The Republican-controlled US Congress has scrapped Obama-era rules on the environment and guns, counting on a new ally in the White House to reverse years of regulation.
The Senate gave final approval to a measure eliminating a rule to prevent coal mining debris from being dumped into streams.
The House approved a separate resolution doing away with extended background checks for gun purchases by some social security recipients with mental disabilities.
The Senate's 54-45 vote sends the repeal of the stream protection rule to the new US president Donald Trump, who is expected to sign it.
Republicans and some Democrats say the rule could eliminate thousands of coal-related jobs and ignores dozens of federal, state and local regulations.
The vote was the first in a series of actions Republicans are expected to take to reverse years of what they call excessive regulation during Barack Obama’s presidency.
Rules on fracking, federal contracting and other issues are also in the cross-hairs as the GOP moves to void a host of regulations finalised during Mr Obama’s last months in office.
Senate majority leader Mitch McConnell said the stream rule was “an attack against coal miners and their families”.
“The legislation we passed today will help stop this disastrous rule and bring relief to coal miners and their families,” he said.
Democrats called the vote an attack on clean water and a clear win for big coal-mining companies and other polluters.
Senator Maria Cantwell said the stream rule had nothing to do with the decline of coal, which faces stiff competition from cheap natural gas.
Background checks
In the House, the issue was an Obama rule extending background checks for disabled Social Security recipients mentally incapable of managing their own affairs. The vote was 235-180.
Under the rule, the Social Security Administration would provide information to the gun-buying background check system on recipients with a mental disorder so severe they cannot work and need someone to handle their benefits.
Republican politicians criticised the regulation for reinforcing a negative stereotype that people with a mental disorder are dangerous.
"There is no evidence suggesting that those receiving disability benefits from the Social Security Administration are a threat to public safety," said representative Bob Goodlatte, chairman of the House Judiciary Committee.
“Once an unelected bureaucrat unfairly adds these folks to the federal background check system, they are no longer able to exercise their second amendment right,” he said.
After the 2012 school massacre in Newtown, Connecticut, Mr Obama directed the justice department to provide guidance to agencies regarding information they are obligated to report to the background check system.
In Newtown, 20 children and six teaching staff were shot dead when a gunman entered the Sandy Hook Elementary School on December 14th, 2012.
The gunman had earlier killed his mother inside their home, and he used a gun and ammunition that she had purchased. His mental health problems have been extensively reported.
Democrats said Republicans were doing the bidding of the National Rifle Association (NRA), which opposed the Social Security Administration’s rule.
Representative Jim McGovern said his constituents have a right not to be victims of gun violence.
“They have a right to protect their loved ones who may use a weapon against themselves or their family members,” he said.
The regulation also established a process for people to appeal having their names submitted to background check database.
But attorneys general from a dozen states wrote to congressional leaders and said such appeals can take months or years to resolve.
They said the regulation violates basic notions of due process by permitting an agency to revoke someone’s second amendment rights without a hearing.
Republicans are employing a rarely used tool to roll back some of the rules issued in the final months of Mr Obama’s tenure.
The Congressional Review Act provides a temporary window for a simple majority of both chambers to invalidate the rule.
Mr Trump would also have to sign the disapproval measure for a regulation to be deemed invalid.
The law also prevents the executive branch from imposing substantially similar regulations in the future.
PA