Glossary of Terms

Aerated Static Pile (ASP) composting is a method of decomposing organic waste in large, static piles where air is supplied through perforated pipes or blowers to maintain aerobic conditions and accelerate composting.

Anaerobic decomposition is the breakdown of organic materials by microorganisms in the absence of oxygen, producing gases such as methane and carbon dioxide and leaving nutrient-rich residues.

An anaerobic digester is a system that breaks down organic materials, such as food waste, manure, or sewage sludge, in the absence of oxygen to produce biogas (mainly methane and carbon dioxide) and a nutrient-rich byproduct called digestate.

A bioreactor landfill is a type of landfill designed to accelerate the decomposition of organic waste by actively managing moisture, air, and sometimes temperature. This process enhances microbial activity, increases landfill gas production, and can reduce the time needed for waste stabilization compared to traditional landfills.

A bottle bill, also known as a container deposit law, is legislation that requires consumers to pay a small refundable deposit on beverage containers. The deposit is returned when the empty container is returned to a designated collection point for recycling or reuse.

Backyard composting is the process of decomposing organic waste, such as fruit and vegetable scraps, yard trimmings, and other biodegradable materials, in a designated compost bin or pile at home. The process produces nutrient-rich compost that can be used to improve soil health and reduce household waste sent to landfills.

Biodegradable refers to a substance or material that can be broken down naturally by microorganisms such as bacteria, fungi, and algae into simpler, non-toxic components like water, carbon dioxide, and biomass within a reasonable timeframe under natural environmental conditions.

Biodegradation is the natural process by which organic substances are broken down by microorganisms such as bacteria, fungi, or algae into simpler compounds, often resulting in water, carbon dioxide, and biomass.

Biodiversity refers to the variety and variability of life on Earth, including the diversity of species, ecosystems, and genetic variation within species. It is essential for ecosystem health, resilience, and the provision of ecosystem services.

Biogas is a renewable energy source produced by the anaerobic decomposition of organic materials, primarily composed of methane (CH₄) and carbon dioxide (CO₂).

Biomedical waste, also known as medical or clinical waste, refers to any waste generated during the diagnosis, treatment, or immunization of humans or animals. It includes materials such as used syringes, bandages, laboratory samples, and other substances that may be infectious or hazardous.

Bulky waste refers to large, oversized items that are not suitable for regular curbside collection, such as furniture, mattresses, large appliances, and carpets.

Commercial recycling and waste bins are containers designed for businesses, institutions, or multi-unit facilities to collect, sort, and store recyclables and waste before collection or processing. They come in various sizes, materials, and configurations to suit different program needs.

Composting facilities are specialized sites where organic waste, such as food scraps, yard trimmings, and other biodegradable materials, is collected and processed under controlled conditions to produce nutrient-rich compost. These facilities manage decomposition, control moisture and temperature, and ensure the end product is safe for agricultural or landscaping use.

A carbon footprint is the total amount of greenhouse gases (GHGs), primarily carbon dioxide (CO₂), emitted directly or indirectly by an individual, organization, product, or activity, usually measured in equivalent tons of CO₂.

A circular economy is an economic system designed to eliminate waste, keep materials and products in use, and regenerate natural systems.

Capacity is the maximum volume or amount that a container, bin, or system can hold or accommodate.

Climate change refers to long-term alterations in Earth's climate patterns, including temperature, precipitation, and weather events, primarily caused by human activities such as greenhouse gas emissions.

Closed-loop recycling is a process in which a product or material is collected, reprocessed, and used to make the same type of product, minimizing waste and the need for virgin resources.

Curbside collection is a waste management service where recyclable materials, compost, and garbage are collected directly from the curb or designated area outside homes or businesses.

Recycling contamination refers to non‑recyclable materials or improperly prepared recyclables that are mixed in with clean recyclable streams. This can include things like food residue in containers, plastic bags, hazardous waste, or items not accepted by the local recycling program. These contaminants degrade the quality of recyclable materials and can disrupt processing.

Diversion rate is the percentage of waste that is diverted from landfills or incineration through recycling, composting, or other recovery methods.

Dual-Stream Recycling is a collection system in which recyclables are separated into two distinct streams before collection. Typically, one bin or cart is used for paper and cardboard, and another for containers such as plastics, metals, and glass. These streams are collected separately and transported to a Materials Recovery Facility (MRF), where the materials are further processed and prepared for reuse.

• Diversion rate measures the percentage of total waste diverted from landfill or incineration through recycling, composting, or other recovery methods.

• Recycling rate measures the percentage of waste specifically sent for recycling, excluding other diversion methods like composting or energy recovery.

E‑waste (electrical and electronic waste) refers to discarded electrical and electronic equipment and its parts that have reached end of life and are no longer wanted or useful.

Earth Day, celebrated annually on April 22, promotes environmental awareness and inspires actions to protect the planet and adopt sustainable practices.

The Environmental Protection Agency (EPA) is an independent agency of the United States federal government responsible for protecting human health and the environment. It develops and enforces regulations, conducts research, and provides guidance on issues such as air and water quality, waste management, chemical safety, and pollution prevention.

Fossil fuels are natural energy sources formed from the remains of ancient plants and animals over millions of years. They include coal, oil, and natural gas, and are primarily used for electricity generation, transportation, and heating.

Food waste refers to edible food that is discarded, lost, or uneaten at any stage of the food supply chain, from production and processing to retail and consumption. It represents a loss of resources, including water, energy, and labor, and contributes to environmental impacts such as greenhouse gas emissions when disposed of in landfills.

Greenhouse gases (GHGs) are gases in Earth’s atmosphere that trap heat, contributing to the greenhouse effect and global warming. Common GHGs include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases.

Global warming is the long-term increase in Earth’s average surface temperature caused primarily by human activities, such as burning fossil fuels and deforestation.

The greenhouse effect is the process by which certain gases in the Earth’s atmosphere trap heat, warming the planet instead of allowing that energy to escape into space.

The Greenhouse Gas Protocol (GHG Protocol) is an internationally recognized framework for measuring, managing, and reporting greenhouse gas (GHG) emissions. Developed through a partnership between the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD), it provides standardized methodologies for organizations, governments, and businesses to account for emissions consistently and transparently.

A waste hauler is a company or service responsible for collecting, transporting, and disposing of waste or recyclable materials from residential, commercial, or industrial locations. Waste haulers may deliver materials to landfills, recycling facilities, composting sites, or other processing centers.

Hazardous waste is waste that poses substantial or potential threats to public health or the environment due to its chemical, physical, or biological properties.

In‑vessel composting is a method of composting in which organic waste is placed in a closed container, drum, silo or reactor where temperature, moisture and aeration are carefully managed to accelerate decomposition.

Incineration is the controlled combustion of waste materials at high temperatures to reduce their volume and mass. This process converts waste into ash, flue gases, and heat, which can sometimes be recovered for energy generation, but it also produces emissions that require careful management.

A landfill is a designated site for the controlled disposal of solid waste by burial. Modern landfills are engineered with liners, leachate collection systems, and gas management to minimize environmental impacts such as groundwater contamination, odors, and greenhouse gas emissions.

LEED® (Leadership in Energy and Environmental Design) is a globally recognized green building certification system developed by the U.S. Green Building Council (USGBC). It provides a framework for planning, designing, constructing, and operating buildings and communities with sustainability in mind, promoting energy efficiency, water conservation, responsible material use, healthy indoor environments, and thoughtful site strategies.

Materials are substances or components used to make products, structures, or goods. They can be natural, synthetic, or a combination of both and include metals, plastics, glass, wood, and textiles.

Microplastics are tiny plastic particles typically smaller than 5 millimeters in size, originating from the breakdown of larger plastic items or manufactured intentionally for products such as cosmetics and industrial abrasives. They are found in the environment, including oceans, freshwater systems, soil, and air. Microplastics are persistent, can accumulate in ecosystems, and may be ingested by wildlife, posing ecological and potential human health concerns.

A Material Recovery Facility (MRF) is a specialized plant where recyclable materials are collected, sorted, and processed for shipment to manufacturers. MRFs help separate paper, plastics, metals, and glass from mixed waste streams, preparing materials for recycling or resale.

Municipal Solid Waste (MSW) is the everyday waste generated by households, commercial establishments, institutions, and small businesses, including items such as paper, food scraps, plastics, metals, textiles, and packaging. It excludes industrial, hazardous, and medical waste.

The National Green Building Standard® (NGBS) is an ANSI approved standard for residential construction, remodeling, and land development. It sets performance criteria across six areas including lot design and development, resource efficiency, water efficiency, energy efficiency, indoor environmental quality, and building operation and maintenance, allowing projects to earn certification at Bronze, Silver, Gold, or Emerald levels.

The National Sword is a Chinese government policy introduced in 2018 that banned the import of most plastic waste and other solid waste with contamination above strict limits.

A Product Carbon Footprint (PCF) measures the total greenhouse gas (GHG) emissions associated with a product throughout its lifecycle, from raw material extraction, manufacturing, and transportation to use and end-of-life disposal or recycling. It is typically expressed in units of carbon dioxide equivalent (CO₂e) and helps businesses, consumers, and policymakers understand a product’s contribution to climate change.

Pay as you throw (PAYT), also known as unit based pricing, is a waste management system in which households and businesses are charged based on the amount of waste they discard rather than paying a fixed fee. The system encourages waste reduction, recycling, and composting by linking disposal costs directly to the quantity of garbage generated.

Polyethylene Terephthalate (PET) is a type of thermoplastic polymer widely used for beverage bottles, food containers, and synthetic fibers. It is lightweight, durable, and highly recyclable, making it a common material in municipal recycling programs.

Post-consumer waste, also known as post-consumer material, refers to products or packaging that have completed their intended use and have been discarded by consumers. It includes materials collected through recycling programs, such as used paper, plastics, metals, and glass.

Pre-consumer recycled content refers to materials that are diverted from the waste stream during the manufacturing process, before they are sold to consumers, and are reprocessed into new products. This includes scrap, trimmings, or defective products generated during production.

Recyclable materials are separated through mechanical, manual, and automated processes at materials recovery facilities to sort items like paper, plastics, metals, and glass for recycling.

Recycling affects climate change by reducing greenhouse gas emissions through decreased energy use, reduced resource extraction, and lower landfill contributions.

Recycled aggregates are construction materials, such as crushed concrete, asphalt, or masonry, that are recovered from demolition or construction waste and reused in new construction projects as a substitute for virgin aggregates.

The recycling rate is the percentage of total waste that is collected, processed, and converted into new materials instead of being sent to landfill or incineration. It measures the effectiveness of recycling systems and waste diversion efforts within a specific area, sector, or organization.

A redemption program is a system in which consumers return specific items (typically beverage containers) to receive a refund or deposit back based on the material’s recyclability.

Recycled content is the portion of a product’s material that comes from previously used, recovered, or reprocessed materials instead of virgin resources.

Recycled timber is wood that has been salvaged from deconstructed buildings, furniture, pallets, or other wooden products and repurposed for new construction, manufacturing, or creative projects.

Recycling is the process of collecting, sorting, and processing materials that would otherwise be discarded as waste and converting them into new products.

The Resource Conservation and Recovery Act (RCRA) is a United States federal law enacted in 1976 that governs the generation, transportation, treatment, storage, and disposal of solid and hazardous waste to protect human health and the environment.

Scope 1 emissions are direct greenhouse gas (GHG) emissions from sources that are owned or controlled by an organization. Examples include emissions from company-owned vehicles, on-site fuel combustion, and industrial processes. These emissions are part of a company’s total carbon footprint and are typically the easiest to measure and manage because they originate from operations under the organization’s direct control.

Scope 2 emissions are indirect greenhouse gas (GHG) emissions from the generation of purchased electricity, heat, or steam that an organization consumes. While the organization does not directly produce these emissions, they are a result of its energy use and are a key component of its overall carbon footprint.

Scope 3 emissions are indirect greenhouse gas (GHG) emissions that occur as a consequence of an organization’s activities but are generated from sources not owned or directly controlled by the organization. They include emissions across the value chain, such as those from purchased goods and services, transportation, product use, waste disposal, and business travel. Scope 3 typically represents the largest portion of a company’s total carbon footprint.

The Sustainable Development Goals (SDGs) are a set of 17 global goals established by the United Nations in 2015 to address social, economic, and environmental challenges by 2030.

Single-stream recycling is a collection system in which all recyclables such as paper, plastics, metals, glass, and cartons go into a single bin or cart. These mixed materials are collected by one truck and taken to a Materials Recovery Facility (MRF), where they are sorted into different commodity streams for further processing.

Source reduction is the practice of minimizing the amount of waste generated at its origin by using fewer materials, designing products to last longer, or improving production efficiency.

Sustainable development is the practice of meeting present needs without compromising the ability of future generations to meet their own needs, balancing environmental, social, and economic considerations.

A tipping fee (also known as a gate fee or disposal fee) is the charge levied by a waste processing facility such as a landfill, incinerator, or composting plant for accepting a given quantity of waste for disposal or processing, often calculated per ton or per load.

Upcycling is the process of transforming by-products, waste materials, or unwanted products into new items of greater value, whether that value is functional, aesthetic, or environmental. Unlike traditional recycling, which breaks materials down to reuse them, upcycling retains much of the original material and reimagines it into something more desirable or useful.

A waste audit is a process used to examine the types and quantities of waste generated in a specific location over a set period of time, helping identify how materials are being disposed of and where improvements can be made.

The waste hierarchy is a framework that ranks waste management strategies from most to least preferred, prioritizing actions such as preventing waste generation, reusing products, recycling materials, recovering energy from waste, and only as a last resort disposing of waste.

Waste-to-Energy (WTE) is the process of generating energy in the form of electricity or heat from the treatment and combustion of municipal solid waste (MSW) or other waste materials. WTE technologies convert materials that would otherwise be sent to landfills into a usable energy resource, reducing waste volume and supporting sustainable energy production.

Waste refers to any material, substance, or by-product that is discarded, no longer wanted, or has no immediate use or value. It includes items produced from human, industrial, or natural processes that are intended for disposal, recycling, or recovery.

Waste diversion refers to the practices and processes that redirect waste away from disposal in landfills (or incineration) and toward reuse, recycling, composting or other recovery methods. It involves keeping waste materials in productive use rather than simply discarding them.

Windrow composting is a method of aerobic composting in which organic materials are arranged in long, narrow piles called windrows that are regularly turned to maintain oxygen flow and promote microbial decomposition.

Wishcycling is the act of placing items in a recycling bin that are not recyclable, with the hope that they will be processed, even though they often contaminate the recycling stream.

Zero waste is a philosophy and strategy that aims to eliminate waste sent to landfills and incinerators by redesigning products and processes to maximize reuse, recycling, and recovery.