A federal judge has cleared the way for a lead and copper mining company’s lawsuit against Union Pacific over lead pollution to move forward.

This lawsuit related to contamination in Idaho’s Coeur d’Alene Basin is one of several pending between Tucson, Arizona-based Asarco and Omaha, Nebraska-based Union Pacific.

A judge decided last week to reject Union Pacific’s motion for summary judgment in the case. Railroad officials didn’t immediately respond Monday to questions about the Idaho case.

Asarco says it filed the lawsuits to help ensure the $1.8 billion it paid for cleanups is effective.

Asarco lawyer Gregory Evans says the lead rocks Union Pacific used along its rail lines could threaten the cleanups.

Asarco, now owned by Grupo Mexico, ran lead smelters, metal refineries and numerous mines.