The National Environmental Policy Act, known as NEPA, sets guidelines for how every government agency makes decisions, mandating that the impact on the environment and public health be considered, while also setting up the procedures for the public to officially register concerns about a project.
"The United States will not be able to compete and prosper in the 21st century if we continue to allow a broken and outdated bureaucratic system [to] hold us back from building what we need -- the roads the airports the schools, everything," President Donald Trump said Thursday at a White House event, surrounded by representatives of the construction, road building and beef industries praising the announcement.
Trump said infrastructure projects are "tied up and bogged down by an outrageously slow and burdensome" government process under the current law and that the proposed changes would speed things up.
"America is a nation of builders. It took four years to build the golden gate bridge, five years to build the Hoover Dam and less than one year to build the Empire State Building. Yet today it can take more than 10 years just to get a permit to build a simple road," he added, calling it "big government at its absolute worst."
Democrats and environmental groups quickly decried the decision, saying the administration is backtracking on environmental progress and ignores the crisis of climate change.
"This means more polluters will be right there next to the water supply of our children, that's a public health issue. That in their denial of climate, they are going to not use the climate issue as anything to do with environmental decision-making. The public should know this," House Speaker Nancy Pelosi said at a press conference before the announcement.
Environmental advocates say NEPA has been crucial for Americans -- especially communities of color that are more frequently affected by pollution and contamination, to raise concerns and prompt changes when government projects in their area could influence them.
The Trump administration argues that broadly evaluating the environmental impact takes too long and can result in unwieldy reports. The proposed change aims to speed up environmental reviews and could make it more difficult to consider a project’s impact on climate change, or how the project could be altered by the affects of climate change.
"These documents were often hundreds and even thousands of pages long and given that the purpose of NEPA is to make an informed decision, when I asked our senior managers if they were reading these documents that were several thousands of pages long they said emphatically no, which does not serve the purpose of NEPA at all," Interior Secretary David Bernhardt said on a call with reporters.
The proposal would change the procedure of how the government considers the environmental impact of a project, but not change the substance of laws to protect the environment like the Clean Air Act and the Clean Water Act.
"Nothing in the proposal would eliminate or diminish the protections that Congress has enacted to safeguard the environment and the American people," said Mary Neumayr, chair of the Council for Environmental Quality that oversees NEPA.
The changes to the NEPA procedure would require a two-year time limit on environmental impact reviews, add a page limit to report and change the guidelines for what kinds of comments about environmental impacts will be considered for a given project. The change will specifically require that environmental impacts are "reasonably foreseeable" and will not require agencies to consider the cumulative environmental effects.
Critics say the changes will allow the government to disregard climate change when considering projects like permits to mine and process fossil fuels, but officials said it will not exclude consideration of greenhouse gas emissions as an environmental impact.
But acting Office of Management and Budget Director Russell Vought said this doesn't mean Americans will be on the hook to pay for projects that could be damaged by climate change impacts like sea level rise or flooding in the future. He told ABC News the administration wants to quickly begin projects that will mitigate the impact of climate change, instead of being held up through years of environmental studies.
"We don't want a long 10-year delay to be able to have mitigation infrastructure projects," he told ABC News, adding "we want those built that want the environmental approval on those done within two years which is what this rule would require."
The change could also allow agencies to exempt more projects from environmental review if they determine the project is small or if similar projects have been given exemptions by other agencies.
The law was passed in 1969 amid protests around the country known as the ""Freeway Revolts," when communities raised concerns about plans to demolish homes to construct the Interstate Highway System.
Environmental groups and experts that work with the law say the changes proposed by the Trump administration could also make it more difficult for concerned citizens to comment on upcoming projects.
"The law was built on decades of activism from people who wanted a say in decisions affecting their health, their lives, their communities, and their environment," Stephen Schima, senior legislative counsel at Earthjustice, an environment non-profit, said in a statement. "By stacking the deck for corporate polluters and eviscerating public participation, this administration is trashing that legacy. Without this law, the government will have an easier time letting dirty industry tear down trees, put up refineries next to children’s schools, and risk our health."
Schima added, "Worse still, this proposal will threaten to silence the voices of the very people government should be listening to -- the people living on the front lines of the climate crisis."
Some projects supported by the Trump administration -- like the Keystone XL natural gas pipeline -- have faced legal obstacles after courts found the government didn't complete a sufficient environmental analysis required under NEPA.
Vought said the changes in the NEPA process are "absolutely" intended to prevent future legal challenges that he called "frivolous lawsuits," but that the administration isn't trying to avoid legal challenges related to environmental impacts.
"We're trying to comply with the law, have clean water, clean air and protect our environment -- but at the same time move important infrastructure projects, roads, bridges, disaster mitigation, pipelines and along the lines which you mentioned," Vought told ABC News. "Those are the kind of things we're trying to move."
A senior administration official said the proposed changes would not exempt Keystone XL or any other project from future environmental reviews.
ABC News' Benjamin Gittleson contributed to this report.