Back Pressure: A pressure that can cause water to backflow into the water supply when a user's waste water system is at a higher pressure than the public system.
Backflow/Back Siphonage: A reverse flow condition created by a difference in water pressures that causes water to flow back into the distribution pipes of a drinking water supply from any source other than the intended one.
Background Level: 1. The concentration of a substance in an environmental media (air, water, or soil) that occurs naturally or is not the result of human activities. 2. In exposure assessment the concentration of a substance in a defined control area, during a fixed period of time before, during, or after a data-gathering operation..
Backwashing: Reversing the flow of water back through the filter media to remove entrapped solids.
Backyard Composting: Diversion of organic food waste and yard trimmings from the municipal waste stream by composting hem in one's yard through controlled decomposition of organic matter by bacteria and fungi into a humus-like product. It is considered source reduction, not recycling, because the composted materials never enter the municipal waste stream.
BACT - Best Available Control Technology: An emission limitation based on the maximum degree of emission reduction (considering energy, environmental, and economic impacts) achievable through application of production processes and available methods, systems, and techniques. BACT does not permit emissions in excess of those allowed under any applicable Clean Air Act provisions. Use of the BACT concept is allowable on a case by case basis for major new or modified emissions sources in attainment areas and applies to each regulated pollutant.
Bacteria (Singular: bacterium): Microscopic living organisms that can aid in pollution control by metabolizing organic matter in sewage, oil spills or other pollutants. However, bacteria in soil, water or air can also cause human, animal and plant health problems.
Bactericide: A pesticide used to control or destroy bacteria, typically in the home, schools, or hospitals.
Baffle: A flat board or plate, deflector, guide, or similar device constructed or placed in flowing water or slurry systems to cause more uniform flow velocities to absorb energy and to divert, guide, or agitate liquids.
Baffle Chamber: In incinerator design, a chamber designed to promote the settling of fly ash and coarse particulate matter by changing the direction and/or reducing the velocity of the gases produced by the combustion of the refuse or sludge.
Baghouse: A combustion plant emission control device that consists of an array of fabric filters through which flue gases pass in an incinerator flue. Particles are trapped and thus prevented from passing into the atmosphere.
Baghouse Filter: Large fabric bag, usually made of glass fibers, used to eliminate intermediate and large (greater than 20 PM in diameter) particles. This device operates like the bag of an electric vacuum cleaner, passing the air and smaller particles while entrapping the larger ones.
Bailer: A pipe with a valve at the lower end, used to remove slurry from the bottom or side of a well as it is being drilled, or to collect groundwater samples from wells or open boreholes. 2. A tube of varying length.
Balanced Schedule: A Scheduling Coordinator's schedule is balanced when generation, adjusted for transmission losses, equals demand.
Baler: A piece of equipment used to compress and form recycled material into bales.
Baling: Compacting solid waste into blocks to reduce volume and simplify handling.
Ballast: A device that provides starting voltage and limits the current during normal operation in electrical discharge lamps (such as fluorescent lamps).
Ballistic Separator: A machine that sorts organic from inorganic matter for composting.
Band Application: The spreading of chemicals over, or next to, each row of plants in a field.
Banking: A system for recording qualified air emission reductions for later use in bubble, offset, or netting transactions.
Bar Screen: In wastewater treatment, a device used to remove large solids.
Barrel: In the petroleum industry, a barrel is 42 U.S. gallons. One barrel of oil has an energy content of 6 million British thermal units. It takes one barrel of oil to make enough gasoline to drive an average car from Los Angeles to San Francisco and back (at 18 miles per gallon over the 700-mile round trip). Barrels Per Day Equivalent (BPD-Equivalent): A unit of measure that tells how much oil would have to be burned to produce the same amount of energy.
Barrel Sampler: Open-ended steel tube used to collect soil samples.
Barrier Coating(s): A layer of a material that obstructs or prevents passage of something through a surface that is to be protected; e.g., grout, caulk, or various sealing compounds; sometimes used with polyurethane membranes to prevent corrosion or oxidation of metal surfaces, chemical impacts on various materials, or, for example, to prevent radon infiltration through walls, cracks, or joints in a house.
Basal Application: In pesticides, the application of a chemical on plant stems or tree trunks just above the soil line.
Basalt: Consistent year-round energy use of a facility; also refers to the minimum amount of electricity supplied continually to a facility.
Base Load: The lowest level of power production needs during a season or year.
Base Load Unit: A power generating facility that is intended to run constantly at near capacity levels, as much of the time as possible.
Basel Convention: An international agreement on the control of transboundary movements of hazardous wastes and their disposal, drawn up in March 1989 in Basel, Switzerland, with over 100 countries as signatories.
Baseline Forecast: A prediction of future energy needs which does not take into account the likely effects of new conservation programs that have not yet been started.
Base Rate: That portion of the total electric or gas rate covering the general costs of doing business unrelated to fuel expenses.
Battery: A device that stores energy and produces electric current by chemical action.
BDT: Acronym for "bone dry tons." This is a measurement of biomass that has zero percent moisture content. Amounts are usually given in BDT/year.
Bean Sheet: Common term for a pesticide data package record.
Bed Load: Sediment particles resting on or near the channel bottom that are pushed or rolled along by the flow of water.
Bench-scale Tests: Laboratory testing of potential cleanup technologies.
Benefit-Cost Analysis: An economic method for assessing the benefits and costs of achieving alternative health-based standards at given levels of health protection.
Benthic/Benthos: An organism that feeds on the sediment at the bottom of a water body such as an ocean, lake, or river.
Bentonite: A colloidal clay, expansible when moist, commonly used to provide a tight seal around a well casing.
Benzene: A type of colorless liquid hydrocarbon that can be used as a motor fuel. Its chemical symbol is C6H6.
Beryllium: A metal hazardous to human health when inhaled as an airborne pollutant. It is discharged by machine shops, ceramic and propellant plants, and foundries.
Best Available Control Measures (BACM): A term used to refer to the most effective measures (according to EPA guidance) for controlling small or dispersed particulates and other emissions from sources such as roadway dust, soot and ash from woodstoves and open burning of rush, timber, grasslands, or trash.
Best Available Control Technology (BACT): For any specific source, the currently available technology producing the greatest reduction of air pollutant emissions, taking into account energy, environmental, economic, and other costs.
Best Available Control Technology (BACT): The most stringent technology available for controlling emissions; major sources are required to use BACT, unless it can be demonstrated that it is not feasible for energy, environmental, or economic reasons.
Best Demonstrated Available Technology (BDAT): As identified by EPA, the most effective commercially available means of treating specific types of hazardous waste. The BDATs may change with advances in treatment technologies.
Best Management Practice (BMP): Methods that have been determined to be the most effective, practical means of preventing or reducing pollution from non-point sources.
Bi-Fuel Vehicle: A vehicle with two separate fuel systems designed to run on either fuel, using only one fuel at a time. These systems are advantageous for drivers who do not always have access to an alternative fuel refuelling station. Bi-fuel systems are usually used in light-duty vehicles. One of the two fuels is typically an alternative fuel.
Bi-Gas: A process being developed as a means of making synthetic gas from coal. The synthetic gas would be intended to substitute for natural gas in meeting industrial and home energy needs.
Bilateral Contract: A two-party agreement for the purchase and the sale of energy products and services.
Bimetal: Beverage containers with steel bodies and aluminum tops; handled differently from pure aluminum in recycling.
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.
Bioaccumulation: An increase in the concentration of a chemical in biological organism overtime, compared to the chemical’s concentration in the environment.
Bioassay: A test to determine te relative strength of a substance by comparing its effect on a test organism with that of a standard preparation.
Bio-availability: Degree of ability to be absorbed and ready to interact in organism metabolism.
Bio-based Product: A product (other than food or feed) that is produced from renewable agricultural (plant, animal and marine) or forestry materials.
Biochemical Oxygen Demand (BOD): A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater the degree of pollution.
Bio-concentration: The accumulation of a chemical in tissues of a fish or other organism to levels greater than in the surrounding medium.
Bio-conversion: Processes that use plants or micro-organisms to change one form of energy into another. For example, an experimental process uses algae to convert solar energy into gas that could be used for fuel.
Biodegradable: Capable of decomposing under natural conditions.
Biodegradable Material: Any organic material that can be broken down by microorganisms into simpler, more stable compounds. Most organic wastes (e.g., food, paper) are biodegradable.
Biodegradation: The process by which a substance or material is broken down (or decomposed or metabolized) by microorganisms and reduce to organic or inorganic molecules which can further utilized by living systems.
Biodiesel: A biodegradable transportation fuel for use in diesel engines that is produced through the transesterification of organically- derived oils or fats. It may be used either as a replacement for or as a component of diesel fuel.
Biodiversity: Refers to 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.
Biofuels: A fuel made wholly or partially from industrial by-products obtained as a result of transforming plant or animal material.
Biogas: Produced by the biological breakdown of organic matter in the absence of oxygen in a process known as anaerobic digestion; It contains a high proportion of methane (50%) and thus has a high calorific and energy potential. In our industries, gas is produced in landfills, methane production units and the sludge digesters of wastewater treatment plants. It must be collected to prevent pollution and environmental damage, specifically odours and heightened greenhouse effect. Biogas can be recovered and used as a renewable energy in place of fossil fuel.
Biological Contaminants: Living organisms or derivates (e.g. viruses, bacteria, fungi, and mammal and bird antigens) that can cause harmful health effects when inhaled, swallowed, or otherwise taken into the body.
Biological Control: In pest control, the use of animals and organisms that eat or otherwise kill or out-compete pests.
Biological Integrity: The ability to support and maintain balanced, integrated, functionality in the natural habitat of a given region. Concept is applied primarily in drinking water management.
Biological Magnification: Refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The substances become concentrated in tissues or internal organs as they move up the chain.
Biological Measurement: A measurement taken in a biological medium. For exposure assessment, it is related to the measurement is taken to related it to the established internal dose of a compound.
Biological Medium: One of the major component of an organism; e.g. blood, fatty tissue, lymph nodes or breath, in which chemicals can be stored or transformed.
Biological Oxidation: Decomposition of complex organic materials by microorganisms. Occurs in self-purification of water bodies and in activated sludge wastewater treatment.
Biological Oxygen Demand (BOD): An indirect measure of the concentration of biologically degradable material present in organic wastes. It usually reflects the amount of oxygen consumed in five days by biological processes breaking down organic waste.
Biological pesticides: Certain microorganism, including bacteria, fungi, viruses, and protozoa that are effective in controlling pests. These agents usually do not have toxic effects on animals and people and do not leave toxic or persistent chemical residues in the environment.
Biological Stressors: Organisms accidentally or intentionally dropped into habitats in which they do not evolve naturally; e.g. gypsy moths, Dutch elm disease, certain types of algae, and bacteria.
Biological Treatment: A treatment technology that uses bacteria to consume organic waste.
Biologically Effective Dose: The amount of a deposited or absorbed compound reaching the cells or target sites where adverse effect occur, or where the chemical interacts with a membrane.
Biologicals: Vaccines, cultures and other preparations made from living organisms and their products, intended for use in diagnosing, immunizing, or treating humans or animals, or in related research.
Biomass: 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.
Biomass: Any organic matter that can be used as fuel to generate energy. Biomass, also known as biofuels or bio-energy, is obtained from organic matter either directly from plants or indirectly from industrial, commercial, domestic or agricultural products. The use of biomass is classed as a 'carbon neutral' process because the carbon dioxide released during the generation of energy from biomass is balanced by that absorbed by plants during their growth.
Biome: Entire community of living organisms in a single major ecological area.
Biomimicry: The study of nature and imitation of nature’s forms. The process of learning from and then emulating life’s genius.
Bio-monitoring: 1. The use of living organisms to test the suitability of effluents for discharge into receiving waters and to test the quality of such waters downstream from the discharge. 2. Analysis of blood, urine, tissues, etc. to measure chemical exposure in humans.
Bioreactor: Bio-reaction accelerates the production of landfill gas by recovering leachate and reincorporating it into the waste mass. Adding moisture and nutrients to the bacteria at work in the mass accelerates the breakdown process, facilitating the recovery of methane usable for energy. Collecting and recovering methane offers both environmental and economic advantages: it reduces methane's greenhouse effect and is a significant source of energy.
Bioremediation: Use of living organisms to clean up oil spills or remove other pollutants from soil, water, or wastewater; use of organisms such as non-harmful insects to remove agricultural pests or counteract diseases of trees, plants, and garden soil.
Biosensor: Analytical device comprising a biological recognition element (e.g. enzyme, receptor, DNA, antibody, or microorganism) in intimate contact with an electrochemical, optical, thermal, or acoustic signal transducer that together permit analyses of chemical properties or quantities. Shows potential development in some areas, including environmental monitoring.
Biosphere: The zone at and adjacent to the earth's surface where all life exists; all living organisms of the earth.
Biostabilizer: A machine that converts solid waste into compost by grinding and aeration.
Biota: The animal and plant life of a given region.
Biotechnology: Techniques that use living organisms or parts of organisms to produce a variety of products (from medicines to industrial enzymes) to improve plants or animals or to develop microorganisms to remove toxics from bodies of water, or act as pesticides.
Biotic Community: A naturally occurring assemblage of plants and animals that live in the same environment and are mutually sustaining and interdependent.
Biotransformation: Conversion of a substance into other compounds by organisms; includes biodegradation.
Bituminous Coal: Soft coal containing large amounts of carbon. It has a luminous flame and produces a great deal of smoke.
Blackwater: Water that contains animal, human, or food waste.
Blood Products: Any product derived from human blood, including but not limited to blood plasma, platelets, red or white corpuscles, and derived licensed products such as interferon.
Bloom: A proliferation of algae and/or higher aquatic plants in a body of water; often related to pollution, especially when pollutants accelerate growth.
BOD5: The amount of dissolved oxygen consumed in five days by biological processes breaking down organic matter.
Body Burden: The amount of a chemical stored in the body at a given time, especially a potential toxin in the body as the result of exposure.
Bog: A type of wetland that accumulates appreciable peat deposits. Bogs depend primarily on precipitation for their water source, and are usually acidic and rich in plant residue with a conspicuous mat of living green moss.
Boiler: A closed vessel designed to transfer heat produced by combustion or electric resistance to water. Boilers may provide hot water or steam.
Boiler (Wheelabrator): A device used to absorb the heat released during the combustion process of burning waste. This combustion produces steam that can be sold or converted into electrical power.
Boiling Water Reactor (BWR): A nuclear power unit in which water used as a coolant is allowed to boil at the core. The resulting steam may be used to drive electric turbines.
Boom: 1. A floating device used to contain oil on a body of water. 2. A piece of equipment used to apply pesticides from a tractor or truck.
Borehole: Hole made with drilling equipment.
Botanical Pesticide: A pesticide whose active ingredient is a plant-produced chemical such as nicotine or strychnine. Also called a plant-derived pesticide.
Bottle Bill: Proposed or enacted legislation which requires a returnable deposit on beer or soda containers and provides for retail store or other redemption. Such legislation is designed to discourage use of throw-away containers.
Bottled Gas: The liquified petroleum gases propane and butane, contained under moderate pressure (about 125 pounds per square inch and 30 pounds per square inch respectively), in cylinders.
Bottoming Cycle: A means to increase the thermal efficiency of a steam electric generating system by converting some waste heat from the condenser into electricity rather than discharging all of it into the environment.
Bottom Ash: The non-airborne combustion residue from burning pulverized coal in a boiler; the material which falls to the bottom of the boiler and is removed mechanically; a concentration of non-combustible materials, which may include toxics.
Bottom Ash: Bottom ash is the slag and solid residue left after waste combustion and recovered from the bottom of furnaces. A distinction is made between municipal waste bottom ash and hazardous waste bottom ash. Current regulations divide the former into three categories: recyclable, treatable and storable. “Recyclable” bottom ash that meets specific technical requirements can be used to build roads. Special industrial waste bottom ash is treated in landfills or recycled in some cases.
Bottom Land Hardwoods: Forested freshwater wetlands adjacent to rivers in the southeastern United States, especially valuable for wildlife breeding, nesting and habitat.
Bounding Estimate: An estimate of exposure, dose, or risk that is higher than that incurred by the person in the population with the currently highest exposure, dose, or risk. Bounding estimates are useful in developing statements that exposures, doses, or risks are not greater than an estimated value. Brackish: Mixed fresh and salt water.
Breakpoint Chlorination: Addition of chlorine to water until the chlorine demand has been satisfied.
Breakthrough: A crack or break in a filter bed that allows the passage of floc or particulate matter through a filter; will cause an increase in filter effluent turbidity.
Breathing Zone: Area of air in which an organism inhales.
Breeder: A nuclear reactor that produces more fuel than it consumes. The breeder, invented in the United States, is used as a power source in several European countries.
Brine Mud: Waste material, often associated with well-drilling or mining, composed of mineral salts or other inorganic compounds.
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 Btu to make a pot of coffee. One Btu is equivalent to 252 calories, 778 foot-pounds, 1055 joules, and 0.293 watt-hours. Note: In the abbreviation, only the B is capitalized.
Broadcast Application: The spreading of pesticides over an entire area.
Broker: A retail agent who buys and sells power. The agent may also aggregate customers and arrange for transmission, firming and other ancillary services as needed.
Brownfields: Abandoned, idled, or under used 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. EPA's Brownfields initiative helps communities mitigate potential health risks and restore the economic viability of such areas or properties.
Brownout: A controlled power reduction in which the utility decreases the voltage on the power lines, so customers receive weaker electric current. Brownouts can be used if total power demand exceeds the maximum available supply. The typical household does not notice the difference.
Bubble: A system under which existing emissions sources can propose alternate means to comply with a set of emissions limitations; under the bubble concept, sources can control more than required at one emission point where control costs are relatively low in return for a comparable relaxation of controls at a second emission point where costs are higher.
Buffer: A solution or liquid whose chemical makeup is such that it minimizes changes in pH when acids or bases are added to it.
Buffer Strips: Strips of grass or other erosion-resisting vegetation between or below cultivated strips or fields.
Building Cooling Load: The hourly amount of heat that must be removed from a building to maintain indoor comfort (measured in British thermal units (Btus).
Building Envelope: The exterior surface of a building's construction--the walls, windows, floors, roof, and floor. It is also called building shell.
Building Related Illness (BRI): Diagnosable illness with symptoms that can be identified and with a cause that can be directly attributed to airborne building pollutants (e.g. Legionnaire’s Disease, hypersensitivity pneumonitis).
Bulk Power Supply: Often this term is used interchangeably with wholesale power supply. In broader terms, it refers to the aggregate of electric generating plants, transmission lines, and related-equipment. The term may refer to those facilities within one electric utility, or within a group of utilities in which the transmission lines are interconnected.
Bulk Sample: A small portion (usually thumbnail size) of a suspect asbestos-containing building material collected by an asbestos inspector for laboratory analysis to determine asbestos content.
Bulky Waste: Waste from household activities that, because of its volume or weight, is not included in the usual collection system, but needs special handling. For the most part, bulky waste is only an occasional occurrence. It includes:
• used household appliances
• construction and demolition waste
• green household waste
Bunker C Fuel Oil: A very heavy substance, left over after other fuels have been distilled from crude oil. It is also called NO. 6 FUEL, it is used in power plants, ships and large heating installations.
Burial Ground (Graveyard): A disposal site for radioactive waste materials that uses earth or water as a shield.
Busbar: In electric utility operations, a busbar is a conductor that serves as a common connection for two or more circuits. It may be in the form of metal bars or high-tension cables.
Butane: A hydrocarbon gas found in the earth along with natural gas and oil. Butane turns into a liquid when put under pressure. It is sold as bottled gas. It is used to run heaters, stoves and motors, and to help make petrochemicals.
Buy-Back Center: Facility where individuals or groups bring recyclables in return for payment.
Buy Through: An agreement between utility and customer to import power when the customer's service would otherwise be interrupted.
Buyer: An entity that purchases electrical energy or services from the Power Exchange (PX) or through a bilateral contract on behalf of end-use customers.
By-product: Material, other than the principal product, generated as a consequence of an industrial process or as a breakdown product in a living system.
By-product: Anything produced in an industrial or biological process in addition to the principal product; a secondary and sometimes unexpected or unintended result.