U.S. Landfills Handle More than 70 Percent of America's Non-Hazardous Trash
by Mary E. Hill

Americans are notorious for a high rate of trash generation compared to the rest of the world. Only an estimated 27 percent is either recycled (metal, glass, paper, plastic) or composted (yard, food waste).

The waste that is not recycled is sent to a landfill. Landfills can either be considered a sanitary landfill that uses a clay liner to isolate trash from the environment around it or a municipal solid waste landfill, which uses a synthetic or plastic liner to protect the environment.

Most states require solid waste facilities to be located away from navigable surface waters, floodplains, wetlands and critical habitats. Regulations include these location restrictions, facility design and operation plans, corrective action measures, monitoring, and conditions for closing and post-closure care.

Landfills receive thousands of tons of waste every day. It is imperative that the operators have extensive qualifications and experience in proper procedure.

Landfills are used for disposal of household garbage and other types of municipal solid waste including sanitary waste from septic tanks. They may also accept wood skids, brush, raw wood, compostable materials and clean fill. Hazardous wastes are turned away, but an alternative method of disposal is usually offered. Some hazardous wastes may be accepted if the material is treated before land disposal and if the treatment complies with the standards set by the EPA. The facility needs to have a specific permit for each type of hazardous waste allowed.

Hazardous wastes include unused paints, batteries, fluorescent lights, and pesticides, to name a few.

Landfills are designed with sections called cells that hold the waste. Cells are created below the surface and have limits set for fill-height. A system of control and containment is implemented to handle drainage during a rainstorm or typical liquid movement.

To have a proposed landfill approved by the proper authorities, the organization needs to provide a detailed description of the:

Site's geology.

Soil composition.

Potential for sinkholes.

Proximity of homes and drinking water wells.

Design of the landfill leachate collection system. This system is a series of plastic slotted or perforated pipes set into each cell to capture its leachate. This material is taken through the pipes to a collection sump, which pumps it to the surface for temporary storage. An off-site disposal facility takes it or it is discharged into the municipal sewer system.

Planned landfill liner system. This liner prevents leachate wastes from leaving the designated areas.

Groundwater monitoring plan.

Methane monitoring system. Methane gas and carbon dioxide are both by-products of waste decomposition and must be monitored. Landfills are required to monitor and collect these gases. Some landfills send the collected gasses to an off-site processor. Others collect them and generate an alternate fuel source for reuse or they burn them by landfill gas flare or incinerator.

Stormwater management plan.

Closure and post closure plans.

Other possible environmental hazards generated by landfills include zinc, lead, and other toxic chemicals, gasoline constituents, diesel fuel, concentrations of rates, flies, birds and other disease carrying animals, waste oils, antifreeze, methane gas, and carbon dioxide. All of these elements are regulated and controlled by landfill operators.

Current studies are focusing on our ability to speed the decomposition process, which would generate more gases to be used as alternative fuel sources. If trash can't be recycled and must be landfilled, the ability to generate alternative fuels from landfills is a positive twist that can greatly impact a landfill's value in today's society.