LOUISVILLE, Ky. — The head of a Kentucky engineering firm who was nominated to run a federal agency that cleans up former surface mines has withdrawn from consideration for the job.

News outlets report Steven Gardner withdrew his nomination to the Office of Surface Mining Reclamation and Enforcement because of a protracted vetting process. He was nominated by President Trump in October.

Gardner told Bloomberg News he decided to withdraw after nearly a year of back and forth over "the conditions of an ethics agreement." He did not return a call seeking comment Thursday.

The Sierra Club said in a release Thursday that Gardner was wrong for the job, saying he "puts the profits of his bosses above the health and safety of coal workers, and the enforcement of our clean air and water laws."