Glossary
Glossary
| blowdown | A blowdown is the act of releasing natural gas from a section of pipeline so work can be done safely. TransCanada employees will close several valves to isolate that section of the pipeline and then open a special blowdown valve to release any natural gas. |
| combined cycle | In a typical natural gas combined-cycle facility, electricity is generated combining the energy from two power generating cycles. Natural gas is burned in the gas turbine which turns an electricity generator. The hot exhaust from the gas turbine is used to produce steam, which turns a steam turbine and another electricity generator. By combining the cycles together, the resulting energy efficiency is about 55% compared to 35% for a typical gas turbine alone. |
| Dow Jones Sustainability Indexes | Launched in 1999, the Dow Jones Sustainability Indexes are the first global indexes tracking the financial performance of the leading sustainability-driven companies worldwide. See www.sustainability-index.com. |
| environmental stewardship | A broad term for reducing the impact of human daily activities on the environment. Such actions may range from individual behavioural changes to large-scale programs such as waste management, contaminated sites management, or energy audits that demand complex, coordinated approaches. |
| fugitive emissions | Emissions that are released into the air from sources other than stacks or vents. They are often due to equipment leaks or evaporative processes. |
| greenhouse gases (GHGs) | Gaseous components of the atmosphere from natural and man-made processes that contribute to the greenhouse effect. Common GHGs include carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride. The operation of TransCanada's pipeline and power facilities produces "direct" emissions of three GHGs: carbon dioxide, methane and nitrous oxide. TransCanada also accounts for indirect emissions, which are produced by companies that generate the electricity TransCanada purchases for use at our facilities. GHG impacts are global, which means reductions in any part of the world will help limit the effects of these emissions on the climate. |
| natural gas storage facilities | Underground caverns across North America used to store natural gas as a means of ensuring a safe and secure supply for domestic and international markets. This extra gas storage capacity also helps to balance seasonal and short-term supply and demand. |
| pipeline integrity | The safe and reliable operation of pipeline infrastructure in conformity with all applicable safety regulations. |
| polychlorinated byphenyls (PCB) | From the 1930s until the 1970s, PCB mixtures were used for a variety of industrial applications. Their use was largely discontinued in the 1970s because of concerns about their negative environmental impact. |
| reclamation | The conversion of lands disturbed by oil and gas activities to other productive land uses, usually involving recontouring, establishment of drainage systems, placement of topsoil or plants, and revegetation through planting or seeding. |
| remediation | The removal of contaminants or pollutants from a specific environmental location. |
| renewable energy | Energy derived from sources that are constantly replenished by natural processes such as wind, water, solar and geothermal. |
| stakeholder | Someone with a vested interest in the outcome of a decision. TransCanada's key stakeholders include our employees, shareholders, customers, community residents, landowners, Aboriginal peoples, regulators, environmental organizations, industry peers, and business partners. |
| traditional knowledge | Information about the land and its resources that has been collected and handed down from generation to generation among Aboriginal peoples. |