Glossary of Commonly Used Terms

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Air Pollutant: Any substance in air that could, in high enough concentration, harm man, other animals, vegetation, or material. Pollutants may include almost any natural or artificial composition of airborne matter capable of being airborne. They may be in the form of solid particles, liquid droplets, gases, or in combination thereof. Generally, they fall into two main groups: (1) those emitted directly from identifiable sources, and (2) those produced in the air by interaction between two or more primary pollutants, or by reaction with normal atmospheric constituents, with or without photo activation. Exclusive of pollen, fog, and dust, which are of natural origin, about 100 contaminants have been identified. Air pollutants are often grouped in categories for ease in classification; some of the categories are: solids, sulfur compounds, volatile organic chemicals, particulate matter, nitrogen compounds, oxygen compounds, halogen compounds, radioactive compound, and odors.¹
Alternative Energy: Energy from a source other than the conventional fossil-fuel sources of oil, natural gas and coal (i.e. wind, running water, the sun). Also referred to as "alternative fuel."¹
Alternative Fuels: Substitutes for traditional liquid, oil-derived motor vehicle fuels like gasoline and diesel. Includes mixtures of alcohol-based fuels with gasoline, methanol, ethanol, compressed natural gas, and others.¹; As defined by the National Energy Policy Act (EPAct), the fuels are methanol, denatured ethanol and other alcohols, separately or in mixtures of 85 percent by volume or more (or other percentage not less than 70 percent as determined by U.S. Department of Energy rule) with gasoline or other fuels; CNG; LNG; LPG; hydrogen; "coal-derived liquid fuels;" fuels "other than alcohols" derived from "biological materials;" electricity, or any other fuel determined to be "substantially not petroleum" and yielding "substantial energy security benefits and substantial environmental benefits."
Alternative Technologies: State-of-the-art technologies that address infrastructure needs of a community while offering a different range of benefits and drawbacks than conventional technologies. These technologies conserve or renew natural resources and are considered environmentally friendly. Research into renewable energy sources such as the sun, wind, and water; building with natural materials, and conserving energy are part of alternative technologies.⁴

Appropriate Technology: A science or technology considered reasonable and suitable for a particular purpose; that conforms to existing cultural, economic, environmental, and social conditions. Appropriate technology is economically viable, regionally applicable, and sustainable.⁴
Aquifer: 1. A geologic formation that will yield water to a well in sufficient quantities to make the production of water from this formation feasible for beneficial use.; 2. Permeable layers of underground rock or sand that hold or transmit groundwater below the water table.¹²
Asbestos: A mineral fiber that can pollute air or water and cause cancer or asbestosis when inhaled. The EPA has banned or severely restricted its use in manufacturing and construction.¹
Best Practices: A management idea which asserts that there is a technique, method, process, activity, incentive or reward that is more effective at delivering a particular outcome than any other technique, method, process, etc. The idea is that with proper processes, checks, and testing, a desired outcome can be delivered with fewer problems and unforeseen complications. Best practices can also be defined as the most efficient (least amount of effort) and effective (best results) way of accomplishing a task, based on repeatable procedures that have proven themselves over time for large numbers of people.⁵

Bioaccumulants: Substances that increase in concentration in living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted.¹
Bioconcentratrion: The accumulation of a chemical in tissues of a fish or other organism to levels greater than in the surrounding medium.¹
Biodegradable: Capable of decomposing under natural conditions.¹
Biodiesel: A biodegradable transportation fuel for use in diesel engines that is produced through the transesterfication of organically-derived oils or fats. It may be used either as a replacement for or as a component of diesel fuel.

Biodiversity: The variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequencies. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the biochemical structures that are the molecular basis of heredity. Thus, the term encompasses different ecosystems, species, and genes.¹
Biomass: 1. All of the living material in a given area; often refers to vegetation.¹; 2. Energy resources derived from organic matter. These include wood, agricultural waste and other living-cell material that can be burned to produce heat energy. They also include algae, sewage and other organic substances that may be used to make energy through chemical processes.
Bioremediation: The cleanup of a contaminated site using biological methods, i.e., bacteria, fungi, plants, etc. Organisms are used to either break down contaminants in soil or water, or accumulate the contaminants in their tissue for disposal. Many bioremediation techniques are substantially less costly than traditional remediation methods using heat, chemical or mechanical means.⁶
Bioswale: A technology that uses plants and soil and/or compost to retain and cleanse runoff from a site, roadway, or other source.⁶

Blackwater: Water that contains animal, human or foodwaste.¹
Brownfields: Abandoned, idled, or underused industrial and commercial facilities/sites where expansion or redevelopment is complicated by real or perceived environmental contamination. They can be in urban, suburban, or rural areas.¹
British Thermal Unit (Btu): The standard measure of heat energy. It takes one Btu to raise the temperature of one pound of water by one degree Fahrenheit at sea level. For example, it takes about 2,000 Btus to make a pot of coffee. One Btu is equivalent to 252 calories, 778 foot-pounds, 1055 joules, and 0.293 watt-hours.
Carbon Footprint: A measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide (CO2).¹¹

Carbon Monoxide: A colorless, odorless, poisonous gas produced by incomplete fossil fuel combustion.¹
Carbon Neutral: A scenario where the net discharge of carbon dioxide into the atmosphere is zero. Carbon neutrality can be achieved by planting enough trees so that CO2 emissions as a result of combustion would be offset by CO2 absorption by the plants. In the presence of water and light, trees convert CO2 into sugar and oxygen thru the process of photosynthesis. The average tree absorbs 10 kg (22 lbs) of CO2 per year. Carbon neutral is also referred to as "net zero carbon."
Carbon Sequestration: The removal and storage of carbon from the atmosphere in carbon sinks (such as oceans, forests or soils) through physical or biological processes, such as photosynthesis. Humans have tried to increase carbon sequestration by growing new forests.
Carcinogen: Any substance that can cause or aggravate cancer.¹

Chlorofluorocarbons (CFCs): A family of inert, nontoxic, and easily liquefied chemicals used in refrigeration, air conditioning, packaging, insulation, or as solvents and aerosol propellants. Because CFCs are not destroyed in the lower atmosphere, they drift into the upper atmosphere where their chlorine components destroy ozone.¹
Cistern: A receptacle for holding water or other liquid, especially a tank for catching and storing rainwater.⁴
Climate Change: Any long-term significant change in the weather patterns of an area. Climate change can be natural or caused by changes people have made to the land or atmosphere.⁴
Cogenerator: Cogenerators use the waste heat created by one process, for example during manufacturing, to produce steam, which is used, in turn, to spin a turbine and generate electricity. Also known as Combined Heat and Power (CHP) Plants.

Compact Fluorescent Lamp (CFL): Small fluorescent lamps used as more efficient alternatives to incandescent lighting. Also called PL, CFL, Twin-Tube, or BIAX lamps.¹
Compressed Natural Gas (CNG): An alternative fuel for motor vehicles; considered one of the cleanest because of low hydrocarbon emissions and its vapors are relatively non-ozone producing. However, vehicles fueled with CNG do emit a significant quantity of nitrogen oxides.¹
Conservation: Steps taken to cause less energy to be used than would otherwise be the case. These steps may involve improved efficiency, avoidance of waste, reduced consumption, etc. They may involve installing equipment (such as a computer to ensure efficient energy use), modifying equipment (such as making a boiler more efficient), adding insulation, changing behavior patterns, etc.
Conservation Easement: Easement restricting a landowner to land uses that are compatible with long-term conservation and environmental values.¹

Cooling Tower: Device which dissipates the heat from water-cooled systems by spraying the water through streams of rapidly moving air.¹
Cradle-to-Cradle: A term used in life-cycle analysis to describe the entire life of a material or product that is recycled into a new product at the end of its defined life.²
Cradle-to-Grave: A term used in life-cycle analysis to describe the entire life of a material or product up to the point of disposal. Also refers to a system that handles a product from creation through disposal.¹
Distribution System, Electric: The substations, transformers and lines that convey electricity from high-power transmission lines to ultimate consumers.

Distribution System, Water: 1. Water pipes, storage reservoirs, tanks, and other means used to deliver drinking water to consumers or store it before delivery.⁹; 2. A network of pipes leading from a treatment plant to customers' plumbing systems.¹⁰
Drainage Systems: A system of watercourses or drains for carrying off excess water.⁴
Ecosystem Services: The benefits people obtain from ecosystems. These include provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services such as nutrient cycling that maintain the conditions for life on Earth.
Embodied Energy: The total amount of energy used to create a product, including energy expended in raw materials extraction, procession, manufacturing, and transportation. Embodied energy is often used as a rough measure of the environmental impact of a product.⁶

Energy: The capacity for doing work. Forms of energy include thermal, mechanical, electrical and chemical. Energy may be transformed from one form into another.
Energy Efficiency: Ratio of energy output of a system to its energy input. Using less energy/electricity to perform the same function or programs designed to use electricity more efficiently by doing the same with less. "Energy conservation" is a term which has also been used but it has the connotation of doing without in order to save energy rather than using less energy to do the same thing.
Energy Resources: Everything that could be used by society as a source of energy.
Energy Self-Sufficiency: Deriving the capacity for doing work from local resources. There are degrees of energy self-sufficiency that can be factored into community goals.

Energy Star: Program administered by the Environmental Protection Agency (EPA) that evaluates products based on energy efficiency.⁶
Environmental Footprint: For an industrial setting, this is a company’s environmental impact determined by the amount of depletable raw materials and nonrenewable resources it consumes to make its products, and the quantity of wastes and emission that are generated in the process. Traditionally, for a company to grow, the footprint had to get larger. Today, finding ways to reduce the environmental footprint is a priority for leading companies. An environmental footprint can be determined for a building, city, or nation as well, and gives an indication of the sustainability of the unit.²
Environmental Impact Statement: A document required of federal agencies by the National Environmental Policy Act for major projects or legislative proposals significantly affecting the environment. A tool for decision making, it describes the positive and negative effects of the undertaking and cites alternative actions.¹
Erosion: The wearing away of land surface by wind or water, intensified by land-clearing practices related to farming, residential or industrial development, road building, or logging.⁶
Fluorocarbons (FCs): Any of a number of organic compounds analogous to hydrocarbons in which one or more hydrogen atoms are replaced by fluorine. Once used in the United States as a propellant for domestic aerosols, they are now found mainly in coolants and some industrial processes. FCs containing chlorine are called Chlorofluorocarbons (CFCs). They are believed to be modifying the ozone layer in the stratosphere, thereby allowing more harmful solar radiation to reach the Earth’s surface.¹
Footprint (Building): The area of a building formed by the perimeter of the foundation. Shrinking the footprint of a building allows for more open space and pervious surface on a site.⁶
Forest Stewardship Council (FSC): A third-party certification organization, evaluating the sustainability of forest products. FSC-certified wood products have met specific criteria in areas such as forest management, labor conditions, and fair trade.⁹
Fossil Fuels: Oil, coal, natural gas or their by-products. Fuel that was formed in the earth in prehistoric times from remains of living-cell organisms.

Fuel Cells: One or more cells capable of generating an electrical current by converting the chemical energy of a fuel (e.g., hydrogen) directly into electrical energy. Fuel cells differ from conventional electrical cells in that the active materials such as fuel and oxygen are not contained within the cell but are supplied from outside.
GASB: Governmental Accounting Standards Board, created in 1984 as an independent, professional body to establish standards of accounting and financial reporting applicable to state and local governmental entities.⁸
GASB 34: GASB 34 requires local governments to inventory their capital assets (including infrastructure) and determine their depreciated value. In government-wide financial statements, capital assets are included in the statement of net assets. They are shown at historical cost, net of accumulated depreciation. In order to determine current capital asset value, local governments need to provide their accountant or auditor with basic inventory data, combined with information about historical costs of assets, their useful life, as well as any prior and accumulated depreciation expense. GASB 34 compliance is facilitated by the local government’s accountant or auditor, who takes the capital asset inventory and applies GASB 34 standards in order to report the assets in a format required by GASB 34.
Geothermal Energy: Hot water or steam extracted from geothermal reservoirs in the earth's crust. Water or steam extracted from geothermal reservoirs can be used for geothermal heat pumps, water heating, or electricity generation.

Geographical Information System (GIS): Allows for the accurate location of all facilities through the use of global positioning system technology and is used to update the system circuit diagrams and detail maps of the city.³
Global Warming: An increase in the near surface temperature of the earth. Global warming has occurred in the distant past as the result of natural influences, but the term is most often used to refer to the warming predicted to occur as a result of increased emission of greenhouse gases. Scientists generally agree that the earth’s surface has warmed by about 1 degree Fahrenheit in the past 140 years. The Intergovernmental Panel on Climate Change (IPCC) recently concluded that increased concentrations of greenhouse gases are causing an increase in the earth’s surface temperature and that increased concentrations of sulfate aerosols have led to relative cooling in some regions, generally over and downwind of heavily industrialized areas.¹
Global Warming Potential: The ratio of the warming caused by a substance to the warming caused by a similar mass of carbon dioxide. CFC-12, for example, has a GWP of 8,500, while water has a GWP of zero.¹
Greywater: Domestic wastewater composed of wash water from kitchen, bathroom, and laundry sinks, tubs, and washers.¹

Greywater Reuse: A strategy for reducing wastewater outputs from a building, by diverting the greywater into productive uses such as subsurface irrigation, or on-site treatment and use for non-potable functions such as toilet flushing. Greywater reuse is restricted in many jurisdictions.⁶
Green Building: A type of design and construction practices that reduce or eliminate negative impacts of building on the environment and the occupants.
Green Infrastructure: The natural life support system for a community. It is a strategically planned and managed network of wilderness, parks, greenways, conservation easements, and working lands with conservation value.
Green Revolution: An increase in food production, especially in underdeveloped and developing nations, through the introduction of high-yield crop varieties and application of modern agricultural techniques. The green revolution greatly increased the availability of food and confounded predictions of worldwide famine that had been made in the early 1970s.⁴

Greenhouse Effect: The warming of the Earth’s atmosphere attributed to a build-up of carbon dioxide or other gases; some scientists think that this build-up allows the sun’s rays to heat the Earth, while making the infrared radiation atmosphere opaque to infrared radiation, thereby preventing a counterbalancing loss of heat.¹
Greenhouse Gases (GHGs): Those gases, such as water vapor, carbon dioxide, nitrous oxide, methane, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride, that are transparent to solar (short-wave) radiation but opaque to long-wave (infrared) radiation, thus preventing long-wave radiant energy from leaving Earth's atmosphere. The net effect is a trapping of absorbed radiation and a tendency to warm the planet's surface.³
Groundwater: The water beneath the surface of the ground, consisting largely of surface water that has seeped down. Groundwater is a source of drinking and spring water for many communities, and can be contaminated by chemical pollutants.⁴
Halogen: A type of incandescent lamp with higher energy efficiency than standard ones.¹

Heat Pump: An air-conditioning unit which is capable of heating by refrigeration, transferring heat from one (often cooler) medium to another (often warmer) medium, and which may or may not include a capability for cooling. This reverse-cycle air conditioner usually provides cooling in summer and heating in winter.⁵
High Efficiency: General term for technologies and processes that require less energy, water, or other inputs to operate. A goal in sustainable building is to achieve high efficiency in resource use when compared to conventional practices.⁶
HVAC (Heating, Ventilation, and Air Conditioning): General term for the heating, ventilation, and air conditioning system in a building. System efficiency and design impact the overall energy performance of a home and its indoor environmental quality.⁶
Hydrocarbons (HC): Chemical compounds that consist entirely of carbon and hydrogen.¹

Hydroelectric Power (Hydro): Electricity produced by falling water that turns a turbine generator.
Impervious Surface: A surface that sheds the precipitation falling on it, rather than infiltrating. Impervious surfaces can lead to excessive stormwater runoff and limit the amount of stormwater that remains onsite or recharges local aquifers.⁶
Import Substitution: A deliberate effort to replace major consumer imports by promoting the emergence and expansion of domestic industries.
Infiltration: 1. The penetration of water through the ground surface into subsurface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls.¹; 2. The technique of applying large volumes of wastewater to land to penetrate the surface and percolate through the underlying soil.¹

Infiltration and Inflow (I&I): The seepage of groundwater into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints, connections or manhole walls.³
Infiltration Rate: The quantity of water that can enter the soil in a specified time interval.¹
Inflow: Entry of extraneous rain water into a sewer system from sources other than infiltration, such as basement drains, manholes, storm drains, and street washing.¹
Infrastructure: The basic facilities, services, and installations needed for the functioning of a community or society, such as transportation and communications systems, water and power lines, and public institutions including schools, post offices, and prisons. The term infrastructure has been used since 1927 to refer collectively to the roads, bridges, rail lines, and similar public works that are required for an industrial economy, or a portion of it, to function.⁴

Institution(s): Norms, rules of conduct, and generally accepted ways of doing things. Social institutions are well-defined, formal organizations of society that govern the way that society operates - for example, the class system, private versus communal ownership, or the educational system. Political institutions are the systems that govern the operations of the government of a particular society - formal power structures, political parties, and mechanisms for obtaining power.
Institutional Barriers: Obstacles created by institutions that make it harder to reach community goals.⁵
Integrated Waste Management: The complementary use of a variety of practices to handle solid waste safely and effectively. Techniques include source reduction, recycling, composting, combustion and landfilling.²
Integration: An essential concept in sustainable building. Viewing a building as a system allows the discovery of synergies and potential tradeoffs or pitfalls with design choices. An integrated design approach helps maximize synergies and minimize unintended consequences.⁶
Kilowatt (kW): One thousand (1,000) watts. A unit of measure of the amount of electricity needed to operate given equipment. On a hot summer afternoon, a typical home, with central air conditioning and other equipment in use, might have a demand of 4 kW each hour.
Kilowatt-Hour (kWh): The most commonly used unit of measure telling the amount of electricity consumed over time. It means one kilowatt of electricity supplied for one hour. A typical household uses 938 kWh every month.⁷
Landfill Gas: Gas generated by the natural degrading and decomposition of municipal solid waste by anaerobic microorganisms in sanitary landfills. The gases produced, carbon dioxide and methane, can be collected by a series of low-level pressure wells and can be processed into a medium Btu gas that can be burned to generate steam or electricity.
Leachate: Water that collects contaminants as it trickles through wastes, pesticides or fertilizers. Leaching may occur in farming areas, feedlots, and landfills, and may result in hazardous substances entering surface water, ground water, or soil.¹

LEED

An acronym for Leadership in Energy and Environmental Design. LEED is a point-based rating system developed by the U.S. Green Building Council that evaluates the environmental performance from a "whole building" perspective over its life cycle, providing a definitive standard for what constitutes a green building according to six categories:

Sustainable Sites
Water Efficiency
Energy and Atmosphere
Material Resources
Indoor Environmental Quality
Innovation and Design Process

Buildings evaluated by LEED are rated as certified, silver, gold, or platinum. There are a total of 69 LEED credits available in the six categories: 26 credits are required to attain the most basic level of LEED certification; 33 to 38 credits are needed for Silver; 39 to 51 credits for Gold; 52 to 69 credits for the Platinum rating.

Low Impact Development (LID)

An approach to development that integrates site-specific ecological and environmental requirements into all phases of community planning and design. LID mimics a site’s predevelopment hydrology, and uses design techniques that infiltrate, filter, store, evaporate, and detain runoff close to its source.

Life Cycle Analysis (LCA)

The assessment of a product’s full environmental costs, from raw material to final disposal, in terms of consumption of resources, energy and waste. Used as a tool for evaluating the relative performance of building materials, technologies, and systems.²

Life Cycle Cost (LCC)

The total cost of acquiring, owning, operating and disposing of a building, building system, or other type of infrastructure over its entire useful life. LCC includes the cost of land acquisition, construction costs, energy costs, the cost to maintain, service and repair the building and its systems, costs of system replacement, financing costs, and residual or salvage value at the end of the building’s or infrastructure’s useful life.

Life Cycle Inventory (LCI): An accounting of the energy and waste associated with the creation of a new product through use and disposal.²
Light-Emitting Diode (LED): A long-lasting illumination technology used for exit signs, among other things, which requires very little power.¹
Megawatt (MW): One thousand kilowatts or one million watts. One megawatt is enough energy to power 1,000 average homes.⁵
Methane: A colorless, nonpoisonous, flammable gas created by anaerobic decomposition of organic compounds. A major component of natural gas used in the home. Methane has also been found to be a potent greenhouse gas. Methane from landfills, livestock, and composting operations can be captured and used as a fuel source for alternative energy production.¹

Modular Building: Building technique using modular, or pre-constructed, components. Building on a "module" also refers to the concept of using standardized dimensions that reduce the amount of construction waste.⁶
Municipal Infrastructure: All physical assets and related services owned by a municipality or over which a municipality has decision-making authority, such as: town forests and trails; wastewater; drinking water; stormwater; parks and recreation; transportation systems, roads, bridges, public vehicles; building design and maintenance; HVAC, etc.; landfills and lighting districts; schools; municipal utilities, etc.
Natural Resources: 1. The natural wealth of a country, consisting of land, forests, mineral deposits, fossil fuels, water, etc. ⁴
2. Resources (actual and potential) supplied by nature.⁴
Nonrenewable Energy: Energy derived from depletable fuels (oil, gas, coal) created through lengthy geological processes and existing in limited quantities on the earth.²

Nonrenewable Resource: A resource that cannot be replaced in the environment (e.g. fossil fuels) because it forms at a rate far slower than its consumption.²
Nuclear Energy: Power obtained by splitting heavy atoms (fission) or joining light atoms (fusion). A nuclear energy plant uses a controlled atomic chain reaction to produce heat. The heat is used to make steam run conventional turbine generators.⁵
On-Site Stormwater Management: Building and landscape strategies to control and limit stormwater pollution and runoff. Usually an integrated package of strategies, elements can include vegetated roofs, compost-amended soils, pervious paving, tree planting, drainage swales, and more.⁶
Passive Solar Energy: Use of the sun to help meet a building's energy needs by means of architectural design (such as arrangement of windows) and materials (such as floors that store heat, or other thermal mass).

Peak Oil: Imagine that all our world’s oil was gathered together in one big tank. At some point in time, we will have used up half of that oil. Peak Oil attempts to determine when this mid-point or "Peak" will be reached, & how rapid the decline in oil production will be after this "Peak" has passed. Many business & government interests speculate that this mid-point (Peak) is decades away, but independent researchers & analysts disagree, claiming Peak Oil will happen much sooner. Little valid disagreement exists over Peak Oil itself, rather arguments center around when Peak Oil will occur.
Photovoltaic (PV) Cell: A semiconductor that converts light directly into electricity.
Porous Paving: Paving surfaces designed to allow stormwater infiltration and reduce runoff.⁶
Radon: A colorless, naturally occurring, radioactive inert gas formed by radioactive decay of radium atoms in soil or rocks. Design strategies help reduce the amount of radon infiltration into a building and remove the gas that does infiltrate.¹

Reclamation: Restoration of materials found in the waste stream to a beneficial use that may be other than the original use.²
Recycling: Process by which materials that would otherwise become solid waste are collected, separated or processed and returned to the economic mainstream to be reused in the form of raw materials or finished goods.²
Renewable Energy: Any naturally occurring, theoretically inexhaustible source of energy, as biomass, solar, wind, tidal, wave, and hydroelectric power, that is not derived from fossil or nuclear fuel. Renewable energy is also called soft energy.⁴
Renewable Resources: Renewable energy resources are naturally replenishable, but flow-limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Some (such as geothermal and biomass) may be stock-limited in that stocks are depleted by use, but on a time scale of decades, or perhaps centuries, they can be replenished. Renewable energy resources include biomass, hydro, geothermal, solar and wind. In the future they could also include the use of ocean thermal, wave, and tidal action technologies.

Solar Cell: A photovoltaic cell that can convert light directly into electricity. A typical solar cell uses semiconductors made from silicon.
Solar Collector: A device designed to receive solar radiation and convert it to thermal energy. Normally, a solar thermal collector includes a frame, glazing, and an absorber, together with appropriate insulation. The heat collected by the solar collector may be used immediately or stored for later use. Solar collectors are used for space heating; domestic hot water heating; and heating swimming pools, hot tubs, or spas.
Solar Energy: Energy derived from the sun in the form of solar radiation.⁴
Source Reduction: The design, manufacture, purchase, or use of materials to reduce the amount or toxicity of waste in an effort to reduce pollution and conserve resources (i.e. reusing items, minimizing the use of products containing hazardous compounds, extending the useful life of a product and reducing unneeded packaging).²

Stormwater: An abnormal amount of surface water due to a heavy rain or snowstorm.⁴
Sustainability: Practices that would ensure the continued viability of a product or practice in perpetuity. The concept of sustainability can be traced back to President Theodore Roosevelt who stated in 1910, "I recognize the right and duty of this generation to develop and use the natural resources of our land; but I do not recognize the right to waste them, or to rob, by wasteful use, the generations that come after us."
Sustainable Development: An approach to progress that meets the needs of the present without compromising the ability of future generations to meet their needs.² In 1987 the United Nations World Commission on Environment and Development (The Brundtland Commission) defined sustainable development as one that "meets the needs of the present without compromising the ability of future generations to meet their own needs." Sustainability has three interdependent dimensions relating to the environment, economics and society often referred to as the triple bottom line.
Thermal Mass: A mass (often stone, concrete, or brick) used to store heat and reduce temperature fluctuation in a space, by releasing heat slowly over time.⁶

True Cost Economics: An economic paradigm that accounts for ecosystem service value and resource depletion/degradation cost. An idea that would drastically change the way value flows within our economy. For example, we couldn't cut down a forest and count only the sale value of the lumber minus production costs; we'd also need to deduct the loss of valuable services the living forest would have provided. Nuclear plants couldn't sell electricity without factoring in the cost of thousands of years of radioactive waste containment.
Volatile Organic Compound (VOC): Organic substances capable of entering the gas phase from either a liquid or solid form.²
Wastewater: The spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter.¹
Watts per Square Foot: A shorthand measure of the energy use of a building, often applied to indoor lighting. Energy codes often limit the watts per square foot based on building type and function.⁶

Wetlands: An area that is saturated by surface or ground water with vegetation adapted for life under those soil conditions, as swamps, bogs, fens, marshes, and estuaries.¹
Wind Power Systems: Wind power systems convert the energy of the wind into electricity. Surplus electricity is often stored in a battery storage system for later use, or the power is passed back to the utility essentially making the meter go in reverse.
Wind Turbine: Device for generating electricity from wind; windmill.⁶

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Glossary of Commonly Used Terms

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INFRASTRUCTURE