Assistant Administrator for EPA's Office of Air and Radiation, Gina McCarthy (Melina Mara/The Washington Post)

McCarthy is replacing Lisa Jackson, who stepped down earlier this month.

It’s long been expected that whoever the nominee was would face tough questions on Capitol Hill — after all, the agency’s portfolio includes flashpoint issues like climate change, a key priority for the White House. Jackson’s tenure was marked by plenty of testy Hill exchanges.

It looks like oil and several other industries regulated by EPA won’t make a fuss over the president’s selection, with the coal folks being the possible exception. But several Senate Republicans, including Sen. David Vitter (R-La.), have made rumblings about McCarthy, signalling her nomination won’t exactly be a cakewalk.