MADISON, Wis. (AP) -

State environmental officials are taking public comments on three businesses' applications to join the Green Tier program.

Badger Mining Corporation, silica sand producer Unimin Corporation and metal recycling outfit Waukesha Iron and Metal all are vying to join the program, which provides regulatory flexibility for businesses that commit to protecting the environment.

The Department of Natural Resources will take written comments on the applicants through Dec. 19.