TUCSON (KGUN9-TV) A conservation group and Congressman Raul Grijalva filed a lawsuit against the Trump administration over the proposed border wall.
Both Grijalva and the Center For Biological Diversity want to know how the wall would impact the environment.
The 42-page complaint alleges the southern border enforcement plan from federal officials does not comply with the National Environmental Policy Act (NEPA).
According to the United States Environmental Protection Agency website, "NEPA's basic policy is to assure that all branches of government give proper consideration to the environment prior to undertaking any major federal action that significantly affects the environment."
Randy Serraglio, a southwest conservation advocate for the center, says environmental impact studies along the border are long overdue.
"The last serious environmental review of United States border security took place in 2001," Serraglio said. "So a tremendous number of things have changed since then."
"We need sound, scientific analysis of what the impacts of these proposals will be on these species," Serraglio said.
Those species include the ocelot, Mexican gray wolf and jaguar, Serraglio said. The jaguars that have been spotted in Arizona migrated from Mexico, and Serraglio believes a border wall would prevent that migration.
"Jaguars are definitely making a comeback in the United States," Serraglio said. "We've now seen seven in the United States in the past 20 years, and three of those were just in the last year and a half."
"If that population is going to be able to expand, it has to expand into the United States," Serraglio said. "We have to protect those places where those cats live and protect their ability to cross the border."
Below is a statement from Grijalva on the lawsuit:
American environmental laws are some of the oldest and strongest in the world, and they should apply to the borderlands just as they do everywhere else," Rep. Grijalva said. "These laws exist to protect the health and well-being of our people, our wildlife, and the places they live. Trump's wall - and his fanatical approach to our southern border - will do little more than perpetuate human suffering while irrevocably damaging our public lands and the wildlife that depend on them.
It's unclear exactly when construction on the proposed wall would begin and how much it would cost. Federal officials have already solicited bids for the wall design.
MORE: Getting President Trump's border wall won't be easy. Here's why.
Experts say a law passed by Congress in 2005 allows the U.S. Department of Homeland Security to waive restrictions that may prevent building barriers along the southern border.
Illegal border crossings have reportedly decreased this year. In Nogales on Tuesday U.S. Attorney General Jeff Sessions credited that in part to President Trump.
Despite the decrease in illegal crossings, Sessions said that the existing structures along the border are effective and the new structures will be more effective.
"The wall is a force multiplier of great proportions," Sessions said. "It is going to enable us when we deport criminal aliens who have entered illegall, that they don't get to come back as we see today."
KGUN9 reached out to U.S. Customs and Border Protection for a comment on the lawsuit, but a spokesperson said the agency does not comment on pending litigation. The acting commissioner of CBP, Kevin McAleenan was named in the suit.
DHS Secretary John Kelly was also named in the suit. An email to a DHS spokesperson was not immediately returned.