Waste Management, Inc. is a holding company, which engages in the provision of waste management environmental services. It operates through the following segments: Tier 1, Tier 2 and Tier 3. The Tier 1 segment comprises of areas in the Southern United States. The Tier 2 segment comprises of areas located in the Midwest and Northeast United States. The Tier 3 segment comprises all remaining areas, including the Northwest and Mid-Atlantic regions of the United States and Eastern Canada. The company was founded on September 30, 1987 and is headquartered in Houston, TX.