Local residents had the opportunity Tuesday to see what happens to trash when it leaves their curb during the annual open house at Waste Management’s Mountain View Reclamation Landfill at Upton.

The landfill averages 1,100 tons per day and the goal is to “responsibly manage trash generated in the surrounding area,” according to Erika Young, public affairs coordinator.

The service area is roughly a 60-mile radius, including Harrisburg, Gettysburg, Hedgesville, West Virginia, and Washington County, Maryland, according to John Wardzinski, senior district manager.

The landfill accepts three kinds of waste:

nonhazardous municipal waste, which includes homes and businesses

construction and demolition

residual industrial or manufacturing, which requires prior approval from Waste Management and the Pennsylvania Department of Environmental Protection.

Monitoring is a significant safety step on the property and ranges from wells on the perimeter that are sampled every three months to equipment that checks each load for radiation.

The landfill sits on 800 acres straddling the Antrim-Montgomery Township line, although the actual landfill is much smaller and the dumping area is divided into four-acre areas called cells, which are prepared in increments.

The current dumping area was permitted in 1996 and has an estimated life of 29 years. Another expansion is approved and work is underway extending toward Letzburg Road. Wardzinski said cells are created as they go and it costs $400,000 an acre just to construct the liner.

The base is 6 inches of compacted clay, topped with the thick plastic liner. A leachate collection systems drains liquids from the landfill and gas is extracted and used to make electricity.

As waste is dumped, it is compacted to reduce the space it consumes in the landfill and to cut down on odors, keep trash from scattering and deter predators, according to the Waste Management graphic Typical Anatomy of a Landfill.

At the end of the day, the trash is covered with at least 6 inches of soil or another approved material. At the Upton landfill, the other approved material is “automobile shredder waste” or ground up cars once the metal has been removed — including seat cushions, dashboards and plastics — and comes from Conservit in Hagerstown, Wardzinski said.

Once a cell reaches its final permitted elevation, it is topped with clay and capped with another thick plastic membrane to keep water out and odors in, Wardzinski explained. He said scientists say the liner system should outlast the amount of time it takes the waste to degrade and “the huge compost pile will become inert someday.”

The whole thing is topped with 2 feet of soil and planted with grass.