Environment terminology · MLC-0121

Environment terms: D (1,500)

Page 2 of 4

Designated state agencyState agency designated by State law or other authority to be responsible for registering pesticides to meet...
Designated use1. Classification specified in water quality standards for each waterbody or segment describing the level of...
Designated uses, see Designated use
Designated volatility attainment areaArea not designated as being in nonattainment with the National Ambient Air Quality Standard for ozone...
Designated volatility nonattainment areaAny area designated as being in nonattainment with the National Ambient Air Quality Standard for ozone...
Designated waste facility1. A hazardous waste treatment, storage, or disposal facility which:(i) Has received a permit (or interim...
Designating agencyExecutive branch agency that designates or approves the designation of a specific item of information as CUI.
Designation dateEffective date of the PM2.5 area designation as promulgated by the Administrator.
Design-basedStatistical inferences using methodology based on the sampling design. Such inferences derive their...
Designer bugPopular term for microbes developed through biotechnology that can degrade specific toxic chemicals at their...
Designer bugs, see Designer bug
Designer drugDrugs designed and synthesized, often for illegal street use, by modification of existing drug structures...
Design-to-CostConcept that establishes cost elements as management goals to achieve the best balance between life-cycle...
Design-unbiasedIndicates that an estimator is unbiased under the design protocol. This property does not, however, prevent...
Desired outcomePreferred result of an action or series of actions.
Desizing facilityThose facilities that desize more than 50 percent of their total production. These facilities may also...
Desk reviewReview of initial data provided by a manufacturer when they initiate registration of products to some...
Desktop & user environment infrastructure operations & maintenanceActivities to provide desktop support and mobile end-user technologies, including maintenance and enhancement...
Desorption1. Desorption is the process by which inorganic nutrients are released from the surface of particles back...
Destination facilities, see Destination facility
Destination facility1. The facility to which regulated medical waste is shipped for treatment and destruction, incineration...
Destination medical waste facilityThe facility to which regulated medical waste is shipped for treatment and destruction, incineration, and/or...
Destination waste facility1. Facility that treats, disposes of, or recycles a particular category of universal waste, except those...
Destratification1. (de-STRAT-uh-fuh-KAY-shun) The development of vertical mixing within a lake or reservoir to eliminate...
Destroyed medical wasteRegulated medical waste that has been ruined, torn apart, or mutilated through thermal treatment, melting...
Destruction1. In records management, the major type of disposal action. Methods of destroying records include selling or...
Destruction and removal efficiency1. A percentage that represents the number of molecules of a compound removed or destroyed in an incinerator...
Destruction device1. For the purposes of subparts II and TT of this part, means a flare, thermal oxidizer, boiler, turbine...
Destruction efficiency1. Efficiency with which a destruction device reduces the mass of a greenhouse gas fed into the device...
Destruction facilityA facility that destroys regulated medical waste.
Destruction or removal efficiencyEfficiency of an abatement system to destroy or remove fluorinated GHGs, N2O, or both. The destruction or...
Destruction treatmentThe destruction of a toxic chemical in waste such that the substance is no longer the toxic chemical subject...
Desulfurization1. Removal of sulfur from fossil fuels to reduce pollution.
DesuperheaterAn energy saving device in a heat pump that, during the cooling cycle, recycles some of the waste heat from...
Detachable fuel lineFuel line or fuel line assembly intended to be used with a portable nonroad fuel tank and which is connected...
Detailed landscapeThe close view of objects or features, particularly surface characteristics, color or touchable nature. There...
Detectable leak rateThe smallest leak (from a storage tank), expressed in terms of gallons- or liters-per-hour, that a test can...
Detection1. To have obtained experimental evidence that the analyte concentration is greater than zero. {ORD} {OW/EAD}...
Detection criterionA predetermined rule to ascertain whether a tank is leaking or not. Most volumetric tests use a threshold...
Detection limit1. The lowest concentration of a chemical that can be distinguished reliably from a zero concentration.
Detection limit (radiochemistry), see Detection limit
Detection monitoringFor purposes of RCRA TSDF ground water monitoring, the first step of monitoring at land disposal units, where...
DetectorCan be any kind of a sensor used to detect a form of energy, but usually refers to nuclear detectors, such as...
DetentionThe slowing, dampening, or attenuating of flows either entering the sewer system or within the sewer system...
Detention basinPractice which hold stormwater temporarily and discharge the stormwater over an extended period of time...
Detention lagThe time period between the moment a change is made and the moment when such a change is finally sensed by...
Detention time1. The theoretical (calculated) time required for a small amount of water to pass through a tank at a given...
Detergent1. Synthetic washing agent that helps to remove dirt and oil. Some contain compounds which kill useful...
Detergent additive package1. Any chemical compound or combination of chemical compounds, including carrier oils, that may be added to...
Detergent blenderAny person who owns, leases, operates, controls or supervises the blending operation of a detergent blending...
Detergent blending facility1. Facility at which detergent is blended with gasoline or post-refinery component
Detergent carrierAny distributor of detergent who transports or stores or causes the transportation or storage of detergent...
Detergent distributorAny person who transports or stores or causes the transportation or storage of detergent at any point between...
Detergent gasolineAny gasoline that contains a detergent.
Detergent manufacturerAny person who owns, leases, operates, controls, or supervises a facility that manufactures detergent...
Detergent-active componentComponents of a detergent additive package which act to prevent the formation of deposits, including, but not...
Detergent-additized gasolineAlso called detergent gasoline, any gasoline that contains base gasoline and detergent.
Detergent-additized post-refinery componentAny post-refinery component that contains detergent.
Deteriorated emission level1. Emission level that results from applying the appropriate deterioration factor to the official emission...
Deteriorated paintAny interior or exterior paint or other coating that is peeling, chipping, chalking or cracking, or any paint...
DeteriorationA symptom or state of reduced quality or strength.
DeterminantAny factor, whether event, characteristic, or other definable entity, that brings about change in a health...
Determinate growth plant(Plant) in which the growth of the main axis is terminated. Typically applied to inflorescences, where the...
Determinate growth processPlant growth in which the growth of the main axis is terminated. Typically applied to inflorescences, where...
Determination of equivalent treatmentA type of variance from the treatment standards in 40 CFR 268.40; applicable when a technology is specified...
Determination of Need for an Investigation - Investigation is Necessary1. This event indicates whether an investigation is necessary to analyze the extent of contamination at this...
Determination of Need for an Investigation - Investigation is Not Necessary1. This event indicates whether an investigation is necessary to analyze the extent of contamination at this...
Determination of technical impracticabilityThe event by which the State or EPA formally notifies the RCRA facility that the selected remedy cannot be...
DeterministicA methodology relying on point (i.e., exact) values as inputs to estimate risk; this obviates quantitative...
Deterministic analysis1. Deterministic Analysis (as opposed to probabilistic analysis) calculation and expression of health risks...
Deterministic causation1. Natural determinism is the position that the state of a system can, in principle, be fully explained by...
Deterministic exposure assessmentUse point estimates (or, single values) to quantify the amount of exposure that is likely to occur for...
Deterministic exposure assessments, see Deterministic exposure assessment
Deterministic mathematical modelA mathematical model designed to produce system responses or outputs to temporal and spatial stimuli or...
Deterministic methodA methodology relying on point (i.e., exact) values as inputs to estimate risk; this obviates quantitative...
Deterministic model1. A model that provides a solution for the state variables rather than a set of probabilistic outcomes...
DeterrentMeasure that discourages, complicates, or delays an adversary’s action or occurrence by instilling fear...
Detoxification processA Detoxification Process consists of activities of biologic molecules, complexes, or subcellular components...
Detritus1. Any loose material produced directly from disintegration processes. Organic detritus consists of material...
Detrivore1. Any organism that gets most of its nutrients from the detritus in an ecosystem.
DeubiquitinationThe generation of ubiquitin from proproteins and the processing of polyubiquitin chains to release monomeric...
DeuteromycotaA large and heterogenous group of fungi whose common characteristic is the absence of a sexual state. Many of...
Develop & implement surface water quality standardsActivities to support the establishment and implementation of scientifically defensible water quality...
Develop drinking water standardsActivities to develop drinking water standards for public water systems.
Develop effluent guidelinesActivities to support the development, publication, and implementation of effluent guidelines to set national...
Develop geospatial policies, standards & guidanceDevelop Geospatial Policies, Standards, and Guidance includes activities to develop and maintain policies...
Developed landA combination of land cover/use categories, large urban and built-up areas, small built-up areas, and rural...
Developer centralAgency portal that provides information and access to EPA resources that developers can use to build...
DEVELOPINGA film-processing step that makes visible the latent image of an exposed photographic emulsion.
Development1. Changing the landscape through agriculture, industry, or building homes.
Development areaArea mined or otherwise excavated in advance of production mining to establish highwalls and drilling benches...
Development document1. A report prepared during the development of an effluent limitation guideline by EPA that provides the data...
Development effectsAdverse effects such as altered growth, structural abnormality, functional deficiency, or death observed in a...
Development facilityAny fixed or mobile structure subject to this subpart that is engaged in the drilling of productive wells.
Development serverA server utilized for the sole purpose of developing and testing an application before putting it into...
Developmental anatomyThe branch of anatomy concerned with the structural changes that take place between fertilization and...
Developmental delayFailure to meet, or late achievement of developmental milestones.
Developmental disorders1. Disorders in which there is a delay in development based on that expected for a given age level or stage...
Developmental neurotoxicityToxic impacts on a developing nervous system of embryos, infants and children...
Developmental orthopedic diseaseA general term for all the various limb anomalies and general growth disturbances of the limbs of young...
Developmental stressorSubstance that may cause developmental toxicity in an organism.
Developmental toxicity1. Adverse effects on the developing organism that may result from exposure prior to conception (either...
Developmentally toxic effect short-term testEither any in vivo preliminary development toxicity screen conducted in a mammalian species, or any in vitro...
Deviation1. Written approval from the Director, Grants Administration Division for exception(s) from financial...
Deviation after September 16, 2020Any instance in which an affected source subject to this subpart, or an owner or operator of such a source...
Deviation before August 24, 2020Any instance in which an affected source subject to this subpart or an owner or operator of such a source:(1)...
Deviation before September 17, 2020Any instance in which an affected source subject to this subpart, or an owner or operator of such a source...
Deviation on and after August 24, 2020Any instance in which an affected source subject to this subpart or an owner or operator of such a source:(1)...
DeviceMeaning contained in the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. 321 et seq., and the regulations...
Device component1. Each metal to metal joint or seal of non-welded connection separated by a compression gasket, screwed...
Device integrityDurability of a device and effect of its malfunction on vehicle safety or other parts of the vehicle system.
Dew pointThe temperature to which air with a given quantity of water vapor must be cooled to cause condensation of the...
Dewater1. To remove or separate a portion of the water present in a sludge or slurry. To dry sludge so it can be...
DewateredSolids or soils are considered dewatered when the free water is removed from the material. Dewatered does not...
Dewatered solidSolids or soils are considered dewatered when the free water is removed from the material. Dewatered does not...
Dewatered uranium byproductTo remove the water from recently produced uranium byproduct material or tailings by mechanical or...
Dewatering effluentWastewater from drilling fluids and drill cuttings dewatering activities (including but not limited to...
Dexamethasone1. A synthetic adrenal corticosteroid with potent anti-inflammatory properties. In addition to binding to...
D-Glucose1. A primary source of energy for living organisms. It is naturally occurring and is found in fruits and...
DHI recordsGeneric term used to refer to records computed by the Dairy Record Processing Centers.
DHI supervisorAn officially trained and DHIA-certified employee qualified to collect milk samples and record milk weights...
Di (2-Ethylhexyl) PhthalatePlastics may contain from 1 to 40% di(2-ethylhexyl) phthalate by weight and are used in consumer products...
Diabetes mellitusA metabolic disorder characterized by abnormally high blood sugar levels due to diminished production of...
DiagenesisProduction of sediment fluxes as a result of the flux of particulate organic carbon in the sediment and its...
Diagnosis1. A type of inference in the Stressor Identification process that uses symptomatology or a set of specific...
Diagnostic exposure indicatorSignatures of gene expression for specific stressors
Diagnostic protocol1. A standard procedure for diagnosing the cause of illness or impairment.
Dial aroundLong distance services that require consumers to dial a long-distance provider’s access code (or "10-10"...
Diameter at breast heightThe average diameter (outside the bark) of a tree 4.5 feet above mean ground level.
DiamondA crystalline form of carbon that occurs as hard, colorless or tinted isomeric crystals. It is used as a...
Diaphragm cellSemipermeable diaphragms, which separate the anode from the cathode chemicals in the production of chlorine...
Diaphragm pumpPump where the driving member is a flexible diaphragm made of metal, rubber, or plastic. In a diaphragm pump...
DiapirA dome or anticlinal fold in which the overlying rocks or sediments have been ruptured when the plastic core...
Diarrhea1. An abnormally frequent discharge of semisolid or fluid fecal matter from the bowel.
Diary studySurvey in which individuals are asked to record food intake, activities, or other factors in a diary which is...
Diatom1. Microscopic algae with cell walls made of silicon and have two separating halves.
Diatomaceous earth1. A fine, siliceous (made of silica) "earth" composed mainly of the skeletal remains of diatoms, a type of...
Diatomaceous earth filtration1. A filtration method resulting in substantial particulate removal, that uses a process in which: 1) a...
Diatomic nitrogenColorless diatomic gas which is about 80% of the Earth's atmosphere.. Atomic Number 7
Diatomic oxygenColorless diatomic gas. Atomic Number 8. About 20% of the atmosphere. Supports combustion.
Diatoms, see Diatom
DiatrizoateA commonly used x-ray contrast medium. As Diatrizoate meglumine and as Diatrizoate sodium, it is used for...
DiazepamA benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a...
DiazinonAn insecticide. In 1986, EPA banned its use on open areas such as sod farms and golf courses because it posed...
DIAZO FILMIn microform records, film containing images produced by exposing an emulsion of diazonium salts to...
DibenzofuranAny of a family of compounds which has as a nucleus a triple-ring structure consisting of two benzene rings...
Dibenzofurans, see Dibenzofuran
Dibenzo-p-DioxinAny of a family of compounds which has as a nucleus a triple-ring structure consisting of two benzene rings...
Dibromoacetic acidWater disinfection by-product. Acetic acid where two methyl hydrogen atoms are replaced by bromine atoms.
Dichloroacetic acidAcetic acid where two methyl hydrogen atoms are replaced by bromine atoms. A chlorination disinfection...
DichlorodiphenyltrichloroethaneA white, odorless and tasteless, very stable, water-insoluble, synthetic, crystalline chlorinated hydrocarbon...
DichlorvosDichlorvos is an insecticide that is a dense colorless liquid. It has a sweetish smell and readily mixes with...
Dichotomous dataQuantal data where an effect for an individual may be classified by one of two possibilities, e.g., dead or...
Dichotomous keyA system that classifies materials by separating choices into two categories.
Dichotomous variableA variable with only two possible values.
DiclofenacA non-steroidal anti-inflammatory agent ( NSAID) with antipyretic and analgesic actions. It is primarily...
DicofolA pesticide used on citrus fruits.
Dictionary2) A reference tool containing an alphabetical list of words, with information given for each word, usually...
Die castingOperations classified under the North American Industry Classification System codes 331521 (Aluminum...
Die cuttingThe process of using sharp steel rules to cut special shapes into printed sheets.
DielInvolving a 24-hour period. (Pronounced "die'-el")
Dieldrin1. An organochlorine insecticide no longer registered for use in the United States. Also a degradation...
Dielectric constantA measure of the ability of a material to store ge when an electric field is applied.
Dielectric materialMaterial that does not conduct direct electrical current. Dielectric coatings are used to electrically...
Dielectric permittivityDescribes the ge separation or polarization in a medium.
Diels-Alder reaction[4+2] cycloadditions between a conjugated diene and a substituted alkene
Diesel1. A type of fuel typically used in a compression-ignition engine. In common maritime use, diesel can refer...
Diesel engine1. An engine where combustion air is first compression heated in the cylinder, and diesel fuel oil is then...
Diesel exhaustDiesel exhaust contains combustion products of compression ignition engines. The gases contain fine...
Diesel exhaust fluid1. Liquid compound used in conjunction with selective catalytic reduction to reduce NOX emissions. Diesel...
Diesel fuel1. Any liquid obtained from the distillation of petroleum with a boiling point of approximately 150 to 360...
Diesel fuel additiveAny substance not composed solely of carbon and/or hydrogen, or of diesel blendstocks, that is added to...
Diesel fuel distribution system downstream locationAny point in the diesel fuel distribution system that is downstream of refineries and import facilities, for...
Diesel fuel downstream locationAny point in the diesel fuel distribution system that is downstream of refineries and import facilities, for...
Diesel fuel manufacturerA fuel manufacturer that owns, leases, operates, controls, or supervises a fuel manufacturing facility where...
Diesel gallon equivalentAmount of electricity or fuel with the energy equivalence of one gallon of diesel fuel. For purposes of this...
Diesel oilGrade of distillate fuel oil, as specified in the American Society for Testing and Materials Standard...
Diesel otherAny distillate fuel oil not defined elsewhere, including Diesel Treated as Blendstock (DTAB).DIPE...
Diesel particulate matter1. A component of diesel exhaust, including soot particles made up of carbon, ash, sulfates and other...
Diesel particulate matter air concentrationDiesel particulate matter level in air in micrograms per cubic meter (µg/m3).
Diesel particulate matter filterDiesel particulate matter filters are ceramic devices that collect the particulate matter in the exhaust...
Diesel reciprocating engine unitInternal combustion engine that combusts only diesel fuel and that thereby generates electricity through the...
Diesel-fired unitFor the purposes of part 75 of this chapter, an oil-fired unit that combusts diesel fuel as its fuel oil...
Dietary accumulationThe net accumulation of a substance by an organism as a result of ingestion in the diet.
Dietary exposure1. The condition of being subject to toxic substance(s) as a result of food consumption.
Dietary supplementProducts in capsule, tablet or liquid form that provide dietary ingredients, and that are intended to be...
Diethyl phthalateDiethyl phthalate is a colorless liquid that has a bitter, disagreeable taste. This synthetic substance is...
Diethylene glycolDiethylene glycol is a colorless liquid. Denser than water. Contact may slightly irritate skin, eyes and...
DiethylnitrosamineA nitrosamine derivative with alkylating, carcinogenic, and mutagenic properties.
DiethylstilbestrolA synthetic nonsteroidal estrogen used in the treatment of menopausal and postmenopausal disorders. It was...
Differ only in waysThe Agency has interpreted the phrase "....or that differ only in ways that would not significantly increase...
Differential log1. A log that records the rate of change of some logged value as a function of depth; the differential log is...
Differential measurement methodMethod of measurement in which the measured value is compared with a known standard.
Differential sample weighting techniqueWeighting the relevant information with the more important receiving higher weights.
DifferentiationThe process by which single cells grow into particular forms of specialized tissue (e.g., root, stem, or...
Differing scientific opinionA differing opinion of an EPA scientist who is or was substantively engaged in the scientific activity that...
Diffey weighting1. A weighting function that indicates which UV wavelengths are most efficient at burning human skin. When...
Difficult to inspect equipmentEquipment cannot be inspected without elevating the inspection personnel more than two meters above a support...
Difficult-to-monitor equipmentEquipment piece may not be monitored without elevating the monitoring personnel more than 2 meters (7 feet)...
Diffuse insolation1. The solar radiation that is scattered or reflected by atmospheric components (e.g., clouds) to the earth's...
Diffuse radiationRadiation received from the sun after reflection and scattering by the atmosphere and ground.
Diffused airA type of aeration that forces oxygen into sewage by pumping air through perforated pipes inside a holding...
Diffusers and grilles1. Components of the ventilation system that distribute and return air to promote air circulation in the...
Diffusion1. The movement of suspended or dissolved particles from a more concentrated to a less concentrated region as...
Diffusion flame stationary combustion turbineAny stationary combustion turbine where fuel and air are injected at the combustor and are mixed only by...
DigestateMaterial that remains following the anaerobic digestion of renewable biomass in an anaerobic digester...
Digester1. In wastewater treatment, a closed tank; in solid-waste conversion, a unit in which bacterial action is...
Digester system1. Each continuous digester or each batch digester used for the cooking of wood in white liquor, and...
Digestion1. The biochemical decomposition of organic matter, resulting in partial gasification, liquefaction, and...
Digestive cropA dilation of the esophagus at the base of the neck of some birds.
Digestive juiceSecretions by multicellular organisms to help break down ingested nutrients into components that may be...
Digestive system1. Encompasses the mouth, esophagus, stomach, intestines, biliary tract, pancreas, liver, and associated...
DIGITALRepresenting data as discrete variables in the form of numerical characters, as in a digital clock or a...
Digital archivistExperts competent to appraise, acquire, authenticate, preserve, and provide access to records in digital form.
Digital curatorExperts knowledgeable of and with responsibility for the content of digital collections.
Digital elevation modelThe digital representation of the ground surface or terrain using a set of elevation data.
Digital line graphDigital data produced by the U.S. Geological Survey. These data include digital information from the USGS map...
Digital log1. A log recorded as a series of discrete numerical values (compare analog recording).
Digital objectA data structure whose principal components are digital material, including data, plus a unique identifier...
Digital object identifierAn alphanumeric string assigned by a registration agency to uniquely identify a digital object, such as a...
Digital readoutUse of numbers to indicate the value or measurement of a variable. The readout of an instrument by a direct...
Digital scientific dataRefers to born-digital and digitized data produced by, in the custody of, or controlled by federal agencies...
Digital signature(not to be confused with a digital certificate) An electronic signature that can be used to authenticate the...
Digital televisionA new technology for transmitting and receiving broadcast television signals. DTV provides clearer resolution...
Digital video discTechnically a disc that carries a digitally recorded video program. Commonly used to mean a program that is...
DiisocyanateCompound containing two isocyanate groups per molecule. The most common diisocyanate compounds used in the...
DiisocyanatesChemicals in auto body part painting operations, especially for clear coat applications, which are a leading...
Diisocyanates (1.0)This category includes only those chemicals listed. See table at...
Dike1. An embankment or wall that contains drainage water or spilled oil inside the walled area.
Diltiazembenzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on...
Diluent1. A diluting agent
Diluent cap valueDefault value of percent CO2 or O2 which may be used to calculate the hourly NOX emission rate, when the...
Diluent gas1. Major gaseous constituent in a gaseous pollutant mixture, which in the case of emissions from fossil...
Diluent gas monitorComponent of the continuous emission monitoring system that measures the diluent gas concentration in a...
Diluent solventSolvent that, when added, reduces the concentration of an already dissolved solute.
Dilutable pesticide1. That the pesticide product's labeling allows or requires the pesticide product to be mixed with a liquid...
Dilute solutionA solution that has been made weaker usually by the addition of water.
Dilution1. The addition of some quantity of less concentrated liquid (water) that results in a decrease in the...
Dilution prohibitionThe LDR requirement that prohibits the addition of soil or water to waste in order to reduce the...
Dilution ratio1. The relationship between the volume of water in a stream and the volume of incoming water. It affects the...
Dilution steam blowdown waste stream1. Any continuously flowing process wastewater stream resulting from the quench and compression of cracked...
Dilution ventilationDilution of contaminated air with uncontaminated air in a general area, room, or building for the purpose of...
Dilution weight1. Parameter in the HRS surface water migration pathway that reduces the point value assigned to targets as...
Dimension stoneDefined as natural rock material quarried for the purpose of obtaining blocks or slabs that meet...
DimerMolecule consisting of two identical simpler molecules. For example, nitrogen dioxide (NO₂) forms a dimer...
DimerizationA physical interaction between exactly two molecules or subunits to create a lasting compound.
Dimethyl phthalateMethyl ester of phthalic acid.
Dimictic1. (die-MICK-tick) Lakes and reservoirs which freeze over and normally go through two stratification and two...
Di-n-Butyl PhthalateDi-n-phtalate is a manufactured chemical that does not occur naturally. It is an odorless and oily liquid...
DinitrofluorobenzeneBenzene derivative used as a reagent for labeling terminal amino acid groups.
DinocapA fungicide used primarily by apple growers to control summer diseases. EPA proposed restrictions on its use...
Dinoflagellate1. A type of algae with long, whip-like structures called flagellates.
DinoflagellidaFlagellate eukaryotes, found mainly in the oceans. They are characterized by the presence of transverse and...
DinosebA herbicide that is also used as a fungicide and insecticide. It was banned by EPA in 1986 because it posed...
DiodeElectronic device that allows current to flow in one direction only.
Dioecious plant1. (Plant with) male flowers and female flowers on different individual plants, as in mistletoe.
Dioscorea bulbifera L.Forms dense vines that smother native plants and trees up to 60 feet high.
Dioxin1. Any of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their...
Dioxin and dioxin-like compoundsThis category includes only those chemicals listed. (Manufacturing; and the processing or otherwise use of...
Dioxin emission monitoring systemSystems designed to replace manual stack sampling techniques used to quantify dioxins in flue gas which are...
Dioxin/Furan1. Total tetra- through octachlorinated dibenzo-p-dioxins and dibenzofurans.
Dioxin/Furan and Dioxins and FuransTetra-, penta-, hexa-, hepta-, and octa-chlorinated dibenzo dioxins and furans.
Dioxin/Furans, see Dioxin/Furan
Dioxins, see Dioxin
Dioxins and furans1. Total tetra- through octachlorinated dibenzo-p-dioxins and dibenzofurans.
Dioxins/Furans1. Please see the ATSDR fact sheet for dioxins/furans.
DipThe angle between a planar feature, such as a sedimentary bed or a fault, and the horizontal plane. The dip...
Dip coating1. A part is dipped or immersed in a resin solution. After the part is removed from the solution and excess...
DiphosphonatesOrganic compounds which contain P-C-P bonds, where P stands for phosphonates or phosphonic acids. These...
Diploid organism1. An organism that normally has two sets of chromosomes, and thus two copies of each gene.
DipmeterA multielectrode, contact-resistivity probe that provides data from which the strike and dip of bedding can...
Dipmeter surveyType of resistivity survey used in boreholes useful in determining the dip of subsurface sedimentary beds.
DipoleA pair of equal ges or poles of opposite signs.
Dipole-dipole forceForces caused by attractions between polar groups
Dip-slip faultDip-slip faults are inclined fractures where the blocks have mostly shifted vertically. If the rock mass...
Direct air capture technologyWith respect to a facility, technology, or system, means that the facility, technology, or system uses carbon...
Direct and indirect energy savingsAir conditioning energy savings from installing a cool roof or planting shade trees to reduce heat transfer...
Direct applicationCold rolling operations which include once-through use of rolling solutions at all mill stands.
Direct beam radiationRadiation received by direct solar rays. Measured by a pyrheliometer with a solar aperture of 5.7° to...
Direct benefitResult that is closely related with the program by cause and effect.
Direct broadcast satelliteA high-powered satellite that transmits or retransmits signals which are intended for direct reception by the...
Direct causation1. The induction of an effect through a single cause-effect relationship; for example, the direct effect of...
Direct chargesThose costs that can be identified specifically with a particular final cost objective. Typical costs charged...
Direct consequenceEffect that is an immediate result of an event, incident, or occurrence
Direct contact evaporator recovery furnaceKraft or soda recovery furnace equipped with a direct contact evaporator that concentrates strong black...
Direct contact evaporator recovery furnace systemDirect contact evaporator recovery furnace and any black liquor oxidation system, if present, at the pulp...
Direct contact transmissionDirect contact transmission requires physical contact between an infected person and a susceptible person...
Direct cost1. Is an accounting term for costs that are clearly and exclusively associated with a product or service and...
Direct costs, see Direct cost
Direct current1. Electrical current flowing in one direction only and essentially free from pulsation.
Direct customerThe individuals or organizations that receive the outputs of a program.
Direct digital controlsThe application of microprocessor technology to building environmental controls. DDC systems make it possible...
Direct discharge1. “Discharge of a pollutant.”
Direct discharger1. A municipal or industrial facility which introduces pollution through a defined conveyance or system such...
Direct discharges, see Direct discharge
Direct effect1. An effect where the stressor itself acts directly on the ecological component of interest, not through...
Direct effect (toxin), see Direct effect
Direct effects -, see Direct effect
Direct emissionEmissions of a criteria pollutant or its precursors that are caused or initiated by the Federal action and...
Direct emissions, see Direct emission
Direct filtration1. A filtration method of treating water which consists of the addition of coagulant chemicals, flash mixing...
Direct final ruleA federal agency may issue a DFR when they do not anticipate receiving a significant adverse comment, or when...
Direct fundingFunding that is provided to an organization directly by a governmental entity.
Direct impactAn effect of a program that addresses a stated goal or objective of that program.
Direct implementation1. The oversight/implementation of a UIC program by an EPA Regional office. EPA assumes DI responsibilities...
Direct insolation1. The solar radiation that is transmitted directly through the atmosphere to the earth's surface without...
Direct liquefactionConversion of coal directly into liquids, rather than passing through an intermediate gaseous state.
Direct load control deviceA remotely controllable switch that can turn power to a load or appliance on or off. Such a device could also...
Direct measurementPoint-of-contact measurement "evaluates an exposure as it occurs, by using direct methods to measure the...
Direct measurement methodMethod of measurement in which the measuring device (secondary standard) is directly applied to the thing...
Direct medical costsThe costs of resources for medical treatment (such as the cost of a physician visit).
Direct microscopic somatic cell countMicroscopic count of the actual number of somatic cells in milk. This system is used to check and verify...
Direct non-medical costsCosts incurred in connection with a health intervention or illness, but which are not expended for medical...
Direct particulate matter 2.5 emissionSolid particles emitted directly from an air emissions source or activity, or gaseous emissions or liquid...
Direct preparationIn direct preparation, the filter is examined by microscopy. In contrast with indirect preparation, where a...
Direct public utility ownershipDirect ownership of equipment and facilities by one or more corporations, the principal business of which is...
Direct push1. A growing family of tools used for performing subsurface investigations by driving, pushing, and/or...
Direct push samplingDirect push sampling is a technique in which a sampling tube is hydraulically pushed or driven into the...
Direct reduction furnaceHigh temperature furnace typically fired with natural gas to produce solid iron from iron ore or iron ore...
Direct runoff1. Water that flows over the ground surface or through the ground directly into streams, rivers, and lakes.
Direct services to citizensThe delivery of a good or service to (or on behalf of) the citizenry by the Federal Government with no other...
Direct shell evacuation system1. Any system that maintains a negative pressure within the EAF above the slag or metal and ducts these...
Direct sunRefers to a measurement based only on direct radiation from the sun's disk and excluding indirect radiation...
Direct transmissionImmediate transfer of an agent from a reservoir to a susceptible host by direct contact or droplet spread.
Direct useDirect use of an ecological end-product (EEP) means that the user or beneficiary directly extracts the EEP or...
Direct use classificationClassification of the different ways in which EEPs are directly used or appreciated by humans. Direct uses...
Direct userA direct user of an EEP is a person or establishment that directly extracts the EEP or interacts with or...
Direct user classificationClassification of the separate economic sectors though which people directly use or appreciate ecological...
Direct vent heaterA type of combustion heating system in which combustion air is drawn directly from outside and the products...
Direct water ingestionConsumption of plain water as a beverage. It does not include water used for preparing beverages such as...
Direct-fired process unitProcess unit that is heated by the passing of combustion exhaust through the process unit such that the...
Direction of overland flowDetermined on a topographic map by drawing flow lines perpendicular to contour lines. Direction of flow will...
Directional survey1. A log that provides data on the azimuth and deviation of a borehole from the vertical.
Directionality1. Hypothesis testing is a statistical technique that uses experimental data to determine whether a...
Directionally-sound strategyStrategies for which adequate procedures to quantify emissions reductions or specify a program baseline are...
Directive1. A written instruction communicating policy and/or procedure in the form of orders, regulations, bulletins...
DirectivityDirectivity is an effect of a fault rupturing whereby earthquake ground motion in the direction of rupture...
Director1. The Regional Administrator or State Director, as the context requires, or an authorized representative...
Direct-reduced ironIron produced by reduction of iron ore (pellets or briquettes) using gaseous (carbon monoxide-carbon dioxide...
Direct-shell evacuation control system1. System that maintains a negative pressure within the electric arc furnace above the slag or metal and...
Dirty ballastSeawater that is occasionally pumped into empty fuel tanks for the specific purpose of improving ship...
Dirty bombAn explosive device that uses conventional material (e.g., dynamite) and radioactive material. It is designed...
Dirty bomb detonationDetonation of a device that spreads radioactive material by exploding a conventional (non-nuclear) explosive...
Disability-adjusted life yearA unit of health care status that adjusts age-specific life expectancy by the loss of health and years of...
Disabled AmericanWith respect to an individual, permanent or temporary physical or mental impairment that substantially limits...
Disabled child(Child with a) long-lasting physical, mental, or emotional condition. This condition can make it difficult...
Disabled personPerson with a long-lasting physical, mental, or emotional condition. This condition can make it difficult for...
DisaccharidesOligosaccharides containing two monosaccharide units linked by a glycosidic bond.
Disadvantaged business enterpriseEntity owned or controlled by a socially and economically disadvantaged individual as described by Public Law...
Disadvantaged communityEntire service area of a public water system that meets affordability criteria established by the State after...
Disadvantaged groupLacking in the basic resources or cal and educational facilities, civil rights) believed to be necessary for...
Disallowed costsThose charges to an award that the Federal awarding agency determines to be unallowable, in accordance with...
Disappearing streamIn karst areas, streams often disappear into the ground usually at a sinkhole.
DISASTERAn unexpected occurrance inflicting widespread destruction and distress and having long-term adverse effects...
Disaster debrisNonhazardous solid waste, such as damaged building debris, household furniture or personal effects; uprooted...
Disaster managementDisaster Management involves the activities required to prepare for, mitigate, respond to, and repair the...
Disaster preparedness & planningDisaster Preparedness and Planning involves the development of response programs to be used in case of a...
Disaster recovery plan1. Minimizes the disruption of mission-critical operations and ensures organizational stability and orderly...
Disaster responseResponse to, and preparation for that response, emergencies and disasters
Disaster shelterTemporary shelter provided in response to a major disaster or emergency.
Disastrous floodingA flow above the carrying capacity of a channel.
Disastrous hurricane1. A cyclonic storm, usually of tropic origin, covering an extensive area, and containing winds in excess of...
Disastrous nor'easterA strong low pressure system that affects the Mid Atlantic and New England States. It can form over land or...
Disastrous storm surge1. A rise or piling-up of water against shore, produced by strong winds blowing onshore. A storm surge is...
Disastrous tornadoA violently rotating column of air, usually pendant to a cumulonimbus, with circulation reaching the ground...
Disastrous tsunami1. A sea wave of local or distant origin that results from large-scale seafloor displacements associated with...
Disastrous volcanic eruptionEruption of magma (molten rock) and associated gases through a vent at the Earth's surface and also the cone...
DisbenefitAn increase in emissions of a pollutant that results when a control measure aimed at reducing another...
Discharge1. The release of any waste into the environment from a point source. Usually refers to the release of a...
Discharge allowanceAmount of pollutant (mg per kg of production unit) that a plant will be permitted to discharge. For this...
Discharge areaAn area of land where there is a net annual transfer of water from the ground water to surface water, such as...
Discharge areas, see Discharge area
Discharge by release typePotentially polluting discharges categorized by their length and/or the conditions occurring during, or...
Discharge by sizeRefers to the following size classes of oil discharges which are provided as guidance to the OSC and serve as...
Discharge by substance type1. Flow of surface water in a stream or canal or the outflow of groundwater from a flowing artesian well...
Discharge cleanupThe range of activities that could occur in the context of addressing environmental contamination resulting...
Discharge consent1. A discharge permit is formal permission to release water, stormwater, combined sewer overflow, or...
Discharge controlThe effects of the dredged or fill material after discharge may be controlled by:(a) Selecting discharge...
Discharge dispersalThe effects of a discharge can be minimized by the manner in which it is dispersed, such as:(a) Where...
Discharge headThe pressure (in pounds per square inch or psi) measured at the centerline of a pump discharge and very close...
Discharge limitationThe effects of a discharge can be minimized by treatment of, or limitations on the material itself, such...
Discharge monitoring report1. Report of effluent characteristics submitted by a municipal or industrial facility that has been granted...
Discharge permitA discharge permit is formal permission to release water, stormwater, combined sewer overflow, or wastewater...
Discharge permits (NPDES)A permit issued by the U.S. EPA or a State regulatory agency that sets specific limits on the type and amount...
Discharge placementThe effects of the discharge can be minimized by the choice of the disposal site.
Discharge response contract(1) A written contractual agreement with an oil spill removal organization that identifies and ensures the...
Discharge response equipmentEquipment (including firefighting equipment), or other mitigating substances and devices, available to an...
Discharge technology adaptionDischarge technology should be adapted to the needs of each site. In determining whether the discharge...
Discharger1. Facility that discharges wastewater directly to waters of the United States or introduces wastewater to a...
Dischargers, see Discharger
Discharges to publicly owned treatment works1. POTW to which your facility discharges or otherwise transfers wastewater containing the reported EPCRA...
Discharges to receiving streams or water bodiesStreams or water bodies to which your facility directly discharges the EPCRA Section 313 chemical on which...
Discipline specific modelingModeling from the viewpoint of a specific discipline
Disclosure-free extractA copy of a record that excludes all exempted information; that is, information deleted or otherwise...
Discount rate1. An assumed interest rate or rate of return used to calculate the present value of a future payment; in...
Discounting1. The treatment of time in valuing costs and benefits, that is, the adjustment of costs and benefits to...
Discouraged workerPersons not in the labor force who want and are available for a job and who have looked for work sometime in...
Discovery1. The initial activity in the Superfund process where a potentially contaminated site is reported to EPA or...
Discrete data1. Data which is limited to defined values. It may be counted.
Discrete distributionA statistical distribution whose elements may only assume discreet values.
Discrete population1. Discrete (from the Latin discretus, meaning to separate) is an adjective meaning separate and individually...
Discrete resourceA resource consisting of a collection of distinct units, such as lakes or stream reaches. Such a resource...
Discrete variable1. A quantitative variable with a finite number of attributes.
Discrete wet scrubbing deviceA discrete wet scrubbing device is a distinct, stand-alone device that removes particulates and fumes from a...
Discrete-mode steady state test1. Relating to a discrete-mode type of steady-state test, as described in the standard-setting part.
Discretionary economic incentive programAny EIP submitted to the EPA as an implementation plan revision for purposes other than to comply with the...
Discriminant analysisStatistical method intended to evaluate the adequacy of a classification by studying the difference between...
Disease carrierPerson or animal that harbors the infectious agent for a disease and can transmit it to others, but does not...
Disease pathwayA sequence of biological or biochemical events that are manifest during the course of a disease.
Disease progressionThe worsening of a disease over time.
Disease reservoir1. Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential...
Disease transmission network disaggregationThe disruption of activities and social interactions that facilitate transmission of influenza (e.g., closure...
Disease vector1. Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.
Disease vehicleInanimate intermediary in the indirect transmission of an agent that carries the agent from a reservoir to a...
Di-sec-Octyl PhthalateFormula: C24H38O4. Di-n-butyl phthalate is an odorless and colorless or faintly yellow oily liquid that does...
DishwasherCabinet-like appliance which with the aid of water and detergent, washes, rinses, and dries (when a drying...
Disinfectant1. A chemical (commonly chlorine, chloramine, or ozone) or physical process (e.g., ultraviolet light) that...
Disinfectant application pointPoint where the disinfectant is applied and water downstream of that point is not subject to recontamination...
Disinfectant by-productA compound formed by the reaction of a disinfectant such as chlorine with organic material in the water...
Disinfectant byproductsChemicals that may form when disinfectants (such as chlorine), react with plant matter and other naturally...
Disinfectant chemicalAny oxidant, including but not limited to chlorine, chlorine dioxide, chloramines, and ozone, that is added...
Disinfectant contact time1. "T" in CT calculations
Disinfectant residualWater additives, e.g. chloramine, chlorine, used to control microbes in water systems.
Disinfectant timeThe time it takes water to move from the point of disinfectant application (or the previous point of residual...
Disinfectant-disinfection by-productDisinfectants and disinfection by-products in drinking water are often studied as a unit because both may...
Disinfectants, see Disinfectant
Disinfection1. The process designed to kill most microorganisms in water, including essentially all pathogenic...
Disinfection by-product1. A compound formed by the reaction of a disinfectant such as chlorine with organic material in the water...
Disinfection byproductA compound formed by the reaction of a disinfectant such as chlorine with organic material in the water...
Disinfection byproducts, see Disinfection byproduct
Disinfection profileSummary of Giardia lamblia inactivation through the treatment plant. The procedure for developing a...
Disintegration moraineA drift topography characterized by chaotic mounds and pits (generally randomly oriented) developed in...
Disinterested individual1. As defined in § 3.3 of CROMERR, an individual who is not connected with the person in whose name the...
DisjunctSpecies that are isolated from their primary range.
DiskingA mechanical method of scarifying the soil to reduce competing vegetation and to prepare a site to be seeded...
Disking (harrowing), see Disking
Dislodgeable arsenicArsenic used as a wood preservative that may transfer to the environment via skin, clothing or weather.
Disparate impactOccurs when an activity which by itself is not discriminatory has adverse effects which disproportionately...
DispatchOperation of a generating unit within a power system at a designated output level to meet demand for...
Dispatch systemAssignment within a dispatch system of generating levels to specific units and generators to effect the...
DispersalSpreading of effluent through the final receiving environment, typically soil.
Dispersal system1. A system that receives pretreated wastewater and releases it into the air, into surface or ground water...
Dispersant1. A chemical agent used to break up concentrations of organic material such as spilled oil.
Dispersant effectiveness protocolEPA document specifying procedures for determining the effectiveness of agents for the dispersal of oil...
Dispersion1. The spreading of chemical or biological constituents, including pollutants, in various directions from a...
Dispersion factorRatio of the increase in the ground level ambient air concentration for a pollutant at or beyond the property...
Dispersion forceCaused by instantaneous dipoles in polarizable molecules
Dispersion model1. A mathematical prediction of how pollutants from a discharge or emission source will be distributed in the...
Dispersion processProcess for producing polyvinyl chloride resin that is characterized by the formation of the polymers in soap...
Dispersion resinResin manufactured in such a way as to form fluid dispersions when dispersed in a plasticizer or...
Dispersion techniqueAny technique which attempts to affect the concentration of a pollutant in the ambient air by:(i) Using that...
Displacement activitySoothing behavior such as grooming or scratching, of an animal under stress when torn between two reactions...
Displacement currentsThe movement of ge within a material by polarization, as opposed to the flow of free ions or electrons...
Displacement savingsSaving realized by displacing purchases of natural gas or electricity from a local utility by using landfill...
Disposable deviceHearing protective device that is intended to be discarded after one period of use.
Disposable payPart of current basic pay, special pay, incentive pay, retired pay, retainer pay, or in the case of an...
DisposablesConsumer products, other items, and packaging used once or a few times and discarded.
Disposal1. The discharge, deposit, injection, dumping, spilling, leaking, or placing of any solid waste or hazardous...
Disposal discharge pointPoint within the disposal site at which the dredged or fill material is released.
Disposal facilities1. Refers to repositories for solid waste including landfills and combustors intended for permanent...
Disposal facility1. A landfill, incinerator, or other facility which receives waste for disposal. The facility may have one or...
Disposal listA document providing one-time approval for the disposal of records no longer accumulating and having no...
Disposal mixing zoneLimited volume of water serving as a zone of initial dilution in the immediate vicinity of a discharge point...
Disposal operationActivities which do not lead to the possibility of resource recovery, recycling, reclamation, direct re-use...
Disposal prohibitionThe LDR requirement that prohibits the land disposal of hazardous waste that has not been adequately treated...
Disposal site1. That portion of the “waters of the United States” where specific disposal activities are permitted and...
Disposal site designation studyCollection, analysis and interpretation of all available pertinent data and information on a proposed...
Disposal wellWell used for the disposal of waste into a subsurface stratum.
DISPOSING OFCarrying out disposal, which includes either the destruction or the donation of temporary records but not the...
DISPOSITION1. The actions taken regarding records no longer needed for current Government business. These actions...
Disposition authority1. Legal approval empowering an agency to transfer permanent records to the National Archives or carry out...
Disposition instructions1. Directions for cutting off records and carrying out their disposition in compliance with NARA's...
Disposition programPolicies and practices designed to achieve effective and efficient disposition of records by scheduling them...
Disproportionate effectTerm used in Executive Order 12898 to describe situations of concern where there exists significantly higher...
Disproportionate effects, see Disproportionate effect
Disproportionate exposureExposure of some segments of the human population to harmful substances more than the exposure of other...
Disproportionate impactRefers to communities of low income and/or color and in the presence of high-risk environmental hazards...
Disproportionate impact (of minority populations), see Disproportionate impact
DisputePresent controversy between parties subject to a test rule over the amount or method of reimbursement for the...
Dissection frequencyThe density of channels in a specified area.
Dissection patternThe distribution of channels in a specified area.
DisseminationAgency-initiated or sponsored distribution of information to the public.
DissociationTemporary or reversible chemical process in which a molecule or ion is broken down into smaller molecules or...
Dissolution1. The process of chemical weathering of bedrock in which the combination of water and acid slowly removes...
Dissolved air flotationAir is dissolved under pressure and then released at atmospheric pressure in a tank. The released air creates...
Dissolved analyte1. The concentration of analyte in an aqueous sample that will pass through a 0.45 μm membrane filter...
Dissolved contaminant removalDissolved contaminants are those that have been absorbed into water making it unfit to drink. Removal...
Dissolved gasNatural gas that occurs in an oil field, either as a free gas cap or in solution; synonymous with gas in oil...
Dissolved gas flotationNatural gas, nitrogen, or other gas is dissolved under pressure and then released at atmospheric pressure in...
Dissolved inorganic carbonThe sum total of carbon dioxide, carbonic acid, bicarbonate anion, and carbonate in water solution.
Dissolved inorganic nitrogenNitrogen that is readily usable by plants.
Dissolved organic carbon1. A measure of the organic compounds that are dissolved in water.
Dissolved organic matterSoluble organic materials produced by the partial decomposition of organic materials, such as soil, plants...
Dissolved organic nitrogenDissolved organic matter which contains nitrogen
Dissolved organic phosphorusOrganic, inorganic, and polymeric phosphorus-containing molecules in water solution.
Dissolved oxygen1. Oxygen that is freely available in water to sustain the lives of fish and other aquatic organisms.
Dissolved oxygen concentrationLow Oxygen (oxygen depletion) levels in water can occur naturally for short periods, but when they are...
Dissolved oxygen deficitDifference between saturated dissolved oxygen and ambient concentrations.
Dissolved oxygen sagLongitudinal variation of dissolved oxygen representing the oxygen depletion and recovery following a waste...
Dissolved reactive phosphorusPhosphorous in the form of orthophosphate which is a plant nutrient

1,500 of 29,894 terms in Environment terminology (MLC-0121). Request the full dataset.