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EPA - Environmental Terms Glossary Category: Earth and Environment Date & country: 13/09/2007, USA Words: 1829

Cost Recovery
A legal process by which potentially responsible parties who contributed to contamination at a Superfund site can be required to reimburse the Trust Fund for money spent during any cleanup actions by the federal government.

Cost Sharing
A publicly financed program through which society, as a beneficiary of environmental protection, shares part of the cost of pollution control with those who must actually install the controls. In Superfund, for example, the government may pay part of the cost of a cleanup action with those responsible for the pollution paying the major share.

Cost-Benefit Analysis
A quantitative evaluation of the costs which would have incurred by implementing an environmental regulation versus the overall benefits to society of the proposed action.

Cost-Effective Alternative
An alternative control or corrective method identified after analysis as being the best available in terms of reliability, performance, and cost. Although costs are one important consideration, regulatory and compliance analysis does not require EPA to choose the least expensive alternative. For example, when selecting or approving a method for cleaning up a Superfund site, the Agency balances costs with the long-term effectiveness of the methods proposed and the potential danger posed by the si…

Cover Crop
A crop that provides temporary protection for delicate seedlings and/or provides a cover canopy for seasonal soil protection and improvement between normal crop production periods.

Cover Material
Soil used to cover compacted solid waste in a sanitary landfill.

Cradle-to-Grave or Manifest System
A procedure in which hazardous materials are identified and followed as they are produced, treated, transported, and disposed of by a series of permanent, linkable, descriptive documents (e.g. manifests). Commonly referred to as the cradle-to-grave system.

Criteria
Descriptive factors taken into account by EPA in setting standards for various pollutants. These factors are used to determine limits on allowable concentration levels, and to limit the number of violations per year. When issued by EPA, the criteria provide guidance to the states on how to establish their standards.

Criteria Pollutants
The 1970 amendments to the Clean Air Act required EPA to set National Ambient Air Quality Standards for certain pollutants known to be hazardous to human health. EPA has identified and set standards to protect human health and welfare for six pollutants ozone, carbon monoxide, total suspended particulates, sulfur dioxide, lead, and nitrogen oxide. The term, 'criteria pollutants' derives from the requirement that EPA must describe the characteristics and potential health and welfare effects of th…

Critical Effect
The first adverse effect, or its known precursor, that occurs as a dose rate increases. Designation is based on evaluation of overall database.

Crop Consumptive Use
The amount of water transpired during plant growth plus what evaporated from the soil surface and foliage in the crop area.

Crop Rotation
Planting a succession of different crops on the same land rea as opposed to planting the same crop time after time.

Cross Contamination
The movement of underground contaminants from one level or area to another due to invasive subsurface activities.

Cross-Connection
Any actual or potential connection between a drinking water system and an unapproved water supply or other source of contamination.

Crumb Rubber
Ground rubber fragments the size of sand or silt used in rubber or plastic products, or processed further into reclaimed rubber or asphalt products.

Cryptosporidium
A protozoan microbe associated with the disease cryptosporidiosis in man. The disease can be transmitted through ingestion of drinking water, person-to-person contact, or other pathways, and can cause acute diarrhea, abdominal pain, vomiting, fever, and can be fatal as it was in the Milwaukee episode.

Cubic Feet Per Minute (CFM)
A measure of the volume of a substance flowing through air within a fixed period of time. With regard to indoor air, refers to the amount of air, in cubic feet, that is exchanged with outdoor air in a minute's time; i.e. the air exchange rate.

Cullet
Crushed glass.

Cultural Eutrophication
Increasing rate at which water bodies 'die' by pollution from human activities.

Cultures and Stocks
Infectious agents and associated biologicals including cultures from medical and pathological laboratories; cultures and stocks of infectious agents from research and industrial laboratories; waste from the production of biologicals; discarded live and attenuated vaccines; and culture dishes and devices used to transfer, inoculate, and mix cultures. (See regulated medical waste.)

Cumulative Exposure
The sum of exposures of an organism to a pollutant over a period of time.

Curbside Collection
Method of collecting recyclable materials at homes, community districts or businesses.

Cutie-Pie
An instrument used to measure radiation levels.

Cuttings
Spoils left by conventional drilling with hollow stem auger or rotary drilling equipment.

Cyclone Collector
A device that uses centrifugal force to remove large particles from polluted air.

Data Call-In
A part of the Office of Pesticide Programs (OPP) process of developing key required test data, especially on the long-term, chronic effects of existing pesticides, in advance of scheduled Registration Standard reviews. Data Call-In from manufacturers is an adjunct of the Registration Standards program intended to expedite re-registration.

Data Quality Objectives (DQOs)
Qualitative and quantitative statements of the overall level of uncertainty that a decision-maker will accept in results or decisions based on environmental data. They provide the statistical framework for planning and managing environmental data operations consistent with user's needs.

Day Tank
Another name for deaerating tank. (See age tank.)

DDT
The first chlorinated hydrocarbon insecticide chemical name Dichloro-Diphenyl-Trichloroethane. It has a half-life of 15 years and can collect in fatty tissues of certain animals. EPA banned registration and interstate sale of DDT for virtually all but emergency uses in the United States in 1972 because of its persistence in the environment and accumulation in the food chain.

Dead End
The end of a water main which is not connected to other parts of the distribution system.

Deadmen
Anchors drilled or cemented into the ground to provide additional reactive mass for DP sampling rigs.

Decant
To draw off the upper layer of liquid after the heaviest material (a solid or another liquid) has settled.

Decay Products
Degraded radioactive materials, often referred to as 'daughters' or 'progeny'; radon decay products of most concern from a public health standpoint are polonium-214 and polonium-218.

Dechlorination
Removal of chlorine from a substance.

Decomposition
The breakdown of matter by bacteria and fungi, changing the chemical makeup and physical appearance of materials.

Decontamination
Removal of harmful substances such as noxious chemicals, harmful bacteria or other organisms, or radioactive material from exposed individuals, rooms and furnishings in buildings, or the exterior environment.

Deep-Well Injection
Deposition of raw or treated, filtered hazardous waste by pumping it into deep wells, where it is contained in the pores of permeable subsurface rock.

Deflocculating Agent
A material added to a suspension to prevent settling.

Defluoridation
The removal of excess flouride in drinking water to prevent the staining of teeth.

Defoliant
An herbicide that removes leaves from trees and growing plants.

Degasification
A water treatment that removes dissolved gases from the water.

Degree-Day
A rough measure used to estimate the amount of heating required in a given area; is defined as the difference between the mean daily temperature and 65 degrees Fahrenheit. Degree-days are also calculated to estimate cooling requirements.

Delegated State
A state (or other governmental entity such as a tribal government) that has received authority to administer an environmental regulatory program in lieu of a federal counterpart. As used in connection with NPDES, UIC, and PWS programs, the term does not connote any transfer of federal authority to a state.

Delist
Use of the petition process to have a facility's toxic designation rescinded.

Demand-side Waste Management
Prices whereby consumers use purchasing decisions to communicate to product manufacturers that they prefer environmentally sound products packaged with the least amount of waste, made from recycled or recyclable materials, and containing no hazardous substances.

Demineralization
A treatment process that removes dissolved minerals from water.

Denitrification
The biological reduction of nitrate to nitrogen gas by denitrifying bacteria in soil.

Density
A measure of how heavy a specific volume of a solid, liquid, or gas is in comparison to water. depending on the chemical.

Depletion Curve
In hydraulics, a graphical representation of water depletion from storage-stream channels, surface soil, and groundwater. A depletion curve can be drawn for base flow, direct runoff, or total flow.

Depressurization
A condition that occurs when the air pressure inside a structure is lower that the air pressure outdoors. Depressurization can occur when household appliances such as fireplaces or furnaces, that consume or exhaust house air, are not supplied with enough makeup air. Radon may be drawn into a house more rapidly under depressurized conditions.

Dermal Absorption-Penetration
Process by which a chemical penetrates the skin and enters the body as an internal dose.

Dermal Exposure
Contact between a chemical and the skin.

Dermal Toxicity
The ability of a pesticide or toxic chemical to poison people or animals by contact with the skin. (See contact pesticide.)

DES
A synthetic estrogen, diethylstilbestrol is used as a growth stimulant in food animals. Residues in meat are thought to be carcinogenic.

Desalination
[Desalinization] (1) Removing salts from ocean or brackish water by using various technologies. (2) Removal of salts from soil by artificial means, usually leaching.

Desiccant
A chemical agent that absorbs moisture; some desiccants are capable of drying out plants or insects, causing death.

Design Capacity
The average daily flow that a treatment plant or other facility is designed to accommodate.

Design Value
The monitored reading used by EPA to determine an area's air quality status; e.g., for ozone, the fourth highest reading measured over the most recent three years is the design value.

Designated Pollutant
An air pollutant which is neither a criteria nor hazardous pollutant, as described in the Clean Air Act, but for which new source performance standards exist. The Clean Air Act does require states to control these pollutants, which include acid mist, total reduced sulfur (TRS), and fluorides.

Designated Uses
Those water uses identified in state water quality standards that must be achieved and maintained as required under the Clean Water Act. Uses can include cold water fisheries, public water supply, and irrigation.

Designer Bugs
Popular term for microbes developed through biotechnology that can degrade specific toxic chemicals at their source in toxic waste dumps or in ground water.

Destination Facility
The facility to which regulated medical waste is shipped for treatment and destruction, incineration, and/or disposal.

Destratification
Vertical mixing within a lake or reservoir to totally or partially eliminate separate layers of temperature, plant, or animal life.

Destroyed Medical Waste
Regulated medical waste that has been ruined, torn apart, or mutilated through thermal treatment, melting, shredding, grinding, tearing, or breaking, so that it is no longer generally recognized as medical waste, but has not yet been treated (excludes compacted regulated medical waste).

Destruction Facility
A facility that destroys regulated medical waste.

Desulfurization
Removal of sulfur from fossil fuels to reduce pollution.

Detectable Leak Rate
The smallest leak (from a storage tank), expressed in terms of gallons- or liters-per-hour, that a test can reliably discern with a certain probability of detection or false alarm.

Detection Criterion
A predetermined rule to ascertain whether a tank is leaking or not. Most volumetric tests use a threshold value as the detection criterion. (See volumetric tank tests.)

Detection Limit
The lowest concentration of a chemical that can reliably be distinguished from a zero concentration.

Detention Time
1. The theoretical calculated time required for a small amount of water to pass through a tank at a given rate of flow. 2. The actual time that a small amount of water is in a settling basin, flocculating basin, or rapid-mix chamber. 3. In storage reservoirs, the length of time water will be held before being used.

Detergent
Synthetic washing agent that helps to remove dirt and oil. Some contain compounds which kill useful bacteria and encourage algae growth when they are in wastewater that reaches receiving waters.

Development Effects
Adverse effects such as altered growth, structural abnormality, functional deficiency, or death observed in a developing organism.

Dewater
1. Remove or separate a portion of the water in a sludge or slurry to dry the sludge so it can be handled and disposed of. 2. Remove or drain the water from a tank or trench.

Diatomaceous Earth (Diatomite)
A chalk-like material (fossilized diatoms) used to filter out solid waste in wastewater treatment plants; also used as an active ingredient in some powdered pesticides.

Diazinon
An insecticide. In 1986, EPA banned its use on open areas such as sod farms and golf courses because it posed a danger to migratory birds. The ban did not apply to agricultural, home lawn or commercial establishment uses.

Dibenzofurans
A group of organic compounds, some of which are toxic.

Dicofol
A pesticide used on citrus fruits.

Diffused Air
A type of aeration that forces oxygen into sewage by pumping air through perforated pipes inside a holding tank.

Diffusion
The movement of suspended or dissolved particles (or molecules) from a more concentrated to a less concentrated area. The process tends to distribute the particles or molecules more uniformly.

Digester
In wastewater treatment, a closed tank; in solid-waste conversion, a unit in which bacterial action is induced and accelerated in order to break down organic matter and establish the proper carbon to nitrogen ratio.

Digestion
The biochemical decomposition of organic matter, resulting in partial gasification, liquefaction, and mineralization of pollutants.

Dike
A low wall that can act as a barrier to prevent a spill from spreading.

Diluent
Any liquid or solid material used to dilute or carry an active ingredient.

Dilution Ratio
The relationship between the volume of water in a stream and the volume of incoming water. It affects the ability of the stream to assimilate waste.

Dimictic
Lakes and reservoirs that freeze over and normally go through two stratifications and two mixing cycles a year.

Dinocap
A fungicide used primarily by apple growers to control summer diseases. EPA proposed restrictions on its use in 1986 when laboratory tests found it caused birth defects in rabbits.

Dinoseb
A herbicide that is also used as a fungicide and insecticide. It was banned by EPA in 1986 because it posed the risk of birth defects and sterility.

Dioxin
Any of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their potential toxicity as contaminants in commercial products. Tests on laboratory animals indicate that it is one of the more toxic anthropogenic (man-made) compounds.

Direct Discharger
A municipal or industrial facility which introduces pollution through a defined conveyance or system such as outlet pipes; a point source.

Direct Filtration
A method of treating water which consists of the addition of coagulent chemicals, flash mixing, coagulation, minimal flocculation, and filtration. Sedimentation is not uses.

Direct Push
Technology used for performing subsurface investigations by driving, pushing, and/or vibrating small-diameter hollow steel rods into the ground/ Also known as direct drive, drive point, or push technology.

Direct Runoff
Water that flows over the ground surface or through the ground directly into streams, rivers, and lakes.

Discharge
Flow of surface water in a stream or canal or the outflow of ground water from a flowing artesian well, ditch, or spring. Can also apply tp discharge of liquid effluent from a facility or to chemical emissions into the air through designated venting mechanisms.

Disinfectant
A chemical or physical process that kills pathogenic organisms in water, air, or on surfaces. Chlorine is often used to disinfect sewage treatment effluent, water supplies, wells, and swimming pools.

Disinfectant By-Product
A compound formed by the reaction of a disinfenctant such as chlorine with organic material in the water supply; a chemical byproduct of the disinfection process..

Disinfectant Time
The time it takes water to move from the point of disinfectant application (or the previous point of residual disinfectant measurement) to a point before or at the point where the residual disinfectant is measured. In pipelines, the time is calculated by dividing the internal volume of the pipe by he maximum hourly flow rate; within mixing basins and storage reservoirs it is determined by tracer studies of an equivalent demonstration.

Dispersant
A chemical agent used to break up concentrations of organic material such as spilled oil.

Displacement Savings
Saving realized by displacing purchases of natural gas or electricity from a local utility by using landfill gas for power and heat.

Disposables
Consumer products, other items, and packaging used once or a few times and discarded.

Disposal
Final placement or destruction of toxic, radioactive, or other wastes; surplus or banned pesticides or other chemicals; polluted soils; and drums containing hazardous materials from removal actions or accidental releases. Disposal may be accomplished through use of approved secure landfills, surface impoundments, land farming, deep-well injection, ocean dumping, or incineration.