DENVER – Colorado officials are weighing whether to let Cotter Corp. transfer ownership and responsibility for cleanup of toxic sites to a newly formed local company.

But The Denver Post reports Denver Water, Arvada Utilities and community activists are challenging the deal. State officials say if they let Cotter walk away, Colorado could lose if the new company fails to get very difficult cleanup jobs done.

Cotter for decades has wrestled with Colorado health and natural resources officials over cleanups at Cotter’s Schwartzwalder Mine west of Denver and a uranium mill site along the Arkansas River near Canon City.

Colorado Division of Reclamation, Mining and Safety Director Ginny Brannon says officials are evaluating Cotter’s proposed deal and discussing it with utilities.

Cotter officials declined to discuss the deal in the works.