Glossary of Terms

This list contains terms and their definitions frequently used either in the waste industry or specifically by Waste Management.

Airspace

The projected bank cubic yards (BCY) of the landfill to be filled with waste as determined by survey and/or other engineering techniques.

Baler

A piece of equipment used to compress, and from the recycled material into bales.

Boiler

A device used to absorb the heat released during the combustion process of burning waste. This combustion produces steam that can be sold or converted into electrical power.

Capping

This is the process of placing the final cover material on the landfill.

Cell

Landfills are constructed in phases (cells) that adjoin one another, separated by a berm to contain leachate within an area. The entire permitted area will be divided into separate cells for construction.

Closed Site (Landfill)

A landfill that has reached its permitted waste capacity and has been permanently capped and certified as closed by the appropriate state regulatory agency.

Closure

The period of time after a landfill has reached its permitted capacity but before it has received certification of closure from a state regulatory agency. During the closure period, certain activities must be performed to comply with environmental and other regulations (e.g. capping, landscaping, etc.).

Construction and Demolition (C&D)

A waste stream that is primarily received from construction sites. Some examples of C&D waste include, but are not limited to, concrete, rebar, wood, paneling, linoleum, and carpet.

Container

Any receptacle used to accumulate waste from residential, commercial and industrial sites. Containers vary in size and type according to the needs of the customer or restrictions of the community. Containers are also referred to as dumpsters.

Chemical Waste Management (CWM)

The operating name of Waste Management's hazardous waste landfills. WM currently owns and operates five hazardous waste landfills in the U.S.

Disposal Fee

A fee charged for the amount of waste disposed of by customers at a landfill. (also see Tipping Fee)

Drop-off Box or Center

Sectioned containers where individuals and businesses can put recyclable material or containers used for waste collection where individual service is not available.

Dumpster

A generic term used for front-load and rear-load containers.

Emission Control Equipment

A category of equipment used at waste-to-energy facilities to meet emission standards and generate reports required by agency regulators.

Gatehouse

A gatehouse is found at a landfill or a transfer station. All incoming vehicles must stop to be processed and weighed, and all outgoing vehicles must stop to be weighed and receive a disposal ticket for charges. See also Scale House.

Hauling Fee

A fee charged to roll-off customers calculated from the amount of time it takes to pick up their roll-off container or compactor, dispose of the waste and return it to the customer.

Hazardous Waste

Waste that is designated such by regulatory agencies either because it has elevated levels of hazardous chemicals or materials, because it exhibits a potentially dangerous characteristic (e.g., ignitable, corrosive, etc.) or because the material belongs to a general family of materials which have been deemed hazardous by regulatory agencies.

Hopper

The hopper is the part of a garbage truck or compactor where trash is emptied before compaction into the container.

Landfill

A modern engineered way to deposit waste into the ground and still protect the environment. As the landfill is built, the base of the cell is lined with a protective layer and materials are installed to monitor and collect leachate and gas emissions. As waste is deposited over the liner, it is compacted with heavy machinery in an effort to get the maximum amount of waste in an area. At the end of the day, the waste is covered with soil or special fabric cover (unless specifically exempted by state regulators.) Once the lined area is completely full, it is covered with an engineer-designed cap. Regulations mandate the periodic testing of groundwater, leachate levels, and gas emissions. Landfills are accounted for a separate line of business within the WM organization. Different types of landfills include MSW, C&D, Asbestos Monofil, Ash Monofil, Special Waste and Hazardous Waste.

The landfill, Hazardous Waste

Wastes that exhibit certain characteristics may be regulated by RCRA. A waste may be considered hazardous if it is ignitable (i.e., burns readily), corrosive, or reactive (e.g., explosive). Waste may also be considered hazardous if it contains certain amounts of toxic chemicals. In addition to these characteristic wastes, EPA has also developed a list of over 500 specific hazardous wastes. Hazardous waste takes many physical forms and may be solid, semi-solid, or even liquid. A hazardous waste landfill is built to specific regulations to allow for the disposal of waste designated by regulatory agencies as being hazardous. These regulations are far more stringent that for an MSW landfill. WM has 5 secure hazardous waste landfills permitted under RCRA. These sites all operate under the name "Chemical Waste Management" (CWM).

The landfill, Municipal Solid Waste (MSW)

A landfill that has been permitted by a state regulatory agency to accept municipal solid waste. This type of landfilling must have properties and design features specific to this type of landfill that has been established by the state regulatory agency.

Landfill footprint

Parcels of land that are designated and permitted to perform landfilling activities. This would include the entrance, staging area, buffer area and the area that will accept waste for disposal (the waste footprint area).

Leachate

Liquids that have come in contact with waste. Leachate accumulates in the waste footprint of the landfill. Leachate levels within the landfill must be monitored and cannot exceed state regulatory agency established levels. Depending upon the site, there are different ways to handle collected leachate. Some of these include
1. Collecting it in tanks and periodically transporting it off-site for treatment and disposal;
2. Collecting it in evaporation ponds which allow it to naturally evaporate into the air;
3. Discharging it into the sewer system,
4. Re-circulating it back into the landfill to aid in the biodegradation of the waste.

Liner

A clay and/or synthetic protective layer that is placed on both the bottom and top of a landfill.

Materials Recovery Facility (MRF)

The line of business where recyclable material is processed, separated and sold. This is a facility where recyclable materials are sorted and processed for sale. This process includes separating recyclable materials (manually or by machine) according to type and baling or otherwise preparing the separated material for sale. Operating costs and revenues for MRF's are accounted for as a separate line of business.

Methane

A gas byproduct generated through natural decomposition of solid waste in landfills. This gas is monitored to maintain state regulatory agency levels. Accumulated gas is either burned off using a flare or is converted to energy by use of a gas plant.

Methane Gas Plant

A plant where methane gas (generated from decomposing solid waste) is collected and transported to a gas-processing facility at the landfill site. Once processed, the methane gas is sold directly to industrial users or to an Affiliate of WM to use as a fuel to power electricity generators.

Municipal Solid Waste (MSW)

"Regular" garbage from non-industrial sources, such as residential homes, restaurants, retail centers, and office buildings. Typical MSW includes paper, discarded food items, and other general discards. Green waste is considered MSW and includes yard clippings, leaves, trees, etc.

Post-closure

The period of time after a landfill is certified as closed by a state regulatory agency until WM has no further monitoring responsibility. Environmental and other regulations require the owner of the closed landfill to continue monitoring activities and general maintenance of the site for a specific period of time (generally 30 years).

Residential Customers

A segment of the collection business that is made up of single and multi-family dwellings.

Solid Waste

Special Waste

Any waste that requires special handling. Special waste is non-hazardous waste generally from an industrial generator and must be profiled to ensure that it does not contain elevated levels of potentially hazardous chemicals or materials.

Stoker

A grate system used to combust refuse in a controlled fashion.

Subtitle D

The Federal rules and regulations that govern the environmental operations of MSW landfills.

Sump

The lowest area of a landfill into which leachate drains.

Tipping fee

A fee paid by anyone disposing of waste at a landfill. (also see Disposal Fee)

Transfer Station

A facility that consists of a large pad where residential and commercial collection vehicles empty the contents of their trucks. Another machinery (e.g. bulldozers) is then used to push the garbage into long-haul trailers for transport to disposal facilities.

Turbine Generator

A device that converts the heat energy of the steam from the boiler into electrical power.

Waste Stream

Specific types of waste found in customer's disposal (trash, cardboard, aluminum, metal, etc.) or a broader definition of disposal type. (e.g. MSW, C&D, Hazardous, etc.)

Waste-to-Energy Plant

These facilities consist of large incinerator-type operations where trash is incinerated (burned). The heat from this combustion process is converted into high-pressure steam, which can be used to generate electricity for sale to public utility companies under long-term contracts. The residue from the incineration process is disposed of in a Landfill.

Working Face

The section of the landfill where waste is being actively placed by disposal vehicles.