Of the groups watching the budget negotiations in Washington this week, environmentalists are among those most keenly interested.

A reported compromise between House and Senate negotiators to cut $32 billion from the remainder of fiscal year 2011 spending could hit environmental programs hard. As much as $3.6 billion in cuts to the Department of Energy and $4.4 billion in cuts to the Department of Interior could affect environmental enforcement, according to the Wilderness Society.

But many environmentalists are even more worried about so-called “riders” that could be attached to any final spending bill. The riders target EPA authority to regulate air quality, greenhouse gas emissions, mountaintop mining restrictions, climate science programs, and clean water programs.

Though President Obama and Senate majority leader Harry Reid say they oppose the riders, it won't be clear until Tuesday or Wednesday which of the riders will be eliminated.

"This thing was so sweeping that a lot of things that otherwise would have received attention, if they had been taken up separately, are in there with little or no attention to their impact," says David Moulton, director of climate policy for the Wilderness Society, a Washington-based environmental group. "These things will not help the budget deficit either – in fact they would increase it."

Those who proposed the policy riders are hopeful.

Rep. Ted Poe (R) of Texas, who has proposed an amendment to strip the EPA of the authority to curb greenhouse-gas emissions, said in a statement: "The EPA’s unnecessary plan to regulate greenhouse gases would have cost taxpayers millions of dollars and destroyed countless jobs in our energy sector."

"The era of the EPA overstepping its authority by imposing over-burdensome and unnecessary regulations at the expense of American businesses is over,” he added.

Rep. Morgan Griffith (R) of Virginia said environmental regulations hold businesses to an unfair standard. He calls his proposal to restrict the EPA’s ability to regulate water quality from coal mines “a time-out on the EPA."

In a speech, he said the EPA guidelines for water coming out of mines is so severe that “Evian water that you purchase to drink would not pass."

But environmentalists maintain that wholesale changes could be in the offing if these riders are permitted, despite a lack of congressional debate over their impacts.

"It's very clear that environmental and energy programs were targeted even though these programs have been successful and enjoy public support," says David Goldston, director of governmental affairs for the Natural Resources Defense Council, a Washington-based environmental group.

They would also add to the cuts now being considered in the compromise spending bill, such as: