SOLID WASTE TERMS AND DEFINITIONS:
Terms Pertaining to the Solid Waste Industry
General Overview of Solid Waste Terms:
The following list of terms and definitions were compiled by different resources
throughout the Solid Waste Industry. The list of terms is not meant to be an all-inclusive
glossary of solid waste management terms. Nor is it meant to provide precise legal
definitions for these terms and should not be referred to for that purpose. Many States
and Provinces have established their own definitions as part of their solid waste
regulatory programs and it would have been impossible and counterproductive to
attempt to reflect all the differences and variations that exist. For the most part, the
terms have been defined to be consistent with (though not necessarily identical to) the
US Federal EPA definitions where such definitions exist.
The purpose of this compilation is to attempt to improve an understanding of solid waste
management terminology and to help residents navigate through some complex and
new ideas and concepts.
Aerobic Digestion A&WM RCRA
Anaerobic Digestion Canadian Compost Recycled Material
Biodegradable CARI-ACIR Recycling
Bioreactor Landfill CMRA Resource Recovery
Carbone Decision EIA Reuse
CESQG Enviro. Canada Sanitary Landfill
Closure EPA Small Quantity
Compactors GRRN Generator
Composting ISRI Solid Waste
Corrective Action ISWA Solid Waste Disposal
Cover (or cap) IWSA Solid Waste
Dioxin OSHA Management
Diversion Rate MWMA Source Reduction
Drop-Off Center NEMA Source Separation
EIS NRC Subtitle C
Energy Recovery NSWMA Subtitle D
Enterprise Fund STMC SWANA Certified
Environmental Justice SWANA TCLP
Ergonomic Injuries USCC Tipping Fee
Financial Assurance WASTEC Transfer Station
Flow Control PAYT Waste Sources
Groundwater PET and Types (partial)
Monitoring Post Closure Care Agricultural
Heavy Metals Privatization Bulky
HDPE Products of C&D
Incinerator Combustion Combustible
Mass burn Product Stewardship Commercial
RDF Publications (partial) E Waste
Incinerator Ash American Waste Food
Bottom Digest Garbage
Fly Biocycle Green
Integrated Solid Waste E-News Hazardous
Management The Hauler Household
Landfill Gas MSW Management HHW
Leachate MSW Solutions Industrial
Liner Public Works Institutional
Clay Journal Medical
Synthetic Recycling Product Municipal
Composite News Organic
Managed Competition Resource Recycling Sewage Sludge
MOLO Solid Waste Digest Sharps
MRF Solid Waste & Special
Municipal Solid Waste Recycling WASTECON
Landfill Waste Age Waste Expo
NIMBY Waste Management Waste Exchange
Organizations (partial) World Waste Reduction
ALMR Waste News Waste Screening
APWA Pyrolysis Waste-to-Energy
ASTSWMO Rail haul Zero Waste
Aerobic Digestion: This is the type of waste degradation that takes place in an aerated
compost pile. Organic wastes (e.g. food, plant and vegetable waste) are decomposed
by microorganisms and bacteria in the presence of oxygen. Carbon dioxide gas and
heat are released in the process. The remaining solid materials (compost) can be used
as a soil amendment.
Anaerobic Digestion: This is the type of waste degradation that takes place deep in a
landfill. Organic wastes (e.g. food, plant and vegetable waste) are decomposed by
microorganisms and bacteria in the absence of oxygen. Methane gas is released in the
process and can be collected and used as a fuel. The remaining solid material is
relatively inert and if excavated and processed may be able to be used as a soil
Biodegradable (or biologically degradable): Organic waste materials that are
capable of being degraded biologically by microorganisms and bacteria. Paper, wood,
food and plants are biodegradable; metals, glass and most plastics are not.
Bioreactor Landfill: A landfill where liquid is added and recirculated in a controlled
fashion in order to accelerate or enhance biological degradation of the waste.
Carbone Decision: Refers to a 1994 U.S. Supreme Court decision in the case C&A
Carbone Inc. v. Town of Clarkson. The Supreme Court overturned a local ordinance
that required that all solid waste within Town of Clarkson be processed at town-
designated privately owned transfer station. The Court found that the ordinance
discriminated against interstate commerce.
CESQG: Pronounced SEE SQUEEGY refers to Conditionally Exempt Small Quantity
Generators, which are facilities that produce less than 100 kg. (220 lbs.) of hazardous
waste (or less than 1 kg. of acutely hazardous waste) per calendar month. CESQGs are
exempt from many of the requirements for hazardous waste generators providing they
comply with certain conditions specified in the RCRA Subtitle C regulations.
Closure: The process of closing and ceasing operations at a solid waste management
facility in order to ensure protection of human health and the environment in the future.
Compactors: Are machines that reduces the volume of solid waste by crushing,
compression or compaction. A landfill compactor is a weighted vehicle equipped with
a blade and cleated metal wheels that rolls over and compacts solid waste. A
compactor collection truck uses a pneumatic ram to compact and push wastes into
the main body of the truck. Stationary compactors compress and compact wastes into
a container or bale.
Composting: Refers to the process of decomposition or decay of organic wastes,
such as leaves, food, paper and sometimes mixed municipal solid waste. Composting
usually takes place under aerobic conditions in an open pile or windrow or in a tank or
container (in-vessel composting). The end product of composting is a humus-like
material that can be added to soils to increase soil fertility, aeration and nutrient
Corrective Action: Refers to actions taken to investigate and cleanup contamination
from solid waste management facilities.
Cover (or Cap): Refers to material that is used to cover solid waste in a sanitary landfill.
Daily cover is soil or other material used to cover the open part of the landfill at the end
of an operating day. Alternative daily cover (ADC) refers to alternative materials to soil
such as tarps, foams, vegetative waste, and ash. The final cover or cap refers to layers
of impermeable materials installed over the top of a closed landfill to minimize the
infiltration of rainwater and the production of leachate. Final covers include layers of
compacted clay, drainage materials, topsoil and vegetation.
Dioxin: Dioxin refers to a group of chemical compounds that share certain similar
chemical structures and biological characteristics. Studies have shown that exposure to
dioxin at high enough levels may cause a number of adverse health effects. Dioxin can
be emitted when burning solid waste if there is incomplete combustion and inadequate
air pollution control devices. Federal air quality standards for municipal solid waste-to-
energy facilities establish very stringent emission limits for dioxin.
Diversion Rate: Is generally referred to as the amount of solid waste that is diverted
from disposal facilities through resource recovery and recycling.
Drop-Off Center: A method of collecting recyclable or compostable waste materials in
which the materials are taken by individuals to collection sites and deposited in
EIS: Environmental Impact Statement, a document that identifies and analyzes in detail
the environmental impacts of a proposed action. State, Provincial and Federal laws
require the preparation of an EIS prior to the construction of various facilities including
solid waste facilities.
Energy Recovery: Generally refers to the recovery of energy from solid waste by
burning it and using the heat to produce steam for direct use or for the generation of
electricity. Energy recovery also includes the use of landfill gas as a fuel and chemical,
thermal and biological processes that convert solid waste into liquid or gaseous fuels.
Enterprise Fund: A self-supporting method of funding solid waste operations through
revenues generated from charges and fees for various services.
Environmental Justice: Refers to the fair distribution of environmental risks across
socioeconomic and racial groups. From a solid waste perspective, environmental justice
concerns arise when solid waste management facilities are perceived to be located
predominantly in areas with minority or lower income populations.
Ergonomic Injuries: Are injuries that affect the musculoskeletal system. There are a
number of ergonomic injuries that can occur with jobs that involve repetitive motion,
heavy lifting, forceful exertion, contact stress, vibration, awkward posture, and rapid
hand and wrist movement. Solid waste management operations should put in place
training programs and workplace controls to reduce ergonomic injuries.
Financial Assurance: Refers to regulatory requirements that are designed to ensure
those solid waste facility owners will have the financial resources to pay for closure,
post-closure, and corrective action costs.
Flow Control: Refers to a situation where waste collectors are required or provided
incentives to take collected solid waste to a landfill, transfer station, materials recovery
facility (MRF) or other solid waste management facility that has been designated by local
government officials. Flow Control can be implemented in several different ways:
through local ordinances (although this option has been significantly restricted by the
Carbone Decision), through requirements placed in contracts or franchises for collection
services, or as economic flow control where a local government creates economic
incentives to take wastes to a designated facility.
Groundwater Monitoring: Refers to the sampling and analysis of ground water for the
purpose of detecting the release of contamination from a solid waste management
Heavy Metals: Are trace metals that are sometimes found in the emissions from solid
waste combustion units or in leachate. Heavy metals include mercury, chromium, lead,
chromium and other metals.
HDPE: High-Density Polyethylene, a plastic used to make a variety of products
including plastic milk jugs and landfill liners. Some HDPE containers can be identified
by the number 2 stamp inside the recycling arrows on the container.
Incinerator: An enclosed device for controlled combustion of solid waste. There are
several different types of incinerators. Mass burn units burn mixed solid waste with
little or no prior separation. RDF (Refuse Derived Fuel) units separate combustible
wastes from noncombustible wastes prior to combustion.
Incinerator Ash: The noncombustible residue remaining after the incineration of solid
waste. Bottom ash is ash that falls to the bottom of the combustion chamber and is
removed mechanically. Fly ash is particles of ash that are entrained in the exhaust
gases during combustion solid wastes in an incinerator. In modern incinerators fly ash
particles are removed from the combustion gases prior to exhaust to the atmosphere.
Integrated Solid Waste Management: A systematic approach to the management of
solid waste that combines and integrates source reduction, reuse, recycling, composting,
energy recovery and landfilling in order to conserve and recover resources and dispose
of solid waste in a manner that protects human health and the environment.
Landfill Gas: Is the gas that is produced when organic waste materials naturally
decompose in a municipal solid waste landfill. Landfill gas is approximately 50 percent
methane, the primary component of natural gas, and 50 percent carbon dioxide. Landfill
gas can be collected and used as a fuel for heating or generating electricity.
Leachate: Is liquid, which often contains suspended or dissolved waste materials
that has percolated through or drained from solid waste. Basically, leachate is water that
comes into contact with garbage.
Liner: A layer of natural or synthetic material, beneath and on the sides of a landfill that
restricts the downward or lateral escape of leachate. Clay liners can be constructed
from tightly compacted clay soils. Synthetic liners are constructed from plastic
membranes (geomembranes). Composite liners combine layers of both synthetic
liners and compacted clay components.
Managed Competition: Refers to a process where municipal or public sector solid
waste departments are allowed to submit proposals or bids in competition with private
sector solid waste companies in response to a publicly tendered service contract.
Managed competition could be applied to any municipal solid waste service (or any other
municipal service) but generally has been applied to solid waste collection services.
MOLO: Manager of Landfill Operations, one of SWANA’s certification disciplines (see
MRF: Materials Recovery Facility (pronounced murf), a facility where recyclable
materials are separated from solid waste and processed for sale to various markets.
Municipal Solid Waste Landfill: Is defined as a sanitary landfill that receives
household waste. A municipal solid waste landfill may also receive other types of non-
hazardous wastes, such as commercial solid waste and nonhazardous industrial
wastes. Municipal solid waste landfills in the U.S are required to meet the criteria
established under Subtitle D of RCRA. These criteria ensure that such landfills are
designed and operated to protect human health and the environment and establish
requirements in seven areas: location, operation, design, ground water monitoring,
corrective action, closure and post-closure, and financial assurance.
NIMBY: Not in My Backyard refers to political opposition to the establishment of solid
waste management facilities in a jurisdiction.
Organizations (partial list)
ALMR: The Association of Lighting and Mercury Recyclers
APWA: The American Public Works Association
ASTSWMO: The Association of State and Territorial Solid Waste Management
A&WM: The Air and Waste Management Association
Canadian Compost Association
CARI-ACIR: Canadian Association of Recycling Industries
CMRA: The Construction Materials Recycling Association
EIA: The Environmental Industries Association
EPA: The U.S. Environmental Protection Agency
GRRN: The Grassroots Recycling Network
ISRI: The Institute of Scrap Recycling Industries
ISWA: The International solid Waste Association
IWSA: The Integrated Waste Services Association
OSHA: The Occupational Safety and Health Administration
MWMA: The Municipal Waste Management Association
NEMA: The National Electrical Manufacturers Association
NRC: The National Recycling Coalition
NSWMA: The National Solid Waste Management Association
STMC: The Scrap Tire Management Council
SWANA: The Solid Waste Association of North America
USCC: The US Composting Council
WASTEC: The Waste Equipment Technology Association.
PAYT: Pay as You Throw refers to charge and fee systems where waste generators are
charged for solid waste collection based on the volume or weight of the solid waste
collected. The purpose is to provide an economic incentive to reduce waste generation
or to separate and recycle waste materials.
PET: Polyethylene Terephthalate is a plastic commonly used to make plastic soft drink
bottles and other containers and products. Some PET containers can be identified by
the number 1 stamp inside the recycling arrows stamped on the container.
Post Closure Care: Refers to activities during the period after closure of a solid waste
disposal facility where the facility owner is required to carry out monitoring, maintenance
and corrective action in order contain waste materials and to detect, prevent or respond
to the release of waste materials.
Privatization: Refers to the use of the private sector in providing solid waste
management services. Privatization can take several different forms including complete
private ownership and operation, contracts or franchise agreements with local
governments to provide services, or contract operation of facilities or equipment owned
by the public sector.
Products of Combustion: The gases and particulates that result from the combustion
of solid waste.
Product Stewardship: Product stewardship is a product-centered approach that calls
on all those in the product life cycle -- manufacturers, retailers, users and waste
managers -- to share responsibility and costs for reducing the adverse environmental
impacts of products. From a solid waste management perspective, product stewardship
involves the actions taken to improve the design and manufacture of products to
facilitate either their reuse, recycling or disposal, as well as actions to establish
programs to collect, process and reuse or recycle products when they are discarded.
Publications (partial list)
American Waste Diges: Solid waste products and information,
Biocycle: Journal of composting and organic recycling,
E News: SWANA’s Monthly Electronic Newsletter,
Hauler Magazine: Solid waste equipment catalog,
MSW Management: SWANA’s Official Journal for municipal solid waste
MSW Solutions: SWANA’s Monthly Membership Newsletter,
Public Works Journal: Information on solid waste and public works issues,
Recycling Product News: Recycling equipment,
Resource Recycling: Recycling and composting journal,
Solid Waste and Recycling: Canadian solid waste issues,
Solid Waste Digest: Regional and state-wide volume and pricing information,
Waste Age: Business magazine for the waste industry,
Waste Management World: ISWA’s Official Magazine, international coverage,
Waste News: Information for businesses that generate and manage wastes.
Pyrolysis: The thermal and chemical decomposition of organic waste in a furnace
operated without sufficient oxygen to allow combustion. The products resulting from
pyrolysis can be combustible gases, oils, char and mineral matter.
Rail Haul: Transporting solid waste (generally long distances) by railroad.
RCRA: Pronounced WRECK RAA, refers to the Resource Conservation and Recovery
Act, the major U.S. Federal Legislation first passed in 1976, and amended several times,
that governs the management of solid and hazardous waste in the U.S.
Recycled Material: A material separated from solid waste that has been processed and
recovered as a usable product or material.
Recycling: Recycling involves the separation and collection of wastes, their
subsequent transformation or remanufacture into usable products or materials, and the
use of products made from recycled materials.
Resource Recovery: A general term used to describe the recovery of materials or
energy from solid waste. Resource recovery encompasses, recycling, reuse,
composting and energy recovery.
Reuse: The use of a product more than once in its same form for the same or different
purpose. Examples include refilling beverage bottles that have been returned a bottling
company or using scrap tires as dock bumpers.
Sanitary Landfill: An engineered method of disposing of solid waste on the land under
regulatory control and in a manner that protects human health and the environment.
Also see Municipal Solid Waste Landfill.
Small Quantity Generator: Pronounced SQEEGY, refers to facilities that generate very
small quantities of hazardous waste e.g. between 100 kg. (220 lbs.) and 1000 kg.
(2,200 lbs.) of hazardous waste per calendar month. The regulatory requirements for
small quantity generators are less stringent the requirements for facilities that generate
larger quantities of hazardous waste.
Solid Waste: Is defined in RCRA to include any garbage, refuse, sludge, and other
discarded material, including solid, liquid, semisolid, or contained gaseous material,
resulting from industrial, commercial, mining, and agricultural operations and from
community activities. RCRA also excludes certain materials from the definition of solid
Solid Waste Disposal: Is defined in RCRA as the discharge, deposit, injection,
dumping, spilling, leaking or placing of solid waste on or in the land or water.
Solid Waste Management: Is a term used to describe the planned and organized
management of solid waste in an environmentally and economically sound manner.
Solid waste management encompasses management of the generation, storage,
collection, transfer, transportation, processing, reuse, recycling, incineration, energy
recover and landfilling of solid waste. It includes all administrative, financial,
educational, environmental, legal, planning, marketing and operational aspects of the
management of solid wastes.
Source Reduction: Actions taken to reduce the quantity or toxicity of wastes that are
produced. Source reduction is accomplished by redesigning products so that less
wastes or less toxic wastes are produced when the product is discarded or by reducing
consumption of certain products that become wastes. Also called Waste Reduction.
Source Separation: Sorting and separating various waste materials from each other by
the waste generator so these materials can be separately collected for recycling or
composting. Examples include separating newspapers, glass bottles, metal cans,
plastic containers, corrugated cardboard, office papers and lawn and garden wastes.
Subtitle C: The subtitle or section of RCRA that authorizes U.S. EPA to establish
regulations regarding the management of hazardous waste.
Subtitle D: The subtitle or section of RCRA that deals with the management of
municipal solid waste and authorizes U.S. EPA to establish criteria for municipal solid
waste landfills that ensure that such landfills are designed and operated to protect
human health and the environment.
Superfund: The common name for the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA), the U.S. Federal law that authorizes EPA to
clean up uncontrolled or abandoned hazardous waste sites and respond to accidents,
spills and other emergency releases of hazardous substances. CERCLA provides EPA
with enforcement authority to ensure that responsible parties pay the cleanup costs.
Superfund refers to the entire CERCLA program as well as to the trust fund established
to fund cleanup of contaminated sites.
SWANA Certified: Designates a solid waste professional who meets SWANA’s
eligibility requirements for education and experience, and who has passed one of
SWANA’s Certification Exams for a particular solid waste management discipline.
SWANA currently offers Certification in seven disciplines:
• Management of Collection Systems,
• Management of Composting Programs,
• Management of Construction and Demolition Materials,
• Management of Recycling Systems,
• Management of Landfill Operations,
• Management of Transfer Stations and
• Principles of Management of Municipal Solid Waste Systems.
TCLP: The Toxicity Characteristic Leaching Procedure, a lab procedure designed to
determine whether a solid waste is a hazardous waste because it leaches releases toxic
Tipping Fee: The fee charged for accepting solid waste at a solid waste facility (e.g.
transfer station, incinerator, MRF or landfill.)
Transfer Station: A facility that receives and consolidates solid waste from collection
trucks and other vehicles and loads the wastes onto tractor trailers, railcars or barges for
long-haul transport to a distant facility.
Waste Sources and Types (partial list)
Agricultural Wastes: Crop residues and animal manures resulting from
Bulky Wastes: Large discarded materials such as appliances, furniture,
automobile parts, large branches and tree stumps.
C&D Debris: Solid wastes resulting from the of construction and demolition
(C&D) waste materials of buildings and other structures. C&D debris generally
includes materials such as metals, wood, gypsum, asphalt shingles, roofing,
concrete, rocks, rubble, soil, paper, plastics and glass.
Combustible Waste: Solid wastes that will burn such as waste paper,
cardboard, wood, plastics, textiles and leaves.
Commercial Waste: Solid waste from businesses, office buildings, stores,
markets and institutional facilities.
E-Waste: Electronic waste refers to discarded electronic equipment including
computers, monitors, printers, TVs, stereo systems and VCRs.
Food Waste: Animal and vegetable materials resulting from the handling and
preparation of foods.
Garbage: A generic and somewhat antiquated term for solid waste.
Green Waste: Grass clippings, shrub and tree cuttings and other solid wastes
resulting from lawn care and gardening.
Hazardous Waste: Hazardous wastes are solid wastes with properties that
make them dangerous or capable of having a harmful effect on human health
and the environment. Under RCRA, hazardous wastes are specifically defined as
wastes that exhibit a specific characteristic (toxicity, flammability, ignitability or
infectious) or are specifically listed as a hazardous waste in the Subtitle C
Household Waste: Solid waste originating from homes and residences. Also
called residential or domestic waste.
HHW, Household Hazardous Waste: Solid wastes from homes and residences
that have properties that make them dangerous or capable of having a harmful
effect on human health and the environment.
Industrial Waste: Solid waste originating from industrial processes or
Institutional Waste: Solid waste originating from schools, universities, hospitals
and other institutions.
Medical Waste: Wastes from hospital and health care facilities and include
infectious materials, human pathological wastes, human blood products and
used sharps. Also referred to as pathological or infectious wastes.
Municipal Waste: Solid waste from residential, commercial sources and similar
wastes from industrial and institutional sources.
Organic Wastes: Waste materials, containing carbon compounds that are
capable of being degraded biologically into a relatively inert material. Paper
wastes, food wastes, wood wastes, lawn and garden wastes, and plant wastes
are organic wastes. Metals and glass are not. Plastics contain carbon
compounds and are theoretically organic in nature but most plastic wastes are
not readily biodegradable.
Sewage Sludge: A solid, semisolid, or liquid wastes generated from a
wastewater treatment plant. Biosolids is the politically correct term for sewage
Sharps: Discarded needles and syringes.
Special Wastes: Is a term that refers to solid wastes that are often separated
from mixed municipal wastes for special handling or management. Special
wastes include household hazardous waste, tires, batteries, discarded
pesticides, discarded electronic equipment and bulky wastes.
WASTECON®: SWANA’s Annual Conference and Solid Waste Exposition
Waste Expo: The other annual solid waste conference and equipment exposition.
Waste Exchange: An organization that arranges for solid wastes from various
generators or industries to be recycled or reused by others.
Waste Screening: Refers to a program of monitoring and inspecting incoming waste
loads at a solid waste management facility in order to screen out wastes that are
prohibited or otherwise unacceptable.
Waste-to-Energy: Refers to the controlled combustion of solid wastes in modern
furnaces, with state-of-the-art pollution controls, and the recovery of energy in the form
of steam or electricity.
Zero Waste: Refers to efforts to reduce solid waste generation waste to zero, or as
close to zero as possible, by minimizing excess consumption and maximizing the
recovery of wastes through recycling and composting.