Solid Waste and Rubble
Solid Waste
Effective March 9, 1998 the Commissioners of St. Mary's County amended the rules and regulations for the use of solid waste disposal facilities to prohibit the disposal of municipal solid waste at the St. Andrews Landfill Facility by commercial waste haulers. As of February 15, 1999 no additional municipal solid waste capacity was available. Generally speaking, residents should handle most of their solid waste disposal needs at the six Convenience Centers. Residents may throw away up to four (4), 35 gallon containers, or equivalent, into the solid waste compactors. Loads in excess of this amount will be directed to the St. Andrews Landfill. The compactors cannot accept yard waste, masonry products, scrap metal and appliances, scrap tires, gas cylinders, liquid waste, furniture, construction & demolition debris, animal carcasses, burned material(s) and contractor waste. The bulky items mentioned above can damage the integrity of the trailer, jam the sweeping blade or prematurely fill the trailers, thus possibly causing the convenience center to temporarily shut down until the trailer is replaced. These items must also be brought to the landfill. Asbestos and special medical waste is not accepted at the convenience centers nor the landfill. All users of these facilities are requested to follow the directions of the Attendants on duty to help us safely segregate the wastes into the appropriate collection locations. Currently, all municipal solid waste accepted from the residents is disposed at the Covanta (energy from waste) incinerator in Lorton, VA.
Rubble
Effective January 18, 2000 commercial haulers were prohibited from disposing of rubble at the St. Andrews Landfill Facility. Beginning January 20, 1998 the Maryland Department of the Environment (MDE) required the County to provide third party inspection services for the "rubble" portion of the St. Andrews Landfill in accordance with the Code of Maryland Regulations(COMAR) 26.04.07.02.18.
An independent Maryland Environmental Services inspector was stationed at the working face of the rubble cell to determine if loads brought to this area are acceptable or unacceptable. Acceptable materials once included: land-clearing debris such as earth, tree stumps, logs and rock; construction and demolition debris associated with the razing of buildings, roads, and bridges which includes steel, concrete, bricks, lumber, plaster and plasterboard, insulation, shingles, floor tile and household appliances; and tires. The State mandated rubble acceptance closure is July 1, 2001. Currently, all rubble accepted from residents is deposited into waste containers and disposed of at the Appeal Transfer Station in Maryland or the King George Landfill in King George, Virginia
Recycling
Effective March 9, 1998 the Commissioners of St. Mary's County amended the Rules and Regulations for the use of solid waste disposal facilities to prohibit the disposal of municipal solid waste at the St. Andrews Landfill Facility by commercial waste haulers. As of February 15, 1999 no additional municipal solid waste capacity was available. Generally speaking, residents should handle most of their solid waste disposal needs at the six Convenience Centers. Residents may throw away up to four (4), 35 gallon containers, or equivalent, into the solid waste compactors. Loads in excess of this amount will be directed to the St. Andrews Landfill. The compactors cannot accept yard waste, masonry products, scrap metal and appliances, scrap tires, gas cylinders, liquid waste, furniture, construction & demolition debris, animal carcasses, burned material(s) and contractor waste. The bulky items mentioned above can damage the integrity of the trailer, jam the sweeping blade or prematurely fill the trailers, thus possibly causing the convenience center to temporarily shut down until the trailer is replaced. These items must also be brought to the landfill. Asbestos and special medical waste is not accepted at the convenience centers nor the landfill. All users of these facilities are requested to follow the directions of the Attendants on duty to help us safely segregate the wastes into the appropriate collection locations. Currently, all municipal solid waste accepted from the residents is disposed at the Covanta (energy from waste) incinerator in Lorton, VA.
Waste-to-Energy (WTE) Facilities
WTE has grown and is absolutely the most environmentally sound way to deal with garbage. In the northeast and other populated areas, it is economically comparable to other disposal methods. All non-recycled residential municipal solid waste collected by the County is exported to waste-to-energy facilities where the volume of trash is reduced by 90%. County trash transfer trailers arrive at the facilities, enter a huge garage-type structure, and dump the trash on the tipping floor. A bulldozer pushes the trash into a pit where large cranes pick up the trash and feed it into a hopper, which leads to a boiler. This is where combustion happens. The trash is burned on a grate at 2,400 degrees Fahrenheit, 24 hours a day, seven days a week. The heat from the combustion heats water in tubes, which creates steam. The steam turns the turbine, which combined with a generator, generates electricity-a renewable energy that is sold to power companies.
The steam leaves the turbine and goes into cooling tanks. The steam is then returned to a liquid state with cooling water. During the process the cooling water can be seen evaporating as water vapor clouds above the cooling tower. The ash from the incinerated trash is sifted for ferrous and nonferrous metals, which are recycled. The remaining ash is land filled, which represents only about 25% of the original weight of the trash.
The combustion air goes through several forms of air pollution control equipment to remove nitrogen oxides, sulfur dioxide, hydrogen chlorides, mercury, and dioxins. The Clean Air Act requires WTE facilities to be at the leading edge with respect to air emissions. New facilities had to meet stringent emissions criteria and older facilities had to be retrofitted. In 2003, the EPA completed a facility by facility inspection of WTE facilities. It was an amazing report. The EPA said that taken together, these retrofits make for an industry that has less environmental impact than almost any other source of electricity in the country. For example, “these retrofits reduced dioxins by 99% and mercury by 90%.”
WTE accounts for 15-16% of waste management in the U.S. Recycling falls in the high teens. According to some researchers, more recycling occurs in communities with WTE than in communities without it.