While the "fiscal cliff" of looming tax increases and spending cuts dominates political conversation in Washington, some Republicans and business groups warn of a "regulatory cliff" that they say could be just as damaging to the economy.
The rules had been largely put on hold during the presidential campaign. Since the election, the Obama administration has reopened the regulations pipeline.
In recent weeks the Environmental Protection Agency has proposed rules to update water quality guidelines for beaches and deal with runoff from logging roads. The National Highway Traffic Safety Administration, meanwhile, has proposed long-delayed regulations requiring automakers to include event data recorders -- better known as "black boxes" -- in all new cars and light trucks beginning in 2014.
The administration also has initiated several rules to implement its health care overhaul, including a new fee to cushion the cost of covering people with pre-existing conditions.
With the election over, it's now "full speed ahead" for federal rules limiting greenhouse gas emissions, requiring cleaner gasoline and putting controls on drilling for oil and natural gas, said Sen. James Inhofe (R-Okla.), the senior Republican on the Senate Environment Committee.
Environmental groups say fears of a second-term regulatory deluge are overstated.
"At this point it still has the appearance of being more of a trickle than a flood," said Frank O'Donnell, president of the environmental group Clean Air Watch.
The EPA is principally focused on meeting court-ordered deadlines, such as today's deadline for a rule intended to reduce the amount of soot that can be released into the air, O'Donnell and others said.