The Indianapolis Resource Recovery Facility, operating as Covanta Indianapolis, Inc., began commercial operation in December 1988. It serves approximately 850,000 residents of Indianapolis and Marion County. The 21-acre facility can process 2,175 tons per day of solid waste that produce no less than 4,500 pounds of steam sold per ton. Citizens Thermal Energy (CTE) purchases the steam to power the downtown heating loop. This loop includes nearly all downtown businesses, as well as Indiana University, Purdue University's Indianapolis campus, and Eli Lilly, the area's largest pharmaceutical manufacturer.