"The outgoing head of the EPA took direct aim at coal miners' jobs and circumvented Congress, targeting and wreaking havoc on the Appalachian economy," he said.
Rahall also promised he would fight the EPA's "ideologically driven agenda."
Sen. Jay Rockefeller, also a Democrat, stopped short of condemning Obama's pick but urged McCarthy to operate within the EPA's legal jurisdiction.
"As she's considered for the post, it's important to examine if she is willing to maintain our water quality, protect human health, and work together on real solutions to save and create jobs in our state, while also acting within the limits of the EPA's authority," he said.
Rockefeller praised Obama's pick of Moniz, who also worked as President Bill Clinton's top energy official.
"He has reiterated the need for an 'all-of-the-above' energy strategy," he said of Moniz. "I'm hopeful that his support of research into carbon capture and storage for coal means that, if confirmed, Dr. Moniz will help us to advance new technologies to create a strong future for coal.
"He has also recognized the importance of natural gas which holds great promise for West Virginia's economy," he said in a prepared statement.
Rep. David McKinley and Sen. Joe Manchin's offices did not respond to requests for comment on Moniz and McCarthy's appointments.