ROANOKE, Va. — Environmental groups have filed a legal challenge against the Mountain Valley Pipeline that says the project could push two endangered species of fish to extinction.

The Roanoke Times reports that the legal challenge was filed Tuesday in the 4th Circuit Court of Appeals in Richmond. It involves the Roanoke logperch and the candy darter species of fish.

The route of the 300-mile long pipeline would go from northern West Virginia to southwestern Virginia and connect with an existing pipeline in North Carolina.

There has been a string of lawsuits that have long delayed work on the pipeline. Mountain Valley has said it plans to have the pipeline finished by early next year.