AUGUSTA — Maine officials are asking residents to sign up for a program to safely dispose of banned pesticides and unusable chemicals.

The program is free and available to owners of homes and family-owned farms and greenhouses. Residents must register by Sept. 25. Collection sites are set for Presque Isle, Bangor, Augusta and Portland in October.

The Maine Department of Agriculture, Conservation and Forestry’s Board of Pesticides Control and the Maine Department of Environmental Protection are running the program. Conservation department Commissioner Walt Whitcomb says the program is important to keep potentially harmful chemicals from contaminating land and water resources, such as drinking water.