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Glossary

You may access the list of commonly used Navy Environmental Restoration glossary items by selecting one of the Quick Links below. Once the desired letter appears on the screen, simply scroll to view the glossary item(s) in question.

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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.
Abatement Reducing the degree or intensity of, or eliminating, pollution.
Abiotic Not relating to living things, not alive.
Absorbance A measure of the decrease in incident light passing through a sample into a detector. It is defined mathematically as:
A = I (solvent) = log Io
I (solution) I
where I = radiation intensity
Absorbed Dose The amount of a chemical that enters the body of an exposed organism. Equal to intake multiplied by an absorption factor.
Absorption 1) The process by which one substance is taken into the body of another substance. 2) The penetration of molecules or ions of one or more substances (gas, liquid or solid) into the interior of another substance. For example, in hydrated bentonite (a type of clay), the water that is held between the mica-like layers (held within the clay) is the result of absorption.
Accelerated Operable Unit (AOU) An action which prevents, controls or responds to a release or threatened release of hazardous substances, pollutants, and contaminants where prompt action is necessary but a response under removal authorities is not appropriate or desirable. The purpose of an AOU is to allow the remedial action for that Operable Unit to proceed prior to completion of the final Record of Decision (ROD) for the total remedial action. AOUs are particularly appropriate where the size and complexity of the total remedial action would seriously delay implementation of independent parts of the action. AOUs will only proceed after complying with applicable procedures in the NCP. It is not intended that AOUs diminish the requirements for, delay the conduct of, or conflict with the total remedial action.
Accident Site The location of an unexpected occurrence, failure or loss, either at a plant or along a transportation route, resulting in a release of hazardous materials.
Accuracy The degree of agreement between a measured value and a true, expected value.
Acetone A colorless, volatile liquid with a sweet odor. It is considered the least toxic solvent in industry. It can occur naturally. It is used in the production of lubricating oils, chloroform, pharmaceuticals, pesticides, paints, varnishes and lacquers. If present in water, it is more likely to volatilize or biodegrade before bioaccumulating or adsorbing to sediments. Acetone will also readily volatilize and biodegrade in soil. It is also a common laboratory contaminant, so its presence in a sample does not always indicate its presence in the environment. Synonyms - Dimethylketone and 2-propanone.
Acid An inorganic or organic compound that 1) reacts with metals to yield hydrogen; 2) reacts with a base to form a salt; 3) dissociates in water to yield hydrogen ions; 4) has a pH of less than 7.0; 5) neutralizes bases or alkalis; and 6) turns litmus paper red. All acids contain hydrogen. They are corrosive to tissue and should be handled with care.
Acid Neutralizing Capacity A measure of the ability of water or soil to resist changes in pH.
Acidic The condition of water or soil that contains a sufficient amount of acid substances to lower the pH below 7.0
Action Level (AL) 1) In the Superfund program, the existence of a contaminant concentration in the environment high enough to warrant action or trigger a response under SARA and the NCP. 2) Regulatory levels recommended by EPA for enforcement by FDA and USDA when pesticide residues occur in food or feed commodities for reasons other than the direct application of the pesticide. As opposed to "tolerances" which are established for residues occurring as a direct result of proper usage, action levels are set for inadvertent residues resulting from previous legal use or accidental contamination. 3) Unless otherwise specified in a NAVOSH standard, one-half the relevant Permissible Exposure Limit (PEL) or Threshold Limit Value (TLV). See Tolerances.
Activated Carbon A highly adsorbent form of carbon used to remove odors and toxic substances from liquid or gaseous emissions. In waste treatment it is used to remove dissolved organic matter from waste water. It is also used in motor vehicle evaporative control systems.
Acute Exposure A single exposure to a toxic substance which results in severe biological harm or death. Acute exposures are usually characterized as lasting no longer than a day, as compared to longer, continuing exposure over a period of time.
Acute Toxicity The ability of a substance to cause poisonous effects resulting in severe biological harm or death soon after a single exposure or dose, usually within 24 hours. Also, any severe poisonous effect resulting from a single short-term exposure to a toxic substance. See Chronic Toxicity, Toxicity.
Adaptation Changes in an organism's structure or habits that help it adjust to its surroundings.
Adjacent Property Either those properties contiguous to the boundaries of the property being surveyed or other nearby properties.
Administrative Order A legal document signed by EPA directing an individual, business, or other entity to take corrective action or refrain from an activity. It describes the violations and actions to be taken, and can be enforced in court. Such orders may be issued, for example, as a result of an administrative complaint whereby the respondent is ordered to pay a penalty for violations of a statute.
Administrative Order On Consent A legal agreement signed by EPA and an individual, business, or other entity through which the violator agrees to pay for correction of violations, take the required corrective or cleanup actions, or refrain from an activity. It describes the actions to be taken, may be subject to a comment period, applies to civil actions, and can be enforced in court.
Administrative Record (AR) A compilation of information established for all CERCLA sites made available to the public at the start of the Remedial Investigation (RI) for remedial actions, or at the time of Engineering Evaluation/Cost Analysis (EE/CA) for removal actions. Information in the Administrative Record supports the selected remedy for remedial actions and removal actions.
Administrative Record File (ARF) 1) Refers to documents, as they are being established and maintained. Until a response action decision has been selected, there is no complete administrative record for that decision. Thus, to avoid creating the impression that the record is complete at any time prior to the final selection decision, the set of documents is referred to as the ARF rather than the AR. 2) A file that contains all information used in order to make decisions on the selection of a response action under CERCLA. Available for public review and comment.
Adsorption The process by which a gas, vapor, dissolved material or very small particle adheres to the surface of a solid due to chemical or physical forces; the attraction and adhesion of ions from an aqueous solution to the solid soil or rock surfaces with which they are in contact.
Advection The transport of dissolved contaminants by the bulk movement of groundwater flow; the main process driving the movement of dissolved contaminants.
Advisory A non-regulatory document that communicates risk information to those who may have to make risk management decisions.
Aeration A process of supplying or introducing air/oxygen into a medium 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).
Aeration Tank A chamber used to inject air into water.
Aerobe Bacteria that use oxygen as an electron acceptor.
Aerobic Life or processes that require, or are not destroyed by, the presence of oxygen. See Anaerobic.
Aerobic Treatment Process by which microbes decompose complex organic compounds in the presence of oxygen and use the liberated energy for reproduction and growth. Such processes include extended aeration, trickling filtration, and rotating biological contactors.
Affected Public The people who live and/or work near a hazardous waste site.
Affinity A chemical attraction or force that causes the atoms of certain elements or compounds to combine with atoms of another element or compound and remain in the combined state.
Air Changes per Hour (ACH) The movement of a volume of air in a given period of time; if a house has one air change per hour, it means that all of the air in the house will be replaced in a one-hour period.
Air Purification Devices Respirators or filtration devices which remove particulate matter, gases, or vapors from the atmosphere. These devices range from full face piece, dual cartridge masks with eye protection, to half-mask face piece, mounted cartridges with no eye protection.
Air Sparging General term for the technology of introducing gases, usually air, beneath the water table to promote site remediation. Air sparging can be divided into two distinct processes: in-well aeration and air injection.
Air Stripping A treatment system that removes volatile organic compounds (VOCs) from contaminated groundwater or surface water by forcing an airstream through the water and causing the compounds to volatilize to the airsteam, enabling separation of the compounds from the water and possible further treatment of the airstream.
Algae Simple rootless plants that grow in sunlit waters, on rocks and in soil, 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.
Aliphatic Hydrocarbon A compound built from carbon and hydrogen atoms joined in a linear chain. Petroleum products are composed primarily of aliphatic hydrocarbons.
Aliquot A measured portion of a sample taken for analysis.
Alkali Any compound having highly basic properties; i.e., one that readily ionizes in aqueous solution to yield OH anions, with a pH above 7.0, and turns litmus paper blue. Examples are oxides and hydroxides of certain metals belonging to group IA of the periodic table (Li, Na, K, Rb, Cs, Fr). Ammonia and amines may also be alkaline. Alkalis are caustic and dissolve tissue. Treat alkali burns by quickly washing with large amounts of water for at least 15 minutes. Common commercial alkalis are sodium carbonate (soda ash), caustic soda and caustic potash, lime, lye, waterglass, regular mortar, portland cement, and bicarbonate of soda.
Alkaline The condition of water or soil which contains a sufficient amount of alkali substances to raise the pH above 7.0.
Alkalinity The capacity of water to neutralize acids.
Alluvial Relating to mud and/or sand deposited by flowing water.
Alternative Fuels Substitutes for traditional liquid, oil-derived motor vehicle fuels like gasoline and diesel. Includes methanol, ethanol, compressed natural gas, and others.
Alternative Technology An approach that aims to use resources efficiently or to substitute resources in order to do minimum damage to the environment. This approach permits a large degree of personal user control over the technology.
Aluminum (Al) A light ductile metal that is easy to weld. It is a good conductor of heat and electricity. When it is exposed to air, it creates a protective film resistant to corrosion. It is used in alloys with copper, zinc, manganese and magnesium. It is a very versatile metal and so has a wide variety of uses: packaging materials, utensils, auto-bodies, airplanes, building materials, electrical conductors, explosives, fireworks, abrasives, cosmetics, paints, and even food additives. It is a natural component in soil, water, and air. Inhalation of the fine powder can lead to pulmonary fibrosis.
Ambient Usual or natural surrounding conditions, e.g., ambient temperature - the natural, uninfluenced temperature of the surroundings.
Anabolism The process whereby energy is used to build organic compounds, such as enzymes and nucleic acids, that are necessary for life functions.
Anadromous Fish that spend their adult life in the sea but swim upriver to freshwater spawning grounds to reproduce.
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.
Analytes The chemicals for which a sample is analyzed.
Analytical Method Defines the sample preparation and instrumentation procedures or steps that must be performed to estimate the quantity of analyte in a sample.
Animal Studies Investigations using animals as surrogates for humans with the expectation that the results are pertinent to humans.
Anion Exchange Capacity A quantitative measure of surface charge of an anion reported in equivalents of exchangeable ions per unit weight of the solid.
Anisotropic / Anisotropy Having different properties in different directions. See isotropic.
Antagonism 1) Interference or inhibition of the effect of one chemical by the action of another. 2) An interaction of two or more chemicals which results in an effect that is less than the sum of their effects taken independently.
Anthropogenic Of or relating to humans or the era of human life. Man-made.
Anthropomorphic Ascribing human motivation, characteristics, or behavior to inanimate objects, animals, or natural phenomena.
Anti-Degradation Clause Part of federal air and water quality requirements prohibiting deterioration where pollution levels are above the legal limit.
Applicable or Relevant and Appropriate Requirement (ARAR) Requirements, including cleanup standards, standards of control and other substantive environmental protection requirements and criteria, for hazardous substances as specified under Federal and state laws and regulations, that must be met when complying with CERCLA and SARA.
Aqueous Something made up of, similar to, or containing water; watery.
Aquiclude A saturated geologic unit that is incapable of transmitting significant quantities of water under ordinary hydraulic gradients.
Aquifer A saturated, permeable geologic formation or structure that is capable of yielding water in usable quantities under ordinary hydraulic gradients.
Aquitard The less permeable beds in a stratigraphic sequence; beds may be permeable enough to transmit water in quantities that are significant in the study of regional groundwater flow or environmental contamination, but their permeability is not sufficient to allow completion of production wells within them.
Area of Concern (AOC) A discrete area of contamination or suspected contamination that is in the PA/SI (or RFA) phase and that has not been entered into the DOD RMIS database.
Aromatic A class of hydrocarbons consisting of cyclic conjugate carbon atoms, such as benzene or toluene, commonly added to gasoline in order to increase octane. Some aromatics are toxic.
Arsenic (Ar) A metalloid occurring naturally in the earth's crust and fossil fuels. It can be released into the environment during combustion of fossil fuels containing arsenic. It is used in the production of glass, enamels, ceramics, oil, cloth, linoleum, electrical semiconductors, pigments, fireworks, pesticides, fungicides, veterinary pharmaceuticals, and wood preservatives. Soluble forms of arsenic can be quite mobile, while less soluble forms tend to adsorb to sediments and soils. It is a known human carcinogen, and bioaccumulates to toxic levels.
Artesian Aquifer A confined aquifer in which groundwater rises in a well above the point at which it is naturally found in the aquifer, due to artesian pressure.
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.
Assessment Endpoint Environmental characteristics, which, if they were found to be significantly affected, would indicate a need for remediation (e.g., decrease in sports fisheries).
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.
Atmosphere-Supplying Devices Respiratory protection devices coupled to an air source. The two types are Self-Contained Breathing Apparatus (SCBA) and supplied air respirators (airline).
Attenuation The process by which a compound is reduced in concentration with distance and time through absorption, adsorption, degradation, dilution, diffusion, dispersion, and/or chemical or biological transformation.
Autochthonous A term applied to rocks of which the dominant constituents have been formed in the natural or original position as opposed to prior erosion and disposition.
Autotrophic An organism that produces food from inorganic substances, e.g. photosynthetic plants.
 

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B

 

  
Background Correction

 

 In data analysis, a technique to compensate for variable background contribution to the instrument signal and the determination of trace metals.
Background Level 1) Naturally occurring levels: ambient concentrations of chemicals present in the environment that have not been influenced by humans; 2) Anthropogenic levels: concentrations of chemicals that are present in the environment due to human-made, non-site sources.
Backwashing Reversing the flow of water back through the filter media to remove the entrapped solids.
Bacteria (Singular: bacterium) Microscopic living organisms ubiquitous in the environment, 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.
Baghouse Filter Large fabric bag, usually made of glass fibers, used to eliminate intermediate and large (greater than 20 microns in diameter) particles. This device operates like the bag of an electric vacuum cleaner, passing the air and smaller particles while entrapping the larger ones.
Bailer A long pipe with a valve at the lower end, used to remove slurry from the bottom or side of a well as it is being drilled or to obtain a water sample from a developed well.
Barium (Ba) The heaviest of the stable alkaline earths, it is a soft, silver-grey metal. It is used in various alloys, paints, soap, paper, rubber, ceramics, glass, insecticides, oil and gas well drilling muds, fireworks, lubricating oil, and steel hardening. It is naturally abundant in nature and is found in plant and animal tissue. Ingestion of barium or some of its compounds can cause muscular problems, and it can accumulate in the skeleton.
Barrier Coating(s) A layer of a material that obstructs or prevents passage of something through a surface that is to be protected, e.g. grout, caulk, or various sealing compounds; sometimes used with polyurethane membranes to prevent corrosion or oxidation of metal surfaces, chemical impacts on various materials, or, for example, to prevent radon infiltration through walls, cracks, or joints in a house.
Base Substances that (usually) liberate OH anions when dissolved in water. Bases 1) react with acids to form salts; 2) have a pH greater than 7.0; 3) turn litmus paper blue; and 4) may be corrosive to tissue. A strong base is called alkaline or caustic. Examples are lye and DRANO.
Base Neutral Acid Compound (BNA) See Semi-Volatile Organic Compound (SVOC).
Base Realignment And Closure (BRAC) Refers to policy, procedures, authorities, and responsibilities for closing or realigning military installations across the Department of Defense. Includes environmental restoration activities.
Baseline Risk Assessment An analysis of the potential adverse health effects (current or future) caused by contaminant releases from a site in the absence of any actions to control or mitigate these releases. According to EPA, the baseline risk assessment can be used to determine whether: 1) A release or threatened release poses an unacceptable risk to human health or the environment that warrants remedial action, and 2) A site presents an imminent and substantial endangerment. The primary purpose is to provide risk managers with an understanding of the actual and potential risks to human health and the environment posed by the site and the uncertainties associated with the assessment.
Bed Load Sediment particles resting on or near the channel bottom that are pushed or rolled along by the flow of water.
Bedrock Any solid rocks exposed at the surface or overlain by unconsolidated materials.
Bench-scale Tests Laboratory testing of potential cleanup technologies. Contaminated media from the site are generally used to determine the applicability of a technology to a specific site. See Pilot Tests and Treatability Studies.
Benthic Organism (Benthos) A form of aquatic plant or animal life that is found on or near the bottom of a stream, lake, ocean or other water body.
Benthic Region The bottom layer of a body of water.
Bentonite Clay made of decomposed volcanic ash which is used to seal wells (hole plug).
Beryllium (Be) A greyish-white metal occurring naturally in certain rocks, soils and volcanic dust. A major emission source to the environment is through the fly ash from combustion of coal and fuel oil, which can contain the metal. It is used in nuclear reactors, radio and television tubes, fluorescent tubes and powders. It is discharged by machine shops, ceramic and propellant plants, and foundries. In the environment, it ultimately accumulates in sediments. Beryllium can cause severe dermatitis problems and can be toxic if inhaled. It is a Group B2, animal carcinogen
Best Demonstrated Available Technology (BDAT) As identified by EPA, the most effective, commercially available means of treating specific types of hazardous waste. The BDATs may change with advances in treatment technologies.
Best Management Practice (BMP) Methods that have been determined to be the most effective, practical means of preventing or reducing pollution from nonpoint sources.
Bias Consistent deviation of measured values from the true value, caused by systematic errors in a procedure.
Bicarbonates Metal + HCO3, e.g. NaHCO3. Can raise the pH to a high concentration which may be corrosive.
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.
Bioassay Study of living organisms to measure the effect of a substance, factor, or condition by comparing before-and-after exposure or other data.
Bioaugmentation The addition of microbe cultures to groundwater or soil to enhance biodegradation.
Bioavailability A general term to describe the accessibility of contaminants to ecological populations. Bioavailability consists of: 1) a physical aspect related to phase distribution and mass transfer, and 2) a physiological aspect related to the suitability of the contaminant as a substrate.
Biobarrier An In Situ remediation technology consisting of a trench filled with biological medium to encourage the growth of bacteria capable of degrading contaminants.
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 an organism (such as a fish) to levels greater than in the surrounding medium in which the organism lives.
Bioconcentration Factor (BCF) Provides a measure of the extent of chemical partitioning at equilibrium between biological medium such as fish tissue or plant tissue and an external medium such as water. The higher the BCF, the greater the accumulation in living tissue is likely to be.
Biodegradable Capable of decomposing under natural conditions.
Biodegradation 1) The reduction in concentration of a chemical or physical agent through naturally occurring microbial activity. 2) The process of an organic molecule becoming transformed by biological means.
Biodegradation Rate The mass of contaminant metabolized by microorganisms per unit time. In soil contamination this is normalized to the mass of soil and usually is expressed as mg contaminant degraded/kg soil/day (mg/kg/day).
Biodiversity Refers to the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequencies. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the biochemical structures that are the molecular basis of heredity. Thus, the term encompasses different ecosystem, species, and genes.
Biological Additive Microbiological cultures, enzymes, or nutrient additives that are deliberately introduced into a discharge for the specific purpose of encouraging biodegradation to mitigate the effects of the discharge.
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. 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 Treatment A treatment technology that uses bacteria to consume waste.
Biomass All of the living material in a given area; often refers to vegetation.
Biome The entire community of living organisms in a single major ecological area. See Biotic Community.
Biomonitoring 1) The use of living organisms to test the suitability of effluents for discharge into receiving waters and to test the quality of such waters downstream from the discharge. 2) Analysis of blood, urine, tissues, etc., to measure chemical exposure in humans or animals.
Biopile Soil pile constructed to allow aerobic bioremediation by aeration, possibly supplemented with water and nutrients.
Bioreactor A container or area in which a biological reaction or biological activity takes place.
Bioreclamation The process of making a contaminated site usable again through biological processes.
Bioremediation 1) Use of living organisms to clean up oil spills or remove other pollutants from soil, groundwater, or wastewater. 2) Use of organisms such as non-harmful insects to remove agricultural pests or counteract diseases of trees, plants, and garden soil.
Bioslurping A technology application that teams vacuum-assisted free-product recovery with bioventing to simultaneously recover free product and remediate the vadose zone.
Biosphere The portion of Earth and its atmosphere that can support life.
Biota The animal and plant life of a given region.
Biotechnology Techniques that use living organisms or parts of organisms to produce a variety of products (from medicines to industrial enzymes) to improve plants or animals or to develop microorganisms to remove toxic compounds from bodies of water, or act as pesticides.
Biotic Community A naturally occurring assemblage of plants and animals that live in the same environment and are mutually sustaining and interdependent. See Biome.
Biotransformation Conversion of a substance into other compounds by organisms; includes biodegradation.
Bioventing The process of aerating vadose zone soils by means of installed vents to stimulate in situ biological activity and optimize biodegradation of organic compounds with some volatilization occurring.
Blank An artificial sample designed to monitor the introduction of artifacts into the sampling and analytical process. For aqueous samples, reagent water is used as a blank matrix; however, a universal blank matrix does not exist for solid samples, but sometimes clean sand is used as a blank matrix. The blank is taken through all appropriate steps of the process. A reagent blank is an aliquot of analyte-free water or solvent analyzed with the analytical batch. Field blanks are aliquots of analyte-free water or solvents brought to the field in sealed containers and transported back to the laboratory with the sample containers. Trip blanks and equipment blanks are two specific types of field blanks. Trip blanks are not opened in the field. They are used to monitor sample contamination originating from transport, shipping, and site conditions. Equipment blanks are opened in the field and the contents poured over or through the sampling equipment, collected in a sample container, and returned to the laboratory as a sample. Equipment blanks monitor sampling device cleanliness and decontamination effectiveness.
Blood Borne Pathogens Pathogenic microorganisms that are present in human blood and can cause diseases in humans. These pathogens include hepatitis B virus (HBV) and human immunodeficiency virus (HIV).
Bloom A proliferation of algae and/or higher aquatic plants in a body of water; often related to pollution, especially when pollutants accelerate growth.
Blower A unit of rotating mechanical equipment used to increase the pressure in a gas stream and providing a total pressure rise of more than 4 inches of water and less than 14.7 psi.
Boiling Point (BP) The temperature at which a liquid changes its phase to a vapor or gas. This is the temperature at which a liquid’s vapor pressure is equal to the surrounding atmospheric pressure, so the liquid rapidly volatilizes.
Boom A floating device used to contain oil on a body of water.
Bottom Ash The non-airborne combustion residue from burning pulverized coal in a boiler which falls to the bottom of the boiler and is removed mechanically. Bottom Ash is a concentration of the non-combustible materials, which may include toxic compounds.
BRAC Cleanup Plan (BCP) The road map for expeditious cleanup of military facilities necessary to facilitate conveyance of property to communities for redevelopment.
BRAC Environmental Coordinator (BEC) The DOD representative on the Base Closure Team; has responsibility and implementation authorities for environmental cleanup programs related to the transfer of the installation's real property.
BRAC Environmental Funding Includes all NAVFAC centrally-managed environmental projects, except NEPA, that are funded through the BRAC account such as environmental studies, clean up, compliance, and restoration. For Marine Corps installations, it includes funding for only restoration work.
Brackish Mixed fresh and salt water.
Brine Mud Waste material, often associated with well-drilling or mining, composed of mineral salts or other inorganic compounds.
Bromine (Br) A halogen that can substitute for hydrogen in many organic compounds, generally making the resultant compound more toxic.
Buffer A substance that reduces the change in pH that would otherwise be produced by adding acids or bases to a solution. A pH stabilizer.
By-product Material, other than the principal product, generated as a consequence of an industrial process.
 

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Cadmium (Cd) A soft metal used in electroplating, pigments, plastic stabilizers, batteries, fusible alloys, soft solder, and solder for aluminum. Pollution sources include smelter fumes and dust, some incineration products, fertilizer, municipal wastewater and sludge discharges. It is also an industrial byproduct of the manufacturing of zinc, copper and lead. Its mobility depends on the pH and redox state of the local environment. It can be adsorbed to sediments and soils or relatively soluble in surface water or groundwater depending on the conditions. Bioaccumulation in the environment is a concern. Ingestion can cause gastrointestinal problems, and inhalation can cause lung problems.
Calcium (Ca) An alkaline earth metal that is very abundant in the environment. Readily forms salts with various metals and halogens. When present in water, it can indicate salinity and alkalinity. Contributes to hard water when present in high concentrations. It is an essential nutrient for animals and humans. Not generally considered toxic.
Calibration The establishment of an analytical curve based on the absorbance, emission intensity, or other measured characteristic of known standards. The calibration standards must be prepared using the same type of acid or concentration of acids as used in the sample preparation, i.e., the same matrix.
Calibration Blank Usually an organic or aqueous solution that is as free of analyte as possible and prepared with the same volume of chemical reagents used in the preparation of calibration standards and diluted to the appropriate volume with the same solvent (water or organic). The calibration blank is used to give the null reading for the instrument response versus concentration calibration curve. One calibration blank should be analyzed with each analytical batch or every method-specified number of samples, whichever is more frequent.
Calibration Check Verification of the ratio of instrument response to analyte amount, a calibration check is done by analyzing for analyte standards in an appropriate solvent. Calibration check solutions are made from a stock solution which is different from the stock used to prepare standards.
Calibration Standards A series of known standard solutions used by the analyst for calibration of the instrument (i.e. preparation of the analytical curve).
Cancer The development of a malignant tumor or abnormal formation of tissue.
Cancer Risk Incremental probability of an individual developing cancer over a lifetime as a result of exposure to a chemical.
Cap A layer of clay, or other impermeable material installed over the top of a closed landfill to prevent infiltration of rainwater and minimize leachate.
Capillary Action Upward movement of water through very small spaces due to molecular forces and surface tension, called capillary forces.
Capillary Fringe A zone of porous material lying between the unsaturated and saturated zone, just above the water table, which may hold water by capillary action in the smaller void spaces.
Carbon (C) An element, the presence of which can be used to separate organic from inorganic compounds.
Carbon Absorber An add-on control device that uses activated carbon to absorb volatile organic compounds from a gas stream. The VOCs are later recovered from the carbon.
Carbon Adsorption A treatment system that removes contaminants from groundwater or surface water by forcing it through tanks containing activated carbon treated to attract the contaminants.
Carbon Dioxide (CO2) A colorless, odorless, non-poisonous gas, which results from fossil fuel combustion and is normally a part of the ambient air.
Carbon Monoxide (CO) A colorless, odorless, poisonous gas produced by incomplete fossil fuel combustion.
Carcinogen 1) Any substance that can cause, aggravate, or contribute to the production of cancer. 2) A chemical classification for the purpose of risk assessment based on the weight of evidence for human carcinogenicity according to USEPA 1986 Guidelines for Risk Assessment, in which carcinogens are summarized as follows: Group A: Human carcinogen: Sufficient evidence from human epidemiological studies. Group B: Probable Human Carcinogen: B1: Limited evidence from human epidemiological studies. B2: Sufficient evidence from animal studies and inadequate or no data from human epidemiological studies. Group C: Possible Human Carcinogen: Limited evidence of carcinogenicity from animal studies in the absence of human data.
Carcinogenic Causing or producing cancer.
Carcinogenic Potency Factor
(CPF) 		The upper 95th percentile confidence limit of the slope of the dose-response curve; expressed in units of (mg/kg/day)-1. When derived from human epidemiological data, the carcinogenic potency factor may be a maximum likelihood estimate.
Carrying Capacity 1) In recreation management, the amount of use a recreation area can sustain without loss of quality. 2) In wildlife management, the maximum number of animals an area can support during a given period.
CAS Registration Number A number assigned by the Chemical Abstracts Service to identify a chemical.
Casing Pipe used in water well construction generally extending from the land surface to the top of the well screen. The type and size of casing used will vary depending on well yield and other design requirements.
Catabolism The process whereby energy is extracted from organic compounds by breaking them down into their component parts.
Catalyst An inorganic substance that changes the speed, yield, or required temperature of a chemical reaction without being consumed or chemically changed by the chemical reaction.
Catanadromous Fish that swim downstream to spawn.
Categorical Exclusion (CE) A class of actions which either individually or cumulatively would not have a significant effect on the human environment and therefore would not require preparation of an Environmental Assessment or Environmental Impact Statement under the National Environmental Policy Act (NEPA).
Cathodic Protection A technique to prevent corrosion of a metal surface by making it the cathode of an electrochemical cell.
Cation Exchange Capacity A quantitative measure of surface charge of a cation, reported in equivalents of exchangeable ions per unit weight of the solid.
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.
Characteristic Any one of the four categories used in defining hazardous waste: ignitability, corrosivity, reactivity, and toxicity.
Characterization Facility or site sampling, monitoring and analysis activities to determine the extent and nature of a release. Characterization provides the basis for acquiring the necessary technical information to develop, screen, analyze, and select appropriate cleanup techniques.
Chelate A coordination complex in which more than one atom or molecule (often an organic compound) binds to a metal. In the environment, chelation effectively removes the metal: it is no longer available for chemical interactions or to biota. See Complexation.
Chemical Oxygen Demand (COD) A measure of the oxygen required to oxidize all compounds, both organic and inorganic, in water.
Chemical
Partitioning 		The preferential separation of a chemical into different media or states. For example, many metals are more likely to partition to sediments than to remain in groundwater.
Chemical
Resistance 		The ability of chemical protective clothing to maintain its integrity and protection qualities when it comes into contact with a hazardous material.
Chemical Stress The result of a chemical reaction of two or more materials. Examples include corrosive materials attacking a metal, the pressure or heat generated by the decomposition or polymerization of a substance, or any variety of corrosive actions.
Chemical Treatment Any one of a variety of technologies that use chemicals or a variety of chemical processes to treat waste.
Chemicals of Concern (COC) Specific constituents that are identified for evaluation in the risk assessment process.
Chemicals of Potential Concern (COPC) Chemicals identified in the initial stages of a site investigation that may pose a risk, and so are further investigated to gather data for a risk assessment.
Chlorides (Cl-) Indicative of the concentration of salt water. Concentrations above 250mg/L are detectable by taste.
Chlorinated Hydrocarbons These include a class of persistent, broad-spectrum organic compounds that linger in the environment and accumulate in the food chain. Among them are the insecticides DDT, aldrin, dieldrin, heptachlor, chlordane, lindane, endrin, mirex, hexachloride, and toxaphene. Other examples include tetrachloroethene, trichloroethene, carbon tetrachloride, and trichloromethane, used as industrial solvents.
Chlorinated Solvent An organic hydrocarbon in which chlorine atoms substitute for one or more hydrogen atoms in the compound’s structure, e.g., methylene chloride and 1,1,1-trichloromethane. Commonly used in aerosol spray containers, in highway paint, for grease removal in manufacturing, dry cleaning, and other operations. The substituted chlorine makes the compound less flammable than the nonsubstituted equivalent, but more toxic.
Chlorination The application of chlorine to drinking water, sewage, or industrial waste to disinfect or to oxidize undesirable compounds.
Chlorine (Cl) A halogen that can substitute for hydrogen in many organic compounds. The resulting compounds are generally less flammable but highly toxic and persistent in the environment.
Chlorofluorocarbons (CFCs) A family of inert, nontoxic, and easily liquified 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.
Chromium (Cr) A heavy metal that exists naturally as the trivalent (III) form and is man-made in the hexavalent (VI) form. It is used in making chrome-steel and chrome-nickel-steel alloys, chrome plating of metals, brick lining for high-temperature industrial furnaces, dyes, pigments, leather, wood preservatives, and cooling tower water treatment. The ultimate fate of chromium is to settle into sediments, however, it is slightly soluble and can persist in the water column for years before settling. In soil, chromium (III) tends to adhere to soil particles whereas chromium (VI) does not. This process depends on the pH and redox state of the soil. Chromium (III) is not very toxic because it does not bioaccumulate and generally does not penetrate biological membranes. However, chromium (VI) is considered more toxic because of its high oxidizing potential and it can penetrate biological membranes. Dermal contact with chromic acid or chromium salts can cause lesions and ulcers. Chromium is a Group B, human carcinogen by inhalation. See Heavy Metals.
Chronic Daily Intake (CDI) Exposure expressed as mass of a substance contacted per unit body weight per unit time averaged over a long period of time (as a Superfund program guideline, seven years to a lifetime) mg/kg/day.
Chronic Effect An adverse effect on a human or animal in which symptoms recur frequently or develop slowly over a long period of time.
Chronic Toxicity The capacity of a substance to cause long-term poisonous human health effects. See Acute Toxicity.
Circle of Influence The circular outer edge of the depression produced in the water table by pumping water from a well. See Cone of Influence, Cone of Depression.
cis In a chiral (directional) organic compound, the prefix cis indicates that the substituted atoms are on the same side of the compound. For example, in cis 1,2-Dichloroethene, the chlorine atoms are on the same side of the carbon to carbon double bond. The presence or absence of cis or trans compounds can indicate whether biological activity or abiotic, chemical reactions have taken place in the environment. See trans.
Clarification Clearing action that occurs during water treatment when solids settle out. This is often aided by centrifugal action and chemically induced coagulation.
Clarifier A tank in which solids settle to the bottom and are subsequently removed as sludge.
Clastic Rock A consolidated sedimentary rock composed of broken fragments that are derived from pre-existing rocks, e.g. sandstone, conglomerate, shale, etc.
Clay 1) Natural material with plastic (flowing) properties; 2) A composition of particles of very fine size grades; and 3) A composition of crystalline fragments of hydrous-aluminum silicate or hydrous-magnesium silicate minerals.
Clay Soil Soil material containing more than 40 percent clay, less than 45 percent sand, and less than 40 percent silt.
Clean Air Act (CAA) The CAA was passed in 1970 as amendments to 42 USC 7401, and was amended in 1990. Its purpose is to "protect and enhance the quality of the Nation's air resources." Its primary application is through Prevention of Significant Deterioration permits to regulate new potentially polluting facilities. Of increasing importance are the National Emissions Standards for Hazardous Air Pollutants (NESHAPs).
Clean Water Act of 1977 (CWA) The CWA amended the Federal Water Pollution Control Act first passed in 1956. Its objective is to "restore and maintain the chemical, physical and biological integrity of the Nation's waters." The Act's major enforcement tool is the National Pollutant Discharge Elimination System (NPDES) permit.
Cleanup Actions taken to deal with a release or threat of release of a hazardous substance that could affect humans and/or the environment. The term "cleanup" is sometimes used interchangeably with the terms remedial action, removal action, response action, or corrective action.
Cleanup Level The residual concentration of a hazardous substance in a medium that is determined to be protective of human health and the environment under specified exposure conditions.
Cleanup Technology A technology that is the whole or part of a treatment train to cleanup hazardous waste sites.
Climatology The science that deals with the climate and climatic phenomena.
Closeout Conducted when DON considers no further response actions under the IR Program to be appropriate for the site and when site cleanup confirms that no significant threat to public health or the environment exists. The Navy forwards closeout documentation to the regulators for concurrence.
Closure The regulatory process of deactivating, stabilizing and or decontaminating waste management units or facilities under RCRA.
Closure Plan Documentation prepared to guide the deactivation, stabilization and surveillance of a waste management unit or facility under RCRA.
Coagulation Clumping of particles in water to settle out impurities, often induced by chemicals such as lime, alum, and iron salts.
Coastal Plains Any plain which has its margin on the shore of a large body of water, particularly the sea, and generally represents a strip of recently emerged sea floor.
Coastal Zone As defined by the NCP, all US waters subject to the tide, US waters of the Great Lakes, specified ports and harbors on inland rivers, waters of the contiguous zone, other waters of the high seas subject to the NCP, and the land surface or land substrata, groundwaters, and ambient air proximal to those waters. The term coastal zone delineates an area of federal responsibility for response action. Precise boundaries are determined by EPA/USCG agreements and identified in federal regional contingency plans.
Cobalt (Co) A hard, ductile, ferromagnetic metal. It is rare but produced primarily as a byproduct of other metals. It is used in chemical agents, electroplating, ceramics, lamp filaments, catalysts, dryers in printing inks, paints and varnishes, and in high temperature alloys. Cobalt can be soluble in water, but depends mainly on the presence and characteristics of adsorbing clay minerals and hydrous oxides of iron, manganese and aluminum in the local environment. Chelation is also possible.
Code of Federal Regulation (CFR) The basic reference source for federal rules. Published annually, it is a compilation of the regulations of various federal agencies. The CFR is divided into 50 titles according to subject. For example, Title 7 deals with agriculture, Title 40 with the environment and Title 49 with transportation. Titles are divided into chapters, then to parts, sections, etc. The section is the basic unit of the CFR. Ideally, it consists of a short, concise presentation of a single point. It is important to note that the CFRs are changed daily by publication of the Federal Register (FR). The CFRs are the combination of regulations published in the FR for the previous year.
Coefficient of Variation (CV) The standard deviation as a percent of the arithmetic mean.
Coliform Bacteria A group of bacteria considered a reliable indicator of the adequacy of treatment for bacterial pathogens.
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.
Colloids Very small, less than 1 ðmm, finely divided solids (that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge.
Combustible A term the NFPA, DOT, and others use to classify certain materials with low flash points that ignite easily. Both NFPA and DOT generally define combustible liquids as having a flash point of 100° F (38° C) or higher. The NFPA classifies nonliquid materials such as wood and paper as ordinary combustibles. OSHA defines combustible liquids within the Hazard Communication Law as any liquid with a flash point at or above 100° F (38° C) but below 200° F (93.3° C).
Combustion 1) Burning, or rapid oxidation, accompanied by release of energy in the form of heat, light, and/or sound. A basic cause of air pollution. 2) Refers to controlled burning of waste, in which heat chemically alters organic compounds, converting into stable compounds such as carbon dioxide and water.
Combustion Chamber The actual compartment where waste is burned in an incinerator.
Cometabolism A reaction in which microbes transform a contaminant even though the contaminant cannot serve as an energy source for the organisms. To degrade the contaminant, the microbes require the presence of other compounds (primary substrates) that can support their growth.
Comment Period Time provided for the public to review and comment on a proposed action or rule making after publication in the Federal Register or as a document.
Commercial Waste All solid waste emanating from business establishments such as stores, markets, office buildings, restaurants, shopping centers, and theaters.
Commercial Waste Management Facility A treatment, storage, disposal, or transfer facility which accepts waste from a variety of sources, as compared to a private facility which normally manages a limited waste stream generated by its own operations.
Community In ecology, a group of interacting populations in time and space. Sometimes, a particular subgrouping may be specified, such as the fish community in a lake or the soil arthropod community in a forest.
Community Environmental Response Facilitation Act of 1992 (CERFA) This law amends CERCLA and requires that the federal government identify real property which is not contaminated, and that offers the greatest opportunity for expedited reuse and redevelopment by the community on each facility. The identified parcels of real property must be either free from hazardous substances and petroleum products, including aviation fuel and motor oil, and their derivatives, or the remediation of contamination by those substances should be expedited to facilitate transfer to the public.
Community Relations The effort to establish two-way communication with the public to create understanding of Installation Restoration Program and related actions, to assure public input into decision-making processes related to affected communities, and to make certain that the Navy is aware of and responsive to public concerns. Specific community relations activities are required in relation to Superfund remedial actions. The term "public" includes citizens directly affected by the site, other interested citizens or parties, organized groups, elected officials, and potentially responsible parties.
Community Relations Plan (CRP) A written plan of action that provides for interaction with the public, elected officials and environmental groups, including obtaining their input at appropriate points during the Installation Restoration (IR) process. A CRP must be developed and implemented for removal actions and remedial actions at all IR sites. It will be based on research conducted by community interviews with state and local officials, citizen and community groups, interested residents, and local media representatives.
Community Reuse Plan The basis for the proposed action and alternatives addressed in the DOD Component's EIS or other NEPA analyses.
Community Water System In Virginia, as defined by the Virginia Department of Health, a water system serving at least 25 individuals or more than 15 residential connections.
Comparability A qualitative measure of the confidence with which one data set can be compared to another. Sample data should be comparable with other measurement data for similar samples and sample conditions.
Completeness A measure of the amount of valid data obtained from a measurement system compared to the amount that was expected to be obtained under routine operating conditions.
Complexation Electrostatic association of positively charged metal ions and negatively charged organic matter, usually with two or more points of attachment. See Chelate.
Composite Sample A representative sample created by the homogenization of multiple samples from multiple sampling locations within the same