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Dictionary or Glossary of Environmental Terms (Definitions)  

Some definitions of commonly used environmental terms. What is....

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DEFINITIONS (Environmental Glossary)
Here is a list of some typical environmental terms used in conservation, open space, pollution prevention or wildlife documents. Be aware that regulations may specify other definitions, and Federal, State and Local definitions may vary. Also see Acronyms List.
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  • AA (atomic absorption) – A spectroscopy method used to determine the elemental composition of a sample. In this method, the sample is vaporized and the amount of light it absorbs is measured.
  • accuracy – The degree of agreement of a measurement with an accepted reference or true value. It can be expressed as the difference between two values, as a percentage of the reference or true value, or as a ratio of the measured value and the reference or true value.
  • activation – The process of making a material radioactive by bombardment with neutrons, protons, or other high energy particles.
  • activation product – A material that has become radioactive by bombardment with neutrons, protons, or other high energy particles.
  • activity – Synonym for radioactivity.
  • adelgid - either of two aphids (genus Adelges) with a white woolly coating that have been accidentally introduced into North America. See article on Wooly Adelgid.
  • Administrative Record – A collection of documents established in compliance with CERCLA. Consists of information the CERCLA lead agency uses in its decision on the selection of response actions. The Administrative Record file should be established at or near the facility and made available to the public. An Administrative Record can also be the record for any enforcement case.
  • aerobic – An aerobic organism is one that lives, acts, or occurs only in the presence of oxygen.
  • aerosol – A gaseous suspension of very small particles of liquid or solid.
  • aesthetic resources - encompasses not only the appearance of a place, from its natural to its built environment, but also the effect of its appearance: how does the place “feel”? (as used in Woodstock A Plan of Open Space and Conservation)
  • air stripping – A process for removing VOCs from contaminated water by forcing a stream of air through the water in a vessel. The contaminants evaporate into the air stream. The air may be further treated before it is released into the atmosphere.
  • ALARA (As Low As Reasonably Achievable) – A phrase that describes an approach to minimize exposures to individuals and minimize releases of radioactive or other harmful material to the environment to levels as low as social, technical, economic, practical, and public policy considerations will permit. ALARA is not a dose limit, but a process with a goal to keep dose levels as far below applicable limits as is practicable. alpha radiation – The emission of alpha particles during radioactive decay. Alpha particles are identical in makeup to the nucleus of a helium atom and have a positive charge. Alpha radiation is easily stopped by materials as thin as a sheet of paper and has a range in air of only an inch or so. Despite its low penetration ability, alpha radiation is densely ionizing and therefore very damaging when ingested or inhaled. Naturally occurring radioactive sources such as radon emit alpha radiation.
  • ambient air – The surrounding atmosphere, usually the outside air, as it exists around people, animals, plants, and structures. It does not include the air immediately adjacent to emission sources.
  • analyte – A constituent that is being analyzed.
  • anneal – To heat a material and then cool it. In the case of thermoluminescent dosimeters (TLDs), this is done to reveal the amount of radiation the material had absorbed.
  • anion – A negatively charged ion, often written as a superscript negative sign after an element symbol, such as Cl-.
  • anthropogenic – Resulting from human activity; anthropogenic radiation is human-made, not naturally occurring.
  • AOC (area of concern) – Under CERCLA, this term refers to an area where releases of hazardous substances may have occurred or a location where there has been a release or threat of a release of a hazardous substance, pollutant, or contaminant (including radionuclides). AOCs may include, but need not be limited to, former spill areas, landfills, surface impoundments, waste piles, land treatment units, transfer stations, wastewater treatment units, incinerators, container storage areas, scrap yards, cesspools, tanks, and associated piping that are known to have caused a release into the environment or whose integrity has not been verified.
  • aquifer – An underground layer of consolidated rock ledge, unconsolidated gravel, or sediment containing enough water to supply a well. (Source: SWAP) Water in an aquifer is commonly called groundwater Aquifers can be a source of water for domestic, agricultural, and industrial uses.
  • Aquifer Protection Area - The critical area in a stratified drift aquifer that provides water to a public water supply well. Approximately 121 aquifer protection areas have been designated around the state for individual wells or groups of wells that serve more than 1,000 people, in accordance with Sections 22a-354a through 22a-354bb of the Connecticut General Statutes
  • ARPA (Archaeological Resources Protection Act) This law, passed in 1979, has been amended four times. It protects any material remains of past human life or activities that are of archaeological interest. Known and potential sites of interest are protected from uncontrolled excavations and pillage, and artifacts found on public and Indian lands are banned from commercial exchange.
  • AS/SVE (air sparging/soil vapor extraction) – A method of extracting volatile organic compounds from the groundwater, in place, using compressed air. (In contrast, air stripping occurs in a vessel.) The vapors are typically collected using a soil vapor extraction system.
  • Atlantic White Cedar - Chamaecyparis thyoides - See article.

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  • background – A sample or location used as reference or control to compare analytical results to those in areas that could not have been impacted by an organization's operations.
  • background radiation – Radiation present in the environment as a result of naturally occurring radioactive materials in the Earth, cosmic radiation, or human-made radiation sources, including fallout.
  • bedrock - the solid rock that underlies all soil, sand, clay, gravel and loose material on the Earth's surface.
  • bedrock well - A well constructed by drilling a hole and inserting a casing to support the sides of the hole. The portion of the well that is in consolidated rock may not require support of a casing. (Source: SWAP)
  • beta radiation – Beta radiation is composed of charged particles emitted from a nucleus during radioactive decay. A negatively charged beta particle is identical to an electron. A positively charged beta particle is called a positron. Beta radiation is more penetrating than alpha radiation, but it may be stopped by materials such as aluminum or Lucite™ panels. Naturally occurring radioactive elements such as potassium-40 emit beta radiation.
  • bioaccumulation - accumulate and concentrate in a biological system.
  • bioretention - A practice to manage and treat stormwater runoff by using a specially designed planting soil bed and planting materials to filter runoff stored in a shallow depression. The areas consist of a mix of elements each designed to perform different functions in the removal of pollutants and attenuation of stormwater runoff. (Source: CT Stormwater Quality Manual)
  • blank – A sample (usually reagent-grade water) used for quality control of field sampling methods, to demonstrate that cross contamination has not occurred.
  • blowdown – Water discharged from either a boiler or cooling tower in order to prevent the build-up of inorganic matter within the boiler or tower and to prevent scale formation (i.e., corrosion).
  • BOD (biochemical oxygen demand) – A measure of the amount of oxygen in biological processes that breaks down organic matter in water; a measure of the organic pollutant load. It is used as an indicator of water quality.
  • Brownfields: Brownfields are real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. Cleaning up and reinvesting in these properties takes development pressures off of undeveloped, open land, and both improves and protects the environment. (Source: EPA)
  • Bq (becquerel) – A quantitative measure of radioactivity. This alternate measure of activity is used internationally and with increasing frequency in the United States. One Bq of activity is equal to one nuclear decay per second.
  • Buffer, Conservation - small areas or strips of land that are permanently vegetated. They are designed to intercept pollutants, and address other environmental concerns.

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  • CAA (Clean Air Act), CAA Amendments (CAAA) – The original Clean Air Act was passed in 1963, but the U.S. air pollution control program is based on the 1970 version of the law. The 1990 Clean Air Act Amendments (CAAA) are the most far-reaching revisions of the 1970 law. In common usage, references to the CAA typically mean to the 1990 amendments. (source: EPA’s “Plain English Guide to the Clean Air Act” glossary @ http://www.epa.gov/oar/oaqps/ peg_caa )
  • cap – A layer of natural or synthetic material, such as clay or gunite, used to prevent rainwater from penetrating and spreading contamination. The surface of the cap is generally mounded or sloped so water will drain off.
  • carbon adsorption/carbon treatment – A treatment system in which contaminants are removed from groundwater, surface water, and air by forcing water or air through tanks containing activated carbon (a specially treated material that attracts and holds or retains contaminants).
  • carbon tetrachloride – A poisonous, nonflammable, colorless liquid, CCl4.
  • catch basin - A structure placed below grade to conduct water from a street or other paved surface to the storm sewer. (Source: CT Stormwater Quality Manual)
  • CERCLA (Comprehensive Environmental Response, Compensation and Liability Act) – Pronounced “sir-klah” and commonly known as Superfund, this law was enacted by Congress on December 11, 1980. It created a tax on the chemical and petroleum industries and provided broad federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment. CERCLA established prohibitions and requirements concerning closed and abandoned hazardous waste sites; provided for liability of persons responsible for releases of hazardous waste at these sites; and established a trust fund to provide for cleanup when no responsible party could be identified The law authorizes two kinds of response actions: short term removals, where actions may be taken to address releases or threatened releases requiring prompt response, and long-term remedial response actions that permanently and significantly reduce the dangers associated with releases or threats of releases of hazardous substances that are serious, but not immediately life threatening. These actions can be conducted only at sites listed on EPA’s National Priorities List (NPL). CERCLA was amended by the Superfund Amendments and Reauthorization Act (SARA) on October 17, 1986.
  • CFR (Code of Federal Regulations) – A codification of all regulations developed and finalized by federal agencies in the Federal Register. The CFR is arranged by “title,” with Title 10 covering energy- and radiation-related issues, and Title 40 covering protection of the environment. Subparts within the titles are included in citations, as in “40 CFR Subpart H.” The CFR is available online at http://www. gpoaccess.gov/cfr/index.html.
  • characterization – Facility or site sampling, monitoring, and analysis activities to determine the extent and nature of contamination. Characterization provides the basis of necessary technical information to select an appropriate cleanup alternative.
  • check dam - Small temporary dam constructed across a swale or drainage ditch to reduce the velocity of concentrated stormwater flows. (Source: CT Stormwater Quality Manual)
  • chemical oxygen demand - A measure of the amount of organic material that can be chemically oxidized. (Source: CT Stormwater Quality Manual)
  • Ci (curie) – A quantitative measure of radioactivity. One Ci of activity is equal to 3.7E+10 decays per second. One curie has the approximate activity of 1 gram of radium. It is named after Marie and Pierre Curie, who discovered radium in 1898.
  • Class I Land - Lands owned by a water company that are within 250 feet of a reservoir used for a drinking water supply, within 100 feet of its tributary, or within 200 feet of a public water supply well. (source: SWAP)
  • Class II Land - Lands within the public drinking water supply watershed but not included in Class I, or completely off the watershed but within 150 feet of a storage reservoir and the tributaries that directly enter it. (Source: SWAP)
  • closure – Under RCRA regulations, this term refers to a hazardous or solid waste management unit that is no longer operating and where potential hazards that it posed have been addressed (through clean up, immobilization, capping, etc.) to the satisfaction of the regulatory agency.
  • COC or chain-of-custody – A method for documenting the history and possession of a sample from the time of collection, through analysis and data reporting, to its final disposition.
  • cocktail – a mixture of chemicals used for scintillation counting.
  • collective Effective Dose Equivalent – A measure of health risk to a population exposed to radiation. It is the sum of the EDEs of all individuals within an exposed population, frequently considered to be within 50 miles (80 kilometers) of an environmental release point. It is expressed in personrem or person-sievert.
  • Committed Effective Dose Equivalent – The total EDE received over a 50-year period following the internal deposition of a radionuclide. It is expressed in rems or sieverts.
  • committed open space - land that is presently open and committed to remain as such. It is usually owned (either outright, or preserved via an easement or development rights) by state, municipal, public utilities and not-profit organizations. Such areas include forests, parks, water accesses, preserves, wildlife management areas, fisheries, and farmland in the Purchase of Development Rights (PDR) Program, local Land Trust and conservation organization areas. (Source: Woodstock A Plan of Open Space and Conservation.)
  • composite sample – A sample of an environmental medium containing a certain number of sample portions collected over a period of time, possibly from different locations. The constituent samples may or may not be collected at equal time intervals over a predefined period of time, such as 24 hours. confidence interval – A numerical range within which the true value of a measurement or calculated value lies.
  • conservative – Estimates that err on the side of caution because all possibly deleterious components are included at generous or high values.
  • conservation buffers - small areas or strips of land that are permanently vegetated. They are designed to intercept pollutants, and address other environmental concerns.
  • conservation easement - A conservation easement is a legal agreement that a property owner makes to restrict the type and amount of development that may take place on a property to preserve natural/historic resources.  Each easement's restrictions are tailored to the particular property and the interests of the individual owner.  An easement "runs with the land", which means that the original owner and all subsequent owners are bound by the restrictions of the easement. 
  • Contaminant Release Points - Sites or locations where a variety of solid and/or liquid wastes resulting from accidental spills, leaks or discharges were released to the environment. These wastes are known or presumed to be capable of impairing surface or groundwater quality. While these sources may fall within a drinking water supply source area, they may or may not presently be discharging to the environment or causing source water contamination. (Source: SWAP)
  • Contaminant Source Inventory - The process of identifying and inventorying potential contaminant sources within a delineated source water area. The process includes recording existing data, describing potential contaminant sources within the drinking water source area, targeting likely contaminant sources for further investigation, collecting and interpreting new information on existing or potential contaminant sources through surveys, and the verifying accuracy and reliability of the information gathered.
  • contamination – Unwanted radioactive and/or hazardous material that is dispersed on or in equipment, structures, objects, air, soil, or water.
  • control – See background.
  • cooling water – Water used to cool machinery and equipment. Contact cooling water is any wastewater that contacts machinery or equipment to remove heat from the metal; noncontact cooling water has no direct contact with any process material or final product. Process wastewater cooling water is water used for cooling that may have become contaminated through contact with process raw materials or final products.
  • cover boards – Sheets of plywood placed on the ground near ponds to serve as attractive habitat for salamanders, usually as part of a population study.
  • Critical Area - All land within 250 ft of the high-water mark of a reservoir or lands within 100 ft of any watercourse inside watershed dividing line (Type-I class land). (Source: SWAP)
  • curie – See Ci.
  • CWA (Clean Water Act) – Growing public awareness and concern for controlling water pollution led to enactment of the Federal Water Pollution Control Act Amendments of 1972. As amended in 1977, this law became commonly known as the Clean Water Act. It established the basic structure for regulating discharges of pollutants into the waters of the United States, giving EPA the authority to implement pollution control programs such as setting wastewater standards for industry. The CWA also continued requirements to set water quality standards for all contaminants in surface waters and made it unlawful for any person to discharge any pollutant from a point source into navigable waters unless a permit was obtained. The CWA also funded the construction of sewage treatment plants and recognized the need for planning to address the critical problems posed by nonpoint source pollution. Revisions in 1981 streamlined the municipal construction grants process. Changes in 1987 phased out the construction grants program. Title I of the Great Lakes Critical Programs Act of 1990 put into place parts of the Great Lakes Water Quality Agreement of 1978, signed by the U.S. and Canada; the two nations agreed to reduce certain toxic pollutants in the Great Lakes. Over the years many other laws have changed parts of the CWA. (source: http://www.epa.gov/region5/ water/cwa.htm)
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  • D2O – See heavy water.
  • Darcy's Law - An equation stating that the rate of fluid flow through a porous medium is proportional to the potential energy gradient within the fluid. The constant of proportionality is the hydraulic conductivity, which is a property of both the porous medium and the fluid moving through the porous medium. (Source: CT Stormwater Quality Manual)
  • daughter, progeny – A given nuclide produced by radioactive decay from another nuclide (the “parent”). See also radioactive series.
  • DCG (derived concentration guide) – The concentration of a radionuclide in air or water that, under conditions of continuous exposure for one year by a single pathway (e.g., air inhalation, absorption, or ingestion), would result in an effective dose equivalent of 100 mrem (1 mSv). The values were established in DOE Order 5400.5.
  • decay product – A nuclide resulting from the radioactive disintegration of a radionuclide, being formed either directly or as a result of successive transformations in a radioactive series. A decay product may be either radioactive or stable. decontamination – The removal or reduction of radioactive or hazardous contamination from facilities, equipment, or soils by washing, heating, chemical or electrochemical action, mechanical cleaning, or other techniques to achieve a stated objective or end condition.
  • deicers - Materials applied to reduce icing on paved surfaces. These consist of salts and other formulated materials that lower the melting point of ice, including sodium chloride, calcium chloride, calcium magnesium acetate,and blended products consisting of various combinations of sodium, calcium, magnesium, chloride, and other constituents. (Source: CT Stormwater Quality Manual)
  • detention basin - holds water for a limited period of time from a larger basin area to prevent flooding and releases all the water contained in a short period of time. Also see retention basin. (Source: wikipedia.org)
  • devise - see testamentary gift
  • disposal – Final placement or destruction of waste.
  • diversion - The taking of water from a stream or other body of water into a canal, pipe or conduit that flows into a drinking water reservoir. (Source: SWAP)
  • DOE (Department of Energy) – The federal agency that promotes scientific and technical innovation to support the national, economic, and energy security of the United States.
  • dosimeter – A portable detection device for measuring exposure to ionizing radiation.
  • downgradient – In the direction of groundwater flow from a designated area; analogous to “downstream.”
  • DQO (Data Quality Objective) –The Data Quality Objective (DQO) process was developed by EPA for facilities to use when describing their environmental monitoring matrices, sampling methods, locations, frequencies, and measured parameters, as well as methods and procedures for data collection, analysis, maintenance, reporting, and archiving. The DQO process also addresses data that monitor quality assurance and quality control.
  • drift fence – A stretch of temporary fencing to prevent an animal population from leaving the area, sometimes used as part of a population study.
  • drumlin - an elongate or oval hill of glacial drift
  • dry weight – The dry weight concentration of a substance is after a sample is dried for analysis. Dry weight concentrations are typically higher than wet weight values.
  • dry well - Small excavated pits or trenches filled with aggregate that receive clean stormwater runoff primarily from building rooftops. Dry wells function as infiltration systems to reduce the quantity of runoff from a site. The use of dry wells is applicable for small drainage areas with low sediment or pollutant loadings and where soils are sufficiently permeable to allow reasonable rates of infiltration. (Source: CT Stormwater Quality Manual)
  • duff - partly decayed dead vegetation on the forest floor. See article about Wood Frogs.
  • dug well - A well excavated into a shallow aquifer. (Source: SWAP)
  • D-waste – Liquid waste containing radioactivity.

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  • EA (Environmental Assessment) – A report that identifies potentially significant effects from any federally approved or funded project that might change the physical environment. If an EA identifies a “significant” potential impact (as defined by NEPA), an Environmental Impact Statement (EIS) must be researched and prepared.
  • ecosystem - the complex of a community of organisms and its environment functioning as an ecological unit (source: Merriam-Webster)
  • EDB (ethylene dibromide) – A colorless, nonflammable, heavy liquid with a sweet odor; slightly soluble in water. Although the U.S. Department of Health and Human Services has determined that ethylene dibromide may reasonably be anticipated to be a carcinogen, it is still used to treat felled logs for bark beetles; to control wax moths in beehives; as a chemical intermediary for dyes, resins, waxes, and gums; to spot-treat milling machinery; and to control Japanese beetles in ornamental plants.
  • EDE (Effective Dose Equivalent) – A value used to express the health risk from radiation exposure to tissue in terms of an equivalent whole body exposure. It is a “normalized” value that allows the risk from radiation exposure received by a specific organ or part of the body to be compared with the risk due to whole-body exposure. The EDE equals the sum of the doses to different organs of the body multiplied by their respective weighting factors. It includes the sum of the EDE due to radiation from sources external to the body and the committed effective dose equivalent due to the internal deposition of radionuclides. EDE is expressed in rems or sieverts. effluent – Any liquid discharged to the environment, including stormwater runoff at a site or facility.
  • environmental monitoring – Sampling for contaminants in air, water, sediment, soil, food stuffs, plants, and animals, either by directly measuring or by collecting and analyzing samples.
  • emissions – Any gaseous or particulate matter discharged to the atmosphere.
  • EMS (Environmental Management System) – a systematic approach to managing environmental hazards and potential impacts. It helps identify potential environmental risks and prevent negative impacts by putting necessary controls and programs in place, monitor and measure environmental performance, continually improve, and communicate to interested parties how an organization is doing.
  • Endangered Species - any native species documented by biological research and inventory to be in danger of extirpation throughout all or a significant portion of its range within the state and to have no more than five occurrences in the state, and any species determined to be an "endangered species" pursuant to the federal Endangered Species Act. (as defined in CT by PA 89-224).
  • Endowment: (as used in conservation). The gift of land may be accompanied by an endowment fund for the purpose of supporting the conservation effort in perpetuity.
  • environment – Surroundings (including air, water, land, natural resources, flora, fauna, and humans) in which an organization operates, and the interrelation of the organization and its surroundings.
  • environmental aspect – Elements of an organization’s activities, products, or services that can interact with the surrounding air, water, land, natural resources, flora, fauna, and humans.
  • environmental impact – Any change to the surrounding air, water, land, natural resources, flora, and fauna, whether adverse or beneficial, wholly or partially resulting from an organization’s activities, products, or services.
  • environmental media – Includes air, groundwater, surface water, soil, flora, and fauna. environmental monitoring or surveillance.
  • environmental sensitivity - General conditions in a drinking water source area, including type and condition of drinking water source, DEP surface or groundwater classification, and evidence of contamination caused by human activity that can have an affect on water quality. (Source: SWAP)
  • EPA (U. S. Environmental Protection Agency) – The federal agency responsible for developing and enforcing environmental laws. Although state or local regulatory agencies may be authorized to administer environmental regulatory programs, EPA generally retains oversight authority.
  • EPCRA (Emergency Planning and Community Right-to- Know Act) – Also known as Title III of SARA, EPCRA was enacted by Congress as the national legislation on community safety, to help local groups protect public health, safety, and the environment from chemical hazards. To implement EPCRA, Congress required each state to appoint a State Emergency Response Commission (SERC). The SERCs were required to divide their states into Emergency Planning Districts and to name a Local Emergency Planning Committee for each district. Broad representation by fire fighters, health officials, government and media representatives, community groups, industrial facilities, and emergency managers ensures that all necessary elements of the planning process are represented. (source: http://www.epa.gov/region5/defs/html/epcra.htm)
  • erosion - The wearing away of land surface by running water, wind, ice or other geological agents, including such processes as gravitational creep. (Source: CT Stormwater Quality Manual)
  • erosion and sediment control - A device placed, constructed on, or applied to the landscape that pre-vents or curbs the detachment of soil, its movement and/or deposition. (Source: CT Stormwater Quality Manual)
  • ESA (Endangered Species Act) – This provides a program for conserving threatened and endangered plants and animals and their habitats. The U.S. Fish & Wildlife Service (FWS) maintains the list of endangered and threatened species. Species include birds, insects, fish, reptiles, mammals, crustaceans, flowers, grasses, and trees. Anyone can petition FWS to include a species on this list. The law prohibits any action, administrative or real, that results in a “taking” of a listed species or adversely affects habitat. Likewise, import, export, interstate, and foreign commerce of listed species are all prohibited. EPA’s decision to register pesticides is based in part on the risk of adverse effects on endangered species as well as environmental fate (how a pesticide will affect habitat). Under FIFRA, EPA can issue emergency suspensions of certain pesticides to cancel or restrict their use if an endangered species will be adversely affected. (source: http://www.epa.gov/region5/defs/html/esa.htm)
  • evapotranspiration – A process by which water is transferred from the soil to the air by plants that take the water up through their roots and release it through their leaves and other aboveground tissue. exposure – A measure of the amount of ionization produced by x-rays or gamma rays as they travel through air. The unit of radiation exposure is the roentgen (R).

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  • fallout – Radioactive material, made airborne as a result of aboveground nuclear weapons testing, that has been deposited on the Earth’s surface.
  • FFCA (Federal Facility Compliance Act) – Formerly, the federal government maintained that it was not subject to fines and penalties under solid and hazardous waste law because of the doctrine of “sovereign immunity.” The State of Ohio challenged this in Ohio v. the Department of Energy (1990). The U.S. Circuit Court of Appeals found in favor of the State (June 11, 1990), writing that the federal government’s sovereign immunity is waived under both the CWA sovereign immunity provision and RCRA’s citizen suit provision. The Circuit Court decision was overturned by the Supreme Court on April 21, 1992, in DOE v. Ohio, which held that the waiver of sovereign immunity in RCRA and CWA is not clear enough to allow states to impose civil penalties directly. After the high court’s ruling, the consensus among lawmakers was that a double standard existed: the same government that developed laws to protect human health and the environment and required compliance in the private sector, was itself not assuming the burden of compliance. As a result, Congress enacted the FFCA (October 6, 1992, Pub. Law 102-386), which effectively overturned the Supreme Court’s ruling. In the legislation Congress specifically waived sovereign immunity with respect to RCRA for federal facilities. Under section 102, FFCA amends section 6001 of RCRA to specify that federal facilities are subject to “all civil and administrative penalties and fines, regardless of whether such penalties or fines are punitive or coercive in nature.” These penalties and fines can be levied by EPA or by authorized states. In addition, FFCA states that “the United States hereby expressly waives any immunity otherwise applicable to the United States.” Although federal agents, employees, and officers are not liable for civil penalties, they are subject to criminal sanctions. No departments, agencies, or instrumentalities are subject to criminal sanctions. Section 104 (1) and (2) require EPA to conduct annual RCRA inspections of all federal facilities. (source: http://tis.eh.doe. gov/oepa/laws/ffca.html)
  • FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act) – The primary focus of this law was to provide federal control of pesticide distribution, sale, and use. EPA was given authority under FIFRA not only to study the consequences of pesticide usage but also to require users (farmers, utility companies, and others) to register when purchasing pesticides. Through later amendments to the law, users also must take exams for certification as applicators of pesticides. All pesticides used in the U.S. must be registered (licensed) by EPA. Registration assures that pesticides will be properly labeled and that if used in accordance with specifications, will not cause unreasonable harm to the environment. (source: http://www.epa.gov/region5/defs/html/ fifra.htm)
  • filter strip - A strip or area of vegetation for removing sediment, organic material,nutrients and chemicals from runoff or wastewater. They are typically located downgradient of stormwater outfalls and level spreaders to reduce flow velocities and promote infiltration/filtration. (Source: CT Stormwater Quality Manual)
  • fisher: Martes pennanti. Sometimes referred to as a Fisher Cat. See article.
  • floodplain - Any land susceptible to being inundated by water, usually adjacent to a stream, river or water body and usually associated with a particular design flooding frequency (e.g., 100-year floodplain). (Source: CT Stormwater Quality Manual)
  • food chain - an arrangement of the organisms of an ecological community according to the order of predation in which each uses the next usually lower member as a food source. (Source: Merriam-Webster).
  • fourth order stream - Stream order indicates the relative size of a stream based on Strahler’s(1957) method. Streams with no tributaries are first order streams, represented as the start of a solid line on a 1:24,000 USGS Quadrangle Sheet .A second order stream is formed at the confluence of two first order streams, and so on. (Source: CT Stormwater Quality Manual)
  • fragmentation - occurs when large, contiguous blocks of habitat like forest are broken up into isolated islands by development, roads, or clearing for agriculture. See article.
  • FS (feasibility study) – A process for developing and evaluating remedial actions using data gathered during the remedial investigation. The FS defines the objectives of the remedial program for the site and broadly develops remedial action alternatives, performs an initial screening of these alternatives, and performs a detailed analysis of a limited number of alternatives that remain after the initial screening stage.
  • FWS (U.S. Fish & Wildlife Service) – The U.S. Fish and Wildlife Service is the principal federal agency responsible for conserving, protecting, and enhancing fish, wildlife, plants, and their habitats for the continuing benefit of the people of the United States. FWS manages the 95- million-acre National Wildlife Refuge System, which encompasses 544 national wildlife refuges, thousands of small wetlands, and other special management areas. It also operates 69 national fish hatcheries, 64 fishery resources offices, and 81 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American tribal governments with their conservation efforts. It also oversees the Federal Assistance Program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies. (source: http://northeast.fws.gov/ameel/petition.html)
  • fugitive source – Unanticipated sources of volatile hazardous air pollutants due to leaks from valves, pumps, compressors, relief valves, connectors, flanges, and various other pieces of equipment.

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  • gamma radiation – Gamma radiation is a form of electromagnetic radiation, like radio waves or visible light, but with a much shorter wavelength. It is more penetrating than alpha or beta radiation, capable of passing through dense materials such as concrete.
  • gamma spectroscopy – This analysis technique identifies specific radionuclides. It measures the particular energy of a radionuclide’s gamma radiation emissions. The energy of these emissions is unique for each nuclide, acting as a “fingerprint.”
  • gateway - entrance to a community (as used in Woodstock A Plan of Open Space and Conservation)
  • geotextile – A product used as a soil reinforcement agent and as a filter medium. It is made of synthetic fibers manufactured in a woven or loose manner to form a blanket-like product. grab sample – A single sample collected at one time and place.
  • GIS (Geographic Information System) - or more commonly referred to as a geospatial information system is a system for capturing, storing, analyzing and managing data and associated attributes which are spatially referenced to the earth. (Source: wikipedia.org)
  • GPS - a satellite navigation system. Also refers to the receiver that can provide latitude and longitude.
  • grass drainage channels - Traditional vegetated open channels, typically trapezoidal, triangular, or parabolic in shape, whose primary function is to provide non-erosive conveyance, typically up to the 10-year frequency design flow. They provide limited pollutant removal through filtration by grass or other vegetation, sedimentation, biological activity in the grass/soil media, as well as limited infiltration if underlying soils are pervious. (Source: CT Stormwater Quality Manual)
  • gravel pack well - A well constructed into unconsolidated material (i.e., loose sand or gravel) (Source: SWAP).
  • Green Building – Construction that adheres to guidelines established by the Green Building Council, a coalition of leaders from across the building industry working to promote structures that are environmentally responsible, profitable, and healthy places to live and work.
  • greenfields: Greenfields include agricultural lands, metropolitan parks, greenways, ecological corridors in metro areas and other places that help delineate one village, city or town from another or where development is occuring and where it is not. When they are protected, greenfields can serve to promote growth in already developed areas and curb urban sprawl. As parks and greenways, they also provide the green infrastructure essential to livable communities.
  • greenway - a corridor of open space. (as used in Woodstock A Plan of Open Space and Conservation, a corridor of open space that (1) may protect natural resources, preserve scenic landscapes and historical resources or offer opportunities for recreation or non-motorized transportation, (2) may connect existing protected areas and provide access to the outdoors, (3) may be located along a defining natural feature, such as a waterway, along a manmade corridor, including an unused right-of-way, traditional trail routes or historic barge canals or (4) may be a green space along a highway or around a village.) See article.
  • groundwater – Water found beneath the surface of the ground (subsurface water). Groundwater usually refers to a zone of complete water saturation containing no air. See article.
  • groundwater recharge - The process by which water that seeps into the ground, eventually replenishing groundwater aquifers and surface waters such as lakes,streams, and the oceans. This process helps maintain water flow in streams and wetlands and preserves water table levels that support drinking water supplies. (Source: CT Stormwater Quality Manual)
  • gunite – A mixture of cement, sand, and water sprayed over a mold to form a solid, impermeable surface. Formerly a trademarked name, now in general usage.

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  • half-life (t1/2) – The time required for one-half of the atoms of any given amount of a radioactive substance to disintegrate; the time required for the activity of a radioactive sample to be reduced by one half.
  • halon – An ozone-depleting fire suppressant; suffixes (-1301, etc.) indicate variants. hazardous waste – Toxic, corrosive, reactive, or ignitable materials that can injure human health or damage the environment. It can be liquid, solid, or sludge, and include heavy metals, organic solvents, reactive compounds, and corrosive materials. It is defined and regulated by RCRA, Subtitle C.
  • hearing officer - An individual appointed by an agency to conduct a hearing in an agency proceeding; such individual may be a staff employee of the agency. (Source: CT DEP)
  • heat input – The heat derived from combustion of fuel in a steam generating unit. It does not include the heat from preheated combustion air, recirculated flue gases, or the exhaust from other sources.
  • heavy metals - Metals such as copper, zinc, barium, cadmium, lead, and mercury, which are natural constituents of the Earth’s crust. Heavy metals are stable and persistent environmental contaminants since they cannot be degraded or destroyed. (Source: CT Stormwater Quality Manual)
  • heavy water (D2O) – A form of water containing deuterium, a nonradioactive isotope of hydrogen.
  • herpetofaunal – Relating to the study of reptiles.
  • hot cell – Shielded and air-controlled facility for the remote handling of radioactive material.
  • hydrocarbons - Inorganic compounds consisting of carbon and hydrogen, including petroleum hydrocarbons derived from crude oil, natural gas, and coal. (Source: CT Stormwater Quality Manual)
  • hydrogeology - a branch of geology concerned with the occurrence, use, and functions of surface water and groundwater; also the phenomena dealt with in hydrogeology (source: Merriam-Webster)
  • hydrologic cycle - The distribution and movement of water between the earth’s atmosphere,land, and water bodies.(Source: CT Stormwater Quality Manual)
  • hydrology – The science dealing with the properties, distribution, and circulation of natural water systems.

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  • impaired waters - Those water bodies not meeting water quality standards. This list of impaired waters within each state is referred to as the “303(d) List” and is prepared pursuant to Section 303(d) of the Federal Clean Water Act. (Source: CT Stormwater Quality Manual)
  • impermeable - a substance through which other substances are unable to pass
  • impervious surfaces - Surfaces that cannot infiltrate rainfall, including rooftops, pavement, sidewalks, and driveways. (Source: CT Stormwater Quality Manual)
  • inert – Lacking chemical or biological action.
  • infiltration rate - A soil characteristic determining or describing the maximum rate at which water can enter the soil under specific conditions. (Source: CT Stormwater Quality Manual)
  • influent – Liquid (such as stormwater runoff or wastewater) flowing into a reservoir, basin, or treatment plant.
  • integrated pest management (IPM) - An approach to pesticide usage that combines monitoring; pest trapping; establishment of action thresholds; use of resistant varieties and cultivars;cultural, physical, and biological controls; and precise timing and application of pesticide treatments to avoid the use of chemical pesticides when possible and use the least toxic pesticide that targets the pest of concern,when pesticide usage is unavoidable. (Source: CT Stormwater Quality Manual)
  • intermittent river – A stream that dries up on occasion, usually as a result of seasonal factors or decreased contribution from a source such as a wastewater treatment plant.
  • invasive species: non-native plants or animals either intentionally or accidentally introduced to another ecosystem which are harmful to the natural environment or human health. See article.
  • ionizing radiation – Any radiation capable of displacing electrons from atoms or molecules, thereby producing ions. High doses of ionizing radiation may produce severe skin or tissue damage. See also alpha, beta, gamma radiation; x-rays.
  • ISO 14001 EMS standard – The International Organization for Standardization (ISO) sets standards for a wide range of products and management operations. Following the success of the ISO 9000 Standards for quality management, ISO introduced the 14000 series for environmental management.
  • isotope – Two or more forms of a chemical element having the same number of protons in the nucleus (the same atomic number), but having different numbers of neutrons in the nucleus (different atomic weights). Isotopes of a single element possess almost identical chemical properties.

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  • leaching – The process by which soluble chemical components are dissolved and carried through soil by water or some other percolating liquid.
  • letterboxing - A hidden stash whose location is found only by following clues. A traditional letterbox contains, at minimum, a rubber stamp and log. See article.
  • light pollution - excess or obtrusive light create humans. (source: wikipedia.org) See article.
  • liquid scintillation counter – An analytical instrument used to quantify tritium, carbon-14, and other beta-emitting radionuclides. See also scintillation.
  • litter - trash, wastepaper, or garbage lying scattered about. Also the uppermost slightly decayed layer of organic matter on the forest floor (see duff). See article.
  • low impact development - Low impact development is a site design strategy intended to maintain or replicate predevelopment hydrology through the use of small-scale controls integrated throughout the site to manage runoff as close to its source as possible. (Source: CT Stormwater Quality Manual)

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  • matrix, matrices – The natural context (e.g., air, vegetation, soil, water) from which an environmental sample is collected.
  • MDL (minimum detection limit) – The lowest level to which an analytical parameter can be measured with certainty by the analytical laboratory performing the measurement. While results below the MDL are sometimes measurable, they represent values that have a reduced statistical confidence associated with them (less than 95 percent confidence).
  • MEI (maximally exposed individual) – The hypothetical individual whose location and habits tend to maximize his/ her radiation dose, resulting in a dose higher than that received by other individuals in the general population.
  • metamorphic – In the state of changing from larval to mature forms.
  • mixed waste – Waste that contains both a hazardous waste component (regulated under Subtitle C of RCRA) and a radioactive component.
  • monitoring – The collection and analysis of samples or measurements of effluents and emissions for the purpose of characterizing and quantifying contaminants, and demonstrating compliance with applicable standards.
  • monitoring well – A well that collects groundwater for the purposes of evaluating water quality, establishing groundwater flow and elevation, determining the effectiveness of treatment systems, and determining whether administrative or engineered controls designed to protect groundwater are working as intended.
  • MSL (mean sea level) – The average height of the sea for all stages of the tide. Used as a benchmark for establishing groundwater and other elevations.

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  • NAAQS or National Ambient Air Quality Standards - The maximum concentrations of pollutants permitted in the ambient air for six "Criteria Pollutants" as required in the Clean Air Act to protect public health and the environment. The Criteria Pollutants are: carbon monoxide, lead, oxides of nitrogen, ozone, particulate matter and sulfur dioxide. (Source: CT DEP)
  • native species - one that normally lives in a particular ecosystem (indigenous) and was not introduced (either accidentally or intentionally) by man. See article.
  • natural attenuation - passive remediation of polluted soils or groundwater plumes through natural chemical, physical, and microbial decay processes.
  • navigable waters - waters that are subject to the ebb and flow of the tide and Federally designated navigable waters which, in Connecticut, include the Connecticut River to the Massachusetts state line. (Source: Title 33 CFR Part 329.)
  • NEPA (National Environmental Policy Act) – Assures that all branches of government give proper consideration to the environment before any land purchase or any construction projects, including airports, buildings, military complexes, and highways. Project planners must assess the likely impacts of the project by completing an Environmental Assessment (EA) and, if necessary, an Environmental Impact Statement (EIS). (source: http://www.epa.gov/region5/ defs/html/nepa.htm)
  • NESHAPs (National Emissions Standards for Hazardous Air Pollutants) – Standards that limit emissions from specific sources of air pollutants linked to serious health hazards. NESHAPs are developed by EPA under the CAA. Hazardous air pollutants can be chemical or radioactive. Their sources may be human-made, such as vehicles, power plants, and industrial or research processes, or natural, such as radioactive gas in soils. (source: www.epa.gov/radiation/ neshaps)
  • nestbox - a birdhouse made for cavity nesters like bluebirds. See article.
  • neutrino – A small, neutral particle created as a result of particle decay. Neutrinos were believed to be massless, but recent studies have indicated that they have small, but finite, mass. Neutrinos interact very weakly.
  • NHPA (National Historic Preservation Act) – With passage of the National Historic Preservation Act in 1966, Congress made the federal government a full partner and a leader in historic preservation. The role of the federal government is fulfilled through the National Park Service. State participation is through State Historic Preservation Offices. “Before 1966, historic preservation was mainly understood in one-dimensional terms: the proverbial historic shrine or Indian burial mound secured by lock and key—usually in a national park—set aside from modern life as an icon for study and appreciation. NHPA largely changed that approach, signaling a much broader sweep that has led to the breadth and scope of the vastly more complex historic preservation mosaic we know today.” (source: http://www.achp. gov/overview.html)
  • nitrate - One of the forms of nitrogen found in aquatic ecosystems. It is produced during nitrification and denitrification by bacteria. Nitrate is the most completely oxidized state of nitrogen commonly found in water, and is the most readily available state utilized for plant growth. (Source: CT Stormwater Quality Manual)
  • nitrite - A form of nitrogen that is the end product of nitrification, which is produced by Nitrobacter spp. Nitrate is also the initial substrate for denitrification. (Source: CT Stormwater Quality Manual)
  • non-native - an intentionally or accidentally introduced species (also referred to as naturalized or exotic) that is not indigenous to a given area or place. See article on invasive species.
  • nonpoint source pollution – Nonpoint source pollution occurs when rainfall, snowmelt, or irrigation water runs over land or through the ground, picks up pollutants, and deposits them into rivers, lakes, and coastal waters or introduces them into groundwater. Nonpoint source pollution also includes adverse changes to the hydrology of water bodies and their associated aquatic habitats. After Congress passed the Clean Water Act in 1972, the nation’s water quality community emphasized point source pollution (coming from a discrete conveyance or location, such as industrial and municipal waste discharge pipes). Point sources were the primary contributors to the degradation of water quality then, and the significance of nonpoint source pollution was poorly understood. Today, nonpoint source pollution remains the largest source of water quality problems. It is the main reason that approximately 40 percent of surveyed rivers, lakes, and estuaries are not clean enough to meet basic uses such as fishing or swimming. (source: http://www. epa.gov/owow/nps)
  • NOX – Nitrogen oxides are gases consisting of one molecule of nitrogen and varying numbers of oxygen molecules. Nitrogen oxides are produced, for example, by the combustion of fossil fuels in vehicles and electric power plants. In the atmosphere, NOX can contribute to the formation of smog, impair visibility, and have health consequences. NOX are considered “criteria air pollutants” under the CAA.
  • nuclide – A species of atom characterized by the number of protons and neutrons in the nucleus.

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  • O3 – See ozone.
  • oil/particle separator - Consist of one or more chambers designed to remove trash and debris and to promote sedimentation of coarse materials and separation of free oil (as opposed to emulsified or dissolved oil) from stormwater runoff.Oil/particle separators are typically designed as off-line systems for pre-treatment of runoff from small impervious areas, and therefore provide minimal attenuation of flow. Also called oil/grit separators, water quality inlets, and oil/water separators. (Source: CT Stormwater Quality Manual)
  • opacity – Under the Clean Air Act (CAA), a measurement of the degree to which smoke (emissions other than water vapor) reduces the transmission of light and obscures the view of an object in the background.
  • open space - land or water that is permanently preserved in either a near-natural or agricultural state that is absent commercial, industrial, or residential development and where any development would be limited to agricultural structures or recreational improvements such as trails, swimming or picnic areas. (as used in the Woodstock A Plan of Open Space and Conservation.)
  • optical brighteners - Fluorescent white dyes that are additives in laundry soaps and detergent sand are commonly found in domestic wastewater. (Source: CT Stormwater Quality Manual)
  • OU (operable unit) – Division of a contaminated site into separate areas based on the complexity of the problems associated with it. Operable units may address geographical portions of a site, specific site problems, or initial phases of an action. They may also consist of any set of actions performed over time, or actions that are concurrent, but located in different parts of a site. An OU can receive specific investigation and a particular remedy may be proposed. A Record of Decision (ROD) is prepared for each OU.
  • outfall – The place where wastewater is discharged. oxides of nitrogen (NOX) – See NOX.
  • Outright Conveyance - (as used in land conservation) Land may be transferred to the town, a local land trust, or nature conservancy through a donation, "Bargain Sale", or sale at fair market value. Restrictions may be imposed on the future use of the property, according to the donor's wishes.
  • ozone (O3) – A very reactive type of oxygen formed naturally in the upper atmosphere which provides a shield for the earth from the sun’s ultraviolet rays. At ground level or in the lower atmosphere, it is pollution that forms when oxides of nitrogen and hydrocarbons react with oxygen in the presence of strong sunlight. Ozone at ground level can lead to health effects and cause damage to trees and crops. See article.

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  • P2 (pollution prevention) – Preventing or reducing the generation of pollutants, contaminants, hazardous substances, or wastes at the source, or reducing the amount for treatment, storage, and disposal through recycling. Pollution prevention can be achieved through reduction of waste at the source, segregation, recycle/reuse, and the efficient use of resources and material substitution. The potential benefits of pollution prevention include the reduction of adverse environmental impacts, improved efficiency, and reduced costs.
  • PAAA (Price-Anderson Act Amendments) – The Price- Anderson Act (PAA) was passed in 1957 to provide for prompt compensation in the case of a nuclear accident. The PAA provided broad financial coverage for damage, injury, and costs, and required DOE to indemnify contractors. The amended act of 1988 (PAAA) extended indemnification for 15 years and required DOE to establish and enforce nuclear safety rules. The PAAA Reauthorization, passed in December of 2002, extended current indemnification levels through 2004. (source: http://tis. eh.doe.gov)
  • Parshall flume – An engineered channel used to measure the flow rate of water. It was named after the inventor, who worked for the U.S. government as an irrigation research engineer.
  • pathogen - A disease-causing organism like certain bacteria or viruses. (Source: SWAP)
  • PCBs (polychlorinated biphenyls) – A family of organic compounds used from 1926 to 1979 (when they were banned by EPA) in electrical transformers, lubricants, carbonless copy paper, adhesives, and caulking compounds. PCBs are extremely persistent in the environment because they do not break down into different and less harmful chemicals. PCBs are stored in the fatty tissues of humans and animals through the bioaccumulation process.
  • percent recovery – For analytical results, the ratio of the measured amount, divided by the known (spiked) amount, multiplied by 100.
  • percolation (of water in soil) - the downward movement through the subsurface soil layers to groundwater
  • permeable paving materials - Materials that are alternatives to conventional pavement surfaces and that are designed to increase infiltration and reduce stormwater runoff and pollutant loads. Alternative materials include modular concrete paving blocks, modular concrete or plastic lattice, cast-in-place concrete grids,and soil enhancement technologies. Stone, gravel, and other low-tech materials can also be used as alternatives for low traffic applications such as driveways, haul roads, and access roads. (Source: CT Stormwater Quality Manual)
  • permit – An authorization issued by a federal, state, or local regulatory agency. Permits are issued under a number of environmental regulatory programs, including CAA, CWA, RCRA, and TSCA. Permits grant permission to operate, to discharge, to construct, and so on. Permit provisions may include emission/effluent limits and other requirements such as the use of pollution control devices, monitoring, record keeping and reporting. Also called a “license” or “certificate” under some regulatory programs.
  • pesticide - Any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest, or any substance or mixture of substances intended for use as a plant regulator, defoliant or desiccant. (Source: CT DEP)
  • pH – A measure of hydrogen ion concentration in an aqueous solution. Acidic solutions have a pH less than 7, neutral solutions have a pH of 7, and basic solutions have a pH greater than 7 and up to 14.
  • phytoremediation - biological treatment of environmental pollution through the use of plants.
  • plume – A body of contaminated groundwater or polluted air flowing from a specific source. The movement of a groundwater plume is influenced by such factors as local groundwater flow patterns, the character of the aquifer in which groundwater is contained, and the density of contaminants. The movement of an air contaminant plume is influenced by the ambient air motion, the temperatures of the ambient air and of the plume, and the density of the contaminants.
  • point source – Any confined and discrete conveyance (e.g., pipe, ditch, well, or stack) of a discharge.
  • pollutant – Any hazardous or radioactive material naturally occurring or added to an environmental medium, such as air, soil, water, or vegetation.
  • porous pavement - similar to conventional asphalt or concrete but is formulated to have more void space for greater water passage through the material. (Source: CT Stormwater Quality Manual)
  • potable water – Water of sufficient quality for use as drinking water without endangering the health of people, plants, or animals.
  • precision – A statistical term describing the dispersion of data around a central value, usually represented as a variance, standard deviation, standard error, or confidence interval.
  • prime agricultural soils - soils considered highly suitable for agricultural activity (defined on maps).
  • productive forest soils - soils with a high carrying capacity for wildlife and the ability to grow high quality timber at a competitive rate. Specifically, soils with a site index (average height in feet of dominant and co-dominant trees at age 50) of 60 or greater for northern red oak, AND/OR 70 or greater for eastern white pine. (Source: Broderick and Kolesinskas, 5/2000, as used by Woodstock Conservation Commission.)
  • productive wildlife habitat - tracts of sufficient size that provide abundant food, water and cover at all seasons of the year. Because of their innate ability to produce food and cover plants in abundance, wildlife biologists agree that the productive forest soils identified in Map 19 are also the best potential habitat sites as well. Productive habitats must also contain water, however, and be large enough to accommodate those interior forest species that cannot tolerate forest edge effects and/or human presence. Productive wildlife habitats are defined as undeveloped areas greater than 250 (two-hundred and fifty) acres in size that consist primarily of productive forest soils, wetlands and/or watercourses.
  • Public Water System (PWS) - Any water company supplying groundwater or surface water or both to fifteen (15) or more consumers or twenty-five (25) or more persons daily at least sixty days (60) of the year. (Source: SWAP)
  • Purchase of Development Rights (PDR) - Under this program, the “right” to develop the land in the future is purchased by the State, and a conservation easement is placed on the agricultural land. An easement is a legal agreement that restricts the type and amount of development that may take place on a property. Each easement's restrictions are tailored to the particular property and the interests of the individual owner. An easement "runs with the land," which means that the original owner and all subsequent owners are bound by its restrictions.  See article.
  • putrescible waste – Garbage that contains food and other organic biodegradable materials.

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  • QA (quality assurance) – In environmental monitoring, any action to ensure the reliability of monitoring and measurement data. Aspects of QA include procedures, inter-laboratory comparison studies, evaluations, and documentation.
  • QC (quality control) – In environmental monitoring, the routine application of procedures to obtain the required standards of performance in monitoring and measurement processes. QC procedures include calibration of instruments, control charts, and analysis of replicate and duplicate samples.
  • qualifier – A letter or series of letter codes in a graph or chart indicating that the associated value did not meet analytical requirements or was estimated.
  • quenching – Anything that interferes with the conversion of decay energy to electronic signal in the photomultiplier tubes of detection equipment, usually resulting in a reduction in counting efficiency.

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  • R (roentgen) – A unit of exposure to ionizing radiation. It is the amount of gamma or x-rays required to produce ions carrying one electrostatic unit of electrical charge in one cubic centimeter of dry air under standard conditions. It is named after the German scientist Wilhelm Roentgen, who discovered x-rays.
  • RA (removal actions, “removals”) – Interim actions that are undertaken to prevent, minimize, or mitigate damage to the public health or environment that may otherwise result from a release or threatened release of hazardous substances, pollutants, or contaminants pursuant to CERCLA, and that are not inconsistent with the final remedial action. Under CERCLA, EPA may respond to releases or threats of releases of hazardous substances by starting an RA to stabilize or clean up an incident or site that immediately threatens public health or welfare. Removal actions are less comprehensive than remedial actions. However, removal actions must contribute to the efficiency of future remedial actions.
  • radiation – Some atoms possess excess energy, causing them to be physically unstable. Such atoms become stable when the excess energy is released in the form of charged particles or electromagnetic waves, known as radiation.
  • radiation event – A single detection of a charged particle or electromagnetic wave.
  • radioactive series – A succession of nuclides, each of which transforms by radioactive disintegration into the next until a stable nuclide results. The first member of the series is called the parent and the intermediate members are called daughters or progeny.
  • radioactivity – The spontaneous transition of an atomic nucleus from a higher energy to a lower energy state. This transition is accompanied by the release of a charged particle or electromagnetic waves from the atom. Also known as “activity.”
  • radionuclide – A radioactive element characterized by the number of protons and neutrons in the nucleus. There are several hundred known radionuclides, both artificially produced and naturally occurring. RCRA (Resource Conservation and Recovery Act) Pronounced “rick-rah,” this act of Congress gave EPA the authority to control the generation, transportation, treatment, storage, and disposal of hazardous waste. RCRA also set forth a framework for the management of nonhazardous wastes. The 1986 amendments to RCRA enabled EPA to address environmental problems that could result from underground tanks storing petroleum and other hazardous substances. RCRA focuses only on active and future facilities and does not address abandoned or historical sites (see CERCLA). In 1984, amendments to RCRA called the Hazardous and Solid Waste Amendments (HSWA, pronounced “hiss-wa”) required phasing out the land disposal of hazardous waste. Some other mandates of this strict law include increased enforcement authority for EPA, more stringent hazardous waste management standards, and a comprehensive underground storage tank (UST) program. (source: http://www.epa.gov/region5/defs/html/rcra.htm)
  • rain barrels - Barrels designed to retain small volumes of runoff for reuse for gardening and landscaping. They are applicable to residential, commercial, and industrial sites and can be incorporated into a site’s landscaping plan.The size of the rain barrel is a function of rooftop surface area and the design storm to be stored. (Source: CT Stormwater Quality Manual)
  • rain garden - Functional landscape elements that combine plantings in depressions that allow water to pool for only a few days after a rainfall then be slowly absorbed by the soil and plantings. (Source: CT Stormwater Quality Manual)
  • rainwater harvesting - The collection and conveyance of rainwater from roofs and storage in either rain barrels or cisterns. Depending on the type and reuse of the rainwater, purification may be required prior to distribution of the rain-water for reuse. Harvested rainwater can be used to supply water for drinking, washing, irrigation, and landscaping. (Source: CT Stormwater Quality Manual)
  • recharge – The process by which water is added to a zone of saturation (aquifer) from surface infiltration, typically when rainwater soaks through the earth to reach an aquifer.
  • recharge basin – A basin (natural or artificial) that collects water. The water will infiltrate to the aquifer.
  • recycling - The processing of solid waste to reclaim material for reuse. (Source: CT DEP)
  • regulated activities (as defined in CT regulation 22a-354i-1) activities include businesses that use hazardous materials such as RCRA hazardous wastes, hazardous substances regulated under CERCLA, pesticides, and petroleum products. Examples of regulated activities include some manufacturing industries, chemical wholesale storage industries, gasoline stations, auto and engine service stations, dry cleaners, and furniture strippers. Installation of new underground storage tanks for storage or transmission of oil or petroleum or hazardous materials is prohibited, with allowances for replacement of existing tanks.
  • release – Spilling, leaking, pumping, pouring, emitting, emptying, discharging, injecting, escaping, leaching, dumping, or disposing of a hazardous substance, pollutant, or contaminant into the environment. The National Contingency Plan also defines the term to include a threat of release.
  • rem – Stands for “roentgen equivalent man,” a unit by which human radiation dose is assessed (see also Sv). The rem is a risk-based value used to estimate the potential health effects to an exposed individual or population. 100 rem = 1 sievert.
  • remedial (or remediation) alternatives – Options considered under CERCLA for decontaminating a site such as an operable unit (OU) or area of concern (AOC). Remedial actions are long-term activities that prevent the possible release, or stop or substantially reduce the actual release, of substances that are hazardous but not immediately life threatening. See also feasibility study (FS) and Record of Decision (ROD).
  • Reservation of Life Estate (Remainder Interest) (as used in land conservation) - In making a gift of land, and a personal residence if located on the property, a life estate may be reserved which permits use of the property (farm and/or residence) for the remainder of the donor's life or, if so stipulated, for the lives of the spouse and children.
  • residual fuel – Crude oil, Nos. 1 and 2 fuel oil that have a nitrogen content greater than 0.05 weight percent, and all fuel oil Nos. 4, 5, and 6, as defined by the American Society of Testing and Materials in ASTM D396-78, Standard Specifications for Fuel Oils, (c. 2001).
  • retention basin (or pond) - a type of constructed wetland that is used to contain stormwater or rain runoff. It provides an area to hold water from a small surrounding drainage area that would otherwise flow into other areas. The water remains in the local area that it was deposited in. Also see detention basin. (Source: wikipedia.org)
  • retention or residence time - The average length of time that a “parcel” of water spends in a stormwater pond or other water body. (Source: CT Stormwater Quality Manual)
  • riparian – An organism living on the bank of a river, lake, or tidewater.
  • riparian zone - the interface between land and a flowing surface water body. Plant communities along the river margins are called riparian vegetation, characterized by hydrophilic plants. (Source: wikipedia.org)
  • ROD (Record of Decision) – A document that records a regulatory agency’s decision for the selected remedial action. The ROD also includes a responsiveness summary and a bibliography of documents that were used to reach the remedial decision. When the ROD is finalized, remedial design and implementation can begin.
  • roentgenSee R.
  • RPD (relative percent difference) – A measure of precision, expressed by the formula: RPD = [(A-B)/(A+B)] x 200, where A equals the concentration of the first analysis and B equals the concentration of the second analysis.
  • runoff – The movement of water over land. Runoff can carry pollutants from the land into surface waters or uncontaminated land.

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  • sampling – The extraction of a prescribed portion of an effluent stream or environmental media for purposes of inspection or analysis.
  • SARA (Superfund Amendments and Reauthorization Act) – This Act of Congress in 1986 reauthorized CERCLA to continue cleanup activities around the country. Several site-specific amendments, definitions clarifications, and technical requirements were added to the legislation, including additional enforcement authorities. Title III of SARA also authorized EPCRA. (source: http://www.epa. gov/region5/defs/html/sara.htm)
  • scenic vista - a viewshed with aesthetic value.
  • scintillation – Flashes of light produced in a phosphor by a radioactive material.
  • SDWA (Safe Drinking Water Act) – The Safe Drinking Water Act was established to protect the quality of drinking water in the United States. It focuses on all waters actually or potentially designed for drinking use, whether from above ground or underground sources. The SDWA authorized EPA to establish safe standards of purity and required all owners or operators of public water systems to comply with health-related standards. State governments assume regulatory power from EPA. (source: http://www.epa.gov/ region5/defs/html/sdwa.htm)
  • sediment – The layer of soil and minerals at the bottom of surface waters, such as streams, lakes, and rivers.
  • sensitivity – The minimum amount of an analyte that can be repeatedly detected by an instrument.
  • sievertSee Sv.
  • skyshine – Radiation emitted upward from an open-topped, shielded enclosure and reflected downward, resulting in the possibility that flora and fauna (including humans) outside the shielded enclosure can be exposed to radiation.
  • sludge – Semisolid residue from industrial or water treatment processes. sole source aquifer – An area defined by EPA as being the primary source of drinking water for a particular region. Includes the surface area above the sole source aquifer and its recharge area.
  • smart growth - a set of policies for transportation and land use planning that benefits communities and preserves the natural environment. (Source: wikipedia.org)
  • source controls - Practices to limit the generation of stormwater pollutants at their source. (Source: CT Stormwater Quality Manual)
  • Source Water Area - An area of land delineated by the state that contributes water to a source of public drinking water supply, whether the source is groundwater or surface water or both. (Source: SWAP).
  • Species of Special Concern - any native plant species or any native nonharvested wildlife species documented by scientific research and inventory to have a naturally restricted range or habitat in the state, to be at a low population level, to be in such high demand by man that its unregulated taking would be detrimental to the conservation of its population or has been extirpated from the state (as used in PA 89-224 in CT.) Definition varies by State.
  • SPDES (State Pollutant Discharge Elimination System) This permit program is delegated to the states, but the effluent limitations and other requirements are set by the federal government.
  • stable – Nonradioactive.
  • stakeholder – People or organizations with vested interests.
  • stormwater - Water consisting of precipitation runoff or snowmelt. (Source: CT Stormwater Quality Manual)
  • stratosphere - the part of the earth's atmosphere that extends from the top of the troposphere to about 30 miles above the surface. Clouds rarely form there. (Source: Merriam-Webster). See article.
  • stripping – A process used to remove volatile contaminants from a substance (see also air stripping).
  • sump – A pit or tank that catches liquid runoff for drainage or disposal.
  • Sv (sievert) – A unit for assessing the risk of human radiation dose, used internationally and with increasing frequency in the United States. One sievert is equal to 100 rem.
  • SVE (soil vapor extraction) – An in situ (in-place) method of extracting VOCs from soil by applying a vacuum to the soil and collecting the air, which can be further treated to remove the VOCs, or discharged to the atmosphere.
  • SVOC – A general term for volatile organic compounds that vaporize relatively slowly at standard temperature and pressure. See also VOC.
  • synoptic – Relating to or displaying conditions as they occur over a broad area.

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  • t1/2 (half-life) – The time required for one-half of the atoms of any given amount of a radioactive substance to disintegrate; the time required for the activity of a radioactive sample to be reduced by one half.
  • TCE (trichloroethylene, also known as trichloroethene) A stable, colorless liquid with a low boiling point. TCE has many industrial applications, including use as a solvent and as a metal degreasing agent. TCE may be toxic when inhaled or ingested, or through skin contact, and can damage vital organs, especially the liver. See also VOC.
  • Testamentary Gift (Devise) - A gift of land by means of a will, may include one or more of the alternatives previously discussed, including a conservation easement and reservation of life estates.
  • Threatened Species - any native species documented by biological research and inventory to be likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range within the sate and to have no more than nine occurrences in the state, and any species determined to be a "threatened species" pursuant to the federal Endangered Species Act, except for such species determined to be endangered by the Commissioner in accordance with section 4 of PA 89-224 in CT. Definition varies by State.
  • Tier III reports – Reports, required by SARA, that are prepared to document annual emissions of toxic materials to the environment. These are also known as TRI Section 313 reports.
  • TLD (thermoluminescent dosimeter) – A device used to measure radiation dose to occupational workers or radiation levels in the environment.
  • total Kjeldahl Nitrogen - The sum of the ammonia nitrogen and the organic bounded nitrogen; nitrates and nitrites are not included. (Source: CT Stormwater Quality Manual)
  • total nitrogen - The sum of total Kjeldahl nitrogen, nitrate, and nitrite. Nitrogen is typically the growth-limiting nutrient is estuarine and marine systems. (Source: CT Stormwater Quality Manual)
  • total organic carbon - A measure of the organic matter content. The amount of organic matter content affects biogeochemical processes, nutrient cycling, biological availability, chemical transport and interactions and also has direct implications in the planning of wastewater treatment and drinking water treatment. (Source: CT Stormwater Quality Manual)
  • total phosphorus - Sum of orthophosphate, metaphosphate (or polyphosphate) and organically bound phosphate. Phosphorus is typically the growth-limiting nutrient is freshwater systems. (Source: CT Stormwater Quality Manual)
  • total suspended solids - The total amount of particulate matter that is suspended in the water column. (Source: CT Stormwater Quality Manual)
  • Transfer in Trust (as used in land conservation) - Property, or a lesser interest therein, may be donated to a nonprofit organization such as a local, state, or national land conservation or historic trust, for the purpose of carrying out personal wishes with respect to the property's preservation and use. This is an effective method of assuring the perpetuation of the donor's intentions where restricted use is a primary concern.
  • tritium – The heaviest and only radioactive nuclide of hydrogen, with a half-life of 12.3 years and a very-low-energy radioactive decay (tritium is a beta emitter).
  • trophic status - A term used to describe the level of nutrients, mainly nitrogen and phosphorus, in a reservoir that contribute to the growth of algae and plankton. The three trophic states used to characterize drinking water reservoirs are oligotrophic, mesotrophic and eutrophic. A reservoir having a low nutrient level and the least biological growth potential is called oligotrophic. A mesotrophic reservoir has a moderate level of nutrients with increased biological growth potential. High nutrient levels and biological growth potentials result in reservoirs that are classified as eutrophic. (Source: SWAP)
  • troposphere - the lowest, densest part of the earth's atmosphere in which most weather changes occur and temperature generally decreases rapidly with altitude and which extends from the earth's surface to the bottom of the stratosphere. (Source: Merriam-Webster.) See article.
  • TSCA (Toxic Substances Control Act) – Enacted by Congress in1976, TSCA empowers EPA to track the 75,000 industrial chemicals produced or imported into the United States. EPA repeatedly screens these chemicals and can require reporting or testing of any that may pose an environmental or human health hazard. EPA can ban the manufacture or import of chemicals that pose an unreasonable risk. (source: http://www.epa.gov/region5/defs/html/tsca.htm)
  • TVOC (total volatile organic compounds) – A sum of all individual VOC concentrations detected in a given sample.

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  • UIC (underground injection control) – A hole with vertical dimensions greater than its largest horizontal dimensions; used for disposal of wastewater.
  • unsaturated zone - a portion of the soil profile that contains both water and air; the zone between teh land surface and the water table.
  • urban sprawl - expansion of a metropolitan area with largely uncontrolled new land use of previously less developed areas surrounding a more urban core. (Source: wikipedia.org)
  • UST (underground storage tank) – A stationary device, constructed primarily of nonearthen material, designed to contain petroleum products or hazardous materials. In a UST, 10 percent or more of the volume of the tank system is below the surface of the ground.
  • upgradient/upslope – A location of higher groundwater elevation; analogous to “upstream.”

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  • vadose – Relating to water in the ground that is above the permanent groundwater level.
  • vegetated buffer - An area or strip of land in permanent undisturbed vegetation adjacent to a water body or other resource that is designed to protect resources from adjacent development during construction and after development by filtering pollutants in runoff, protecting water quality and temperature,providing wildlife habitat, screening structures and enhancing aesthetics,and providing access for recreation. (Source: CT Stormwater Quality Manual)
  • vegetated filter strips and level spreaders - Uniformly graded vegetated surfaces (i.e., grass or close-growing native and vegetation) located between pollutant source areas and downstream receiving waters or wetlands. A level spreader is usually located at the top of the slope to distribute overland flow or concentrated runoff (seethe maximum overland flow length guidelines above) evenly across the entire length of the filter strip. (Source: CT Stormwater Quality Manual)
  • vernal pool – A small, isolated, and contained basin that holds water on a temporary basis, most commonly during winter and spring. It has no aboveground outlet for water and is extremely important to the life cycle of many amphibians (such as the tiger salamander), as it is too shallow to support fish, a major predator of amphibian larvae. See article.
  • viewshed - an area of land, water, and other environmental elements that is visible from a fixed vantage point. (Source: wikipedia.org)
  • VOC (volatile organic compound) –A general term for organic compounds capable of a high degree of vaporization at standard temperature and pressure. Because VOCs readily evaporate into the air, the potential for human exposure is greatly increased. Due to widespread industrial use, VOCs are commonly found in soil and groundwater.
  • vulnerability assessment - An evaluation of drinking water source quality and its vulnerability to contamination by pathogens and toxic chemicals.

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  • waste minimization – Action that avoids or reduces the generation of waste, consistent with the general goal of minimizing current and future threats to human health, safety, and the environment. Waste minimization activities include recycling, improving energy usage, reducing waste at the source, and reducing the toxicity of hazardous waste. This action is associated with pollution prevention, but is more likely to occur after waste has been generated.
  • waters of the U.S. in inland areas - inland rivers, streams, lakes, ponds and wetlands. (Source: title 33 CFR 328.4(c))
  • water table – The water-level surface below the ground where the unsaturated zone ends and the saturated zone begins. It is the level to which a well that is screened in the unconfined aquifer will fill with water.
  • watershed – The region draining into a river, a river system, or a body of water.
  • watershed management - Integrated approach addressing all aspects of water quality and related natural resource management, including pollution prevention and source control. (Source: CT Stormwater Quality Manual)
  • weighting factor – A factor which, when multiplied by the dose equivalent delivered to a body organ or tissue, yields the equivalent risk due to a uniform radiation exposure of the whole body. See also EDE.
  • wet weight – The wet weight concentration of a substance is before a sample is dried for analysis (in other words, in its “natural” state), and is the form most likely to be consumed. Wet weight concentrations are typically lower than dry weight values.
  • wildlife (habitat) corridor - The junction between land and water is by far the richest of our wildlife habitats. (Source: ENFO, 1991). Often fragmented habitats joined together. See article.
  • wind rose – A diagram that shows the frequency of wind from different directions at a specific location.

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  • x-rays – A form of electromagnetic radiation with short wavelength, generated when high-energy electrons strike matter or when lower-energy beta radiation is absorbed in matter. Gamma radiation and x-rays are identical, except for the source.
  • xeriscaping - Landscaping to minimize water usage (“xeri” is the Greek prefix meaning”dry”) by using plants that are adapted to the local climate and require minimal watering, fertilizer, and pesticide application, and improving soils by adding soil amendments or using mulches to reduce the need for watering by increasing the moisture retained in the soil. (Source: CT Stormwater Quality Manual)

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  • zeolite – A naturally occurring group of more than 100 minerals, formed of silicates and aluminum, with unique and diverse crystal properties. Zeolites can perform ion exchange, filtering, odor removal, and chemical sieve and gas absorption tasks. Synthetic zeolites are now used for most applications.
  • zone of saturation - the region below the surface in which all voids are filled with liquid


Other references:

  • ATSDR - health risk terms
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