An immigration watchdog group is suing the Department of Homeland Security over the negative environmental impact of both legal and illegal immigration, which have caused "explosive population growth" since 1990.

The Immigration Reform Law Institute planned to file the suit against DHS on Monday in the U.S. District Court for the Southern District of California, alleging the department has ignored the National Environmental Policy Act, a 1970 law requiring "any agency considering an action that will affect the environment to analyze and publicize those effects."

The IRLI argues that mass migration into the United States, including unauthorized border crossings, has "a very significant impact on the environment, which DHS has spent the last 46 years ignoring."

The plaintiffs include former Colorado Gov. Richard Lamm, a Democrat, who called it "environmental malpractice" to disregard the impact of immigration.

The New Mexico Cattle Growers Association, Californians for Populations Stabilization, Arizona Association of Conservation Districts and Floridians for Sustainable Population are also plaintiffs in the case.

The IRLI lists several negative consequences of DHS's failure to study the environmental impact of immigration.

"Communities across America are being harmed and overwhelmed by damage to air quality, increasing urban sprawl, increasing demand for water, increasing water pollution, exacerbated traffic congestion, school overcrowding, loss of green space, farmland, forests and wildlife, and other non-renewable resources," IRLI officials said in a statement explaining the lawsuit. It also said the "massive numbers of people" coming across illegally has led to the destruction of native species, garbage dumping, water pollution and fires.

The IRLI describes itself as an advocacy law firm that defends communities and individuals against "the harms and challenges posed by mass migration to to the United States."