The 2006 law was signed by then-Gov. Kathleen Blanco after a legislative fight between landowners and oil companies. The measure concerns sites where landowners leased property for oil and natural gas drilling and later sued over contamination from waste and saltwater.
The law gives the state Department of Natural Resources new power to determine who is responsible for the cleanup and how much money they must pay. Petroleum companies supported the measure.
State District Judge Kathy Johnson made her ruling in a case involving M.J. Farms Ltd. and Exxon Mobil Corp. and about 42,000 acres of land in Catahoula and Avoyelles parishes.
Ruling in favor of M.J. Farms, the judge said the law violated sections of the state constitution regarding court jurisdiction and access to the courts.
But the high court said the law does not cut away the district court's jurisdiction even though it brings a state agency more into play.
The Supreme Court noted that "the district court remains an active participant in the entire restoration process," including making the determination whether environmental damage exists and who caused the damage and overseeing a restoration plan.
The high court's decision sends the case back to district court.