Now that Environmental Protection Agency administrator Gina McCarthy has been confirmed, she faces a lengthy to-do list.

To get a sense of the pent-up demand for EPA action, consider how Sen. Sheldon Whitehouse (D-R.I.) put it in a statement Friday. "With so many challenges facing public health and the environment, it's important for Administrator McCarthy to hit the ground running," Whitehouse said. "Per the President's climate action plan, I expect priorities to include the carbon pollution standards for new and existing sources, and the post-2018 fuel economy standards for heavy-duty vehicles. We also need her leadership pushing for the release of rules that have been stuck at OMB for far too long, such as the Clean Water Act guidance. The backlog can't continue."

Sen. James M. Inhofe (R-Okla.) had another take on what McCarthy will do now that she's in office, saying in a statement Thursday night, “The Obama administration has a history of putting forth Cabinet officials who will advance his liberal agenda through administrative regulations, skirting the will of Congress, and Gina McCarthy will now be a key player in this.” 

Here are half dozen of the top issues McCarthy will tackle in the months ahead in her new job.

1. Greenhouse gas emissions for new and existing power plants. Proposed rules to limit carbon dioxide emissions from new utilities, which will set a separate rregulations for coal and gas-fired plants, are pending at the Office of Management and Budget and will likely come out in September. Even as the EPA works to finalize that proposal it will have to tackle the much more daunting task of proposing a rule to limit these emissions from existing power plants.

Many in the coal industry are wary of what that proposal will look like. “Our argument is not with climate change but with the administration’s proposal for addressing it," said Luke Popovich, a spokesman for the National Mining Association. "We think there should be room to accommodate economic as well as environmental concerns.”

And Jeffrey Holmstead, who headed EPA's air and radiation office under George W. Bush, wrote in an e-mail that McCarthy faces "a real dilemma" when it comes to limiting carbon emissions under existing law. "If she tries to be too creative in expanding EPA authority under the Clean Air Act, her efforts are likely to be struck down in court," Holmstead wrote. "On the other hand, if she follows the plain language of the Act, she may disappoint her supporters in the environmental community because she won’t get much in the way of emission reductions."

2. Regulations strengthening wetlands protection. The definition of exactly what qualifies for protection as a wetland under the Clean Water Act has been a source of contention for a dozen years. The Supreme Court has issued two decisions, the George W. Bush administration issued guidance in 2003 and 2008 limiting the scope of the act, and the EPA has issued guidance on the matter that has been tied up at the Office of Management and Budget for more than a year and a half. Advocates such as Whit Fosburgh, president and CEO of the Theodore Roosevelt Conservation Partnership, will be pressing not only for final guidance but a rule on what constitutes a wetland in order to slow the rapid pace of wetlands conversion in the United States. Fosburgh noted in an interview that the country has lost at least 7 million acres in wetlands since Obama took office.

3. Requiring cleaner gasoline and lower-pollution vehicles nationwide. In March the EPA proposed a rule that would reduce the amount of sulfur in U.S. gasoline by two-thirds and impose fleet-wide pollution limits on new vehicles by 2017. Oil refining companies are trying to make the rule less stringent, arguing that it could raise gas prices, but the agency counters it will add less than a penny to the cost of a gallon of gas,

4. Deciding whether to block construction of Pebble Mine in Alaska. Two mining firms, Northern Dynasty and Anglo American, have proposed building North America's largest gold and copper mine in the Bristol Bay watershed, home to more than 40 percent of the world's sockeye salmon. Six tribes have asked the EPA to invoke its powers under the Clean Water Act to block the mine on the grounds that it would harm the region’s waterways, fish and wildlife. The agency is in the midst of an extensive environmental assessment, which has come under attack from mining proponents, who argue the mine will yield major economic benefits to the state. Trout Unlimited Chris Wood said McCarthy may be pressed to make a decision as soon as the agency issues its final environmental assessment of the mine in the fall. "They've been consistent in saying they will not make a decision until the science is in, and that is the science.

5. Tighter smog standards. In September, 2011, President Obama delayed issuing tougher restrictions on ozone, a major contributor to smog, on the grounds that they could hurt the economy and were due for a federal review in 2013 anyway. Now it's 2013, but as Clean Air Watch president Frank O'Donnell noted in an e-mail, "the latest regulatory calendar shows it is not on EPA’s radar at all," and a coalition of groups are suing to force a decision deadline. "I assume eventually EPA will be forced to deal with it," O'Donnell wrote.

6. The Keystone XL pipeline. While EPA does not have permitting authority over Keystone XL, it has submitted a comment letter raising questions about aspects of the State Department's draft environmental assessment of the project. If - -once State finalizes the environmental assessment and issues a determination on whether the massive pipeline is in the country's national interest -- the EPA lodges a formal assessment, this will force President Obama to formally sign off on whether or not the pipeline receives a presidential permit.

What does McCarthy think of what she faces in her new job? At her swearing-in Friday, she remarked that it was a "wicked cool day." Clearly she was not referring to Washington D.C.'s climate, since the temperature had reached the 90s by the time she took her oath.