Frequently Used Terms and Abbreviations

Acid Gas

Any gas or gaseous mixture that forms an acidic compound when mixed with water, such as hydrogen chloride (HCI), hydrogen fluoride (HF) and sulphur dioxide (SO2).

Air Cooled Condenser (ACC)

Air Cooled Condensers condense exhaust steam from the steam turbine back into waster that is retuned to the boiler without water loss.

Air Emissions

From stationary sources, the release or discharge of a pollutant from a facility or operation into the surrounding air, either by means of a stack or as a fugitive dust, mist or vapour.

Air Pollution Control (APC) Equipment

Specialized equipment used to cool, collect and clean the combustion gases before they are released into the atmosphere. This equipment operates under stringent environmental regulatory standards.

Ambient Air

Refers to the outdoor air in the surrounding environment. Its content and quality are directly affected by the day-to-day activities of humans (e.g. industry, vehicle pollution, etc.) and natural events (e.g. forest fires, volcanic activity, etc.).


The non-combustible fraction that remains after combustion of material. See also bottom ash and fly ash.


A component of the air pollution control equipment consisting of a series of fabric filters through which flue gases are passed to remove particulates prior to release to the atmosphere.

Base Load Power/Energy

The delivery of dependable power over a given period at a constant rate, day and night, seven days a week (e.g. 24/7) as opposed to peak load power that is generated intermittently to supplement base load power during periods of high demand.

Bottom Ash

Ash that remains on the stoker grate and does not become entrained in the flue gas stream.

British Thermal Unit (BTU)

A traditional unit of energy (heat) equal to the amount of heat required to raise the temperature of one pound of water by one-degree Fahrenheit at sea level. A BTU is equivalent to approximately 1.06 kilojoules or 0.25 kilocalories.

Calorific Value

The amount of energy (heat) produced by a specific material type when combusted under specific conditions. Calorific Value is usually expressed in Calories or Joules per kilogram (e.g. Cal/KG or J/Kg) or BTU per pound (e.g. BTU/lb).

Certificate of Approval or Environmental Compliance (ECA)

An approval issued by the Ministry of the Environment and Climate Change (MOECC) for the operation of a waste disposal site. In 2011, a multi-media Certificate of Approval (#7306-8FDKNX) for waste, air, noise, and storm water was issued by the MOECC for the Durham York Energy Centre. The MOECC now refers to Certificates of Approval as Environmental Compliance Approvals or ECAs.


The simultaneous generation of thermal energy (steam or hot water) and electrical energy from the same fuel source.


Burning, or rapid oxidation, of waste or other fuel material accompanied by the release of exhaust gases and energy in the form of heat and light.

Combustion Chamber

 The section of the boiler where waste material is dried, volatized and combusted.

Continuous Emissions Monitoring System (CEMS)

The equipment required to analyze, measure, and provided, on a continuous basis, a permanent record of emissions as established in the air emission monitoring plan to ensure compliance with air quality guidelines.

Cover Material

Material, with natural or synthetic used to cover compacted waste in a sanitary landfill to reduce waste filtration, control odours, det animals and improve appearance. Bottom ash from the Durham York Energy Centre will be used a landfill cover material, reducing the need for soil or other cover materials.


The final step in the management of waste, where waste is collected and moved to a permanent location (e.g. a landfill).

District Heating

A system for distributing heat generated in a centralized location for residential and commercial heating requirements such as space heating and water heating.


The management of waste materials by reduction, reuse, recycling, and composting that results in waste being kept out of landfill.

Diversion rate

The percentage of waste materials diverted from traditional disposal (e.g. landfilling) through reduce, reuse and recycling programs and activities.

Dry Lime Reactor

A component of the air pollution control equipment that uses lime to neutralize acidic chemicals compounds (e.g. hydrogen chloride, hydrogen fluoride and sulphur dioxide) from flue gas before they reach the atmosphere.

Durham York Energy Centre (DYEC)

An authorized municipal non-hazardous waste facility that produces energy from the combustion of residential garbage. The DYEC safely processes 140,000 tonnes per year of non-hazardous residential garbage that remains after maximizing waste diversion programs – reducing, reusing, recycling and composting – in Durham and York Regions.

Durham York Residual Waste Study

The Durham York Residual Waste Study was a joint initiative between Durham and York Regions to work together to find a way to manage solid waste remaining after at-source diversion.

Ecological/Environmental Risk Assessment (ERA)

A scientific method used to examine the nature and magnitude of risks from the exposure of plants and animals to contaminants in the environment.


The economizer reclaims heat from the combustion gases to preheat water, which increases overall energy efficiency of the boiler in the Energy from Waste process.


Technically, all solid, liquid, or gaseous discharges from a processing facility, but commonly used to refer to gaseous emissions (with solids refereed to as residue and liquids as effluent).

Energy from Waste (EFW)

The recovery of energy in the form of steam heat and/or electricity from the thermal treatment of waste.

Energy Recovery

Capturing energy contained in waste materials for a beneficial use such as producing electricity or industrial heating.

Environmental Assessment (EA)

A systematic process that is conducted in accordance with applicable regulations or guidelines in order to assess the effects of a proposed undertaking on the environment and included identification of mitigation, remedial, monitoring and/or compensatory measures. In 2005, Durham and York Regions initiated a join EA (see Durham York Residual Waste Study) that included extensive public consultation to determine the “preferred alternative” for managing residual waste considering social, environmental and economic factors.

Environmental Protection Act (EPA)

An Ontario Act that provided for the protection and conservation of the natural environment.

Environmental Standard

A policy, regulation, or guideline that establishes a measurable performance standard to limit the effect of human activity upon the environment.

Evaporative Cooling Tower

A component of the air pollution control equipment that reduces flue gas temperature and increase flue gas humidity to help ensure optimal conditions for acid gas neutralization reactions.


The input material to be processed at a waste management facility.

Ferrous Metal

Metals derived from iron or steel. At the Durham York Energy Centre, ferrous metals are recovered for recycling after the combustion process through magnetic separation.

Flue Gas

The exhaust gases resulting from combustion.

Fly Ash

The airborne ash resulting from burning material in the combustion chamber. Fly ash is suspended in the flue gas and is removed by air pollution control equipment.

Fossil Fuels

A fuel (such as coal, oil, or natural gas) that is formed in the earth from dead plants or animals.

Fugitive Emissions

Unintended emissions associated with garbage, fly ash and bottom ash transport and handling that are not captured by a control system.


A mechanical device used to grasp, hold and release materials, such as waste.

Grapple Feeding

A process in which material, such as waste, is fed into a processing system using a grapple.

Greenhouse Gas (GHG)

Gases that trap heat in the atmosphere by absorbing and emitting infrared radiation are called greenhouse gases (e.g. carbon dioxide, methane, nitrous oxide and fluorinated gases.)

Hazardous Waste

Materials that can pose a hazard to human health and/or the environment when improperly managed. Hazardous waste as defined in Ontario Regulation 347 included waste that is toxic, ignitable, corrosive, reactive, radioactive or pathological (human or animal remains), but excluded small quantities of these materials (less than 5 kg) mixed with other non-hazardous wastes.

Household Hazardous Waste (HHW)

Common hazardous products used and disposed of b households (e.g. paints, stains, fuels, lubricants, varnishes, solvents, pesticides etc.). It includes products containing volatile chemicals that can catch fire, react or explode, or that are corrosive or toxic.


A thermal treatment process whereby waste is burned at a high temperature in a controlled environment to reduce the total volume of waste requiring disposal.


A furnace used for burning waste under controlled conditions.

Industrial, Commercial & Institutional (IC&I) Waste

Wastes generated by industrial, commercial and institutional sectors. IC&I Waste that is not managed through the Regions' municipal collection and diversion programs will not be accepted at the Durham York Energy Centre.

Integrated Solid Waste Management (ISWM)

A comprehensive waste prevention, recycling, composting and disposal system that maximizes the resource value of the waste material while protecting the health and safety of our community and environment.

Magnetic Separation

Use of magnets to separate ferrous materials (containing iron and steel) from other waste materials.

Mass Burn Incineration

>A waste incineration process where the waste is burned in a large, custom manufactured furnace with no significant pre-processing of the raw waste.

Materials Recovery (or Recycling) Facility (MRF)

A recycling facility that separates recyclable materials into individual product streams (e.g. newsprint, cardboard, plastics, metals, glass, etc.) for shipment to end markets that use them to produce new products.

Mechanical Separation

The physical separation of wastes by material type, size or density using various types of mechanical equipment.

Ministry of the Environment and Climate Change (MOECC)

The Province of Ontario's regulatory agency that serves to protect Ontario's environment. The MOECC monitors pollution and restoration trends in Ontario and uses that information to develop environmental laws, regulations, standards, policies, programs, and guidelines.


Measures taken to reduce adverse impacts on the environment.


The act of conducting periodic or continuous surveillance and testing to determine that a project, process or product conforms to regulatory requirements and emissions levels.

National Pollutant Release Inventory (NPRI)

A legislated, nation-wide, publicly accessible inventory of the annual quantities of specific pollutants released to the environment, disposed and recycled by all sectors in Canada.

Negative Pressure

Refers to a situation whereby an enclosed space has lower pressure than its surroundings. As a result, air moves from areas of higher pressure to areas of lower pressure. At the Durham York Energy Centre, negative pressure is used to contain odours inside the building by drawing outside air into the building and using the odourous air in the combustion process thereby capturing and destroying odours.

Non-Combustible Waste

Waste that cannot be burned (e.g. stone, glass and metals)

Non-Continuous Monitoring

Collection of samples by equipment in the field at discrete periods of time that are sent to a certified laboratory for analysis.

Non-Ferrous Metals

Non-magnetic metals including aluminum, brass, copper, nickel, lead, and zinc, as well as presious metals like gold and silver that do not contain iron. At the Durham York Energy Centre, non-ferrous metals are recovered for recycling after the combustion process through the use of eddy current separators.

Ontario Guideline A-7

Air emission guidelines developed by the Ministry of the Environment and Climate Change (MOECC) to govern combustion and air pollution control requirements for new municipal waste incinerators and Energy from Waste (EFW) facilities in the Province of Ontario.

Ontario Regulation 347 (O.Reg.347)

A regulation under the Environmental Protection Act that specifies standards and approval requirements for waste management sites and systems in Ontario.

Particulate Matter

Particles of a solid or liquid that are suspended in the air.

Point of Impingement (POI)

A point of impingement is any point at which a contaminant contacts the ground or a building. Under Ontario law, average contaminant concentrations at various points of impingement are calculated using approved mathematical models and compared to air quality standards and guidelines.

Powdered Activated Carbon (PAC)

Used in air pollution control systems to control heavy metals and dioxins/furans. PAC has a large surface area which allows the contaminants to adsorb (e.g. stick to) the carbon.


A material used in the fly ash conditioning process along with Portland cement to bind or stabilize materials contained within the fly ash.

Public Information Session

In accordance with the Durham York Energy Centre Community Communication Plan, a public information session forum involving informational displays, and/or presentations and provides the public with the opportunity to discuss a particular aspect or all aspects of waste management.

Public Meeting

In accordance with the Durham York Energy Centre Community Communication Plan, a public meeting is a public forum providing the opportunity to discuss the design, consultation, and operation of the EFW undertaking. The format for public meetings may include, but not limited to: open houses, information sessions, workshops, meetings, and tours.


A person, plant or wildlife species that may be affected by exposure to a potential contaminant/pollutant released from a specific source(s).


Taking materials or items no longer suitable for their original use and processing them for use in some other manner.

Relative Accuracy Test Audit (RATA)

A procedure used to establish the ability of a Continuous Emissions Monitoring System (CEMS) to accurately measure and report a given pollutant concentration or emissions rate from a source ad to determine a bias in those measurements. For the Durham York Energy Centre (DYEC), A RATA is required for initial CEMS certification and must be performed annually thereafter during routine operation of the DYEC.

Residential Garbage

The portion of municipal solid waste generated by residences that remains after recyclable waste, organic waste and yard waste have been separated by residents.

Residential Waste

Municipal solid waste generated by residences including all categories of waste, both recyclable and non-recyclable.

Resource Recovery

The process of obtaining materials (e.g. metals) or energy from waste.

Reverse Osmosis (RO)

A method of water treatment that relies on a semi-permeable membrane to separate water from dissolved contaminants. An external force is used to reverse the normal osmotic process resulting in the solvent moving from a solution of higher concentration to one of lower concentration. At the Durham York Energy Centre, reverse osmosis is used to demineralize boiler water tor reduce formation of boiler scale.

Sanitary Landfill

An engineered facility designed and developed to contain and control non-hazardous solid waste and its emissions.


A component of the air pollution control equipment that removes pollutants by causing the pollutants to react with, or be trapped by water, chemical or other substances in the scrubbing device.

Selective Non-Catalytic Reduction (SNCR)

An air pollution control method that converts nitrogen oxide into elemental nitrogen and water by injecting a chemical reagent, typically urea, or another ammonia-based solution into the flue gas.

Solid Waste Management Hierarchy

The waste hierarchy ranks waste management options according to what is best for the environment. It is usually presented diagrammatically in the form of an inverted pyramid. Top priority is given to preventing waste generation in the first place. When waste is produced, precedence is given to preparing it for reuse, recycling, recovery, and last of all disposal.

Source Separation

A waste management practice, where waste generators sort their waste at the source to aid waste diversion. For example, Durham and York Region residents sort their waste into recyclable waste, organic waste, yard waste and garbage at their homes.

Source Testing

Non-continuous sampling and testing to measure emissions under normal operating conditions. In accordance with the Environmental Compliance Approval for the Durham York Energy Centre, source testing will be carried out on an annual basis and will follow the Ontario Source Testing Code protocols.


A tall vertical or pipe through which gases are discharged into the atmosphere.

Stoker grate

A mechanical device that transports waste material through the furnace and discharges the bottom ash into the ash management system. The stoker grate agitates the waste to promote air flow and good, complete combustion.

Thermal conversion/treatment

Any process where heat is used to treat waste (e.g. combustion or gasification)

Tipping floor

Unloading area for vehicles delivering waste to a waste facility.

Transfer Station

A facility where waste material is transferred from collection vehicles to larger trucks or rail cars for longer distance transport.

Turbine Generator

A device (e.g. rotary engine) that converts mechanical energy into electrical energy by pressure from water, steam, or air.


Pests or nuisance animals or insects, especially those that can spread diseases.

Very Low NOx (VLNTM)

The Durham York Energy Centre is equipped with a patented technology to reduce Nitrogen Oxides (NOx) referred to as the VLNTM process.

Waste Reduction

The first “R” in the solid waste hierarchy, waste reduction is intended to remove materials from the waste stream before they become a waste.

Waste-to-Energy (WTE)

The process of generating energy in the form of electricity and/or heat from incineration of waste. See Energy from Waste.

Zero Waste Water Discharge

The Durham York Energy Centre reuses all process water generated within the facility and there is no discharge of process water to the municipal sanitary sewer system.

Units of Measurement


m3 Cubic metre
Scf standard cubic foot


g gram
kg kilogram = 1 x 103 grams
mg milligram = 1 x 10-3 grams
µg microgram = 1 x 10-6 grams
ng nanogram = 1 x 10-9 grams
pg picogram = 1 x 10-12 grams
t metric tonne = 1 x 103 kg
kt kilotonne = 1 x 106 kg
lb pound 1 lb = 453.592 grams


W watt
KW kilowatt = 1 x 103 W
MW megawatt = 1 x 106 W


L litre
mL milliliter = 1 x 10-3 L
m3 cubic metre = 1 x 103 L
Rm3 or DSCm3 Dry standard cubic metre of flue gas corrected to standard conditions (25oC, 101.3 kPa, 11% O2) as specified in the Environmental Compliance Approval.


s second
min min
hr hour
w week
y year


As Arsenic
Cd Cadmium
Co Cobalt
Cr Chromium
Cu Copper
Hg Mercury
Mn Manganese
Ni Nickel
Pb Lead
Sb Antimony
Th Thallium
V Vanadium


CO Carbon Monoxide
CO2 Carbon Dioxide
CH4 Methane
HCI Hydrogen Chloride
HF Hydrogen Fluoride
TPM Total Particulate Matter
PM2.5 Particulate Matter Diameter <2.5 microns
NOx Nitrogen Oxides
N2O Nitrous Oxide
PCDDs Polychlorinated Dibenzodioxins
PCDFs Polychlorinated Dibenzofurans
SO2 Sulphur Dioxide
VOCs Volatile Organic Compounds


BTU British Thermal Unit
oC Temperature in degrees for Celsius
N/A not available
% per cent
cfm cubic feet per minute
ppmdv part per million by dry volume
ppmv part per million by volume
ppm part per million

Contact Us