NEW YORK (Reuters) - The U.S. Customs and Border Patrol plans to use a 2005 anti-terror law to sidestep an environmental impact study for a section of President Donald Trump’s border wall that will pass through a Texas national refuge for endangered ocelots, according to two government sources familiar with the matter.

President Donald Trump applauds his crowd as he holds a "Make America Great Again" rally at Orlando Melbourne International Airport in Melbourne, Florida, February 18, 2017. REUTERS/Kevin Lamarque

Trump’s 2018 budget proposal calls for 32 miles (51 km) of new border wall in the Rio Grande Valley Sector of the U.S.-Mexico border, where the 2,000-acre Santa Ana National Wildlife Refuge is located.

The area near the southern tip of Texas is home to 400 species of birds as well as a dwindling population of federally protected ocelots. Only about 50 ocelots remain in the United States, according to the Fish and Wildlife Service.

The sources said CBP officials had informed them CBP would rely on exemptions provided to the U.S. Department of Homeland Security under the Real ID Act, a law created on recommendations from the 9/11 Commission, so they can start building the section of wall without waiting for the years-long environmental study.

Environmental impact studies are generally required under federal law whenever a proposal is made to build on public lands, including national forests, wildlife refuges and land managed by the Bureau of Land Management.

The Real ID Act also allows the secretary of Homeland Security to exempt CBP from adhering to the Endangered Species Act, which the sources said would otherwise make the wall’s construction inside the refuge impossible due to the presence of the ocelots. The sources asked not to be named because they are not authorized to speak publicly on the matter.

CBP spokesman Carlos Diaz declined to comment on the sources’ assertion directly. He said in emails to Reuters that plans for constructing the wall were still uncertain and that the wall’s construction depended upon whether Congress authorizes Trump’s proposed 2018 budget.

He added, however, that a government contractor has already begun testing soil samples on land near the refuge and that CBP got an official waiver for permission to do so.

“CBP, like all other federal agencies, may rely on Categorical Exclusions to achieve NEPA compliance for routine agency activities, like the soil sampling, that have minimal to no environmental impact,” he said.

Environmental studies are mandates under the National Environmental Policy Act (NEPA).

The Texas Observer first reported on July 14 that the CBP was testing soil in Santa Ana.

Congress is expected to take up the 2018 budget in September. The sources said CBP hopes to start building the wall before the end of 2017.

The CBP’s Acting Border Patrol Chief Carla Provost said in testimony to Congress on June 13 the agency’s activities building the wall would include “environmental planning.”

Private industry advocates have said National Environmental Policy Act requirements for impact studies take too long. Mining industry executives want the Trump administration to help shorten the process.