The Trump administration's push for a complete barrier along the southern U.S. border is already controversial. But planned construction near San Diego may further stoke the fire.
On Tuesday, the Department of Homeland Security announced a waiver for the San Diego area. It lets the department bypass environmental laws and other regulations to build barriers and roads near the border.
For example, Homeland Security won't have to conduct an environment impact study before construction.
The agency says the San Diego area's border is especially vulnerable and that the need is immediate.
Last year in the San Diego sector, the department says it apprehended 31,000 undocumented immigrants and seized over 10,000 pounds of marijuana and cocaine.
But activists say several endangered species live in the San Diego area, meaning the environment is also vulnerable.
They argue the waiver is unconstitutional. But there might be some precedent for it.
During former President George W. Bush's administration, the agency used this kind of waiver five times.
The Army Corps of Engineers is expected to begin construction-related tests sometime in August.