House Oversight and Government Reform Committee chairman Darrell Issa subpoenaed Environmental Protection Agency Administrator Gina McCarthy on Friday to produce documents he requested more than six months ago.

Issa, a California Republican, and Sen. David Vitter, R-La., the ranking Republican on the Senate Environment and Public Works Committee, had requested in an April 2013 letter to McCarthy documents and communications between the EPA and the White House concerning the agency’s response to several congressional requests.