Calumet Water Reclamation Plant is the oldest of the seven wastewater treatment facilities within the metropolitan Chicago area. Calumet treats the wastewater from an area of approximately 300 square miles which includes parts of the City of Chicago and the southern suburbs. The Plant provides both primary and secondary treatment which removes more than 90 percent of the contaminants. The TARP Pumping Station is located adjacent to the treatment plant. The Calumet Tunnel helps control pollution and eliminates 85 percent of the combined sewer over-flows.