Prior to 1995, leaves and grass comprised over 30% of all household solid waste going to landfills and incinerators.
Not only is that a lot of space being filled by a clean resource, but yard clippings in landfills may contribute to methane gas and leachate production which may pollute the air and local water supplies. The moisture in yard waste causes it to burn poorly in incinerators, raising pollution levels, and operating costs.
Because of the many problems caused by yard clippings in landfills, starting in 1995, yard clippings were banned from Michigan landfills. Yard clippings are defined as leaves, grass clippings, vegetable or other garden debris, shrubbery, or brush or tree trimmings, less than 4 feet in length and 2 inches in diameter, that can be converted to compost humus.