The Mill Seat Landfill, opened in 1993, derives its name from local town history. The Mill Seat Landfill is situated in the southwest corner of Monroe County and was originally part of the Phelps Gorham Purchase known as the Mill Seat Tract. Monroe County is situated on the southern shores of Lake Ontario.

During the 1980s, the leadership of Monroe County recognized the need to provide long-term, environmentally sound and reliable solid waste management to businesses and citizens of the region. The result was the development of the Mill Seat Landfill, a state-of-the-art solid waste management facility.

By the late 1990s, the County realized it lacked the resources necessary to run the landfill and issued an RFP to prospective operators. One of the proposers was Waste Management of New York, LLC, which proposed buying the landfill outright. It was a proposal Monroe County liked. But by local law, no company could buy the landfill without the approval of the host town of Riga. And Riga’s leaders at the time preferred a long-term lease as apposed to private ownership, which resulted in a 49-year lease. Today, Monroe County owns the landfill and leases it to Waste Management of New York, LLC.

"We're thrilled with what we've accomplished here. Waste Management recognizes the environmental investment we've made and are protecting it with resources we ourselves could never afford." -John Graham, Director Monroe County Department of Environmental Services

Waste Management of New York, LLC, assumed the operation of the Mill Seat Landfill on January 15, 2002. With the largest network of landfills in the industry, we utilize state-of-the-art engineering, construction and monitoring methods to help protect the environment and ensure the safe and responsible disposal of waste.

The landfill's total property occupies some 385 acres. The footprint of the landfill is 98.6 acres. The construction cost was approximately $60 million. The design capacity is for 1,945 tons per day. Stage one and stage two of the landfill comprise 52.3 acres. Future stages three and four, approximately 46.3 acres. The site life is expected to last until the year 2018.