A Glossary
Date: 14 Aug 2006
Abandoned Well: A well whose use has been permanently discontinued or which is in a state of such disrepair that it cannot be used for its intended purpose
Abiotic: A nonliving factor or element (e.g., light, water, heat, rock, energy, mineral)
Absorption: The uptake of water , other fluids, or dissolved chemicals by a cell or an organism (as tree roots absorb dissolved nutrients in soil)
Acclimatization: The physiological and behavioral adjustments of an organism to changes in its environment
Acid Deposition: A complex chemical and atmospheric phenomenon that occurs when emissions of sulfur and nitrogen compounds and other substances are transformed by chemical processes in the atmosphere, often far from the original sources, and then deposited on earth in either wet or dry form. The wet forms, popularly called "acid rain," can fall to earth as rain, snow, or fog. The dry forms are acidic gases or particulates
Acid Mine Drainage: Drainage of water from areas that have been mined for coal or other mineral ores. The water has a low pH because of its contact with sulfur-bearing material and is harmful to aquatic organisms
Acid Rain:Precipitation, in the form of snow, sleet, hail, rain, or fog, that has a low pH due to the emissions of pollutants into the atmosphere, especially sulfur dioxide and nitrogen oxides. (See: Acid Deposition.)
Acidic: The condition of water or soil that contains a sufficient amount of acid substances to lower the pH below 7.0
Active Ingredient: In any pesticide product, the component that kills, or otherwise controls, target pests. Pesticides are regulated primarily on the basis of active ingredients
Acute: The rapid development of severe symptoms that occur once or more than once in a short period of time following an exposure.
Adaptation: Changes in an organism's physiological structure or function or habits that allow it to survive in new surroundings
Adsorption: Removal of a pollutant from air or water by collecting the pollutant on the surface of a solid material; e.g., an advanced method of treating waste in which activated carbon removes organic matter from waste-water
Advisory: A non-regulatory document that communicates risk information to those who may have to make risk management decisions
Aeration: A process which promotes biological degradation of organic matter in water. The process may be passive (as when waste is exposed to air), or active (as when a mixing or bubbling device introduces the air)
Aerobic: Life or processes that require, or are not destroyed by, the presence of oxygen (See: Anaerobic)
Aerosol: A finely divided material suspended in air or other gaseous environment
Agent: Any physical, chemical, or biological entity that can be harmful to an organism (synonymous with Stressors)
Agricultural Pollution: Farming wastes, including runoff and leaching of pesticides and fertilizers; erosion and dust from plowing; improper disposal of animal manure and carcasses; crop residues, and debris
Air: A colorless, odorless, tasteless, gaseous mixture that is composed of oxygen, nitrogen, carbon dioxide, water vapor, argon and a small amount of other gases.
Air Quality Index (AQI): A guide used to measure and classify contaminants in the air.
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 photoactivation. About 100 contaminants have been identified, exclusive of pollen, fog, and dust, which are of natural origin. Air pollutants are often grouped in categories for ease in classification: solids, sulfur compounds, volatile organic chemicals, particulate matter, nitrogen compounds, oxygen compounds, halogen compounds, radioactive compound, and odors.
Air Pollution: The presence of contaminants or pollutant substances in the air that interfere with human health or welfare, or produce other harmful environmental effects
Air Quality Standards: The level of pollutants prescribed by regulations that are not be exceeded during a given time in a defined area.
Algae: Simple rootless plants that grow in sunlit waters in proportion to the amount of available nutrients. They can affect water quality adversely by lowering the dissolved oxygen in the water. They are food for fish and small aquatic animals.
Algal Blooms: Sudden spurts of algal growth, which can affect water quality adversely and indicate potentially hazardous changes in local water chemistry
Alkaline: The condition of water or soil which contains a sufficient amount of alkali substance to raise the pH above 7.0
Alkalinity: The capacity of bases to neutralize acids. An example is lime added to lakes to decrease acidity.
Allergen: A substance that causes an allergic reaction in individuals sensitive to it
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
Ambient Air: Any unconfined portion of the atmosphere: open air, surrounding air.
Ambient Air Quality Standards: (See: Criteria Pollutants and National Ambient Air Quality Standards)
Anaerobic: A life or process that occurs in, or is not destroyed by, the absence of oxygen
Anaerobic Decomposition: Reduction of the net energy level and change in chemical composition of organic matter caused by microorganisms in an oxygen-free environment
Animal Dander: Tiny scales of animal skin, a common indoor air pollutant
Aquifer: An underground geological formation, or group of formations, containing water. Aquifers are sources of groundwater for wells and springs. (See: Confined Aquifer and Unconfined Aquifer)
Area Sources: These sources are smaller polluters (electroplating operations, dry cleaners, and gas stations) previously exempt from any regulation of toxic air emissions.
Artesian well: A place on the surface where water from a confined aquifer flows out of the ground which occurs because the pressure pushes the water up
Asbestos: A mineral fiber that can pollute air or water and cause cancer or asbestosis when inhaled. EPA has banned or severely restricted its use in manufacturing and construction
Ash: The mineral content of a product remaining after complete combustion
Assimilation: The ability of a body of water to purify itself of pollutants
Assimilative Capacity: The capacity of a natural body of water to receive wastewaters or toxic materials without deleterious effects and without damage to aquatic life or humans who consume the water
Attainment: An area or region is said to be in attainment when it meets the set standards for air quality established by the EPA for the six criteria pollutants.
Attrition: Wearing or grinding down of a substance by friction. Dust from such processes contributes to air pollution.
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
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.
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.
Bed Load: Sediment particles resting on or near the channel bottom that are pushed or rolled along by the flow of water
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
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. (See: Biological Magnification)
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.
Bioconcentration: The accumulation of a chemical in tissues of a fish or other organism to levels greater than in the surrounding medium
Biodegradable: Capable of decomposing under natural conditions
Biodiversity: (See: Biological Diversity)
Biological Diversity:The variety and complexity of species present and interacting in an ecosystem and the relative abundance of each
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. (See: Bioaccumulants)
Biological Oxidation: Decomposition of complex organic materials by microorganisms that 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 Pollutants: Usually refers to the airborne pollutants of pollen, dust mites and pet dander
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
Biomass: All of the living material in a given area; often refers to vegetation
Biome: Entire community of living organisms in a single major ecological area (See: Biotic Community)
Biosphere: The portion of Earth and its atmosphere that can support life
Biota: The animal and plant life of a given region
Biotic: An environmental factor related to or produced by living organisms
Biotic Community: A naturally occurring assemblage of plants and animals that live in the same environment and are mutually sustaining and interdependent (See: Biome)
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
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
Buffer: A solution or liquid whose chemical makeup is such that it minimizes changes in pH when acids or bases are added to it
Bulky Waste: Large items of waste materials, such as appliances, furniture, large auto parts, trees, stumps
Burial Ground: (Graveyard) A disposal site for radioactive waste materials that uses earth or water as a shield
Buy-Back Center: Facility where individuals or groups bring reyclables in return for payment
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
Cap: A layer of clay, or other impermeable material installed over the top of a closed landfill to prevent entry of rainwater and minimize leachate.
Carbon Adsorption: A treatment system that removes contaminants from ground water or surface water by forcing it through tanks containing activated carbon treated to attract the contaminants.
Carbon Dioxide CO2: A colorless, odorless gas that consists of one atom of carbon and two atoms of oxygen.
Carbon Monoxide (CO): A colorless, odorless, poisonous gas produced by incomplete fossil fuel combustion.
Carcinogen: Any substance that can cause or aggravate cancer.
Carrier: 1.The inert liquid or solid material in a pesticide product that serves as a delivery vehicle for the active ingredient. Carriers do not have toxic properties of their own 2. Any material or system that can facilitate the movement of a pollutant into the body or cells
Carrying Capacity: 1. In wildlife management, the maximum number of animals an area can support during a given period 2. In recreation management, the amount of use a recreation area can sustain without loss of quality
Car Pooling: The process of two or more people sharing a car ride to save on fuel and cut down on emissions. Some major cities require car pooling on certain portions of roads during designated hours.
CAS Registration Number: A number assigned by the Chemical Abstract Service to identify a chemical
Case Study: A brief fact sheet providing risk, cost, and performance information on alternative methods and other pollution prevention ideas, compliance initiatives, voluntary efforts, etc.
Catalyst: A substance that changes the speed or yield of a chemical reaction without being consumed or chemically changed by the chemical reaction
Catalytic Converter: An air pollution abatement device that removes pollutants from motor vehicle exhaust, either by oxidizing them into carbon dioxide and water or reducing them to nitrogen
Catalytic Incinerator: A control device that oxidizes volatile organic compounds (VOCs) by using a catalyst to promote the combustion process. Catalytic incinerators require lower temperatures than conventional thermal incinerators, thus saving fuel and other costs
Cells: 1. In solid waste disposal, holes where waste is dumped, compacted, and covered with layers of dirt on a daily basis 2. The smallest structural part of living matter capable of functioning as an independent unit
Central Collection Point: Location were a generator of regulated medical waste consolidates wastes originally generated at various locations in his facility. The wastes are gathered together for treatment on-site or for transportation elsewhere for treatment and/or disposal. This term could also apply to community hazardous waste collections, industrial and other waste management systems
Channelization: Straightening and deepening streams so water will move faster, a marsh-drainage tactic that can interfere with waste assimilation capacity, disturb fish and wildlife habitats, and aggravate flooding
Chemical Oxygen Demand (COD): A measure of the oxygen required to oxidize all compounds, both organic and inorganic, in water
Chemical Stressors: Chemicals released to the environment through industrial waste, auto emissions, pesticides, and other human activity that can cause illnesses and even death in plants and animals
Chemical Treatment: Any one of a variety of technologies that use chemicals or a variety of chemical processes to treat waste
Chilling Effect: The lowering of the Earth's temperature because of increased particles in the air blocking the sun's rays (See: greenhouse effect)
Chisel Plowing: Preparing croplands by using a special implement that avoids complete inversion of the soil as in conventional plowing. Chisel plowing can leave a protective cover or crops residues on the soil surface to help prevent erosion and improve filtration
Chlorination: The application of chlorine to drinking water, sewage, or industrial waste to disinfect or to oxidize undesirable compounds
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 (See: fluorocarbons)
Chlorophenoxy: A class of herbicides that may be found in domestic water supplies and cause adverse health effects
Chlorosis: Discoloration of normally green plant parts caused by disease, lack of nutrients, or various air pollutants
Chronic Exposure: Multiple exposures occurring over an extended period of time or over a significant fraction of an animal's or human's lifetime (Usually seven years to a lifetime)
Cistern: Small tank or storage facility used to store water for a home or farm; often used to store rain water
Clarification: Clearing action that occurs during wastewater treatment when solids settle out. This is often aided by centrifugal action and chemically induced coagulation in wastewater
Clean Fuels: Blends or substitutes for gasoline fuels, including compressed natural gas, methanol, ethanol, and liquified petroleum gas
Clear Well: A reservoir for storing filtered water of sufficient quantity to prevent the need to vary the filtration rate with variations in demand. Also used to provide chlorine contact time for disinfection
Climate Change (Global Climate Change): The term 'climate change' is sometimes used to refer to all forms of climatic inconsistency, but because the Earth's climate is never static, the term is more properly used to imply a significant change from one climatic condition to another. In some cases, 'climate change' has been used synonymously with the term, 'global warming'; scientists however, tend to use the term in the wider sense to also include natural changes in climate (See: Global Warming)
Closed-Loop Recycling: Reclaiming or reusing wastewater for non-potable purposes in an enclosed process
Closing the Loop: A link in the circular chain of recycling events that promotes the use of products made with recycled materials
Closure: The procedure a landfill operator must follow when a landfill reaches its legal capacity for solid ceasing acceptance of solid waste and placing a cap on the landfill site
Coastal Zone: Lands and waters adjacent to the coast that exert an influence on the uses of the sea and its ecology, or whose uses and ecology are affected by the sea
Coliform Index: A rating of the purity of water based on a count of fecal bacteria
Coliform Organism: Microorganisms found in the intestinal tract of humans and animals. Their presence in water indicates fecal pollution and potentially adverse contamination by pathogens
Combined Sewers: A sewer system that carries both sewage and storm-water runoff. Normally, its entire flow goes to a waste treatment plant, but during a heavy storm, the volume of water may be so great as to cause overflows of untreated mixtures of storm water and sewage into receiving waters. Storm-water runoff may also carry toxic chemicals from industrial areas or streets into the sewer system.
Commingled Recyclables: Mixed recyclables that are collected together
Commodities: Economic goods or products before they are processed and/or given a brand name, such as a product of agriculture
Community: In ecology, an assemblage of populations of different species within a specified location in space and time. Sometimes, a particular subgrouping may be specified, such as the fish community in a lake or the soil arthropod community in a forest.
Complete Treatment: A method of treating water that consists of the addition of coagulant chemicals, flash mixing, coagulation-flocculation, sedimentation, and filtration. Also called conventional filtration.
Composting: The process of mixing decaying leaves, manure and other nutritive matter to improve and fertilize soil
Combustion: Burning, or rapid oxidation, accompanied by release of energy in the form of heat and light. A basic cause of air pollution.
Cone of Depression: A depression in the water table that develops around a pumped well
Cone of Influence: The depression, roughly conical in shape, produced in a water table by the pumping of water from a well
Confined Aquifer: An aquifer where the water is located between two impermeable layers. These are the source of artesian wells. (See: Aquifer)
Consumer: 1) Those organisms that obtain energy by feeding on other organisms and their remains or 2) a person buying goods or services for personal needs or to use in the production of other goods for resale
Consumptive Water Use: Water removed from available supplies without return to a water resources system, e.g. water used in manufacturing, agriculture, and food preparation
Contact Pesticide: A chemical that kills pests when it touches them, instead of by ingestion. Also, soil that contains the minute skeletons of certain algae that scratch and dehydrate waxy-coated insects
Contamination: Introduction into water, air, and soil of microorganisms, chemicals, toxic substances, wastes, or wastewater in a concentration that makes the medium unfit for its next intended use. Also applies to surfaces of objects, buildings, and various household and agricultural use products.
Contaminate: When a substance or organism is threatened by harmful or hazardous matter that has been introduced into its environment. A contaminant is any physical, chemical, biological or radiological substance or matter that has an adverse effect on air, water, or soil
Contour Plowing: Soil tilling method that follows the shape of the land to discourage erosion
Contour Strip Farming: A kind of contour farming in which row crops are planted in strips, between alternating strips of close-growing, erosion-resistant forage crops
Conventional Filtration: (See: Complete Treatment)
Cover Crop: A crop that provides temporary protection for delicate seedlings and/or provides a cover canopy for seasonal soil protection and improvement between normal crop production periods
Criteria Pollutants: Certain pollutants known to be hazardous to human health. The EPA has identified and set standards to protect human health and welfare for six: ozone, carbon monoxide, total suspended particulates, sulfur dioxide, lead, and nitrogen oxide. The term, "criteria pollutants" derives from the requirement that EPA must describe the characteristics and potential health and welfare effects of these pollutants. It is on the basis of these criteria that standards are set or revised.
Crop Consumptive Use: The amount of water transpired during plant growth plus what evaporated from the soil surface and foliage in the crop area
Crop Rotation: Planting a succession of different crops on the same land rea as opposed to planting the same crop time after time
Cross Contamination: The movement of underground contaminants from one level or area to another due to invasive subsurface activities
Cultural Eutrophication: Increasing rate at which water bodies "die" by pollution from human activities
Cumulative Exposure: The sum of exposures of an organism to a pollutant over a period of time
Decomposer: An organism, often microscopic in size, that obtains nutrients by consuming dead organic matter, thereby making nutrients accessible to other organisms; examples of decomposers include fungi, scavengers, rodents and other animals
Deep-Well Injection: Deposition of raw or treated, filtered hazardous waste by pumping it into deep wells, where it is contained in the pores of permeable subsurface rock
Delineate: To trace the outline; to draw; to sketch; to depict or picture
Delist: Use of the petition process to have a facility's toxic designation rescinded
Demand-side Waste Management: Process whereby consumers use purchasing decisions to communicate to product manufacturers that they prefer environmentally sound products packaged with the least amount of waste, made from recycled or recyclable materials, and containing no hazardous substances
Detection Limit: The lowest concentration of a chemical that can reliably be distinguished from a zero concentration
Dermal Toxicity: The ability of a pesticide or toxic chemical to poison people or animals by contact with the skin (See: Contact Pesticide)
Destratification: Vertical mixing within a lake or reservoir to totally or partially eliminate separate layers of temperature, plant, or animal life
Detectable Leak Rate: The smallest leak (from a storage tank), expressed in terms of gallons- or liters-per-hour, that a test can reliably discern with a certain probability of detection or false alarm
Development Effects: Adverse effects such as altered growth, structural abnormality, functional deficiency, or death observed in a developing organism
Dewater: 1. Remove or separate a portion of the water in a sludge or slurry to dry the sludge so it can be handled and disposed of 2. Remove or drain the water from a tank or trench
Diffused Air: A type of aeration that forces oxygen into sewage by pumping air through perforated pipes inside a holding tank
Diffusion: The movement of suspended or dissolved particles (or molecules) from a more concentrated to a less concentrated area. The process tends to distribute the particles or molecules more uniformly.
Dike: A low wall that can act as a barrier to prevent a spill from spreading
Diluent: Any liquid or solid material used to dilute or carry an active ingredient
Direct Discharger: A municipal or industrial facility which introduces pollution through a defined conveyance or system such as outlet pipes; a kind of point source pollution
Direct Runoff: Water that flows over the ground surface or through the ground directly into streams, rivers, and lakes
Discharge: Flow of surface water in a stream or canal or the outflow of ground water from a flowing artesian well, ditch, or spring. Can also apply tp discharge of liquid effluent from a facility or to chemical emissions into the air through designated venting mechanisms
Dispersant: A chemical agent used to break up concentrations of organic material such as spilled oil
Dissolved Oxygen (DO): The oxygen freely available in water, vital to fish and other aquatic life and for the prevention of odors. DO levels are considered a most important indicator of a water body's ability to support desirable aquatic life. Secondary and advanced waste treatment are generally designed to ensure adequate DO in waste-receiving waters.
Distillation: The act of purifying liquids through boiling, so that the steam or gaseous vapors condense to a pure liquid. Pollutants and contaminants may remain in a concentrated residue.
Diversion: 1. Use of part of a stream flow as water supply 2. A channel with a supporting ridge on the lower side constructed across a slope to divert water at a non-erosive velocity to sites where it can be used and disposed of
Downgradienat: The direction that groundwater flows; similar to "downstream" for surface water
Drainage Basin: The area of land that drains water, sediment, and dissolved materials to a common outlet at some point along a stream channel
Drainage Well: A well drilled to carry excess water off agricultural fields. Because they act as a funnel from the surface to the groundwater below. Drainage wells can contribute to groundwater pollution.
Drawdown: 1. The drop in the water table or level of water in the ground when water is being pumped from a well 2. The amount of water used from a tank or reservoir 3. The drop in the water level of a tank or reservoir
Dredging: Removal of mud from the bottom of water bodies. This can disturb the ecosystem and causes silting that kills aquatic life. Dredging of contaminated muds can expose biota to heavy metals and other toxics. Dredging activities may be subject to regulation under Section 404 of the Clean Water Act.
Dystrophic Lakes: Acidic, shallow bodies of water that contain much humus and/or other organic matter; contain many plants but few fish
Ecological/Environmental Sustainability: Maintenance of ecosystem components and functions for future generations
Ecological Integrity: A living system exhibits integrity if, when subjected to disturbance, it sustains and organizes self-correcting ability to recover toward a biomass end-state that is normal for that system. End-states other than the pristine or naturally whole may be accepted as normal and good.
Ecology: The relationship of living things to one another and their environment, or the study of such relationships
Ecosphere: The "bio-bubble" that contains life on earth, in surface waters, and in the air (See: Biosphere)
Ecosystem: A community of living organisms and their interrelated physical and chemical environment
Ecotone: A habitat created by the juxtaposition of distinctly different habitats; an edge habitat; or an ecological zone or boundary where two or more ecosystems meet
Effluent: Wastewater--treated or untreated--that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters.
Electrodialysis: A process that uses electrical current applied to permeable membranes to remove minerals from water. Often used to desalinize salty or brackish water.
Emission: Pollution discharged into the atmosphere from smokestacks, other vents, and surface areas of commercial or industrial facilities; from residential chimneys; and from motor vehicle, locomotive, or aircraft exhausts
Emission Factor: The relationship between the amount of pollution produced and the amount of raw material processed. For example, an emission factor for a blast furnace making iron would be the number of pounds of particulates per ton of raw materials.
Emission Standard: The maximum amount of air polluting discharge legally allowed from a single source, mobile or stationary
Emissions Trading: The creation of surplus emission reductions at certain stacks, vents or similar emissions sources and the use of this surplus to meet or redefine pollution requirements applicable to other emissions sources. This allows one source to increase emissions when another source reduces them, maintaining an overall constant emission level. Facilities that reduce emissions substantially may "bank" their "credits" or sell them to other facilities or industries.
Endangered Species: A species that is in danger of extinction throughout all or a significant portion of its range
Engineered Controls: Method of managing environmental and health risks by placing a barrier between the contamination and the rest of the site, thus limiting exposure pathways
Enrichment: The addition of nutrients (e.g. nitrogen, phosphorus, carbon compounds) from sewage effluent or agricultural runoff to surface water, greatly increases the growth potential for algae and other aquatic plants
Environment: The total of the surroundings (air, water, soil, vegetation, people, wildlife) influencing each living being's existence, including physical, biological and all other factors; the surroundings of a plant or animal, including other plants or animals, climate and location
Environmental Indicator: A measurement, statistic or value that provides a proximate gauge or evidence of the effects of environmental management programs or of the state or condition of the environment
Epidemiology: Study of the distribution of disease, or other health-related states and events in human populations, as related to age, sex, occupation, ethnicity, and economic status in order to identify and alleviate health problems and promote better health
Epilimnion: Upper waters of a thermally stratified lake subject to wind action
Equilibrium: The ability of an ecosystem to maintain stability among its biological resources (e.g., forest, fisheries, crops) so that there is a steady optimum yield
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
Estuary: Region of interaction between rivers and near-shore ocean waters, where tidal action and river flow mix fresh and salt water. Such areas include bays, mouths of rivers, salt marshes, and lagoons. These brackish water ecosystems shelter and feed marine life, birds, and wildlife (See: Wetlands)
Eutrophic Lakes: Shallow, murky bodies of water with concentrations of plant nutrients causing excessive production of algae (See: Dystrophic Lakes)
Eutrophication: The slow aging process during which a lake, estuary, or bay evolves into a bog or marsh and eventually disappears. During the later stages of eutrophication the water body is choked by abundant plant life due to higher levels of nutritive compounds such as nitrogen and phosphorus. Human activities can accelerate the process
Evaporation Ponds: Areas where sewage sludge is dumped and dried
Exempted Aquifer: Underground bodies of water defined in the Underground Injection Control program as aquifers that are potential sources of drinking water though not being used as such, and thus exempted from regulations barring underground injection activities
Exotic Species: A species that is not indigenous to a region
Exports: In solid waste program, municipal solid waste and recyclables transported outside the state or locality where they originated
Exposure: Radiation or pollutants that come into contact with the body and present a potential health threat. The most common routes of exposure are through the skin, mouth, or by inhalation.
Exposure Indicator: A characteristic of the environment measured to provide evidence of the occurrence or magnitude of a response indicator's exposure to a chemical or biological stress
Extinction: The complete elimination of a species from the earth
Extraction Well: A discharge well used to remove groundwater or air.
Fabric Filter: A cloth device that catches dust particles from industrial emissions
Facultative Bacteria: Bacteria that can live under aerobic or anaerobic conditions
Feasibility Study: 1. Analysis of the practicability of a proposal; e.g., a description and analysis of potential cleanup alternatives for a site such as one on the National Priorities List. The feasibility study usually recommends selection of a cost-effective alternative. It usually starts as soon as the remedial investigation is underway; together, they are commonly referred to as the "RI/FS". 2. A small-scale investigation of a problem to ascertain whether a proposed research approach is likely to provide useful data
Fecal Coliform Bacteria: Bacteria found in the intestinal tracts of mammals. Their presence in water or sludge is an indicator of pollution and possible contamination by pathogens
Feedlot: A confined area for the controlled feeding of animals. Tends to concentrate large amounts of animal waste that cannot be absorbed by the soil and, hence, may be carried to nearby streams or lakes by rainfall runoff
Fen: A type of wetland that accumulates peat deposits. Fens are less acidic than bogs, deriving most of their water from groundwater rich in calcium and magnesium. (See: Wetlands)
Filling: Depositing dirt, mud or other materials into aquatic areas to create more dry land, usually for agricultural or commercial development purposes, often with ruinous ecological consequences
Filtration: A treatment process, under the control of qualified operators, for removing solid (particulate) matter from water by means of porous media such as sand or a man-made filter; often used to remove particles that contain pathogens
Finished Water: Water is "finished" when it has passed through all the processes in a water treatment plant and is ready to be delivered to consumers
First Draw: The water that comes out when a tap is first opened, likely to have the highest level of lead contamination from plumbing materials
Flare: A control device that burns hazardous materials to prevent their release into the environment; may operate continuously or intermittently, usually on top of a stack
Flocculation: Process by which clumps of solids in water or sewage aggregate through biological or chemical action so they can be separated from water or sewage
Floodplain: The flat or nearly flat land along a river or stream or in a tidal area that is covered by water during a flood
Flue Gas: The air coming out of a chimney after combustion in the burner it is venting. It can include nitrogen oxides, carbon oxides, water vapor, sulfur oxides, particles and many chemical pollutants
Fluoridation: The addition of a chemical to increase the concentration of fluoride ions in drinking water to reduce the incidence of tooth decay
Food Waste: Uneaten food and food preparation wastes from residences and commercial establishments such as grocery stores, restaurants, and produce stands, institutional cafeterias and kitchens, and industrial sources like employee lunchrooms
Food Web: The feeding relationships by which energy and nutrients are transferred from one species to another
Fossil Fuel: Fuel derived from ancient organic remains; e.g. peat, coal, crude oil, and natural gas
Fresh Water: Water that generally contains less than 1,000 milligrams-per-liter of dissolved solids
Fuel Efficiency: The proportion of energy released by fuel combustion that is converted into useful energy
Fuel Switching: 1. A precombustion process whereby a low-sulfur coal is used in place of a higher sulfur coal in a power plant to reduce sulfur dioxide emissions. 2. Illegally using leaded gasoline in a motor vehicle designed to use only unleaded
Fugitive Emissions: Emissions not caught by a capture system
Fumigant: A pesticide vaporized to kill pests. Used in buildings and greenhouses
Fungistat: A chemical that keeps fungi from growing
Fungus (Fungi): Molds, mildews, yeasts, mushrooms, and puffballs, a group of organisms lacking in chlorophyll (i.e. are not photosynthetic) and which are usually non-mobile, filamentous, and multicellular. Some grow in soil, others attach themselves to decaying trees and other plants whence they obtain nutrients. Some are pathogens, others stabilize sewage and digest composted waste
Furrow Irrigation: Irrigation method in which water travels through the field by means of small channels between each groups of rows
Garbage: Animal and vegetable waste resulting from the handling, storage, sale, preparation, cooking, and serving of foods
Gas Chromatograph/Mass Spectrometer: Instrument that identifies the molecular composition and concentrations of various chemicals in water and soil samples
Gasahol: Mixture of gasoline and ethanol derived from fermented agricultural products containing at least nine percent ethanol. Gasohol emissions contain less carbon monoxide than those from gasoline
Gaseous: Of or pertaining to existing in the state of gas, as opposed to solid or liquid states.
Generator: 1. A facility or mobile source that emits pollutants into the air or releases hazardous waste into water or soil. 2. Any person, by site, whose act or process produces regulated medical waste or whose act first causes such waste to become subject to regulation. Where more than one person (e.g. doctors with separate medical practices) are located in the same building, each business entity is a separate generator
Geological Log: A detailed description of all underground features (depth, thickness, type of formation) discovered during the drilling of a well
Geophysical Log: A record of the structure and composition of the earth encountered when drilling a well or similar type of test hold or boring
Geothermal Heat Pump (Groundsource Heat Pump): These heat pumps are underground coils to transfer heat from the ground to the inside of a building (See: Heat Pump; Water Source Heat Pump)
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 emissions 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 (See: Climate Change)
Grain Loading: The rate at which particles are emitted from a pollution source. Measurement is made by the number of grains per cubic foot of gas emitted
Grasscycling: Source reduction activities in which grass clippings are left on the lawn after mowing
Grassed Waterway: Natural or constructed watercourse or outlet that is shaped or graded and established in suitable vegetation for the disposal of runoff water without erosion
Gray Water: Domestic wastewater composed of wash water from kitchen, bathroom, and laundry sinks, tubs, and washers
Greenhouse Effect: The warming of the Earth's atmosphere attributed to a buildup 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 infra-red radiation atmosphere opaque to infra-red radiation, thereby preventing a counterbalancing loss of heat
Greenhouse Gas: A gas, such as carbon dioxide or methane, which contributes to potential climate change
Groundwater: Water that infiltrates the soil and is located in underground reservoirs called aquifers
Groundwater Discharge: Ground water entering near coastal waters which has been contaminated by landfill leachate, deep well injection of hazardous wastes, septic tanks, etc
Gully Erosion: Severe erosion in which trenches are cut to a depth greater than 30 centimeters (a foot). Generally, ditches deep enough to cross with farm equipment are considered gullies
Habitat: The place where a population (e.g. human, animal, plant, microorganism) lives and its surroundings, both living and non-living
Habitat Indicator: A physical attribute of the environment measured to characterize conditions necessary to support an organism, population, or community in the absence of pollutants; e.g. salinity of estuarine waters or substrate type in streams or lakes
Half-Life: 1. The time required for a pollutant to lose one-half of its original coconcentrationor example, the biochemical half-life of DDT in the environment is 15 years. 2. The time required for half of the atoms of a radioactive element to undergo self-transmutation or decay (half-life of radium is 1620 years). 3. The time required for the elimination of half a total dose from the body
Hard Water: Alkaline water containing dissolved salts that interfere with some industrial processes and prevent soap from sudsing
Hauler: Garbage collection company that offers complete refuse removal service; many will also collect recyclables
Hazardous Substance: 1. Any material that poses a threat to human health and/or the environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically reactive. 2. Any substance designated by EPA to be reported if a designated quantity of the substance is spilled in the waters of the United States or is otherwise released into the environment (See: Household Hazardous Waste)
Hazardous Waste: By-products of society that can pose a substantial or potential hazard to human health or the environment when improperly treated, stored, transported, disposed, or otherwise managed. Possesses at least one of four characteristics (ignitability, corrosivity, reactivity, or toxicity), or appears on special EPA lists
Heat Island Effect: A "dome" of elevated temperatures over an urban area caused by structural and pavement heat fluxes, and pollutant emissions
Heat Pump: An electric device with both heating and cooling capabilities. It extracts heat from one medium at a lower (the heat source) temperature and transfers it to another at a higher temperature (the heat sink), thereby cooling the first and warming the second (See: Geothermal Heat Pump, Water Source Heat Pump)
Heavy Metals: Metallic elements with high atomic weights; (e.g. mercury, chromium, cadmium, arsenic, and lead); can damage living things at low concentrations and tend to accumulate in the food chain
Herbivore: An animal that feeds on plants
Heterotrophic Organisms: Species that are dependent on organic matter for food
High-Risk Community: A community located within the vicinity of numerous sites of facilities or other potential sources of envienvironmentalosure/health hazards which may result in high levels of exposure to contaminants or pollutants
Holding Pond: A pond or reservoir, usually made of earth, built to store polluted runoff
Homeostasis: The tendency for a system by resisting change to remain in a state of equilibrium
Household Hazardous Waste: Hazardous products used and disposed of by residential as opposed to industrial consumers. Includes paints, stains, varnishes, solvents, pesticides, and other materials or products containing volatile chemicals that can catch fire, react or explode, or that are corrosive or toxic (See: Hazardous Waste; Hazardous Substance)
Household Waste (Domestic Waste): Solid waste, composed of garbage and rubbish, which normally originates in a private home or apartment house. Domestic waste may contain a significant amount of toxic or hazardous waste
Hydrologic Cycle: The cyclic transfer of water vapor from the Earth's surface into the atmosphere, from the atmosphere back to earth, and through runoff into streams, rivers, and lakes, and ultimately into the oceans
Incinerating: Burning to ashes; reducing to ashes
Integrated Pest Management: A variety of pest control methods that include repairs, traps, bait, poison, etc. to eliminate pests
Irrigation: Water used for agriculture (growing crops)
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Land Subsidence: Occurs when large amounts of ground water have been withdrawn from certain types of rocks, such as fine-grained sediments. When the water is withdrawn, the rocks fall in on itself.
Legionnaires' Disease: A severe illness of uncertain cause that has occurred sporadically in various locations. It was named after its initial outbreak during a 1976 American Legion convention where several attendees became ill.
Lentic: Relating to or living in still water
Lotic:Relating to or living in actively moving water
Microorganism: Bacteria, yeast, simple fungi, algae, protozoan, and a number of other organisms that are microscopic in size. Most are beneficial, but some produce disease.
Mitigation: The policy of constructing or creating man-made habitats, such as wetlands, to replace those lost to development
Mobile Sources: Include passenger cars, trucks, buses, motorcycles, boats, and aircraft. These emissions account for over half of our air pollution.
National Ambient Air Quality Standards: Standards established by EPA that apply for outdoor air throughout the country (See: Criteria Pollutants, Emissions Trading)
Niche: (Ecological) The role played by an organism in an ecosystem; its food preferences, requirements for shelter, special behaviors and the timing of its activities (e.g., nocturnal, diurnal), interaction with other organisms and its habitat
Nitrogen Oxides: NOx - Gases formed in great part from atmospheric nitrogen and oxygen when combustion takes place under conditions of high temperature and pressure. Nitrogen oxides include nitric oxide (NO) and nitrogen dioxide (NO2).
Non-attainment: A region or area that fails to meet the national standards set by EPA for each of the six criteria pollutants.
Nonpoint Source Pollution: Contamination that originates from many locations that all discharge into a location (e.g., a lake, stream, land area)
Nonrenewable Resources: Substances (e.g., oil, gas, coal, copper, gold) that, once used, cannot be replaced in this geological age
Organic: Any substance that contains carbon, the element usually associated with life processes.
Ozone: Three-molecule oxygen compound (03) found in two layers of the Earth's atmosphere. One layer of beneficial ozone occurs seven to 18 miles above the surface and shields the Earth from ultraviolet light. Scientists have documented several holes in this layer. Ozone also concentrates at the surface as a result of reactions between byproducts of fossil fuel combustion and sunlight, having harmful respiratory health effects in some people.
Particulate Matter: Liquid or solid particles such as smoke, dust, mist, or smog found in air emissions.
Pet Dander: Scaly or shedded dry skin from the coat or feathers of an animal.
Photochemical: A chemical reaction in the atmosphere that is triggered by sunlight. Pollutants are often created from a photochemical reaction.
Point Source Pollution: Pollutants discharged from a single identifiable location (e.g., pipes, ditches, channels, sewers, tunnels, containers of various types)
Pollution : Any substances in water, soil, or air that degrade the natural quality of the environment, offends the senses of sight, taste, or smell, or causes a health hazard. The usefulness of the natural resource is usually impaired by the presence of pollutants and contaminants.
Polychlorinated Biphenyl: PCBs - A group of toxic, persistent chemicals used in electrical transformers and capacitors for insulating purposes, and in gas pipeline systems as a lubricant. The sale and new use of PCBs were banned by law in 1979.
Pest: A label applied to an organism when it is in competition with humans for some resource
Predator: an organism that uses other live organisms (prey) as an energy source and, in doing so, removes the prey individuals from the population (Colinvaux 1986).