application.

Gordon said a Right-to-Know request of communication about the Homer City project found that a DEP staffer said the goal was “to provide a concierge level of service.”

“DEP’s job is to protect us and to protect Pennsylvania residents who are living alongside these major industrial projects. Their duty is not to be a concierge for industry,” Gordon said.

Gov. Josh Shapiro has made quick reviews of permit applications a priority in his administration. DEP has long been criticized, mainly by Republican lawmakers, for slow permit processing. The agency reviews more than 45,000 permit applications every year.

The Shapiro administration launched the PAyback program in November 2023, which promises to refund companies their permit fees if their application is overdue for review by DEP. The administration also opened the SPEED program this year, which aims to give applicants flexibility by allowing a professional outside DEP conduct the initial review of the application.

Homer City Generation declined to comment on the appeal.