Education, And
     ^	     —	 Pubte Affairs (A-107)
Terms Of Environment

Glossary, Abbreviations, And

 Terms Of Environment defines in non-technical language the more
 coxnmonijNifad environmental terms appearing in EPA publications,
 news releases, and other Agency documents available to the general
 public, students, the media, and Agency employees. The definitions
 do not constitute the Agency's official use of terms and phrases for
 regulatory  purposes,  and nothing in  this document  should be
 construed to alter or supplant any other federal document. Official
 terminology may be found in the laws and related regulations as
 published in such sources as the Congressional Record, Federal
 Register, and elsewhere.
       The terms selected for inclusion are derived from previously
 published lists, internal glossaries produced by various programs
 and specific suggestions made by personnel in many Agency offices.
 The chemicals and pesticides selected for inclusion are limited to
 those most frequently referred to in Agency publications or that are
 the subject of major regulatory or program activities.
       Definitions  or  information about substances or program
.activities not included herein may be  found  in EPA  libraries or
 scientific/technical reference documents, or may be obtained from
 various program offices.
      Those with suggestions for future editions should write to the
 Editorial Services Division, Office of Communications, Education, and
 Public Affairs, A-107, USEPA, Washington DC  20460.
Abbreviation and acronymn list begins on page 31

  A—Scale Sound Levefc A measurement of
,  sound approximating the sensitivity of the
  human ear, used to note the intensity or
  annoyance level of sound*.

  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 inten-
  sity of, or eliminating, pollution.

  Accident Site: The location of an unexpect-
  ed occurrence, failure or loss, either at a
  plant or  along  a  transportation  route,
  resulting in a release of hazardous materi-

  Acclimatization:  The physiological and
  behavioral adjustments of an organism to
  changes in its environment.

  Acid Deposition: A complex chemical and
  atmospheric  phenomenon that  occurs
  when emissions of sulfur  and nitrogen
  compounds and other substances are trans-
  formed by chemical processes in the atmo-
  sphere, often far from the original sources,
 and then deposited on earth in either wet
 or dry form. The  wet forms, popularly
 called "acid rain," can fall as rain, snow, or
 fog. The dry forms  are acidic  gases or

 Acid Rain:  (See: acid deposition)

 Action Levels: 1. Regulatory levels recom-
 mended 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 occur-
ring as a direct result of proper usage,
action levels are set for inadvertent resi-
dues resulting from previous legal use or
accidental contamination. 2. In the Super-
fund program, the existence of a contami-
nant concentration in the environment high
enough  to warrant.-action or trigger  a
response under SARA and the National Oil
and Hazardous Substances  Contingency
Plan. The term is also used in other regu-
latory programs. (Seer 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 vehi-
cle evaporative control systems,

Activated Sludge:  Product that  results
when primary effluent is mixed with.bac-
teria-laden sludge and then agitated and •
aerated to promote biological treatment,
speeding the breakdown of organic matter
in raw sewage  undergoing, secondary
waste treatment.

Activator A chemical added to a pesticide
to. increase its activity.
  Active Ingredient: In any pesticide prod-
  uct, the component that kills, or otherwise
  controls, target pests. Pesticides are regu-
  lated primarily on the basis of active ingre-

  Activity Plans: Written procedures in a
  school's asbestos- management plan that
  detail the steps a Local Education Agency
  (LEA) will follow in performing the initial
  and additional  cleaning, operation and
  maintenance-program tasks; periodic sur-
  veillance; and reinspections required by
  the Asbestos Hazard Emergency Response
  Act (AHERA).

  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. 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

 Add-on Control Device: An  air pollution
 control device such as carbon absorber or
 incinerator that reduces the pollution in an
 exhaust gas. The control device usually
 does not affect the process being controlled
 and thus is "add-on" technology, as  op-
 posed to a scheme to control pollution
 through altering the basic process itself.

 Adequately Wet:  Asbestos containing
 material that is sufficiently mixed or pene-
 trated with liquid to prevent the release of

 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 re-
 quired 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 Order. A legal document
 signed by EPA directing an  individual,
 business, or other entity to take corrective
 action or refrain from an  activity. It de-
 scribes 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 Procedures Act: A law that
spells out procedures and requirements
related .to the promulgation of regulations. •
  Administrative  Record: All documents
  which EPA considered or relied  on in
  selecting the response action at a Super-
  fund site, culminating in the record of
  decision for remedial action or, an action
  memorandum for removal actions.
  Adsorption: An advanced   method  of
  treating waste in which activated carbon
  removes organic  matter from wastewater
  Adulterants: Chemical impurities or sub-
  stances that by law do not  belong in a
  food, or pesticide.  '

  Adulterated: 1.  Any  pesticide whose
  strength or purity falls below the quality
  stated on its label. 2. A food,feed, or prod-
  uct that contains illegal pesticide residues.
  Advanced Treatment: A level of waste-
  water treatment more stringent than sec-
  ondary treatment; requires an 85-percent
  reduction in conventional pollutant concen-
  tration or a significant reduction in non-
  conventional pollutants.

  Advanced  Wastewater Tislbnenfc  Any
  treatment of sewage that g&*es beyond the
  secondary  or biological water treatment
  stage and includes the removal of nutrients
  such  as phosphorus and nitrogen and a
  high percentage of suspended solids. (See
  primary, secondary treatment.)

  Advisory: A non-regulatory document that
  communicates risk  information to those
  who may have to make risk management

 Aerated Lagoon: A holding and/or treat-
 ment  pond  that  speeds  up the  natural
 process of  biological decomposition  of
 organic waste by  stimulating the growth
 and activity of bacteria that degrade organ-
 ic waste.

 Aeration: A process which promotes bio-
 logical 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 intro-'
 duces the air).

 Aeration Tank: A chamber used to inject
. air into water.

 Aerobic Treatment: Process by which mi-
 crobes decompose complex
 pounds 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.)
 Aerobic: Life or processes that require, or
are not destroyed  by,  the  presence of
oxygen. (See: anaerobic.)
Aerosol: A suspension of liquid or solid
particles in a gas.
Affected Public: The  people  who live
and/or work near a hazardous waste site.

Afterburner: In incinerator technology, a
burner located so that the combustion
gases are made to pass through its flame
in order to remove smoke and odors.  It
may be attached to or be separated from
the incinerator proper.
Agent Orange: A toxic herbicide and defo-
liant used in the Vietnam conflict, contain-
ing   2,4,5-trichlorophenoxyacetic  acid
(2,4,5-1)  and 2-4 dichlorophenoxyacetic
acid (2,4-D) with trace amounts of dioxin.
Agricultural Pollution: Farming  wastes,
including runoff and leaching of pesticides
and fertilizers; erosion and  dust  from
plowing;  improper  disposal  of  animal
manure and carcasses; crop residues, and
Agro-ecosystem:   Land used for crops,
pasture, and livestock; the adjacent unculti-
vated land that supports other vegetation
and wildlife; and the associated atmo-
sphere, the underlying soils, groundwater,
and drainage networks.
AHERA Designated Person  (ADP):  A
person designated by a Local Education
Agency to ensure that the AHERA require-
ments for asbestos management and abate-
ment are properly implemented.
Air Changes Per Hour (ACH): The move-
ment 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 peri-
Air Contaminant: Any particulate matter,
gas, or combination thereof,  other than
water vapor, pee: air pollutant.)
Air Curtain: A method of containing oil
spills. Air bubbling through a perforated
pipe causes an upward water flow that
ilows the spread of oiL It can also be used
to stop fish from entering polluted water.
Air Mass: A large  volume of  air with
certain meteorological or polluted charac-
toristics-e.g, a heat inversion  or  smoggi-
ness-white in one location. The character-
istics can change aa the air mass moves
 Air Monitoring:  (See: monitoring)  .
 Air Plenum:  Any space used to convey
 ur in a building, furnace, or structure. The
 • above a suspended ceiling is often
  ,iod as an air plenum..
 Air Pollutant: Any substance in air that
' could, in high enough concentration, harm
 man, other animals, vegetation, or material
 Pollutants may include almost any natural
 or artificial composition of airborne matter
 capable of being airborne. They may be in
 the form of solid particles, liquid droplets,
 gases, or in combination thereof. Generally,
 they fall into two main groups: (1) those
 emitted directly from identifiable sources
 and (2) those produced in the air by inter-
 action between two or more primary pol-
 lutants, or by reaction  with normal atmo-
 spheric  constituents,  with  or  without
 photoactivation.  Exclusive of pollen, fog,
 and dust, which are  of natural origin,
 about 100 contaminants have been identi-
 fied and fall into the following categories:
 solids, sulfur compounds, volatile organic
 chemicals, nitrogen compounds, oxygen
 compounds, halogen compounds, radioac-
 tive compounds,  and odors.

 Air Pollution Episode: A period of abnor-
 mally high concentration of air pollutants,
 often  due to low winds and temperature
 inversion, that can cause illness and death.
 (See: episode, pollution.)
 Air Pollution Control Device: Mechanism
 or equipment that cleans emissions gener-
 ated by an incinerator by removing pollut-
 ants that would  otherwise be released to
 the atmosphere.

 Air Pollution: The presence of contami-
 nant or pollutant substances in the air that
 do not disperse properly and interfere with
 human health or welfare, or produce other
 harmful environmental effects.

 Air Quality Criteria: The levels of pollu-
 tion and lengths of exposure above which
 adverse health and welfare effects may
 Air Quality Control  Region:  An area-
 designated by the federal govemment-in
 which communities share a common  air
 pollution problem, sometimes  embracing
 several states.
 Air Quality .Standards: The level of pollut-
 ants prescribed by regulations that may
 not be exceeded during a given time in a
' defined area.
 Air Stripping: A treatment system that re-
 moves volatile organic compounds (VOCs)
 from  contaminated ground water or sur-
 face water by forcing an airstream through
 the water and causing the compounds to
 Air Toxics:  Any air pollutant for which a
 national ambient air quality standard
 (NAAQS) does  not exist  (i.e.,  excluding
. ozone, carbon monoxide, PM-10, sulfur
 dioxide, nitrogen oxide) that may reason-
 ably be anticipated to  cause cancer, devel-
 opmental effects, reproductive  dysfunc-
 tions, neurological disorders, heritable
 gene  mutations, or other  serious or irre-
 versible chronic  or acute health effects in
Airborne Particulates:  Total suspended
particulate matter found in the atmosphere
as solid particles or liquid droplets. Chemi-
cal composition of particulates varies wide-
ly, depending on location and time of year.
Airborne particulates include: windblown
dust, emissions from industrial processes,
smoke from the burning of wood and coal,
and motor vehicle  or non-road  engine
exhausts, exhaust of motor vehicles.

Airborne Release: Release of any chemical
into the air.
Alachlon A herbicide, marketed, under the
trade name Lasso, used mainly to control
weeds in corn and soybean fields.

Alar: Trade name for daminozide, a pesti-
cide that makes apples redder, firmer,  and
less likely to drop off trees before growers
are ready to pick them. It is also used  to a
lesser  extent  on peanuts,  tart cherries,
concord grapes, and other fruits.

Aldicarb: An insecticide sold under the
trade name Temik.  It is made frjjm ethyl

Algae: Simple rootless plants that  grow in
sunlit waters in proportion to the amount
of  available  nutrients. They  can affect
water quality adversely by lowering the
dissolved oxygen in the water. They are
food for fish and small aquatic animals.

Algal Blooms:  Sudden spurts  of algal
growth,  which can affect  water quality
adversely and indicate potentially hazard-
ous changes in local water chemistry.

Alternate Method: Any method  of sam-
pling and analyzing for an air pollutant
that is not a reference or equivalent meth-
od but that has been demonstrated in
specific cases-to EPA's satisfaction-to  pro-
duce  results  adequate  for compliance

Alternative Remedial Contract Strategy
Contractors: Government contractors  who
provide project management and technical
services  to support remedial  response
'activities at National Priorities List sites.

Ambient Air Quality Standards:  (See:
Criteria Pollutants and National Ambient
Air Quality Standards.)
Ambient Air: Any unconfined portion of
the atmosphere: open air, surrounding air.

Anaerobic: A life or process that occurs in,
or  is  not  destroyed  by, the absence of
Anaerobic Decomposition: Reduction of
the net energy level and change in chemi-
cal composition of organic matter caused
by  microorganisms  in  an oxygen-free
Antarctic  "Ozone  Hole":  Refers to the
seasonal depletion of ozone in a large area
over Antarctica.

  Anti-Degradation ClauM: Part of federal
  air quality and water quality requirements
  prohibiting deterioration where pollution
  levels are above the legal limit

  Applicable or Appropriate Requirement
  (ARARs): Any state or federal statute that
  pertains to protection of human life and
  the environment  in addressing  specific
  conditions or use  of a particular cleanup
  technology at a Superfund site.

  Aquifer An underground geological for-
  mation, or group of formations, containing
  usable amounts of groundwater that can
  supply wells and springs.

  Area of Review: In the UIC program, the
  area surrounding an injection well that is
  reviewed during the permitting process to
  determine if flow between aquifers will be
  induced by the injection operation.

  Area Source: Any small  source of non-
  natural air pollution that is released over a
  relatively small area but which cannot be
  classified as a point source. Such sources
  may include  vehicles and other small
  engines, small businesses  and household

  Aromatics: A type of hydrocarbon, such as
  benzene or toluene, added to gasoline in
  order to increase octane. Some- aromatics
  are toxic.

  Arsenicals: Pesticides containing arsenic.

  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. .

  Asbestos  Abatement: Procedures to con'
  trol fiber release from asbestos-containing
  materials in a building or to remove them
  entirely, including removal, encapsulation,
  repair, enclosure, encasement, arid opera-
  tions,and maintenance programs.

  Asbestos-Containing Waste Materials
  (ACVVM): Mill tailings or any waste that
  contains commercial asbestos and is gener-
  ated by a source covered by the dean Air
  Act Asbestos NESHAES.

  Asbestosis:  A disease associated, with
  inhalation of asbestos fibers. The disease
 makes breathing progressively rnore diffi-
 cult and can be fataL

 Asbestos Program Manager A  building
 owner or designated representative who
 supervises all aspects of the facility asbes-
 tos management and control program.

 Ash: The mineral content of a product re-
 maining after complete combustion.

 Assessment: Ln the asbestos-in-schools pro-
 gram, the evaluation of the physical condi-
 tion and potential for damage of all friable
 asbestos containing  materials and thermal
 insulation systems.

. Assimilation: The  ability of a body of
 water to purify itself of pollutants.
  Assimilative Capacity: The capacity of a
  natural body  of water to receive waste-
  waters or toxic materials without deleteri-
  ous effects and without damage to aquatic
  life or humans who consume the water.

  Attainment Area: An  area considered to
  have air quality as good as or better than
  the national ambient air quality standards
  as defined in the dean Air Act. An area
  may be an attainment area for one pollut-
  ant and a non-attainment area for others.

  Attenuation: The process by which a com-
  pound is  reduced in concentration over
  time,  through  absorption, adsorption,
  degradation, dilution, and/or transforma-

  Attractanb A chemical  or agent that lures
  insects or  other pests by stimulating their
  sense of smell

  Attrition:  Wearing or grinding down of a
  substance  by  friction.  Dust  from such
  processes contributes to air pollution.

  Availability Session: Informal meeting at
  a public location where interested citizens
  can talk with EPA and  state officials on a
  one-to-one basis.

 Background Level: In air pollution control,
 the concentration of air pollutants in a
 definite area during a fixed period of time
 prior to the starting up or on the stoppage
 of a source of emission under control. In
 toxic substances monitoring, the average
 presence  in the environment,  originally
 referring to naturally occurring phenome-

 BACT-Best Available Control Technolo-
 gy: An emission limitation based on the
 maximum degree  of emission  reduction
 (considering energy, environmental, and
.economic  impacts)  achievable  through
 application of production processes and •'
 available  methods,  systems, and tech-
 niques. BACT does not permit emissions in
 excess of those allowed under any applica-
 ble Clean Air Act  provisions. Use of the
 BACT concept is allowable on a case by
 case basis for major new or modified emis-
 sions  sources  in   attainment areas and
 applies to each regulated pollutant.

 Bacteria: (Singular  bacterium) Microscopic
 living organisms that can aid in pollution
 control by metabolizing organic matter in
 sewage, oil spills or other pollutants. How-
ever, bacteria in soil, water or air can also
cause  human,  animal  and plant health

Baffle Chamber: In incinerator design, a
chamber designed to promote the settling
of fly ash and coarse particulate matter by
changing  the direction  and/or  reducing
the velocity of the gases produced by the
combustion of the refuse or sludge.
  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 parti-
  cles while entrapping the larger ones.

  Baling: Compacting solid waste into blocks
  to reduce volume and simplify handling.

  Ballistic Separator: A machine that sorts
  organic from inorganic matter for compost-

  Band Application: The spreading of chem-
  icals over, or next to, each row of plants in

  Banking: A system for recording qualified
  air emission reductions for  later use in
  bubble, offset, or netting transactions. (See:
  emissions trading.)

  Bar Screen: In wastewater  treatment, a
  device used to remove large solids.

  Barrier Coating(s): A layer, fff a material
  that obstructs or prevents passage of some-
  thing through a surface that  is to be pro-
  tected, e.g. grout, caulk, or various sealing
  compounds; sometimes used with polyure-
  thane membranes to prevent corrosion or
  oxidation of metal  surfaces, .chemical im-
  pacts on various materials, or, for example,
  to prevent radon infiltration through walls,
 cracks, or joints in a house.

 Basal Application: In pesticides, the appli-
 cation of a chemical on plant stems or tree
 trunks just above the soil line.

 Bed Load: Sediment particles resting on en-
 near the channel bottom that are pushed or
 rolled along by the  flow of water.

 BEN: EPA's computer model for analyzing
 a violator's economic gain from not com-
 plying with the law.

 Bench-scale Tests:  Laboratory testing of
 potential cleanup technologies (See: treat-
 ability studies.)               .          '

 Beryllium: An airborne metal  hazardous
 to human health .when inhaled. It is dis-
 charged by machine shops, ceramic and
 propellant plants, and foundries.

 Best  Available   Control   Measures
 (BACM): A term used to refer to the most
 effective  measures  (according to EPA
 guidance)  for controlling small  or dis-
 persed particulates from sources  such as
 roadway dust, soot  and ash from wood-
 stoves and open burning of rush, timber,
 grasslands, or trash.

 Best Demonstrated Available Technology
 (BOAT): 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.

   Bc*t Management Practice (BMP): Meth-
   ods that have been determined to be the
   moat effective, practical maim of prevent-
   ing or reducing pollution frosa non-point

  Bimetal: Beverage containers with  steel
  bodies and aluminum tops; handled differ-
  ently from pure aluminum in recycling.

  Bioaccumulants: Substances that increase
  in concentration in living organisms as
  they take  in contaminated air, water, or
  food because the substances are very slow-
  ly metabolized or excreted. (See: biological

  Bioasuy:  Study of living organisms to
  measure the effect of a substance, factor, or
  condition by comparing before-and-after
  exposure or other data.

  Biochemical Oxygen Demand (BOD): A
  measure of the amount of oxygen con-
  sumed  in  the biological processes  that
  break down organic matter in water.  The
  greater the BOD, the greater the degree of

  Biodegradable: Capable of decomposing.
  rapidly under natural conditions.

  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 frequen-
  cies.  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 Control: In pest control, the use
 of animals and organkmc that eat or other-
 wise kill or out-compete pests.

 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 rum are eaten  by
 large birds,  animals or humans. The sub-
 stances become concentrated in tissues or
 internal organs as they move up the chain.'
 (See: bJoaccumulative.)

 Biological Oxidation: Decomposition  of
 complex organic materials by microorgan-
 isms. Occurs in self-purification of water
 bodies and in activated sludge wastewater

 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 technol-
ogy that uses bacteria to consume organic
   Biologicals: Vaccines, cultures and other
   preparations made from living organisms
   and their products, intended for  use in
   diagnosing, immunizing, or treating hu-
   mans or animals, or in related research.

   Biomass: All of the living material in a
   given area; often refers to vegetation.

   Biome: Entire community of living organ-
   isms in a single major ecological area. (See:
   biotic community.)

   Biomonitoring: 1. The use of living organ-
   isms 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.

   Bioremediation: Use of living organisms to
  clean up oil spills or remove other pollut-
  ants from soil, water, or wastewater; use of
  organisms such as non-harmful insects to
  remove  agricultural pests  or counteract
  diseases of trees, plants, and garden soiL

  Biosphere: The portion of Earth  and its
  atmosphere that can support life.

  Biostabilizen  A machine  that converts
  solid waste into compost by grinding and

  Biota: The animal and plant life of a given

  Biotechnology: Techniques that use living
  organisms  or parts of organisms  to pro-
  duce a variety of products (from medicines
  to industrial enzymes)  to improve plants
  or animals or to develop microorganisms
  to remove toxics 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.)

•  Blackwater Water that contains animal,
 human, or food waste.

 Blood  Products: Any  product derived
 from human blood, including but not
 limited to blood plasma, platelets,  red or
 white corpuscles, and  derived licensed
 products such as interferon.

 Bloom: A proliferation of algae and/or
 higher aquatic plants in a body of  water;
 often related to pollution, especially when
 pollutants accelerate growth.

 BODS: The amount of dissolved oxygen
 consumed in five days by biological pro-
 cesses breaking down organic matter.

 Bog: A type of wetland that accumulates
 appreciable peat deposits. Bogs depend
 primarily on precipitation for their  water
 source, and are usually acidic and rich in
 plant residue with a conspicuous mat of
living-green moss.

Boom: 1. A floating device used to contain
oil on a body of water. 2. A piece of equip-
   Botanical Pesticide:  A pesticide whose
   active ingredient  is a  plant-produced
   chemical such as nicotine or strychnine.
   Also called a plant-derived pesticide.

   Bottle Bill: Proposed or enacted legislation
   which requires a returnable  deposit on
   beer or soda containers and provides for
   retail store  or other redemption.  Such
   legislation is designed to discourage use of
   throwaway containers.

  Bottom Ash: The non-airborne combustion
  residue from burning pulverized coal in a
  boiler; the material which falls to the bot-
  tom of the boiler and is removed mechani-
  cally; a concentration of the non-combusti-
  ble materials, which may include toxics.

  Bottom Land Hardwoods: Forested fresh-
  water wetlands adjacent to rivers in the
  southeastern  United  States,  especially
  valuable for wildlife breeding, nesting and

  Brine Mud: Waste material, ofterfaBsociat-
  ed with well-drilling or mining, composed
  of mineral salts or other inorganic com-

  Building   Cooling  Load: The  hourly
  amount of heat that must be removed from
  a building to  maintain  indoor  comfort
  (measured in British Thermal Units BTUs).

  Broadcast Application: The spreading of
 pestkides over an entire area.

 Bubble Policy: (See: emissions trading.)

 Bubble: A system under which  existing
 emissions  sources can propose alternate
 means  to comply with a set of emissions
 limitations; under the bubble  concept,
 sources can control more than required at
 one emission point where control costs are
 relatively low in return for a comparable
 relaxation of controls at a second emission
 point where costs are higher.

 Buffer Strips: Strips  of grass or other
 erosion-resisting vegetation between  or
 below cultivated strips or fields.

 Bulk Sample: A small portion (usually
 thumbnail size) of a suspect asbestos-con-
 taining building material collected by an
 asbestos inspector for laboratory analysis
 to determine asbestos content.

 Bulky Waste: Large items of waste materi-
 als, such as appliances, furniture, large
 auto parts, trees, stumps.

 Burial Ground (Graveyard): A disposal
 site for radioactive waste  materials  that
 uses earth or water as a shield.

 By-product: Material, other than the prin-
cipal product, generated as a consequence
of an industrial process.

Cadmium (Cd): A heavy metal element
that accumulates in fee- environment.

Cancellation: Refers to Section 6 (b) of the
Federal Insecticide, Fungicide and Roden-
ticide Act (FIFRA) which authorizes cancel-
lation of a pesticide registration if unrea-
sonable adverse effects to the environment
and public health develop when a product
is used according to widespread and com-
monly recognized practice, or if its labeling
or other material required to be submitted
does not comply with FIFRA provisions.

Cap: A layer of clay, or other impermeable
material installed over the top of a closed
landfill to prevent entry of rainwater and
minimize leachate.

Capacity Assurance Plan: A statewide
plan which  supports a state's ability to
manage the hazardous waste generated
within its boundaries over a twenty year

Capture Efficiency: The fraction of organic
vapors generated  by a process that are
directed to an abatement or recovery de-

Carbon Absorber: An add-on control de-
vice 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 ground
water  or  surface  water  by forcing it
through tanks containing activated carbon
treated to attract the contaminants, con-
taminants.  .

Carbon Monoxide (CO): A colorless, odor-
less, poisonous  gas produced by incom-
plete fossil fuel combustion.

Carboxyhemoglobin:   Hemoglobin   in
which the iron is bound to carbon monox-
ide (CO) instead of oxygen.

Carcinogen: Any substance that can cause
or aggravate cancer.

Carrier: The inert liquid or solid material
added to an active ingredient in a, pesti-

Carrying Capacity: 1. In recreation man-
agement, 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.

Cask: A thick-walled container (usually
lead) used to transport radioactive materi-
al. Also called a coffin.

Catalytic Converter  An  air pollution
abatement device that removes, pollutants
from motor vehicle  exhaust,  either by
oxidizing them into carbon dioxide and
water or reducing them to nitrogen and
Catalytic Incinerator: A control device mat
oxidizes  volatile   organic   compounds
(VOCs) by using a catalyst to promote the
combustion process. Catalytic incinerators
require lower temperatures than conven-
tional  thermal incinerators, thus saving
fuel and other costs.

Categorical Exclusion: 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 environmen-
tal assessment or environmental impact
statement under the National Environmen-
tal Policy  Act (NEPA).

Categorical Pretreatment  Standard:  A
technology-based effluent limitation for an
industrial facility discharging into a munic-
ipal sewer system. Analogous in stringency
to Best Availability Technology (BAT) for
direct dischargers.

Cathodic  Protection: A technique to pre-
vent corrosion of a metal surface by mak-
ing it  the cathode of an electrochemical

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.

Cementitious: Densely packed and  non-
fibrous friable materials.

Central Collection Point: Location were a
generator of  regulated  medical waste
consolidates wastes originally generated at
various locations in his facility, the wastes
are gathered together for treatment on-site
or for transportation elsewhere for treat-
ment and/or disposal. This  term could
also apply to community hazardous waste
collections, industrial and other waste
management systems.

Centrifugal Collector A mechanical sys-
tem  using centrifugal force  to  remove
aerosols from -a gas stream or to de-water

Channelization: Straightening and deepen-
ing streams so water will move faster, a
marsh-drainage tactic that  can interfere
with waste assimilation capacity, disturb
fish and wildlife habitats, and aggravate

Characteristic: Any one of the four catego-
ries used, in  defining hazardous waste:
ignitability, corrosivity,, reactivity,  and

Chemical  Oxygen Demand  (COD):  A
measure of the oxygen required to oxidize
all compounds, both organic and inorganic,
in water.

Chemical Treatment: Any one of a variety
of technologies that use chemicals or a
variety  of chemical  processes  to treat
 Chemnefc Mutual aid network of chemical
 shippers  and contractors that  assigns a
 contracted emergency  response company
 to provide technical support if a represen-
 tative of the firm whose  chemicals are
 involved in an incident is not readily avail-

 Chemosterilanb A chemical that controls
 pests by preventing reproduction.
 Chemterc: The industry-sponsored Chemi-
 cal Transportation Emergency Center; pro-
 vides information and/or emergency assis-
 tance to emergency responders.
 Chilling  Effect:  The  lowering  of the
 Earth's temperature because of increased
 particles in the air blocking the sun's rays.
 (See: greenhouse effect.)

 Chlorinated Hydrocarbons: These include
 a class of persistent, broad-spectrum insec-
 ticides that linger in the environment and
 accumulate in the food chain. Among them
 are  DDT, aldrin, dieldrin,  jwptachlor,
•chlordane, lindane, endrin, irtirex, hexa-
 chloride, and toxaphene. Other examples
 include' TCE, used as an industrial solvent.
 Chlorinated Solvent: An organic solvent
 containing chlorine atoms, e.g., methylene
 chloride and 1,1,1-trichloromethane, used
 in aerosol spray containers and in highway

 Chlorination: The application of chlorine
 to drinking water, sewage, or industrial
 waste to disinfect or to oxidize undesirable
 Chlorinaton A device that adds chlorine,
 in gas or liquid form, to water or sewage
 to kill infectious bacteria.
 Chlorine-Contact Chamber That part of a
 water  treatment plant  where effluent is
 disinfected by chlorine.
 Chlorofluorocarboiu (CFCs): A family of
 inert, nontoxk, and easily liquified chemi-
 cals 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.
 Chlorosis: Discoloration of normally green
plant parts  caused by disease, lack  of
nutrients, or various air pollutants.
Cholinesterase: An enzyme found in ani-
mals that regulates nerve impulses. Cholin-
esterase inhibition is associated with a
variety of acute symptoms such as nausea,
vomiting, blurred vision, stomach cramps,
and rapid heart rate.
Chromium: (See: heavy metals.)
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 Toxldty: The capacity of a sub-
 stance to cause long-term poisonous hu-
 man health effect*. (See; acute tenacity.)
 Clarification: Clearing action, that occurs
 during wastewater treatment when solids
 settle out. This is often aided by centrifugal
 action and chemically induced coagulation
 in wastewater.
 Clarifien A tank in which solids settle to
 the bottom and are subsequently removed
 as sludge.
 Clay Soil: Soil material containing more
 than 40 percent clay, less than 45 percent
 sand, and less than 40 percent silt.
 Clean Coal Technology: Any technology
 not in widespread use prior to the Clean
 Air Act amendments of 1990. This Act will
 achieve significant reductions in pollutants
 associated with the burning of coaL
 Clean  Fuels: Blends or substitutes for
 gasoline fuels, including compressed natu-
 ral gas, methanol, ethanol, liquified petro-
 leum gas, and others.
 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.
 Clear Cub Harvesting all the trees in one
 area at one time, a practice  that can en-
 courage fast rainfall or snowmelt runoff,
 erosion,  sedimentation  of  streams  and
 lakes, flooding, and destroys vital habitat.

 Cloning: In biotechnology,  obtaining  a
 group of genetically identical cells from a
 single cell; making identical copies  of  a

 Clo*ed-Loop Recycling: Reclaiming or
 reusing wastewater for non-potable  pur-
 poses in an enclosed process.
 Closure: The procedure a landfill operator
 must follow when a landfill reaches its
 legal capacity  for solid  waste: ceasing
 acceptance'of solid waste and placing  a
 cap on the landfill site.
 Coagulation: Clumping  of  particles in
wastewater to settle out impurities, often
induced by chemicals such as lime, alum,.
and iron salts.

 Coastal Zone: Lands and waters adjacent
 to the coast that exert an influence on the
uses of the sea and its ecology, or whose
uses and ecology are affected by the sea.
Coefficient of Haze (COH): A measure-
ment of visibility interference in the atmo-

Coke Oven: An industrial process which
converts coal into coke, one of the bask
materials used  in blast furnaces for  the
conversion of iron ore into iron.
 Cold Temperature CO: A standard for
 automobile carbon monoxide (CO) emis-
 sions to be met at a low temperature (ie.
 20  degrees  Fahrenheit).  Conventional
 automobile catalytic converters are  less
 efficient upon start-up at  low tempera-

 Colifonn Index: A rating of the purity of
 water based on a count of fecal bacteria.

 Colifonn   Organism:  Microorganisms
 found in the intestinal tract of humans and
 animals. Their presence in water indicates
 fecal pollution and potentially adverse con-
 tamination by pathogens.

 Collector Sewers: Pipes used to collect and
 carry wastewater from individual sources
 to an interceptor sewer that will carry it to
 a treatment facility.

 Combined Sewer Overflows: Discharge of
 a mixture  of storm water  and domestic
 waste when the flow capacity of a sewer
 system is exceeded during rainstorms.

 Combined Sewers: A sewer system that
 carries both sewage and storm-water run-
 off.  Normally,  its  entire flow goes to a
 waste treatment plant, but during a heavy
 storm,  the volume of  water may be so
 great as to cause overflows of untreated
 mixtures of storm water and sewage into
 receiving waters. Storm-water runoff may
 also carry toxic chemicals from industrial
 areas or streets into the sewer system.

 Combustion: 1. Burning, or rapid oxida-
 tion, accompanied by release of energy in
 the form of heat and light. A basic cause of
 air pollution. 2. Refers to controlled bum-
 ing  of waste,  in  which heat chemically
 alters organic compounds, converting into
 stable inorganics such as carbon dioxide
 and water.

 Combustion Chamber: The actual com-
 partment where waste  is  burned in an

 Combustion Product: Substance produced
 during the burning or oxidation of a mate-

 Command Post: Facility located at a safe
 distance upwind  from an  accident site,
 where the on-scene coordinator, respond-
 ers,  and technical representatives make
 response decisions, deploy manpower and
 equipment,  maintain liaison with news
 media, and handle communications.

 Comment Period: Time provided for  the
public to review and comment on a prcf-
 posed EPA action  or  rulemaking after
 publication in the Federal Register.

Commercial Waste Management Facility:
A treatment, storage, disposal, or transfer
facility which accepts waste from a variety
of sources, as compared to a private facili-
 ty which  normally manages  a limited
waste stream generated by its own opera-

Commercial Waste: All solid waste ema-
nating from business establishments such
as'stores, markets, office buildings, restau-
rants, shopping centers, and theaters.
 Commingled Recyclables: Mixed recyclab-
 les that are collected together.

 Comminuten A  machine that shreds  or
 pulverizes solids to make waste treatment

 Comminution: Mechanical shredding or
 pulverizing of waste. Used in both solid
 waste management and wastewater treat-

 Community: In ecology, a group of inter-
 acting 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 Relations: The EPA effort to
 establish two-way communication with the
 public to create understanding of EPA pro-
 grams and related actions, to assure public
 input into decision-making processes relat-
 ed to affected communities, and to make
 certain that the Agency is aware of and
 responsive to public  concerns. .Specific
 community relations activities arefequired
 in relation to Superfund remedial actions.

 Community Water System: A public water
 system which serves at least 15 service
 connections used  by year-round residents
 or regularly serves at least 25 year-round

 Compaction: Reduction of the bulk of solid
 waste by rolling and tamping.

 Compliance Coating: A coating whose
 volatile organic compound content does
 not exceed that allowed by regulation.

 Compliance Monitoring: Collection and
 evaluation of data, including self-monitor-
 ing  reports,  and verification  to  show
 whether pollutant concentrations and loads
 contained in permitted discharges  are in
 compliance with the limits and conditions
 specified in the permit.

 Compliance Schedule: A negotiated agree-
 ment between a  pollution source and  a
 government agency  that specifies dates
 and  procedures by which a  source will
 reduce emissions and, thereby,  comply
 with a regulation.

 Composite Sample:  A series of  water
 samples taken over a given period of time
 and weighted .by flow rate.

 Compost:  The  relatively  stable humus
 material that is produced from a compost-
 ing process in which bacteria in soil mixed
with garbage and degradable  trash break
down the mixture into organic fertilizer.

Composting:  The controlled  biological
decomposition of  organic material in the
presence of air to form a humus-like mate-
rial.  Controlled methods of composting
include mechanical mixing and aerating,
ventilating the materials by dropping them
 through a vertical series of aerated cham-
bers, or placing the compost in piles out in
the open air and  mixing it or turning it

Conditional Registration: Under special
circumstances,  the Federal  Insecticide,
Fungicide, and Rodentieide Act (FIFRA)
permits registration of pesticide products
that is "conditional" upon the submission
of additional data. These special circum-
stances include a finding by the EPA Ad-
ministrator that a new product or use of an
existing pesticide  will  not significantly
increase the risk of unreasonable adverse
effects.  A product containing a new (pre-
viously unregistered)  active  ingredient
may be conditionally registered only if the
Administrator finds that such conditional
registration is in the public interest, that a
reasonable time for conducting the addi-
tional studies has not elapsed, and the use
of the pesticide for the period of condi-
tional  registration will  not present an
unreasonable risk.

Conditionally Exempt Generators (CE):
Persons or enterprises which produce less'
than 220 pounds of hazardous waste per
month. Exempt from most regulation, they
are required merely to determine whether
their waste is hazardous, notify appropri-
ate state or local agencies, and ship it by
permitted facility for proper disposal.  (See
:an authorized transporter to a small quan-
tity generator.)

Cone of Depression: A  depression in the
water  table   that  develops   around  a
pumped welL

Confined  Aquifer An  aquifer in which
ground water  is confined under pressure
which is significantly greater than atmo-
spheric pressure.

Consent Decree:  A legal document, ap-
proved  by a  judge, that formalizes' an
agreement  reached between  EPA  and
potentially  responsible  parties  (PRPs)
through which PRPs will conduct all or
part of a cleanup  action at a Superfund
site; cease or correct actions or processes
that are polluting the  environment; or
otherwise comply with EPA initiated regu-
latory enforcement actions to resolve the
contamination at  the Superfund site in-
volved. The consent decree describes the
actions PRPs will take and may be subject'
to a public comment period.

Conservation: Preserving and renewing,
when possible, human and natural resourc-
es. The use, protection, and improvement
of natural resources according to principles
that will assure their highest economic or
social benefits.

Construction  and Demolition Waste:
Waste building materials, dredging materi-
als, tree stumps, and rubble resulting from
construction, remodeling, repair, and de-
molition of homes, commercial buildings
and other structures and pavements. May
contain lead, asbestos, or other hazardous
Contact  Pesticide: A chemical that kills
pests when it touches .them, instead of by
ingestion. Also, soil that contains the min-
ute skeletons of certain algae that scratch
and dehydrate waxy-coated insects.

Contaminant:  Any  physical,  chemical,
biological, or radiological substance or
matter that has an adverse affect on air,
water, or soil.

Contingency Plan: A document setting out
an  organized, planned, and  coordinated
course of action to be followed in case of a
fire, explosion, or other accident that re-
leases toxic chemicals, hazardous waste, or
radioactive materials that threaten human
health or the environment. (See: National
Oil and Hazardous Substances Contingen-
cy Plan.)

Continuous Discharge: A routine release
to the environment  that occurs without
interruption,  except for infrequent  shut-
downs for maintenance, process changes,

Contour Plowing: Soil tilling method that
follows the shape of the land to discourage

Contract Labs: Laboratories under contract
to EPA, which analyze samples taken from
waste, soil, air, and water or carry out re-
search projects.

Control Technique Guidelines (CTG): A
series of EPA documents designed to assist
states  in defining  reasonable  available
control  technology  (RACT)  for  major
sources  of volatile organic  compounds

Controlled Reaction: A chemical reaction
under temperature and pressure conditions
maintained within safe limits to produce a
desired product or process.

Conventional Pollutants: Statutorily listed
pollutants understood well by  scientists.
These may be in the form of organic waste,
sediment, acid, bacteria, viruses, nutrients,
oil and grease, or  heat.

Conventional Systems: Systems that have
been traditionally used to collect municipal
wastewater in gravity sewers  and convey
it to a central primary or secondary  treat-
ment plant prior  to discharge to surface

Conventional Tilling: Tillage operations
considered standard for a specific location
and crop and that tend to bury the crop
residues; usually considered as a base for
determining the cost effectiveness of con-
trol practices.

Cooling  Electricity Use: Amount of elec-
tricity used to meet the building cooling
load. (See: building cooling load.)

Cooling  Tower:  A structure that helps
remove heat from  water used as  a coolant;
e.g., in electric power generating plants.
 Cooperative Agreement:- An  assistance
 agreement whereby EPA transfers money,
 property, services or anything of value to
 a state for the accomplishment of CERC-
 LA-authorized  activities or tasks.

 Core: The uranium-containing heart of a
 nuclear reactor, where energy is released.

 Core Program Cooperative Agreement: An
 assistance agreement whereby  EPA sup-
 ports states or tribal governments with
 funds to help defray the cost of non-item-
 specific administrative and training activi-

 Corrosion: The dissolution and wearing
 away of  metal caused by a chemical reac-
 tion such as between water and the pipes,
 chemicals  touching  a metal surface,  or
 contact between two metals.

 Corrosive: A chemical agent that reacts
 with the surface of a material causing it to
 deteriorate or wear away.

 Cost-Effective Altemative:.An alternative
 control or corrective me'tnocl  identified
 after analysis as being the best available in
 terms of  reliability, performance, and cost.
 Although costs are one important consider-
 ation, regulatory  and compliance analysis
 does not require  EPA to choose the least
 expensive alternative. For example, when
 selecting a method for cleaning up a site
 on the Superfund National Priorities List,
 the Agency balances costs with the long-
 term effectiveness of the  methods pro-

 Cost Recovery: A legal process by which
 potentially responsible parties who contrib-
 uted 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.

 Cover Material: Soil used  to cover com-
 pacted solid waste in a sanitary landfill.

 Cover: Vegetation or other material pro-
 viding protection  as ground cover.

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

 Criteria Pollutants: The 1970 amendments
 to the dean Air Act required EPA to set
National  Ambient Air Quality Standards
for certain pollutants known to be hazard-
ous to  human health. EPA has identified
and set standards  to protect human health
and  welfare for  six pollutants: ozone,
carbon monoxide, total suspended particu-
lates, sulfur dioxide, lead, and nitrogen
oxide. The term,  "criteria pollutants" de-
rives from the requirement that EPA must
describe  the characteristics and potential
health and welfare effects of these pollut-
ants. It is on the basis of these criteria that
standards are'set or revised.

 Criteria: Descriptive  factors taken  into
 account by EPA in setting standards for
 various pollutants. These factors are used
 to determine limits on allowable concentra-
 tion 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.
 Crop Coiuumptive Use: The amount of
 water transpired during plant growth plus
 what evaporated from the soil surface and
 foliage in the crop area.
 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 ex-
 changed  with indoor air in a  minute's
 time, Le., the air exchange rate.
 Cullefc 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  Working  Level  Months
 (CWLM): The sum of lifetime exposure to
 radon working  levels  expressed in total
 working level months.
 Curbside Collection: Method of collecting
 recyclable materials at homes, community
 districts or businesses.
 Cutie-Pie: An instrument used to measure
 radiation levels.

 Cyclone Collector:  A device that uses
 centrifugal force to pull large  particles
 from polluted air.
DaU Call-In: A part of the Office of Pesti-
cide Programs (OFF) process of developing'
key required test data, especially on the
long-term, chronic effects of existing pesti-
cides, in advance of scheduled Registra-
tion Standard reviews. Data Call-in from
manufacturers is an adjunct of the Regis-
tration Standards program  intended to
expedite re-registration.

DDT: The first chlorinated hydrocarbonin-
sectfcide chemical name: Dichloro-Diphe-
nyl-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 envi-
ronment and accumulation 'in  the food
 Decay  Products:  Degraded radioactive
 materials, often referred to as "daughters"
 or  "progeny"; radon decay products  of
 most concern from a public health stand-
 point are polonium-214 and polonium-218.

 Dechlorination: Removal of chlorine from
 a substance by chemically replacing it with
 hydrogen or hydroxide ions in  order  to
 detoxify a substances.

 Decomposition: The breakdown of matter
 by bacteria and fungi, changing the chemi-
 cal  makeup and physical appearance  of

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

 Deep-Well Injection: Deposition of raw or
 treated, filtered hazardous waste by pump-
 ing 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.

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

 Delegated State: A state (or other govern-
 mental 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.

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

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

 Denitrification: The anaerobic biological
 reduction of nitrate to nitrogen gas.

 Depletion Curve: In hydraulics, a graphi-
 cal 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

 Depressurization: A condition that occurs
 when the air pressure inside a structure is
 lower that the air pressure outside. Depres-
 surization  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 Toxicity: The ability of a pesticide
 or toxic chemical to poison  people or ani-
 mals by contact with the skin. (See:  contact
 DES: A synthetic estrogen, diethylstilbes-
 trol is used as a growth stimulant in food
 animals. Residues in meat are thought to
 be carcinogenic.

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

 Desiccanh 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.

 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 perform-
 ance standards exist. The Clean Air Act
 does require states to control these pollut-
 ants,  which  include  acid  mjst,   total
 reduced sulfur (TRS), and fluorides.

 Designated Uses: Those water uses identi-
 fied in state  water quality standards that
 must be achieved and maintained as re-
 quired under 'the Clean Water Act.  Uses
 can include  cold water fisheries,  public
 water supply, irrigation, etc.

 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

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

 Destroyed- Medical  Waste:  Regulated
 medical waste that has been ruined,  torn
 apart, or mutilated through thermal treat-
 ment, melting, shredding, grinding, tear-
 ing, or breaking, so that it is no longer
 generally recognized as medical waste, but
 has not yet been treated  (excludes com-
 pacted regulated medical waste.)

 Destruction  and  Removal  Efficiency
 (DRE): A percentage  that represents the
 number of molecules of a compound re-
 moved or destroyed in  ah incinerator
 relative to the number  of molecules en-
 tered  the  system (e.g.,  a DRE of 99.99
 percent means that 9,999 molecules are
 destroyed for every 10,000 that enter; 99.99
 percent is known as  "four  nines."   For
some  pollutants, the RCRA removal re-
quirement may be a  stringent as  "six

Destruction Facility: A facility that de-
stroys regulated medical waste by mashing
or mutilating it.

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: volu-
 metric tank tests.)

 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.

 Diatomaceous Earth (Diatomite): A chalk-
 like  material (fossilized diatoms) used  to
 filter out solid waste in wastewater treat-
 ment plants, also used as an active ingredi-
 ent 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 com-
 mercial establishment uses.

 Dibenzofurans: A group of highly toxic
 organic compounds.

 Dicof ol: 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

 DigestenJn 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 gasi-
fication, liquefaction, and mineralization of

 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.
 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-dioxina.
  Concern  about them arises  from  their
  potential tenacity  and contaminants in
  commercial products. Tests on laboratory
  animals indicate that it is one of the more
  toxic man-made compounds.

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

  Disinfectant: A chemical or physical pro-
  cess  that kills  pathogenic organisms in
  water. Chlorine is often used to disinfect
  sewage treatment effluent, water supplies,
  wells, and swimming pools.

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

  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 haz-
  ardous materials from removal actions or
  accidental  releases. Disposal may be ac-
  complished through use of approved se-
  cure landfills, surface impoundments, land
  farming, deep-well injection, ocean dump-
  ing, or incineration.

  Dissolved  Oxygen (DO):  The  oxygen
  freely available in  water, vital to fish and
  other aquatic life and for the prevention of
  odors. 1X5 levels are 'considered a most
  important  indicator of a  water body's
  ability to support desirable aquatic life.
 Secondary and advanced waste treatment
 are generally designed to ensure adequate
  DO in waste-receiving waters.

  Dissolved  Solids: Disintegrated organic
 and inorganic material in water.  Excessive
 amounts make water unfit to drink or use
 in industrial processes.

 'Distillation: The act of purifying liquids
 through boiling, so that the steam condens-
 es to a pure liquid and the  pollutants
 remain in a concentrated residue.

 Diversion: A channel with a supporting
 ridge on the lower side constructed across
' a slope  to divert water at a non-erosive
 velocity to  sites  where it can be used or
 disposed of through a stable outlet.

 Diversion Rate:  The percentage of waste
 materials diverted from traditional dispos-
 al such as landfilling or incineration to be
 recycled, composted, or re-used.

 DNA Hybridization: Use of a segment of
 DNA, called a DNA probe, to identify its
 complementary DNA; used to detect spe-
 cific genes.
 Dose Response:  How a biological orga-
 nism's response to a toxic substance quan-
 titatively shifts as its overall exposure to
 the substance changes (e.g., a small dose of
 carbon monoxide may cause drowsiness; a
 large dose can be fatal)

 DOT Reportable Quantity: The quantity
 of a substance specified in U.S. Department
 of Transportation regulation that triggers
 labelling, packaging and other require-
 ments related to shipping such substances.

 Draft Permit: A preliminary permit draft-
 ed and published by EPA; subject to public
 review and  comment before  final action
 on the application.

 Dredging:  Removal of  mud  from the
 bottom of water bodies. This  can disturb
 the ecosystem and causes silting that kills
 aquatic  life. Dredging of contaminated
 muds can expose biota to heavy metals
 and other toxics. Dredging activities may
 be subject to regulation under Section 404
 of the dean Water Act.           ,
                                • *
 Drop-off: Recyclable materials  c<5llection
 method in which individuals bring them to
 a  designated collection site.

 Dump: A site  used  to dispose of  solid
 waste without environmental controls.

 Dustfall Jar. An open container used to
 collect  large particles from  the  air for
 measurement and analysis.

 Dystrophic Lakes: Acidic, shallow bodies
 of water that contain much humus and/or
 other organic matter; contain many plants
 but few fish.
Ecological Impact: The effect that a man-
made  or  natural  activity  has on living
organisms, and their non-living (abiotic)

Ecology: The relationship of living things
to one another and.their environment, or
the study of such relationships.

Ecological Indicator  A characteristic of
the environment  that, when measured,
quantifies  magnitude of stress,  habitat
characteristics, degree of exposure to a
stressor, or ecological response to expo-
sure.   The term is a collective term  for
response, exposure. •  The term is a collec-
tive term for response, exposure,  habitat,
and stressor indicators.

Ecological Risk Assessment: The applica-
tion of a  formal  framework, analytical
process, or model to estimate the effects of
human actions(s) on a natural resource and
to interpret the significance of those effects
in light of the uncertainties identified in
each component of the assessment process.
Such analysis includes initial hazard identi-
fication, exposure  and dose-response  as-
sessments, and risk characterization.

Economic  Poisons: Chemicals  used  to
control peats and to defoliate cash crops
such as cotton.
Ecospheie: The "bio-bubble* that contains
life on earth, in surface waters, and in the
air. (See: biosphere.)
Ecosystem:  The interacting system of a
biological community and its non-living
environmental surroundings.

Ecosystem Structure: Attributes related to
instantaneous physical state of an ecosys-
tem; examples include species population
density, species richness or evenness, and
standing crop biomass.
Eco tone: A habitat created by the juxtapo-
sition of distinctly  different  habitats; an
edge habitat; or an ecological  zone or
boundary where two or more ecosystems
Effluent: Wastewater-treated or untreated-
that flows out of a treatment plant, sewer,
or industrial outfall. Generally refers to
wastes discharged into surface waters.
Effluent Guidelines: Technical EPA docu-
ments which set effluent limitations for
given industries and pollutants.-
Effluent Limitation: Restrictions establish-
ed by a State or EPA on quantities, rates,
and concentrations in wastewater discharg-
Effluent Standard: (See effluent  limita-
Electrodialysis: A process that uses electri-
cal  current  applied  to permeable mem-
branes  to remove minerals from  water.
Often used to desalinize salty or brackish
Electrostatic Precipitator (ESP): A device
that removes particles from a gas stream
(smoke) after combustion occurs. The ESP
imparts an electrical charge to the particles,
causing them to adhere to metal plates
inside,the  precipitator.  Rapping  on the
plates causes the particles to fall into a
hopper for disposal.
Eligible Costs: The construction costs for
waste-water treatment works upon which
EPA grants are based.
EMAP Data:  Environmental monitoring
data collected under the auspices of the
Environmental Monitoring and Assessment
Program,    All  EMAP data share the
common attribute  of  being of  known
quality,  having been collected  in the
context of explicit data quality objectives
(DQOs) and a consistent quality assurance
Emergency (Chemical): A situation created
by an accidental release or spill of hazard-
ous chemicals that poses a threat to the
safety of workers, residents, the environ-
ment, or property.
Emergency  Episode: (See: air pollution
 Emergency Response Values: Concentra-
 tions of chemicals, published by various
 groups, defining  acceptable  levels  for
 short-term exposures in emergencies.

 Emission: Pollution  discharged into the
 atmosphere from smokestacks, other vents,
 and surface areas of commercial or indus-
 trial facilities; from residential chimneys;
 and from motor vehicle,  locomotive, or
 aircraft exhausts.

 Emission Factor The relationship between
 the amount of pollution produced and the
 amount of raw material processed.   For
 example, an emission factor for a blast fur-
 nace making iron would be the number of
 pounds of  participates per ton of  raw

 Emission Inventory: A listing, by source,
 of the amount of air pollutants discharged
 into the atmosphere of a community; used
 to establish emission standards.

 Emission Standard: The maximum amount
 of air polluting discharge legally allowed
 from a  single source, mobile or stationary.

 Emissions Trading: EPA policy that allows
 a plant complex with several facilities to
 decrease  pollution from   some facilities
 while increasing it from others, so long as
 total results are equal to  or better  than
 previous  limits. Facilities  where this is
 done are treated as if they exist in a bubble
 in which total emissions are averaged out.
 Complexes that reduce emissions substan-
 tially may "bank"  their "credits" or sell
 them to other  industries.  Encapsulation:
 The treatment of asbestos-containing mate-
 rial with a liquid that covers the surface
 with a protective coating or embeds fibers
 in an adhesive matrix to prevent their re-
 lease into the air.

 Enclosure: Putting an airtight, imperme-
 able, permanent barrier around asbestos-
 containing materials to prevent the release
 of asbestos fibers into the air.

 Endangered Species: Animals, birds, fish,
 plants,  or other living organisms threat-
 ened with  extinction by  man-made or
 natural changes in  their  environment.
•Requirements for declaring a species en-
 dangered are contained in the Endangered
 Species Act.

 Endangerment Assessment: A 'study to
 determine the  nature and  extent of  con-
 tamination at a site on the National Priori-
 ties List and the risks posed  to public
 health  or the environment.  EPA or the
 state conduct the study when a legal action
 is to be taken to direct potentially responsi-
 ble parties to clean up a site or pay for it.
, An endangerment assessment supplements
 a remedial investigation.

 Energy Recovery: Obtaining energy from
 waste through a variety of  processes (e.g.,
 Enforceable Requirements: Conditions or
 limitations in permits issued under the
 Clean Water Act ,Section 402 or 404  that,
 if violated, could result in the issuance of
 a compliance order or initiation of a civil
 or criminal action under federal or applica-
 ble state laws. If a permit has not been
 issued, the term includes any requirement
 which,  in the Regional Administrator's
 judgement, would be included in the per-
 mit when issued. Where no permit applies,
 the term includes any requirement which
 the RA determines is necessary for the best
 practical waste  treatment  technology  to
 meet applicable criteria.

 Enforcement:  EPA,  state,  or local legal
 actions to obtain compliance with environ-
 mental laws, rules,  regulations, or agree-
 ments and/or obtain penalties or criminal
 sanctions for violations. Enforcement pro-
 cedures may vary, depending on the re-
 quirements of different environmental laws
 and  related  implementing  regulations.
 Under CERCLA, for exampje, EPA will
 seek to require potentially responsible par-
 ties to clean up a Superfund site, or pay
 for the cleanup,  whereas under the Clean
 Air Act the agency may invoke sanctions
 against cities failing to meet ambient air
 quality standards that  could prevent cer-
 tain types of construction or federal fund-
 ing. In other situations, if investigations by
 EPA  and state  agencies uncover willful
 violations, criminal trials and penalties are

 Enforcement Decision Document (EDD):
 A document that provides an explanation
 to the public  of EPA's selection of the
 cleanup alternative at enforcement sites on
 the National Priorities  List.  Similar to a
 Record of Decision.

 Enhanced- Inspection  and Maintenance
 (I&M): An improved automobile inspec-
 tion and maintenance program—aimed at
 reducing automobile emissions—that con-
 tains, at a minimum, more vehicle types
 and model years, tighter inspection, and
 better management practices. It may also
 include annual computerized  or central-
 ized inspections, under-the-hood inspec-
 tion- for signs of tampering with pollution
 control equipment, and increased  repair
waiver cost.

 Enrichment:  The addition  of nutrients
 (e.g.,  nitrogen, phosphorus, carbon  com-
pounds) from sewage effluent or agricul-
tural  runoff  to surface water,  greatly in-
creases the growth potential for algae and
other aquatic plants.

Environment:  The  sum of all  external
conditions affecting  the life, development
and survival of an organism.

 Environmental Assessment An environ-
 mental analysis prepared pursuant to the
 National  Environmental Policy  Act to
 determine whether a federal action would
 significantly affect the environment and
 thus require a more detailed environmen-
 tal impact statement.

 Environmental Audit: An independent as-
 sessment of the current status of a party's
 compliance with applicable environmental
 requirements or of a party's environmental
 compliance policies, practices, and controls.

 Environmental Impact Statement: A docu-
 ment required of federal agencies by the
 National Environmental Policy Act for
 major projects  or  legislative  proposals
 significantly affecting the environment. A
 tool for  decision making, it describes the
 positive  and negative effects of the under-
 taking and cites alternative actions.

 Environmental Indicator A measurement,
 statistic or value that provides a proximate
 gauge or evidence of the effects of environ-
 mental management programs  or of the
 state or condition of the environment.

 Environmental Response Team: EPA ex-
 perts located in  Edison, N.J., and Cincin-
 nati, OH, who can provide around-the-c-
 lock technical assistance to EPA regional
 offices and states during all types of haz-
 ardous waste site emergencies and spills of
 hazardous substances.

 Epidemiology: Study of the distribution of
 disease, or other health-related states and
 events in human populations, as related to
 age, sex,  occupation, ethnic, and economic
 status in order  to identify and  alleviate
 health problems and promote better health.

 Epilimnion: Upper waters of a thermally
 stratified lake subject to wind action.

 Episode  (Pollution): An air pollution inci-
 dent in a given area caused by a concen-
 tration of atmospheric  pollutants under
 meteorological conditions that may result
 in a  significant  increase in illnesses or
 deaths. May also describe water .pollution
 events or hazardous material spills.

 Equilibrium: In  relation  to radiation, the
 state at which the radioactivity of consecu-
 tive elements within a radioactive series is
 neither increasing nor decreasing..

 Equivalent Method: Any method of sam-
 pling and analyzing for air pollution which
 has been  demonstrated to the EPA Admin-
istrator's  satisfaction to be, under specific
conditions, an acceptable alternative to
 normally used reference methods.

 Erosion: The wearing away of land surface
by wind or water, intensified by land-clea-
ring practices related to farming, residen-
tial or industrial development, road build-
ing, or logging.
  Estuary: Regions of interaction between
  rivers and near-shore ocean waters, where
  tidal action and river flow mix fresh and
  salt  water.  Such  .areas include  bays,
  mouths of rivers, salt marshes, and la-
  goons. These brackish water ecosystems
  shelter and feed marine life,  birds, and
  wildlife. (See: wetlands.)

  Ethylene Dibromide (EDB): A chemical
  used as an agricultural fumigant and in
  certain  industrial  processes.  Extremely
  toxic and  found to be a carcinogen in
  laboratory animals,  EDB has been banned
  for most agricultural uses in the United

  Eutrophic Lakes: Shallow, murky bodies
  of water with concentrations of plant nutri-
  ents causing excessive production of algae.
  (See: dystrophk lakes.)

  Eutrophication: The slow aging process
  during which  a lake,  estuary, or  bay
 evolves into a bog or marsh and eventually
  disappears.  During  the  later stages of
 eutrophication the water body is choked
 by abundant plant life due to higher levels
 of nutritive compounds such" as nitrogen
 and phosphorus. Human activities  can
 accelerate the process.

 Evaporation Ponds:'Areas where sewage
 sludge is dumped and dried.

 Evapotranspiration: The loss of water from
 the soil both by evaporation and by tran-
 spiration from the plants growing in the

 Exceedance:  Violation of the  pollutant
 levels permitted by  environmental  pro-
 tection standards.

 Exclusion: In the asbestos program, one of
 several situations that permit a Local Edu-
 cation Agency (LEA) to delete one or more
 of  the items  required  by the  Asbestos
 Hazard Emergency Response Act (AHER-
 A), e.g., records of previous asbestos sam-
 ple collection and analysis may be used by
 the accredited inspector in lieu of AHERA
 bulk sampling.

 Exclusionary Ordinance: Zoning that ex-
 cludes classes of persons  or businesses
 from a particular neighborhood or area.

 Exempt Solvent: Specific  organic com-
 pounds not  subject to requirements of
 regulation because are deemed by EPA to
 be of negligible photochemical reactivity.

 Exempted Aquifer. Underground bodies
 of water  defined in the  Underground
 Injection Control program as aquifers that
 are  potential sources of drinking water
 though not being used as such, arid thus
 exempted from regulations barring under-
 ground injection activities.

 Exotic Species: A species that is not indig-
 enous to a region.

 Experimental  Use Permit: Obtained by
 manufacturers for testing new pesticides or
 uses of thereof  whenever they  conduct
experimental field studies to support regis-
tration on 10 acres or more on land or one
acre or more of water.-
  Explosive limits: The amounts of vapor in
  the air that form explosive mixtures; limits
  are expressed as lower and upper limits
  and give the range of vapor concentrations
  in  air that will explode if an ignition
  source is present.

  Exposure: The  amount of radiation or
  pollutant present in a given environment
  that represents a potential health threat to
  living organisms.

  Exposure Indicator: A characteristic of the
  environment measured to  provide evi-
  dence of the occurrence or magnitude of a
  response indicator's exposure to a chemical
  or biological stress.

  Extraction Procedure (E P Toxic):  Deter-
  mining  toxfcity by a  procedure  which
  simulates leaching; if a certain concentra-
  tion of a  toxic substance can be leached
  from  a  waste,  that  waste  is considered
 hazardous, i.e., "EP Toxic."

 Extremely Hazardous Substances: Any of
 406 chemicals identified by EP^\ as toxic,
 and listed under SARA Title II*. The list is
 subject to periodic revision. • ••
 Fabric Filter A cloth device that catches
 dust particles from industrial emissions.

 Facilities Plans: Plans and studies related
 to the construction of treatment works
 necessary to comply with the Clean Water
 Act or RCRA. A facilities plan investigates
 needs and  provides  information on .the
 cost effectiveness of alternatives, a recom-
 mended plan, an environmental assess-
 ment  of the  recommendations, and de-
 scriptions of the treatment works, costs,
 and a completion schedule.

 Facility .Emergency Coordinator Repre-
 sentative of a facility covered by environ-
 mental law (e.g, a chemical plant)  who
 participates in the emergency reporting
 process with the Local  Emergency Plan-
 ning Committee (LEPQ.

 Feasibility Study: 1. Analysis of the practi-
 cability of a proposal; e.g., a description
 and analysis of potential cleanup alterna-
 tives for a site such as one on the National
 Priorities List. The feasibility study usually
 recommends selection of a  cost-effective
 alternative. It usually starts as soon as the
 remedial investigation is  underway; to-
 gether, they are commonly referred to as
 the "RI/FS". 2. A small-scale investigation
 of a problem to ascertain whether a  pro-
 posed research approach is likely to  pro-
vide useful data.

Fecal Colif orm Bacteria: Bacteria found in
the intestinal tracts of  mammals. Their
presence in water or sludge is an indicator
of pollution and possible contamination by

 Federal  Implementation  Flan:  Under
 current law, a federally implemented plan
 to achieve attainment of air quality stan-
 dards,  used when a state is  unable to
 develop an adequate plan.   .   ,
 Feedlob A confined area for the controlled
 feeding of animals. Tends  to concentrate
 large amounts of animal waste that cannot
 be absorbed by the soil and, hence, may be
 carried to  nearby  streams or  lakes by
 rainfall runoff.
 Fen: A type of wetland that accumulates
 peat deposits.  Fens are less acidic  than
 bogs, deriving most of their water from
 groundwater rich in calcium and magne-
 sium. (See: wetlands.)
 FIFRA Pesticide Ingredient: An ingredient
 of a pesticide that must be registered with
 EPA under the Federal Insecticide, fungi-
 cide, and Rodenticide Act.  Products mak-
 ing pesticide  claims mst  register under
 FIFRA and may be subject to labeling and
 use requirements.
 Filling:  Depositing  dirt, mud  or other
 materials into aquatic areas to create more
 dry land, usually for agricultural or com-
 mercial development purposes, often with
' ruinous ecological consequences.
 Filter Strip: Strip or area of vegetation
 used for removing sediment, organic mat-
 ter, and other pollutants from runoff and
 waste water.
 Filtration: A treatment process, under the
 control of qualified operators, for removing
 solid (particulate) matter from water by
 means of porous media such as sand or a
 man-made  filter; often  used  to remove
 particles that containing pathogens.
 Financial Assurance for Closure: Docu-
 mentation or proof that an owner or opera-
 tor of a facility such as a landfill or other
 waste repository is capable of paying the
 projected costs of closing the facility and
 monitoring it afterwards as provided in
 RCRA regulations.
 Finding  of No' Significant Impact: A
 document prepared by a federal agency
 showing why a proposed action would not
 have a significant impact on- the environ-
 ment and thus would not require prepara-
 tion of an Environmental Impact State-
 ment. An FNSI ia based on the results of
 an environmental assessment
 First'Draw: The water that  comes out
 when a tap is first opened, likely to have
 the highest level of lead  contamination
 from plumbing materials.
 Flare:-A control device that bums hazard-
 ous materials  to prevent their release into
 the environment; may operate continuous-
 ly or intermittently, usually on top a stack.
 Floe: A clump of solids formed in sewage
 by biological or chemical action.
 Flocculatioru Process by which clumps of
 solids  in  water or  sewage  aggregate
 through biological  or chemical action so
 they can  be separated from water or sew-
Floor Sweep: Capture of heavier-than-air
gases that collect at floor level.

Flow Rate: The rate, expressed in gallons-
or liters-per-hour, at which a fluid escapes
from  a  hole or  fissure  in  a  tank. Such
measurements  are also  made of liquid
waste, effluent, and surface water move-

Flowmeter A gauge indicating the velocity
of wastewater moving through a treatment
plant or of any liquid  moving through
various industrial processes.

Flue Gas Desulfurization: A technology
that  employs a sorbent, usually lime or
limestone, to remove sulfur dioxide from
the gases produced by burning fossil fuels.
Flue gas desulfurization is current state-of-
the art technology for major SCh emitters,
like power plants.

Flue Gas: The air coming out of a chimney
after combustion in the burner it is vent-
ing. It can include nitrogen oxides, carbon
oxides, water vapor,  sulfur oxides,  parti-
cles and many chemical pollutants.   .  ,

Fluidized Bed Incinerator An incinerator
that uses a bed of hot sand or other granu-
lar material  to transfer  heat directly to
waste. Used mainly for destroying munici-
pal sludge.

Flume: A natural or man-made channel
that diverts water.

Fluorides: Gaseous,  solid, or dissolved
compounds containing fluorine that result
from  industrial   processes.  Excessive
amounts in food can lead to fluorosis.

Fluorocarbons (FCs): Any of a number of
organic compounds analogous to hydrocar-
bons  in  which one  or  more hydrogen
atoms are replaced by fluorine. Once used
in the United  States as a propellant for
domestic  aerosols, they are now found
mainly in coolants and some industrial
processes. FCs containing chlorine  are
called chlorofluorocarbons  (CFCs). They
are believed to be modifying the ozone
layer in the stratosphere, thereby allowing
more harmful solar radiation to reach the
Earth's surface.

Flush: 1. To open a cold-water tap to clear
out all the water which may have been
sitting for a long time in  the pipes. In new
homes, to flush a system means to send
large volumes  of water  gushing through
the unused pipes to remove loose particles.
of solder and flux. 2. To  force  large
amounts of water through liquid to clean
out piping or  tubing, storage or process

Fly Ash: Non-combustible residual parti-
cles expelled by flue gas.

Fogging: Applying a pesticide by rapidly
heating the liquid chemical so that it forms
very fine droplets that resemble smoke or
fog.  Used to  destroy mosquitoes,  black
flies, and similar pests.

Food Chain: A  sequence  of organisms,
each of which uses the next, lower member
of the sequence as a food source.
Formaldehyde: A colorless, pungent, and
irritating gas, CH20, used chiefly  as  a
disinfectant and preservative and in syn-
thesizing other compounds like resins.

Formulation: The substances  comprising
all active and inert ingredients in a pesti-
Fresh Water. Water that generally contains
less than 1,000 milligrams-per-liter of dis-
solved solids,
Friable Asbestos: Any material containing
more than one percent asbestos, and that
can be crumbled or reduced to powder by
hand pressure.  (May include previously
non-friable material which becomes broken
or damaged by  mechanical force.)

Friable: Capable of being  crumbled, pul-
verized, or reduced  to powder  by hand

Fuel Economy  Standard:  The Corporate
Average Fuel Economy Standard (CAFE)
effective in 1978. It enhanced the national
fuel conservation effort irripftsing a miles-
per-gallon floor for motor vehicles.

Fugitive Emissions: Emissions not caught
by a capture system.

Fume: Tiny particles trapped in vapor in a
gas stream. •

Fumiganb A pestkide vaporized to kill
pests. Used in buildings and greenhouses.

Functional  Equivalent: Term  used  to
describe EPA's decision-making process
and its relationship to the  environmental
review  conducted  under  the  National
Environmental  Policy Act  (NEPA).  A
review is considered functionally equiva-
lent  when it addresses the substantive
components of a NEPA review.

Fungi: (Singular Fungus) Molds, mildews,
yeasts, mushrooms, and puffballs, a group
organisms lacking in chlorophyll (Le., are
not photosynthetic) and which are usually
non-mobile, filamentous, and mulricellular.
Some grow in  soil,  others attach them-
selves to decaying trees and other plants
whence they obtain nutrients. Some are
pathogens, others  stabilize sewage and
digest composted waste.

Fungicide: Pesticides which are used  to
control, deter, or destroy fungi.
Fungistat: A chemical that keeps fungi
from growing.

Furrow Irrigation:  Irrigation  method  in
which water travels  through the field by
means of small channels between each row
or groups of rows.

Future  Liability:  Refers  to  potentially
responsible parties' obligations to pay for
additional response activities beyond those
specified in the Record  of Decision  or
Consent Decree.

 Game Fish: Specks like trout, salmon, or
 bass, caught for sport Many of them show
 more sensitivity to environmental change
 than "rough" fish.

 Garbage: Animal and vegetable waste
 resulting from the handling, storage, sale,
 preparation, cooking, and serving of foods.

 Gas Chromatograph/Mass Spectrometer
 Highly sophisticated instrument that iden-
 tifies the molecular composition and con-
 centrations of various chemicals in water
 and soil samples.

 Gasification: Conversion of solid material
 such as coal into a gas for use as a fuel

 Gasoline Volatility: The property of gaso-
 line whereby it evaporates into a vapor.
 Gasoline vapor is  a volatile organic com-

 General Permit: A permit applicable to a
 class or category of dischargers.

 General  Reporting  Facility: A  facility
 having one or more hazardous chemicals
 above the  10,000 pound  threshold  for
 planning quantities. Such facilities must
 file MSDS and emergency inventory infor-
 mation with the SERC and LEEC and local
 fire departments.

 Generator 1. A facility or mobile source
 that emits pollutants into the air or releases
 hazardous waste into water or soil. 2. Any
 person, by site, whose act or process pro-
 duces regulated medical waste or whose
 act  first causes such waste to become
 subject to  regulation.   In a  case  where
 more than one person (e.g., doctors with
 separate medical practices) is located in the
 same building, each business entity is a
 separate generator.

 Genetic Engineering: A process of insert-
 ing new genetic information into existing
 cells in order to .modify  any organism for
 the purpose of changing one of its charac-

 Geographic Information System (GIS): A
 computer system  designed  for storing,
 manipulating, analyzing, and displaying
 data in a geographic context.

 Germicide: Any compound that kills dis-
 ease-causing microorganisms.

 Glovebag:  A polyethylene or polyvinyl
 chloride bag-like enclosure affixed around
 an asbestos-containing source (most often
 thermal system insulation) permitting the
 material'to be removed while minimizing
 release of airborne fibers in the surround-
 ing atmosphere.

 Grain Loading: The rate at which particles
are emitted from a  pollution source. Mea-
surement is made by the number of grains
per cubic foot of gas emitted.
  Granular Activated Carbon Treatment: A
  filtering system often used in small water
  systems and individual homes to remove
  organics. GAC can be^highly effective in
  removing elevated levels' of  radon from

  Grassed Waterway: Natural or constructed
  watercourse or outlet  that is shaped or
  graded and established in suitable vegeta-
  tion for the disposal of runoff water with-
  out erosion.

  Gray Water Domestic wastewater com-
  posed  of wash water from kitchen, bath-
  room, and laundry sinks, tubs, and wash-

  Greenhouse Effect: The warming of the
  Earth's atmosphere attributed to a build-up
 of carbon dioxide or other gases; some
 scientists think that this build-up allows
 the sun's rays to heat the Earth, while in-
 fra-red radiation  makes the atmosphere
 opaque to a counterbalancing loss of heat.

 Grinder Pump: A mechanical device that
 shreds solids and raises sewage to a higher
 elevation through  pressure sewers.

 Ground Cover Plants grown to keep soil
 from eroding.

 Ground Water The supply of fresh water
 found beneath the Earth's surface, usually
 in aquifers,  which  supply  wells  and
 springs. Because ground water is a major
 source of drinking water, there is growing
 concern over contamination from leaching
 agricultural or  industrial  pollutants or
 leaking underground  storage tanks.

 Ground-Water Discharge: Ground water
 entering near coastal waters  which has
 been contaminated by  landfill leachate,
 deep well injection of hazardous wastes,
 septic tanks, etc.

 Gully Erosion: Severe erosion in  which
 trenches are cut to a depth greater than 30
 centimeters  (a foot).  Generally, ditches
 deep enough to cross with farm equipment
 are considered gullies.

Habitat: The place where a population
(e.g., human, animal,  plant, microorgan-
ism) lives and its surroundings, both living
and non-living.

Habitat Indicator  A physical attribute of
the environment measured to characterize
conditions necessary to support an organ-
ism, population, or  community  in  the
absence of pollutants, e.g., salinity of estur-
ine waters or substrate type in streams or
  Half-Life: 1.  The time required for a pol-
  lutant to lose half its affect on the envi-
  ronment. For example, the biochemical
  half-life of DDT in the environment is 15
  years of Radium. 1,580 yean. 2. The time
  required for half of the atoms of a radioac-
  tive element to undergo self-transmutation
  or decay.  3.  The time required  for  the
  elimination of one half a total dose from
  the body.

  Halon:  Bromine-containing  compounds
  with  long atmospheric lifetimes whose
  breakdown in the  stratosphere  causes
  depletion of ozone. Halons are used in fire-

  Hammermill: A high-speed machine that
  uses hammers and cutters to crush, grind,
  chip,  or shred solid waste.

  Hard Water Alkaline water containing dis-
  solved salts that interfere with some indus-
  trial  processes and  prevent soap from

  Hauler Garbage collection company that
 offers complete refuse  removal service;
 many also will also collect recytlables.

 Hazard Communication Standard:  An
 OSHA regulation that requires chemical
 manufacturers, suppliers, and importers to
 assess the hazards of the chemicals that
 they make, supply, or import, and to in-
 form employers, customers, and workers
 of these hazards through MSDS sheets.

 Hazardous Air Pollutants: Air pollutants
 which are  not covered by  ambient air
 quality standards but which, as defined in
 the Clean Air Act, may reasonably be
 expected to cause or contribute to irrevers-
 ible illness or death.  Such pollutants in-
 clude  asbestos, beryllium, mercury, ben-
 zene, coke oven emissions, radionuclides,
 and vinyl chloride.

 Hazardous Chemical: An EPA designation
 for any hazardous material  requiring an
 MSDS under OSHA's Hazard Communica-
 tion Standard. Such substances are capable
 of producing fires and explosions or ad-
 verse health effects like cancer and derma-
 titis. Hazardous chemicals are distinct from
 hazardous waste.(See: Hazardous Waste.)

 Hazardous Ranking System: The principle
 screening tool used by EPA to evaluate
 risks to public health and the environment
 associated with abandoned or uncontrolled
 hazardous waste sites. The HRS calculates
 a score based on the potential of hazardous
 substances spreading from the site through
the air, surface water, or ground water,
 and on other factors such as density and
proximity of human population. This score
is the primary factor in deciding if the site
should be on the National Priorities List
and, if so, what ranking it should have
compared to other sites on the list.

 Hazardous Substance 1. Any material that
 poses a threat to human health and/or the
 environment Typical hazardous substances
 are toxic, corrosive, ignitable, explosive, or
 chemically reactive. 2. Any substance des-
 ignated by EPA to be reported if a desig-
 nated quantity of the substance is spilled
 in the waters of  the United States or if
 otherwise released into the environment.

 Hazardous Waste: By-products of society
 that can pose a substantial or  potential
 hazard to  human health or the environ-
 ment when improperly managed. Possess-
 es at least one of four characteristics (ignit-
 ability, corrosivity, reactivity, or toxicity),
 or appears on special EPA lists.

 Hazardous Waste Landfill: An excavated
 or engineered site where hazardous waste
 is deposited and covered.

 Hazards Analysis: Procedures used to (1)
 identify  potential  sources of release of
 hazardous materials from fixed facilities or
 transportation accidents; (2) determine the
 vulnerability of a geographical area  to a
 release  of  hazardous materials;  and (3)
 compare hazards  to determine  which
 present greater or lesser risks to a commu-
 Hazards Identification: Providing infor-
 mation on which facilities have extremely
 hazardous  substances, what those chemi-
 cals are, how much there is at each facility,
 how the chemicals are stored, and whether
 they are used at high temperatures.
 Health  Assessment:  An  evaluation of
 available data on existing or potential risks
 to human health posed by a Superfund
 site. The Agency for Toxic Substances and
 Disease Registry (ATSDR) of the Depart-
 ment of Health  and Human  Services
 (DHHS) is  required to perform  such an
 assessment at  every site on the National
 Priorities List.

 Heat Island Effect: A "dome" of elevated
 temperatures over an urban area caused by
 structural and pavement heat fluxes, and
 pollutant emissions.

 Heavy Metals: Metallic elements with high
 atomic weights, e.g., mercury, chromium,
 cadmium, arsenic, and lead; can damage
 living things at low  concentrations and
 tend to accumulate in the food'chain.
 Heptathlon An   insecticide  that was
 banned on some food products in 1975 and
 all of them 1978. It was allowed for use in
 seed treatment until 1983. More recently it
 was found  in milk and other dairy prod-
 ucts in Arkansas and Missouri where dairy
 cattle were  illegally fed treated seed.
 Herbicide: A chemical pesticide designed
 to control or destroy plants, weeds,  or

Herbivore: An animal that feeds on plants.

Heterotrophic Organisms: Species that are
dependent on organic  matter for food.
 High-Density Polyethylene: A  material
 used  to  make  plastic  bottles  and other
 products that produces toxic fumes when

 High-Level Radioactive Waste  (HLW):
 Waste generated in core fuel of a nuclear
 reactor, found at nuclear reactors  or  by
 nuclear fuel  reprocessing;  is  a serious
 threat to  anyone  who comes near  the
 waste without  shielding. (See: low-level
 radioactive waste.)

 High-Level Nuclear Waste Facility: Plant
 designed to handle disposal of used nucle-
 ar fuel, high-level radioactive waste, and
 plutonium waste.

 Holding Pond: A pond or reservoir, usual-
 ly made of earth, built to store polluted

 Homeowner Water System: Any water
 system which supplies  piped water to a
 single residence.

 Homogeneous Area: In accordance with
 Asbestos Hazard and Emergency Response
 Act (AHERA) definitions, an area of sur-
 facing materials, thermal surface insula-
 tion, or miscellaneous  material  that  is
 uniform in color and texture.

 Hood Capture Efficiency:  Ratio of the
 emissions captured by a hood and directed
 into a control or disposal device, expressed
 as a percent of all emissions. '

 Host: 1. In genetics, the organism, typically
 a bacterium, into which a gene from anoth-
 er organism is transplanted. 2. In medicine,
 an animal infected or parasitized by anoth-
 er organism.

 Household Waste (Domestic Waste): Solid
 waste, composed of garbage and rubbish,
 which normally originated  in a  private
 home or apartment house. Domestic waste
 may contain a significant amount  of toxic
 or hazardous waste.

 Hydraulic Gradient: In general, the direc-
 tion of groundwater flow due to changes
 in the depth of the water table.

 Hydrocarbons  (HQ:    Chemical  com-
 pounds that consist entirely of carbon and

 Hydrogen  Sulfide  (HS): Gas  emitted
 during organic decomposition. Also a by-
 product of oil refining and burning. Smells
 like rotten eggs and, in  heavy concentra-
 tion, can kill or cause illness.

 Hydrogeology: The geology of ground
 water, with particular emphasis  on the
 chemistry and movement of water.

 Hydrology: The  science  dealing with the
 properties,distribution, and circulation of

Hypolimnion: Bottom waters of a thermal-
ly  stratified lake., The hypolimnion of  a
eutrophic lake is  usually  low or lacking in

 Identification Code or EPA I.D. Number
 The unique code assigned to each genera-
 tor, transporter, and treatment, storage, or
 disposal facility by regulating agencies to
 facilitate identification  and tracking of
 chemicals or hazardous waste.

 Ignitable: Capable of burning or causing a

 Immediately  Dangerous to  Life, and
 Health  (IDLH):   The maximum level to
 which a healthy individual can be exposed
 to a chemical for 30  minutes and escape
 without suffering irreversible health effects
 or impairing symptoms. Used as a "level of
 concern." (See: level of concern.)

 Impoundment: A body of water or sludge
 confined by a dam, dike,  floodgate, or
 other barrier.

 Incident Command Post: A facility located
 at a safe distance from an emergency site,
 where the incident commander, key staff,
 and technical  representatives  can make
 decisions and deploy emergency manpow-
 er and equipment.

 Incident' Command  System (ICS):  The
 organizational arrangement wherein one
 person,  normally the Fire  Chief of  the
 impacted district, is in charge of  an inte-
 grated, comprehensive emergency response
 organization and the emergency incident
 site, backed by an Emergency Operations
 Center staff with resources, information,
 and advice.

 Incineration:  A  treatment  technology
 involving destruction of  waste by con-
 trolled burning at high temperatures, e.g.,
 burning  sludge to remove the water and
 reduce the remaining residues  to a safe,
 non-burnable ash that can be disposed of
 safely on land, in  some waters, or in un-
 derground locations.

 Incineration at Sea: Disposal of waste by
 burning at sea on specially-designed incin-
 erator ships.

 Incinerator A furnace for burning waste
 under controlled conditions.

 Incompatible Waste:  A waste unsuitable
 for mixing with another waste or material
 because it may react to form a hazard.

 Indicator In biology, an organism, species,
 or community whose characteristics show
 the presence  of  specific  environmental
 conditions, good or bad.

 Indirect Discharge: Introduction of pollut-
 ants from a non-domestic source into a
 publicly  owned waste-treatment system.
 Indirect dischargers can be commercial or
 industrial facilities whose wastes enter
local sewers.

Indoor Air The  breathing  air inside a
habitable structure or conveyance.

Indoor Air Pollution: Chemical, physical,
or biological contaminants in indoor air.

 Indoor Climate: Temperature, humidity,
 lighting,  and noise levels in a habitable
 structure or conveyance.  Indoor climate
 can affect indoor air pollution.

 Industrial Pollution Prevention: Combi-
 nation of industrial source reduction and
 toxic chemical use substitution

 Industrial Source Reduction: Practices that
 reduce the amount of any hazardous sub-
 stance, pollutant, or contaminant entering
 any waste  stream  or otherwise  released
 into  the environment; Also reduces the
 threat to public health and the  environ-
 ment associated with such releases. Term
 includes equipment or technology modifi-
 cations, substitution of raw materials, and
 improvements in  housekeeping,  mainte-
 nance, training or inventory control.

 Industrial  Waste:  Unwanted materials
 from an industrial operation; may be liq-
 uid, sludge, solid, or hazardous waste.

 Inert Ingredient: Pesticide  components
 such as solvents, carriers, dispersants>and
 surfactants  that  are not  active  against
 target pests. Not all inert ingredients are

 Inertia!  Separator:  A  device  that  uses
 centrifugal force to separate waste parti-
 cles.                       • •

 Infectious Agent: Any organism, such as
 a  virus or bacterium,  that is pathogenic
 and capable of  being communicated by
 invasion and  multiplication in body tis-

 Infectious Waste: Hazardous waste with
 infectious characteristics, including:  con-
 taminated animal waste; human blood and
 blood products; isolation waste, pathologi-
 cal waste; and discarded sharps (needles,
 scalpels or broken medical instruments.)

 Infiltration: 1. The penetration of water
 through the ground surface into sub-sur-
 face soil or the penetration of water from
 the soil into sewer or other pipes through
 defective joints,- connections, or manhole
 walls. 2. The technique  of applying large
 volumes of waste water to land to pene-
 trate the surface and percolate through the
 underlying soil (See: percolation.)

 Infiltration  Rate: The quantity 'of water
 than can enter the soil in a specified time

 Inflow: Entry of extraneous rain water into
 a sewer system from sources other than
 infiltration, such as basement drains, man-
 holes, storm drains, and street washing.

 Influent:  Water,  wastewater, or other
 liquid flowing into a reservoir, basin, or
 treatment plant.                         •

 Information File: In the Superfund pro-
 gram, a file that contains accurate, up-to-d-
ate documents on a Superfund site.  The
file is usually located in  a public building
 (school, library, or city hall) convenient for
local residents.
  Injection Well: A well into which fluids
  are injected for purposes such as waste
  disposal, improving the recovery of crude
  oil, or solution mining.

  Injection Zone:  A geological •formation
  receiving fluids through a well

  Innovative Technologies: New or inven-
  tive methods to treat effectively hazardous
  waste and reduce risks to human health
  and the environment.

  Inoculum: 1. Bacterium placed in compost
  to start biological action. 2. A medium
  containing organisms that is introduced
  into cultures or living organisms.

  Inorganic Chemicals: Chemical substances
  of mineral origin, not of basically carbon

  Insecticide: A pesticide compound specifi-
 cally used to kill or prevent the growth of

 Inspection and Maintenance  (1/M): 1.
 Activities  to assure that vehicles' emis-
 sions-controls work properly. 2. Also ap-
 plies to wastewater treatment plants and
 other anti-pollution facilities and processes.

 Instream Use: Water use taking place
 within a stream channel, e.g., hydro-elec-
 tric power generation, navigation, water
 quality improvement,  fish propagation,

 In-Situ Stripping: Treatment system that
 remove or "strips" volatile organic com-
 pounds  from  contaminated  ground  or
 surface water  by  forcing an airstream
 through the water and causing the com-
 pounds to evaporate.

 Integrated Pest Management (IPM): A
 mixture of chemical and other, non-pestici-
 de, methods to control pests.

 Integrated Waste Management: Using a
 variety of practices to handle municipal
 solid waste; can include source reduction,
 recycling, incineration, and landfilling.

 Interceptor Sewers: Large sewer lines that,
 in a combined system,  control the flow of
 sewage to the treatment plant. In a  storm,
 they allow some of the sewage to flow
 directly into a receiving stream, thus keep-
 ing it from overflowing onto the streets.
 Also used in separate systems to collect the
 flows from main and  trunk sewers and
 carry them to treatment points.

 Interim (Permit) Status: Period during  '
 which  treatment,  storage  and disposal
 facilities coming under RCRA in 1980 are
 temporarily  permitted  to operate  while
 awaiting a  permanent permit.  Permits
 issued under these circumstances, are usu-
 ally called "Part A" or "Part B" permits.

 Interstate Carrier Water Supply: A source
of water for drinking and sanitary use on
planes, buses, trains, and ships operating
in more than one state. These sources are
federally regulated.
  Interstate Commerce Clause: A clause of
  the U.S. Constitution which reserves to the
  federal government the right to regulate
  the conduct of business across state lines.
  Under  this clause, for example, the U.S.
  Supreme Court has ruled that states may
  not inequitably restrict the disposal out-of-
  state wastes in their jurisdictions.

  Interstate Waters: Waters that flow across
  or form part of state or international boun-
  daries, e.g., the Great Lakes, the Mississip-
  pi River, or coastal waters.

  Interstitial Monitoring: The  continuous
  surveillance of the space between the walls
  of an underground storage tank.

  Inventory (TSCA): Inventory of chemicals
  produced pursuant to Section 8 (b) of the
  Toxic Substances  Control Act.

  Inversion: A layer of warm air preventing
  the rise of cooling air and  pollutants
  trapped beneath it. Can cause an air pollu-
  tion episode.

 Ion: An electrically chargeAatom that can
 be drawn from waste watetfluring electro-

 Ion Exchange Treatment: A common wa-
 ter-softening method often  found on  a
 large scale at water purification plants that
 remove  some  organics  and radium by
 adding calcium oxide or calcium hydrox-
 ide to increase the ph to a level where the
 metals will precipitate out.

 lonization Chamber A device that mea-
 sures the intensity of ionizing radiation.

 Ionizing Radiation:  Radiation that can
 strip electrons from atoms, Le., alpha, beta,
 and gamma radiation.

 Irradiated Food:  Food  subject  to brief
 radioactivity, usually gamma rays, to kill
 insects, bacteria, and mold, and to permit
 storage'without refrigeration.

 Irradiation: Exposure to radiation of wave-
 lengths shorter than those of visible light
 (gamma, x-ray, or  ultraviolet), for medical
 purposes, to sterilize milk or other food-
 stuffs, or  to  induce  polymerization of
'monomers or vulcanization of rubber.

 Irrigation: Applying water or wastewater
 to land  areas to  supply  the water  and
 nutrient needs of plants.

 Irrigation Efficiency: The amount of water
 stored in the crop  root zone compared to
 the amount of irrigation water applied.

 Irrigation Return Flow: Surface and sub-
surface water which leaves the field fol-
 lowing application of irrigation water.

Irritant: A substance that can cause irrita-
tion of the skin, eyes, or respiratory sys-
tem. Effects may be acute from a single
high level exposure, or chronic from re-
peated low-level exposures to such com-
pounds as chlorine, nitrogen dioxide, and
nitric acid.

    Itotope: A variation of an element that has
    the same atomic number of protons but a
    different weight because of the number of
    neutrons.  Various isotopes  of  the same
    element may have different radioactive
    behaviors, some are highly unstable..

   Kant: A geologic formation of irregular
   limestone  deposits  with  sinks,  under-
   ground streams, and caverns.
   Kinetic Rate Coefficient: A number that
   describes the rate at which a water constit-
   uent such as a biochemical oxygen demand
   or dissolved oxygen rises or falls.
  Lagoon: 1. A shallow pond where sunlight,
  bacterial action, and oxygen work to purify
  wastewater; also used for storage of waste-
  water or spent nuclear fuel rods. 2. Shal-
  low body of water, often separated from
  the sea by coral reefs or sandbars.

  Land Application: Discharge of wastewa-
  ter onto the ground for treatment or reuse.
  (See: irrigation.)

  Land Ban: Phasing out of land disposal of
  most untreated hazardous wastes, as man-
  dated by the 1984 RCRA amendments.

  Land  Fanning (of waste): A disposal
  process in which hazardous waste deposit-
  ed on or in the sod is degraded naturally
  by microbes.

  Landfill*: 1. Sanitary landfills are disposal
  sites  for  non-hazardous  solid  wastes
  spread in layers, compacted to the smallest
  practical volume, and covered by material
  applied at the end of each operating day.
  2.  Secure chemical landfills are disposal
  sites for  hazardous waste, selected and
  designed to minimize the chance of release
  of hazardous substances into the environ-

 Landscape: The traits, patterns, andstruc-
 ture of a  specific geographic area, includ-
 ing its biological composition, its physical
 environment, and  its anthropogenic  or
 social patterns. An area where interacting
 ecosystems are  grouped  and repeated in
 similar form.

 Landscape Characterization:  Documenta-
 tion of the traits  and patterns of the essen-
 tial elements of the landscape.

 Landscape  Ecology: The study of the
 distribution patterns of communities and
 ecosystems, the  ecological processes that
 affect those patterns, and changes in pat-
 tern and process over time.
    kinds of environmental degradation such
    as forest fragmentation.

    Large Quantity Generator  Person or
    facility generating more than 2200 pounds
    of hazardous waste per month. Such gen-
    erators produce about 90 percent of the
    nation's hazardous waste, and are subject
    to all RCRA requirements.

    Lateral Sewers: Pipes that run under city
    streets and receive the sewage from homes
    and  businesses,  as  opposed to domestic
   feeders and main trunk lines.

   LCStyLethal Concentration: Median level
   concentration, a  standard   measure of
   toxicity. It tells how much of a substance is
   needed to kill half of a group of experi-
   mental organisms in a given-time  (See-
   LD50.)                            l   '

   LD SO/ Lethal Dose: The dose of a toxicant
   that will kill 50 percent of the test organ-
   isms within a designated period. The lower
   the LD 50, the more toxic the compound.

   Leachate: Water that collects contaminants
   as it trickles through wastes, pesticides or
   fertilizers. Leaching may occur in farming
   areas,  feedlots, and landfills,  and may
   result  in hazardous substances entering
   surface water,  ground water, -or soil.

   Leachate Collection System: A system that
  gathers leachate and pumps it to the  sur-
  face for treatment.

  Leaching: The process by which  soluble
  constituents are  dissolved and filtered
  through the soil by  a percolating fluid.
  (See: leacnate.)

  Lead (Pb): A heavy metal that is hazard-
  ous to health if breathed or swallowed. Its
  use in gasoline,  paints, and  plumbing
  compounds has been sharply restricted or
  eliminated by federal laws and regulations.
  (See: heavy metals.)

  Level of Concern (LOC): The concentra-
  tion in air of  an  extremely hazardous
  substance above which there may be seri-
  ous immediate health effects to anyone
  exposed to it for short .periods  Lift In a
 sanitary landfill, a compacted layer of solid
 waste and the top layer of cover material.

 Lifting SUtion: (See: pumping station.)

 Limestone Scrubbing: Use of a limestone
 and  water solution to  remove  gaseous
 stack-pipe sulfur  before it  reaches- the

 Limited Degradation: An environmental
 policy  permitting  some  degradation  of
 natural systems  but terminating at a level
 well beneath an established health stan-
Landscape Indicator A measurement of
the landscape, calculated from mapped or
remotely sensed data, used  to describe
spatial patterns of land use and land cover
Limiting Factor A condition whose ab-
sence or excessive concentration, is incom-
patible  with  the needs or tolerance of a
species or population and which may have
a negative influence  on their ability to
'thrive, survive.

Limnology: The  study  of the physical.
   Linen 1. A relatively impermeable barrier
   designed to keep leachate inside a landfill.
   Liner materials include plastic and dense
   clay. 2. An insert or sleeve for sewer pipes
   to prevent leakage or infiltration.

   Lipid Solubility: The maximum concentra-
   tion of a chemical that will dissolve in fatty
   substances. Lipid soluble substances  are
   insoluble in water. They  will very selec-
   tively disperse through the environment
   via uptake in living tissue.

   Liquefaction: Changing  a  solid  into a

   Liquid Injection Incinerator Commonly
   used system that relies on high pressure to
   prepare  liquid  wastes for incineration
   breaking  them up into tiny droplets to
   allow easier combustion.

   List Shorthand term for EPA list of violat-
   ing facilities or firms debarred from obtain-
   ing government contracts Jsecause they
   violated certain sections of-the Clean Air
  or Clean Water Acts. The list is maintained
  by The Office of Enforcement and Compli-
  ance Monitoring.

  Listed Waste: Wastes listed as hazardous
  under  RCRA but  which have  not  been
  subjected to the Toxic Characteristics List-
  ing Process because  the  dangers  they
  present are considered self-evident.

  Litter The highly visible portion of solid
  waste   carelessly discarded  outside the
  regular garbage and trash collection and
  disposal system.

  Local  Education Agency  (LEA): In the
  asbestos program, an educational agency at
  the local level that exists primarily to
  operate schools or to contract for educa-
  tional  services,  including  primary  and
  secondary public and private schools. A
  single,  unaffiliated school can be consid-
 ered an LEA for AHERA purposes.

 Local Emergency Planning  Committee
 (LEPC): A committee appointed by the
 state emergency response commission, as
 required by SARA Title m, to formulate a
 comprehensive emergency  plan  for its

 Low NO" Burners: One of several combus-
 tion technologies used to reduce emissions
 of Nitrogen Oxides (NO".)

 Low-Level  Radioactive  Waste (LLRW):
 Wastes less hazardous than most of those
 associated with nuclear reactor; generated
 by hospitals,  research laboratories,  and
 certain  industries.  The  Department of
 Energy, Nuclear Regulatory Commission,
 and  EPA share responsibilities for  manag-
 ing  them.  (See:   high-level radioactive

 Lower Explosive Limit (LEL): The concen-
tration of a compound in air  below which
the mixture will not catch on fire.

  Lowest Achievable Emission Rate; Under
  the Clean Air Act, the rate of emissions
  that reflects (a) the most stringent emission
  limitation in the implementation plan of
  any state for such source unless the owner
  or operator demonstrates such limitations
  are not achievable; or (b) the most strin-
  gent emissions limitation achieved in prac-
  tice, whichever is more stringent.  A pro-
  posed new or modified source may not
  emit pollutants in excess of existing new
  source standards.

  Magnetic Separation: Use of magnets to
  separate .ferrous materials from  mixed
  municipal waste stream.

  Mandatory Recycling: Programs which by
  law require consumers to separate trash so
  that some  or all recyclable materials are
  recovered for recycling rather than going
  to landfills.

  Manual Separation: Hand sorting of reycl-
  able or compostabte materials in waste.

  Major Modification: This term is used to
  define modifications of major stationary
  sources of emissions with respect to Pre-
  vention of Significant Deterioration and
  New Source Review under the Clean Air

  Major Stationary Sources: Term used to
  determine the applicability of Prevention
  of Significant Deterioration and new source
  regulations. In a nonattainment area, any
  stationary pollutant source with potential
  to emit more than  100 tons per year is
  considered a major stationary source. In
  PSD areas the cutoff level may be either
•  100 or 250 tons,  depending  upon the

  Majors: Larger publicly owned treatment
 works  (POTWs) with flows equal to at
  least one million gallons per day (mgd) or
  servicing population equivalent to 10,000
  persons;  certain other POTWs having
 significant  water quality impacts.  (See:

 Management Flan: Under the Asbestos
 Hazard Emergency Response Act (AHER-
 A), a document that each Local Education
 Agency is required to prepare, describing
 all activities planned and undertaken by a
 school to comply with AHERA regulations,
 including building inspections to identify
 asbestos-containing  materials,  response
 actions, and operations and maintenance
 programs to minimize the risk of exposure.

 Manifest System: Tracking of hazardous
 waste from "cradle to grave" (generation
 through  disposal)   with accompanying
 documents known as manifests.(See: Cra-
 dle to Grave.) •

 Manual Separation: Hand  separation of
 compostable or recyclable material from
 Manufacturers Formulation: A list of sub-
 stances or component parts as described by
 the maker of a coating, pesticide, or other
 product containing chemicals or other sub-
 stances.            :  '

 Marine Sanitation Device: Any equip-
 ment or process installed on board a vessel
 to receive, retain, treat, or discharge sew-

 Marsh: A type of wetland that does not
 accumulate appreciable peat deposits and
 is dominated by herbaceous vegetation.
 Marshes may be either fresh or saltwater,
 tidal or non-tidal. (See: wetlands.)

 Material Category: In the asbestos pro-
 gram, broad classification of materials into
 thermal surfacing  insulation, surfacing
 material, and miscellaneous material.

 Materials Recovery Facility: A facility that
 processes  residentiaily  collected  mixed
 recyclables into new products available for

 Material Type is classification of suspect
 material by its specific use or application,
 e.g., pipe insulation, fireproofing, and floor
 tile.          .

 Material Safety Data Sheet (MSDS): A
 compilation of information required under
 the OSHA Communication Standard on
 the identity of hazardous chemicals, health,
 and physical hazards, exposure limits, and
 precautions. Section 311 of SARA requires
 facilities to submit MSDSs under  certain

 Materials Recovery Facility (MRF): Facili-
 ty that processes residentiaily collected
 mixed recyclables into new products.

 Maximum Contaminant Level: The maxi-
 mum permissible level of a contaminant in
 water delivered to any user of a  public
 system. MCLs are enforceable standards.

 Maximum  Contaminant  Level  Goal
 (MCLG): Under the Safe Drinking Water
 Act, a non-enforceable concentration of a
 drinking water contaminant, set  at the
 level  at which no known or anticipated
 adverse effects on human health occur and
 which allows an  adequate safety margin.
 The MCLG is usually the starting point for
 determining the regulated Maximum Con-
 taminant Level. (See; Maximum Contami-
 nant Level.)

 Mechanical  Aeration: Use of mechanical
 energy to inject air into water to cause a
 waste stream to absorb oxygen.

 Mechanical Separation: Using mechanical
 means to separate waste into various com-

 Mechanical Turbulence: Random irregu-
 larities of fluid motion in air caused by
 buildings or other non-thermal, processes.

Media:  Specific environments-air, water,
soil-which are the subject of regulatory
concern and activities.
  Medical Surveillance: A periodic compre-
  hensive review of a worker's health status;
  acceptable elements of such surveillance
  program  are listed in the Occupational
  Safety  and Health Administration stan-
  dards for asbestos.

  Medical Waste: Any solid waste generated
  in the diagnosis, treatment, or immuniza-
  tion of human beings or animals, in re-
  search pertaining thereto, or in the produc-
  tion or testing of  biologicals, excluding
  hazardous waste identified or listed under
  40 CFR Part 261 or any household waste as
  defined in 40 CFR Sub-section 261.4 (b)(l)).

  Mercury: A heavy metal that can accumu-
  late in the environment and is highly toxic
  if breathed or swallowed. (See: heavy

  Metabolites: Any substances produced by
  biological  processes, such as those  from

  Methane: A colorless, nonpoisonous, flam-
  mable gas created by anaerobic decomposi-
  tion of organic compound^ *

  Method 18: An EPA  test method which
  uses gas cnromatographic techniques to
 measure the concentration of volatile or-
 ganic compounds in a gas stream.

 Method 24: An EPA reference method to
 determine density, water content and total
 volatile content (water and VOC) of coat-

 Method 25: An EPA reference method to
 determine the VOC concentration in a gas

 Microclimate: The localized climate condi-
 tions with in an urban area or neighbor-

 Microbial Pesticide: A microorganism that
 is used to control a pest, but of minimum
 toxicity to man.

 Million-gallons Per Day (MGD): A mea-
 sure of water flow.

 Minimization: A comprehensive program
 to minimize or eliminate wastes, usually
 applied to wastes at their point of origin.
 (See: waste minimization.)

 Minors:  Publicly owned treatment works
 with flows less than 1 million gallons per
 day. (See: majors.)

 Miscellaneous ACM: Interior asbestos-con-
 taining building material or structural
 components, members or fixtures, such as
 floor and ceiling tiles; does not include
 surfacing materials  or thermal  system

 Miscellaneous materials: Interior building
 materials on structural components, such
 as floor or ceiling tiles.

 Miscible Liquids: Two or more liquids
 that  can be mixed and  will remain mixed
 under normal conditions.

 Missed Detection: The situation that oc-'
curs  when  a test indicates  that a tank is
 "tight" when in fact it is leaking.


Milt Liquid particles measuring 40 to 500
microns, are formed by condensation of
vapor. By companion, fog particles are
smaller than 40 microns.

Mitigation:  Measures taken  to  reduce
adverse impacts on the environment.

Mixed  Funding:  Settlements in  which
potentially responsible parties and EPA
share the cost  of a response action.
Mixed  Liquor: A mixture  of activated
3ludge and water containing organic mat-
ter undergoing activated sludge treatment
in an aeration tank.
Mobile Incinerator Systems: Hazardous
waste incinerators that can be transported
from one site to another.
Mobile Source: Any non-stationary source
of air pollution such as cars, trucks, motor-
cycles, buses, airplanes, locomotives.
Model Plant  A hypothetical plant design
used for developing economic,  environ-
mental,  and energy  impact  analyses  as
support for regulations or regulatory gu-
idelines; first step in exploring the econom-
ic impact of a potential NSPS.
Molten Salt Reactor. A thermal treatment
unit that rapidly heats waste in a heat-
conducting fluid bath of carbonate salt.
 Monitoring Welt 1. A well used to obtain
water quality  samples or measure ground-
water levels. 2. Well drilled at a hazardous
 waste management  facility or Superfund
 site to collect ground-water samples for the
 purpose of physical, chemical, or biological
 analysis to determine the amounts, types,
 and distribution of contaminants in the
 ground water beneath the site.
 Monitoring:  Periodic or  continuous sur-
 veillance or testing to determine the level
 of compliance with statutory requirements
 and/or pollutant levels in various media
 or in humans, plants, and animals.

 Monoclonal   Antibodies:  (Also  called
 MABs and MCAs) 1. Man-made clones of
 a molecule, produced in quantity for medi-
 cal or research purposes. 2. Molecules of
 living organisms that selectively find and
 attach to other molecules to which their
 structure.conforms exactly. This could also
 apply "to equivalent activity by chemical
 Moratorium: During the negotiation pro-
 cess, a period of 60 to  90 days during
 which  EPA  and potentially responsible
 parties may  reach settlement but no  site
 response activities can be conducted.
 Morbidity: Rate of disease incidence.

 Muck Soils: Earth made from decaying
 plant materials.      . •
 Mulch: A layer of  material (wood chips,
 straw, leaves, etc.) placed around plants to
  hold moisture, prevent weed growth, and
  enrich or sterilize the soil.'
Multiple Use: Use of land for more than
one  purpose;  i.e., grazing of livestock,
watershed and wildlife protection, recre-
ation, and timber production. Also applies
to use of bodies of water for recreational
purposes, fishing, and water supply.

Multistage Remote Sensing:  A strategy
for landscape characterization that involves
gathering and analyzing  information at
several  geographic  scales,  ranging from
generalized levels of detail at the national
level through  high levels of detail at the
local scale.

Municipal Discharge: Discharge of efflu-
ent  from waste water  treatment plants
which receive waste water from house-
holds,  commercial  establishments,  and
industries in the coastal drainage basin.
Combined sewer/separate storm overflows
are included in this category.
 National Ambient Air Quality Standards
 (NAAQS): Standards established by EPA
 that apply for outside air throughout the
 country.  (See: criteria  pollutants, state
 implementation plans, emissions trading.)
 National Emissions Standards For Haz-
 ardous Air Pollutants (NESHAPS): Emis-
 sions  standards  set by EPA for an air
 pollutant not covered by NAAQS that may
 cause an increase in fatalities or in serious,
 irreversible, or incapacitating illness. Pri-
 mary  standards  are designed to protect
 human  health, secondary  standards  to
 protect  public welfare  (e.g., building fa-
 cades, visibility, crops,  and domestic ani-
 National  Estuary  Program: A program
 established under  the  dean Water Act
 Amendments of 1987 to develop and im-
 plement conservation  and management
 plans for protecting estuaries and restoring
 and maintaining their chemical; physical,
 and biological integrity, as well as control-
 ling point and nonpoint pollution sources.

 National Municipal Plan: A policy created
 in 1984 by EPA  and the states in 1984 to
 bring all publicly owned treatment works
 (POTWs)  into  compliance with  Clean
 Water Act requirements.

 National  Oil and Hazardous Substances
 Contingency Plan (NOHSCP/NCP): The
 federal regulation  that guides determina-
 tion of the sites to be corrected under both
 the Superfund program and the program
 to  prevent or control  spills into surface
 waters  or elsewhere.

 National Pollutant Discharge Elimination
 System (NPDES): A provision of the Clean
 Water  Act which prohibits discharge of
 pollutants into waters of the United States
 unless a special permit is issued by EPA, a
 state, or, where delegated, a tribal govern-
 ment on, an Indian reservation.
National Priorities List (NPL): EPA's list
of the most serious uncontrolled or aban-
doned hazardous waste sites identified for
possible long-term remedial action under
Superfund. The list is based primarily on
the score a site receives from  the Hazard
Ranking System. EPA is  required to up-
date the NPL at least once a year. A site
must be  on the NPL to  receive  money
from the Trust Fund for remedial action.

National Response Team (NRT): Repre-
sentatives of 13 federal agencies that, as a
team,  coordinate  federal  responses  to
nationally significant incidents of pollu-
tion-an oil spill, a major chemical  release,
or a Superfund response action-and pro-
vide advice and technical assistance to the
responding agency(ies) before and during
a response action.
National  Response  Center The  federal
operations center that receives notifications
of all releases of oil and hazardous sub-
stances into the environmgnt; open  24
hours a day, is operated by the U.S. Coast
Guard, which evaluates all reports and
notifies the appropriate agency.

Navigable Waters: Traditionally,  waters
sufficiently deep and wide for navigation
by all, or specified vessels; such waters in
the United States come under federal juris-
diction and are protected by certain provi-
sions of the Clean Water Act.
Necrosis: Death of plant or animal cells or
tissues. In  plants,  necrosis can ^discolor
stems or leaves or kill a plant entirely.
Negotiations:  (Under Superfund) After
potentially responsible parties are identi-
fied for a site, EPA coordinates with them
to reach a settlement that will result in the
PRP paying for or conducting the cleanup
under EPA supervision. If negotiations fail,
 EPA can order the PRP to  conduct  the
 cleanup or EPA can pay for the  cleanup
 using Superfund monies and then sue to
 recover the costs.
 Nematocide: A chemical agent which  is
 destructive to nematodes.
 Neutralization: Decreasing the acidity or
 alkalinity of a substance by adding alkaline
 or acidic materials, respectively.
 New Source Performance Standards (NS-
 PS): Uniform national EPA  air emission
 and water effluent standards which limit
 the amount of pollution allowed from new
 sources  or from modified existing sourc-
 New  Source: Any stationary source built
 or modified  after publication of final  or
 proposed regulations that prescribe a given
 standard of performance.
 Nitrate: A compound containing nitrogen
 that can exist in the atmosphere or as a
 dissolved gas in water and which  can have
 harmful effects on  humans and  animals.
 Nitrates in water can cause severe illness
 in infants and domestic animals.

Nitric  Oxide (NO):  A gas formed  by
combustion under high temperature and
high pressure in an internal combustion
engine; changes into nitrogen  dioxide in
the ambient air and contributes to photo-
chemical, smog.
Nitrification: The process whereby ammo-
nia in wastewater is oxidized to nitrite and
then to nitrate by bacterial or chemical
Nitrilotriacetic  Acid (NTA): A  compound
now replacing phosphates in detergents:
Nitrite: 1. An intermediate in the process
of nitrification. 2. Nitrous oxide salts used
in food preservation
Nitrogen  Dioxide (NOj):  The result of
nitric oxide combining with oxygen in the
atmosphere; major component of photo-
chemical smog.
Nitrogen Oxide (NOJ: Product of combus-
tion from transportation  and stationary
sources and  a  major contributor to the
formation of ozone in the troposphere and
to acid' deposition.
Nitrogenous Wastes: Animal or vegetable
residues that contain significant amounts
of nitrogen.
Nitrophenols: Synthetic organopesticides
containing carbon, hydrogen, nitrogen, and
No Further  Remedial Action Planned:
Determination made by EPA following a
preliminary assessment that a site does not
pose a significant  risk and so requires no
further activity under CERCLA.
Noise: Product-level or product-volume
changes occurring during a test that  are
not related to a leak but may be mistaken
for one.
Non-Attainment Area: Area that does not
meet one or more of the National Ambient
Air Quality  Standards for the  criteria
pollutants designated in the Clean Air Act.
Non-Binding Allocations of Responsibili-
ty (NBAR): Process for EPA to propose a
way for potentially responsible parties to
allocate costs among themselves.
Non-Community Water System: A public
water system  that is  not a  community
water system, e.g., the water supply at a'
camp  site or national park,
Non-Conventional Pollutant:  Any pollut-
ant not statutoriry listed or which is poorly
 understood by the scientific community.
No Further  Remedial Action Planned:
Determination  made by EPA  following a
preliminary assessment that a site does not
 pose a significant risk  and so  requires no
 further activity under CERCLA.
Non-Point Source: Diffuse pollution sourc-
es (i.e., without a single point of origin or
not introduced  into a receiving  stream
from a specific outlet). The pollutants are
generally  carried off the'land by storm
water. Common non-point  sources are
agriculture, forestry, urban, mining, con-
struction,  dams, channels, land disposal,
saltwater intrusion, and city streets.

Non-Contact Cooling Water Water used'
for cooling  which  does not come into
direct contact with any raw material, prod-
uct, byproduct, or waste.

Non-degradation: An environmental poli-
cy which disallows any lowering of  natu-
rally occurring quality regardless of prees-
tablished health standards.

Non-ionizing Electromagnetic Radiation:
1. Radiation that  does not  change the
structure of atoms but does heat tissue and
may cause harmful biological effects. 2.
Microwaves,  radio waves, and  low-fre-
quency electromagnetic fields from  high-
voltage transmission lines.

Nondischarging Treatment Plant: A treat-
ment plant that does not discharge treated
wastewater into any stream or river. Most
are pond systems that dispose of the total
flow they  receive by means of evaporation
or percolation to groundwater, or facilities
that dispose of their effluent by recycling
or reuse (e.g., spray irrigation or ground-
water discharge).

Nonfriable Asbestos-containing Materials:
Any material containing more than one
percent asbestos (as determined by Polar-
ized Light Microscopy) that, when dry,
cannot be crumbled,  pulverized, or  re-
duced to powder by hand pressure.

Non-Road Emissions: Pollutants  emitted
by combustion engines on farm and con-
struction  equipment,  gasoline-powered
lawn and garden equipment, and power
boats and outboard motors.

Notice of Deficiency: An EPA request to
a facility  owner or operator requesting
additional information before a prelimi-
nary decision on a permit application can
be made.

Notice of Intent to Deny: Notification by
EPA of its preliminary intent to deny a
permit application.

No  Till:  Planting  crops without  prior
seedbed preparation, into an existing cover
crop, sod, or crop residues, and eliminat-_
ing subsequent tillage operations.

Nuclear Reactors and Support Facilities:
Uranium mills, commercial power reactors,
fuel  reprocessing plants, and uranium
enrichment facilities.

Nuclear Winter Prediction by some  scien-
tists that  smoke and  debris rising from
massive fires of a nuclear war could block
sunlight for weeks or months, cooling the
earth's surface and   producing  climate
changes that could, for example, negatively
effect world agricultural and weather pat-
Nutrient:  Any  substance  assimilated  by
living things that promotes  growth. The
term is generally applied to nitrogen and
phosphorus  in  wastewater, but  is also
applied  to other essential and trace ele-
Ocean Discharge Waiver A variance from
Clean Water Act  requirements  for  dis-
charges into marine waters.

Off-Site Facility: A hazardous waste treat-
ment, storage or disposed area that is locat-
ed away from the generating site.

Oil Fingerprinting: A method that identi-
fies sources  of oil and allows spills to be
traced to their source.

Oil Spill: An accidental or intentional dis-
charge  of oil which reaches  bodies of
water. Can be  controlled  by chemical
dispersion, combustion, mechanical con-
tainment, and/or adsorption. !jgills from
tanks and pipelines can also occur away
from water bodies, contaminating the soil,
getting into sewer systems and threatening
underground water sources.

Oligotrophic Lakes: Deep clear lakes with
few nutrients, little organic matter and a
high dissolved-oxygen level.

On-Scene Coordinator (OSC): The predes-
ignated EPA, Coast Guard, or Department
of Defense official who coordinates and
directs Superfund removal actions or Clean
Water Act oil-or hazardous-spill  response

On-Site Facility: A hazardous waste treat-
ment, storage or disposal area that is locat-
ed on the generating site.

Onboard  Controls: Devices  placed on
vehicles to capture gasoline vapor during
refueling and route it to the engines when
the vehicle is starting so that it  can be effi-
ciently burned.

Opacity: The amount of light obscured by
particulate pollution in the air; clear win-
dow glass has zero opacity, a brick wall is
100 percent opaque. Opacity is an  indicator
of changes in performance of  particulate
control systems.

Open Burning:.Uncontrolled  fires in an
open dump.

Open Dump: An uncovered site used for
disposal of waste  without environmental
controls. (See: dump.)

Operable Unit: Term for each of a number
of separate activities undertaken as part of
a Superfund site cleanup. A typical opera-
ble unit would be removal of  drums and
tanks from the surface of a site.

Operating Condition*: Conditions speci-
fied in a RCRA peon* that dictate how an
incinerator mu«t operate as it bums differ-
ent waste type*. A trial bum is  used  to
identify operating condition* needed  to
meet specified performance standards.
Operation And Maintenance; 1. Activities
conducted after a Superfund site action is
completed  to ensure that the action is
effective. 2. Actions taken after construc-
tion to assure that facilities constructed to
treat waste water will be properly operated
and maintained to achieve normative effi-
ciency levels and prescribed effluent limi-
tations  in an  optimum manner. 3. On-
going asbestos management plan in a
school or other publk building, including
regular inspections,  various methods  of
maintaining asbestos in place, and removal
when necessary.
Oral  Tosdcity:  Ability of a pesticide to
cause injury when ingested.
Organic: 1. Referring to or derived from
living organisms. 2. In chemistry, any com-
pound containing carbon.
Organic Chemicals/Compounds: Animal
or plant-produced substances containing
mainly carbon, hydrogen, nitrogen, and
Organic Matter Carbonaceous waste con-
tained in plant  or animal matter and origi-
nating from domestic or industrial sources.
Organophosphates: Pesticides that contain
phosphorus; short-lived, but some can be
 toxic when first applied.
 Organotina: Chemical compounds used in
 anti-foulant paints to protect the hulls of
 boats arid ships, buoys, and pilings from
 marine organisms such as barnacles.
 Original  AHERA  Inspection/Original
 Inspection/Inspection: Examination   of
 school buildings arranged by Local Educa-
 tion Agencies to identify asbestos-contain-
 ing-materials, evaluate their condition, take
 samples of materials suspected to contain
 asbestos; performed by EPA-accredited
 Original Generation Point: Where regulat-
 ed medical or other material first becomes
 Outfall: The place where effluent is  dis-
 charged into receiving waters.
 Overburden: Rock and soil cleared away
 before mining.
 Overfire Air: Air forced into the top of an
 incinerator or  boiler to fan the flames.
 Overland Flow: A  land application tech-
 nique that cleanses waste water by allow-
 ing it to flow over a sloped surface. As the
 water flows over the surface, contaminants
 are absorbed and the water is collected at
 the bottom of the slope for reuse.
  Oversized  Regulated  Medical  Waste:
  Medical waste that is too large for plastic
  bags or standard containers.
 Overturn: One complete cycle of top to
 bottom  mixing of  previously stratified
 water masses.  This phenomenon may
 occur in spring or fall, or after storms, and
 results in uniformity of chemical and phys-
. ical properties of water at all depths.

 Oxidanfc A substance containing oxygen
 that reacts chemically in air to produce a
 new substance; the primary ingredient of
 photochemical smog.

 Oxidation: The addition of oxygen that
 breaks down organic waste or chemicals
 such as cyanides, phenols, and  organic
 sulfur compounds in sewage by bacterial
 and chemical means.
 Oxidation Pond: A man-made body of
 water in which waste is  consumed by
 bacteria, used most frequently with other
 waste-treatment processes;  a  sewage la-
 Oxygenated  Fuels: Gasoline  which has
 been blended with alcohols or ethers that
 contain oxygen in order to reduce carbon
 monoxide and other emissions.

 Oxygenated  Solvent: An organic solvent
 containing oxygen as part of the molecular
 structure. Alcohols and ketones are oxy-
 genated compounds often  used as paint
 Ozone  (O3):  Found in two layers of the
 atmosphere,  the stratosphere and  the tro-
 posphere. In the stratosphere (the atmo-
 spheric layer 7 to 10 miles or  more above
 the earth's surface) ozone is a natural form
 of oxygen that provides a protective layer
 shielding the earth from ultraviolet radiati-
 on.In the troposphere (the layer extending
 up 7 to 10 miles from the earth's surface),
 ozone is  a  chemical oxidant and major
 component of photochemical smog. It can
  seriously impair  the respiratory system
  and is one of the most widespread of all
  the criteria pollutants for which the dean
  Air Act required EPA to  set standards.
  Ozone in the troposphere is produced
  through complex chemical  reactions of
  nitrogen  oxides, which are  among the
  primary pollutants emitted by combustion
  sources; hydrocarbons, released into the
  atmosphere through the combustion, han-
  dling and processing of petroleum prod-
  ucts; and sunlight.
  Ozonaton A device that adds ozone to
  Ozone Depletion: Destruction of the st-
  ratospheric ozone layer which shields the
  earth from ultraviolet radiation harmful to
  life. This destruction of ozone is caused by
  the breakdown of certain chlorine and/or-
  bromine containing compounds (chloroflu-
  orocarbons or halons), which break down
  when they reach the stratosphere and then
  catalytically destroy ozone molecules.
Ozone Hole:Thinning break in the stra-
tospheric  ozone  layer; Designation of
amount of such depletion as a "ozone hole"
is made when detected amount of deple-
tion exceeds fifty percent, seasonal ozone
holes have been observed over both the
Antarctic region and the Arctic region and
part of Canada and the extreme northeast-
ern United States.
Packaging: The assembly of one or more
containers  and  any  other  components
necessary to assure minimum compliance
with a program's storage and shipment
packaging requirements. Also, the contain-
ers, etc, involved.
Packed Bed Scrubber An air pollution
control- device in which emissions pass
through alkaline water to neutralize hydro-
gen chloride gas.       „ ,
Packed Tower A pollution control device
that forces dirty air through  a tower
packed with crushed rock or wood chips
while liquid is sprayed over the packing
material. The pollutants in the air stream
either dissolve or chemically react with the
Pandemic: A Widespread throughout an
area, nation or the world.
Parameter A variable, measurable proper-
ty whose  value is a  determinant of the
characteristics of a system; e.g., tempera-
ture, pressure, and density are parameters
of the atmosphere.
Paraquat: A standard herbicide used to kill
various types of crops, including

Part A Permit, Part B Permit: (See: Interim
Permit Status.)
Particulate Loading: The mass of particula-
 tes per unit volume of air  or water.

 Participation Rate:  Portion of population
 participating in a recycling program.

 Particulates: Fine liquid or solid particles
 such as dust, smoke, mist, fumes, or smog,
 found in air or emissions.

 Partition  Coefficient:  Measure  of the
 sorption phenomenon, whereby a pesticide
 is  divided between  the  soil  and watei
 phase; also referred to as adsorption parti-
 tion coefficient.
 Parts Per  Billion (ppb)|/Parts Per Millior
 (ppm): Units commonly  used to express
 contamination ratios, as in establishing th«
 maximum permissible amount of a  con
 taminant in water, land, or air.

     Pathogens: Microorganisms that can cause
     disease in other organisms or in humans
     animals and plants (e.g., bacteria, viruses
     or parasites)  found in sewage, in  runoff
     from farms or rural areas populated with
     domestic and wild animals, and in water
     used for swimming. Fish and shellfish con-
    taminated by pathogens, or the contam-
    inated  water  itself, can cause serious ill-

    Peak Electricity Demand: The maximum
    electricity used to meet the cooling load of
    a building or buildings in a given area.

    Peak Levels: Levels of airborne pollutant
    contaminants much higher than average or
    occurring for short periods of time in re-
    sponse to sudden releases.

    Percolation: The movement of water do-
   wnward and radially through sub-surface
   sou layers, usually continuing downward
   to ground water; can also involve upward
   movement of water.

   Performance Data (for incinerators): Infor-
   mation collected, during a trial burn, on
   concentrations of designated organic com-
   pounds and pollutants found in incinerator
   emissions. Data analysis must show  that
   the incinerator meets performance stan- -
   dards under operating conditions specified
   m the RCRA permit. (See: trial burn;  per-
   formance standards.)            "

   Performance Standards: (1) Regulatory
   requirements limiting the concentrations of
   designated organic compounds, paniculate
  matter, and hydrogen chloride in emissions
  from incinerators. (2) Operating standards
  established by EPA for various permitted
  pollution control systems, asbestos inspec-
  tions, and various program operations and
  maintenance requirements.

  Permeability: The rate at which liquids
  pass through soil or other materialTin a
  specified direction.
 Permit: An authorization, license, or equiv-
 alent control document issued by EPA or
 an approved state agency to implement the
 requirements of an environmental regula-
 tion; e.g., a permit to operate a wastewater
 treatment plant or to operate a facility that
 may generate harmful emissions.

 Persistence: Refers to the length of time a
 compound stays in the environment,  once
 introduced. A compound may persist for
 less than a second or indefinitely.

 Persistent Pesticides: Pesticides that do
 not break down chemically or break down
 very slowly and remain in the  environ-
 ment after a growing season.

 Personal Air Samples: Air samples taken
 with a pump is directly attached to the
 worker with the collecting filter and  cas-
 sette placed in the worker's breathing zone
 (required under OSHA asbestos standards
and EPA worker protection rule).

FeskAn "f6**; rodent' nematode, fungus.
    Pesticide: Substances or mixture there of
    intended for preventing, destroying, repel-
    ling, or mitigating  any pest.  Also, any
    substance or mixture intended for use as a
    plant regulator, defoliant, or desiccant.

    Phenols: Organic  compounds  that are
    byproducts of petroleum refining, tanning,
    and textile, dye, and resin manufacturing
    Low concentrations cause taste and odor
    problems in water; higher concentrations
    can kill aquatic life and humans.

    Phosphates: Certain chemical compounds
    containing phosphorus.

    Phosphogypsum Piles (stacks): Principal
    byproduct  generated in production  of
   phosphoric acid from  phosphate rock
   These piles may generate radioactive radon

   Phosphorous Plants:  Facilities using elec-
   tric furnaces to produce elemental phos-
   phorous for commercial use, such as high
   grade phosphoric acid, phosphate-based
   detergent, and organic chemicals use.

   Phosphorus: An essential chemical food
   element that can contribute to the eutro-
   phication of lakes and other water bodies
   Increased phosphorus levels result from
   discharge of phosphorus-containing mate-
  nals into surface waters.

  Photochemical  Oxidants: Air  pollutants
  formed by the action of sunlight on oxides
  of nitrogen and hydrocarbons,

  Photochemical Smog: Air pollution caused
  by chemical reactions of various  pollutants
  emitted from different sources.
     Plasma-arc Reactor An incinerator that
     operates at extremely high temperatures;
     treats highly toxic wastes that do not burn

     Plasmid:  A circular piece of DNA  that
     exists apart from  the  chromosome  and
     replicates  independently of it. Bacterial
     plasrruds carry information that renders
     the bacteria resistant to antibiotics. Plasm-
     ids are of ten used in genetic engineering to
    carry desired genes into organisms.

    Plastics: Non-metallic chemoreactive com-
    pounds molded into rigid or pliable con-
    struction materials,  fabrics, etc.

    Plate Tower Scrubber An air pollution
    control device  that neutralizes hydrogen
    chloride  gas by bubbling alkaline water
    through holes in a series of nujtjl plates.

    Plugging: Act or process of stopping the
    flow of water, oil, or gas into or out of a
    formation-through a borehole or well pene-
    trating that formation.

   Plume: 1. A visible or  measurable dis-
   charge of a  contaminant  from a given
   point of origin.  Can  be visible or thermal
   in water, or visible in the air as, for exam-
   ple, a plume of smoke. 2 The area of radia-
   tion leaking from a  damaged reactor. 3
   Area downwind within which a release
   could be dangerous  for those exposed  to
   leaking fumes.                ^^

   Plutonium: A radioactive metallic element
   chemically similar to  uranium.

   PM-lft A new standard for measuring the
  amount of solid or liquid matter suspend-
  ed in the atmosphere, ie. the amount of
  paniculate matter over 10 micrometers in
 Photosynthesis:  The  manufacture  by
 plants of carbohydrates and oxygen from
 carbon dioxide mediated by chlorophyll in
 the presence if sunlight.

 Physical and Chemical Treatment: Pro-
 cesses generally used in large-scale waste-
 water treatment facilities. Physical process-
 es may include air-stripping or filtration.
 Chemical treatment includes coagulation,
 chlonnation, or ozonation. The term can
 also refer to treatment of toxic materials in
 surface and ground waters, oil spills, and
 some methods of dealing with hazardous
 materials on or in the ground.

 Phytoplankton: That portion of the plank-
 ton community comprised of tiny plants
 e.g., algae, diatoms.

 Phytotoxic: Harmful to plants.

 Picocuries  Per Liter  pC^L): A  unit of
 measure for levels of radon gas.

Pilot Tests: Testing a cleanup technology
under actual site. conditions to identify
 parucuiate matter over 10 micrometers in
 diameter; smaller PM-10 particles penetrate
 to the deeper portions of the lung, affect-
 ing sensitive population groups such as
 children and individuals with respiratory
 ailments.                      *  ,   y

 Point  Source:  A  stationary location or
 fixed  facility from whkh pollutants are
 discharged; any single identifiable source
of pollution, e.g., a pipe, ditch, ship, ore
pit, factory smokestack.
   	— --.— ...„.~....-llt,j, r-iTnu^ni;orl
 plants; background air pollutant.

 Pollutant: Generally, any substance intro-
 duced into the environment that adversely
 affects the usefulness of a resource.

 Pollution Prevention: The active process
 of identifying areas, processes, and activi-
 ties which create excessive waste byprod-
 ucts for the purpose of substitution,  alter-
 ation,  or  elimination of the  process to
 prevent waste generation.

 Pollutant Standard Index (PSI): Measure
of adverse health effects, of air pollution
levels in major cities.   .

 Foliation: Generally, the presence of mat-
 ter or energy whoie nature, location, or
 quantity produce* undented environmen-
 tal effects. Under the dean Water Act, for
 example, the term i> defined as the man-
 made or man-induced  alteration of the
 physical, biological; chemical, and radio-
 logical integrity of water.

 Polonium: A radioactive  element that
 occurs in pitchblende and other uranium-
 containing ores.
 Polyelectrolytes: Synthetic chemicals that
 help solids to clump during sewage treat-
 Polymer: Basic molecular  ingredients in
 Polyvinyl Chloride (PVC): A tough, envi-
 ronmentally  indestructible  plastic  that
 releases  hydrochloric acid when burned.
 Population:  A group  of interbreeding
 organisms occupying a  particular space;
 the number of humans or  other living
 creatures in a designated area.
 Post-Closure: The time period following
 the shutdown of a waste management or
 manufacturing  facility;  for monitoring
 purposes, often considered to be 30 years.
 Post-Consumer Recycling: Reuse of mate-
 rials generated from residential and con-
 sumer waste, e.g. converting wastepaper
 from offices into corrugated boxes or new-
 Potable Water Water that is safe for drin-
 king and cooking.
 Potentially Responsible Party (PRP): Any
 individual or company-including owners,
 operators, transporters or genera tors-poten-
 tially responsible for, or contributing to a
 spill or other contamination at a Superfund
 site. Whenever possible, through adminis-
 trative and legal  actions, GPA requires
 PRPs to  clean up hazardous sites they
 have contaminated.
 Precipitate: A solid that separates from a

 Precipitation: Removal of hazardous solids  .
 from liquid waste to permit safe disposal;,
 removal  of particles from airborne ^mis-

 Precipitaton Pollution control device that
 collects particles from an air stream.
 Precursor In photochemistry, a compound
 antecedent to a volatile organic compound
 (VOQ. Precursors react in sunlight to form
 ozone or other photochemical oxidants.
 Preliminary Assessment: The process of
collecting and reviewing available informa-
 tion about a known or suspected waste site
or release.
Pressure  Sewers: A  system of pipes  in
which water, wastewater, or other liquid is
pumped to a higher elevation.
  Pretreatmenfc Processes used to reduce,
  eliminate, or alter the nature of wastewater
  pollutants  from  non-domestic  sources
  before they are discharged into publicly
  owned treatment works (POTWs).

  Prevalent Level Samples: Air samples
  taken  under  normal  conditions  (also
  known as ambient background samples).

  Prevalent Levels: Levels of airborne con-
  taminant occurring under normal condi-

  Prevention of Significant Deterioration
  (PSD): EPA program in which state and-
  /or federal permits are required in order
  to restrict emissions from new or modified
  sources in places where air quality already
  meets or exceeds primary and secondary
  ambient air quality standards.

  Primary  Drinking  Water Regulation:
  Applies to public water systems and speci-
  fies a contaminant level, which, in the
  judgment of the EPA Administrator, will
  not adversely  affect human health.

  Primary Waste Treatment: First steps-in
  wastewater treatment; screens and  sedi-
  mentation tanks are used to remove most
  materials that float or will settle. Primary
  treatment removes  about 30 percent of
  carbonaceous biochemical oxygen demand
  from domestic sewage.

  Principal Organic Hazardous Constituents
  (POHCs): Hazardous compounds moni-
  tored during an  incinerator's trial burn,
  selected for high concentration in the waste
  feed and difficulty of combustion.

  Probability of Detection : The likelihood,
  expressed as a percentage, that a test meth-
  od will correctly identify a leaking tank.

  Process Verification: Verifying that pro-
 cess raw materials, water usage, waste
 treatment processes, production rate and
 other facts relative to quantity and quality
 of pollutants contained in discharges are
 substantially described in the permit appli-
 cation and the issued permit.

 Process Wastewater Any water that comes
 into contact with any raw material, prod- .
 uct, byproduct, or waste.

 Process Weight: Total weight of all mate-
 rials, including fuel, used in a manufactur-
 ing process; used to calculate the allowable
 particulate emission rate.

 Product Level: The level of a product in a.
 storage tank.

 Products  of  Incomplete  Combustion
 (PICs): Organic compounds formed by
 combustion.  Usually  generated in small
 amounts  and sometimes toxic, PICs are
 heat-altered versions of the original materi-
 al fed into the incinerator (e.g., charcoal is
 a P.C. from burning wood).

 Propellant: Liquid in a self-pressurized
 pesticide product  that expels the active
 ingredient from its container.

, Proposed Plan: A plan for a site cleanup
 that is available to the public for comment.
  Proteins: Complex  nitrogenous  organic
  compounds  of  high  molecular  weight
  made of amino acids; essential for growth
  and repair of animal tissue. Many, but not
  all, proteins are enzymes.

  Protocol: A series of formal steps for con-
  ducting a test.

  Protoplast: A membrane-bound cell from
  which the outer wall has been partially or
  completely removed. The term often is ap-
  plied to plant cells.

  Protozoa: One-celled animals  that  are
  larger and more complex than bacteria.
  May cause disease.

  Public Comment Period: The time allowed
  for the  public to express  its  views and
 concerns regarding an action by EPA (e.g.,
 a Federal Register Notice of proposed rule-
 making, a public notice of  a draft permit,
 or a Notice of Intent to Deny).

 Public Hearing: A formal meeting wherein
 EPA officials hear the public's views and
 concerns about an EPA actianwr proposal.
 EPA is  required to consider  such com-
 ments when evaluating its  actions. Public
 hearings must be held upon request during
 the public comment period.

 Public  Notice:  1.  Notification  by EPA
 informing the public of Agency actions
 such as  the issuance of a draft permit or
 scheduling of a hearing. EPA is required to
 ensure  proper public notice,  including
 publication in newspapers and broadcast
 over radio stations. 2. In the safe drinking
 water program, water suppliers are  re-
 quired to publish and broadcast notices
 when pollution problems are discovered.

 Public Water System:   A system that
 provides piped water for human consump-
 tion to at least 15 service connections or
 regularly serves 25 individuals.

 Publicly  Owned Treatment Works:  A
 waste-treatment works owned by a state,
 unit of local government, or Indian tribe,
 usually designed to treat domestic waste-

 Pumping Station:   Pumping devices in-
 stalled in sewer or water systems or other
 liquid-carrying pipelines to  move the liq-
 uids to a higher level.

 Putrescible: Able to rot quickly enough to
 cause odors and attract flies.

 Pyrolysis: Decomposition of a chemical by
 extreme heat.
Quality Assurance/Quality Control:   A
system of procedures, checks, audits, and
corrective actions to ensure that all EPA
research design and performance, environ-
mental monitoring and  sampling,   and
other technical and reporting activities are
of the highest achievable quality.

   Quench Tank: A water-filled tank used to
   cool incinerator residues or hot materials
   during industrial processes.
   Radiation Standards: Regulations that set
   maximum exposure limits for protection of
   the public from radioactive materials.

   Radio Frequency Radiation: (See Non-
   ionizing Radiation.)

   Radioactive Substances: Substances that
   emit ionizing radiation.

   Radioisotopes: Chemical  variants of an
   element with potentially oncogenic, terato-
   genic, and mutagenic effects on the human

   Radionuclide: Radioactive particle, man-
   made or natural, with a distinct atomic
  weight number. Can have a long life as
  soil or water pollutants.

  Radius of Vulnerability Zone: The maxi-
  mum distance from the point of release of
  a hazardous substance in  which the air-
  borne concentration could reach the level
  of concern under specified weather condi-

  Radon Decay Products: A term used to
  refer collectively to the immediate prod-
  ucts of the radon decay chain. These in-
  clude Po-218, Pb-214, Bi-214, and Po-214,
  which have an average combined half-life
  of about 30 minutes.

  Radon:  A colorless naturally occurring,
  radioactive, inert gas formed by radioac-
  tive decay of radium atoms in soil or

  Rasp: A machine that grinds waste into a
  manageable material and helps prevent

  Raw Sewage: Untreated wastewater and
  its contents.

•  Raw Water  Intake water  prior  to any
  treatment or use.

 Reasonably Available Control Measures
 (RACM): A broadly defined term referring
 to technological  and other measures for
 pollution control.

 Reasonably Available Control Technolo-
 gy (RACT): Control technology that is both
 reasonably available, and both, technologi-
 cally and economically feasible.  Usually
 applied to existing sources in nonattain-
 ment areas; in most cases is less stringent
 than new source, performance standards.
 Receiving Waters: A river, lake,  ocean,
 stream or other watercourse into which
 wastewater or treated effluent  is  dis-

 Recharge: The process by which water is
 added to a zone of saturation, usually by
percolation from the soil surface, e.g., the
recharge of an aquifer.
   Recharge  Area: A  land area in which
   water reaches the zone of saturation from
   surface infiltration, e.g.,  where rainwater
   soaks through the earth to reach an aqui-

   Recombinant Bacteria: A microorganism
   whose genetic makeup has been altered by
   deliberate  introduction  of  new  genetic
   elements. The offspring  of  these altered
   bacteria  also contain  these new  genetic
   elements, i.e. they "breed true."

   Recombinant DNA: The new DNA that is
   formed by combining pieces of DNA from
   different organisms or cells.

   Recommended Maximum Contaminant
   Level  (RMCL): The maximum level of a
   contaminant in drinking water at which no
   known or anticipated  adverse affect  on
   human health would occur, and that  in-
   cludes an adequate margin of safety. Rec-
   ommended  levels  are  nonenforceable
  health goals. (See: maximum contaminant

  Reconstructed Source:  Facility in which
  components are replaced to such an extent
  that the fixed capital cost of the new com-
  ponents exceed 50 percent of the capital •
  cost of constructing a comparable brand-
  new facility. New-source  performance
  standards may  be  applied  to sources
  reconstructed after the proposal of the
  standard  if it is technologically and eco-
  nomically feasible to meet the standard.

  Record of Decision (ROD): A public docu-
  ment that explains which cleanup alterna-
  tive^) will be used at National Priorities
  List sites  where,  under CERCLA, Trust
  Funds pay for the cleanup.

  Recovery Rate: Percentage of usable recy-
  cled materials that have  been removed
  from the total amount of municipal  solid
  waste generated in a specific area or by a
  specific business.

 Reclamation: (In recycling) Restoration of
 materials found in the waste stream to a
 beneficial use which may be for purposes
 other than the original use.

 Recycle/Reuse: Minimizing waste genera-
 tion by recovering and reprocessing usable
 products that  might otherwise become
 waste (.ie. recycling of  aluminum  cans,
 paper, and bottles, etc.).

 Red Bag Waste: (See: infectious waste.)

 Red  Border   An  EPA document under-
 going review before being  submitted for
 final management decision-making.

 Red  Tide: A proliferation of  a marine
 plankton toxic and often fatal to fish, per-
 haps  stimulated by the addition of nutri-
 ents.  A tide can be red, green, or brown,
 depending  on the coloration of the plank-

 Reentry  Interval: The period of time im-
mediately following the application  of a
pesticide during which unprotected work-
ers should not enter a field.

   Reference Dose (RfD): The concentration
   of a chemical known to cause health prob-
   lems; also be referred to as the ADI, or
   acceptable daily intake.

   Reformulated Gasoline: Gasoline with a
   different composition  from conventional
   gasoline (e.g., lower aromatics content) that
   cuts air pollutants.

   Refuse Reclamation: Conversion of solid
   waste into useful products, e.g., compost-
   ing organic wastes to make soil condition-
   ers or separating aluminum  and  other
   metals for recycling.

   Refuse: (See: solid waste.)

   Regeneration: Manipulation of cells to
   cause them to develop into whole plants.

   Regional Response Team (RRT): Repre-
   sentatives of federal, local, and state agen-
   cies who may assist in coordination of
   activities at the  request of the On-Scene
   Coordinator before and during a signifi-
  cant pollution incident such as an 
Release: Any spilling, leaking, pumping,
pouring, emitting, emptying, discharging,
injecting, escaping, leaching, dumping, or
disposing into the environment of a haz-
ardous  or  toxk chemical  or extremely
hazardous substance.

Remedial Action (RA): The actual con-
struction or implementation phase of a
Superfund site cleanup that follows reme-
dial design.
Remedial Design: A phase of remedial
action that follows the remedial investiga-
tion/feasibility study and includes devel-
opment of  engineering  drawings and
specifications for a site cleanup.

Remedial  Investigation:   An  in-depth
study designed to gather data needed to
determine the nature and extent of con-
tamination at a Superfund  site; establish
site cleanup criteria;  identify preliminary
alternatives for remedial action; and sup-
port technical and cost analyses of alterna-
tives. The remedial investigation is usually
done with the feasibility study. Together
they are usually referred to as the "RI/FS".
Remedial Project Manager (RPM): The
EPA or state official responsible for over-
seeing on-site remedial action.

Remedial Response: Long-term action that
stops or substantially reduces a release or
threat of a release of hazardous substances
that is serious but not an immediate threat
to public health.
Remediation: 1. Cleanup or other methods
used to remove or contain a toxic spill or
hazardous materials from a Superfund site;
2. for  the Asbestos  Hazard Emergency
Response program, abatement  methods
including  evaluation, repair, enclosure,
encapsulation, or removal of greater than
3 linear feet or  square feet of asbestos-
containing materials from a building.
Remote Sensing: The collection and inter-
pretation of information about an  object
without physical contact with the object;
c.g., satellite  imaging and  aerial photo-.
Removal Action: Short-term immediate ac-
tions taken to address releases of hazard-
ous substances  that require expedited
response. (See: cleanup.)

Reportable Quantity (RQ): Quantity of a
hazardous substance that triggers reports
under CERCLA. If a substance exceeds its
RQ, the release  must be reported to the
National Response Center, the SERC, and
community emergency coordinators for
areas likely to be affected.

Repowering: Replacement of an existing
coal-fired boiler with one or more clean
coal technologies in order to achieve signif-
icantly greater emission reduction relative
to the performance of technology in wide-
spread  use at the time the Clean Air Act
amendments of 1990 were  enacted. (See:
dean coal technology.)
Reregistration: The reevaluation and reli-
censing of existing pesticides originally
registered prior to current scientific and
regulatory  standards.   EPA  reregisters
pesticides through its Registration Stan-
dards Program.

Reserve Capacity: Extra treatment capacity
built into solid waste   and wastewater
treatment plants and interceptor sewers to
accommodate flow increases due to future
population growth.

Reservoir: Any natural or artificial holding
area used to  store, regulate, or  control

Residual: Amount of a pollutant remaining
in the environment after a natural or tech-
nological process has taken place, e.g., the,
sludge remaining after initial wastewater
treatment, or participates remaining in air
after it passes through a scrubbing or other

Residual Risk: The extent of health risk
from air pollutants remaining after applica-
tion of the Maximum Achievable Control
Technology (MACT).

Resistance: For 'plants and animals,  the
ability  to withstand poor environmental
conditions or attacks by chemicals or dis-
ease. May be inborn or acquired.

Resource Recovery: The process of obtain-
ing matter or  energy from materials for-
merly discarded.

Response Action: 1. Generic term  for
actions  taken  in  response  to actual  or
potential health-threatening environmental
events such as spills, sudden releases, and
asbestos  abatement/management  prob-
lems;  2. A  CERCLA-authorized action
involving either  a short-term removal
action or a long-term removal response.
This may include but is not limited to:
removing hazardous materials from a site
to  an  EPA-approved hazardous  waste
facility for treatment, containment or treat-
ing the wiste  on-site, identifying and re-
moving the sources of ground-water con-
tamination and halting further migration of
contaminants;  3.  Any  of the, following
actions taken  in  school buildings  in re-
sponse to AHERA to reduce the risk of
exposure to asbestos: removal, encapsula-
tion, enclosure, repair, and operations and
maintenance. (See: cleanup) .

Responsiveness Summary: A summary of
oral and/or  written public comments
received by EPA during a comment period
on  key  EPA documents, and  EPA's re-
sponse to those comments.

Restoration: Measures  taken to return a
site to pre-violation conditions.

Restricted Use: A pesticide may be classi-
fied (under FIFRA regulations) for restrict-
ed  use if the it requires special handling
because of its toxicity, and, if so, it may be
applied only by trained, certified applica-
tors or those under their direct supervi-
Restriction Enzymes: Enzymes that recog-
nize specific regions of a long DNA mole-
cule and cut it at those points.

Reuse: Using a product or component of
municipal solid waste in its original form
more than once, e.g., refilling a glass bottle
that has been returned or using a coffee
can to hold nuts and bolts.
Reverse Osmosis: A treatment  process
used in water systems by adding pressure
to force water through a  semi-permeable
membrane. Reverse osmosis removes most
drinking water contaminants. Also used in
wastewater treatment. Large-scale reverse
osmosis plants are being developed.

Ribonucleic Acid (RNA): A molecule that
carries the genetic message from DNA to
a cellular protein-producing mechanisms.

Ringlemann Chart: A series of shaded
illustrations used to measure the opacity of
air pollution emissions, ranging from light
grey through black; used to set and enforce
emissions standards.          ff
Riparian Habitat: Areas adjacentlo rivers
and streams with a high density, diversity,
and productivity of  plant  and animal
species relative to nearby  uplands.

Riparian Rights:  Entitlement of a land
owner to certain uses of water on or bor-
dering his property, including the right to
prevent diversion or misuse  of upstream
waters. Generally a matter of state law.

Risk: A measure of the probability  that
damage to life, health, property, and/or
the environment will occur as a result of a
given hazard.
Risk Assessment: Qualitative and quanti-
tative evaluation of the risk posed to hu-
man health and/or the environment by the
actual or potential presence and/or use of
specific  pollutants.

Risk Communication: The exchange of
information about health or environmental
risks among risk assessors and managers,
the general public, news  media, interest
groups,  etc.
Risk Management: The process of evaluat-
ing and selecting alternative regulatory
and non-regulatory responses to risk. The
selection process necessarily requires the
consideration of legal, economic, and be-
havioral factors.
River Basin: The land area drained by a
river and its tributaries.
Rodenticide: A chemical or agent used to
destroy  rats or other rodent pests, or to
prevent them from damaging food, crops,
Rotary  Kiln Incinerator  An incinerator
with a rotating combustion chamber that
keeps waste moving, thereby allowing it to
vaporize for easier burning.
Rough  Fish: Fish not prized for eating,
such as gar  and suckers.  Most are more
tolerant of changing environmental condi-
tions than game species.

    Rubbish: Solid waste,  excluding  food
    waste and ashes, from homes, institutions,
    and work-places.

    Run-Off: That part of precipitation, snow
    melt, or irrigation water that runs off the
    land into streams or other surface-water. It
    can carry pollutants from the air and land
    into receiving waters.
    Safener. A chemical added to a pesticide
    to keep it from injuring plants.

    Salinity: The percentage of salt in water.

    Salt Water Intrusion: The invasion of fresh
    surface or ground water by salt water. If it
    comes from the ocean it may be called sea
    water intrusion.

    Salts: Minerals that water picks up as it
    passes through the air, over and under the
   ground, or from households and industry.

   Salvage: The utilization of waste materials.

   Sanctions: Actions taken by the federal
   government for failure to plan or imple-
   ment a State Improvement Plan (SIP). Such
   action  may.  be include withholding  of
   highway funds and a ban on construction
   of new sources of potential pollution.

   Sand Filters:  Devices  that remove  some
   suspended solids from sewage. Air and
   bacteria decompose  additional wastes
   filtering through the sand so that cleaner
   water drains from the bed.

   Sanitary Landfill: (See: landfills.)

   Sanitary Sewers: Underground pipes that
   carry off only domestic or industrial waste,
   not storm water.

   Sanitary Survey: An on-site review of the
   water sources, facilities, equipment, opera-
   tion and maintenance of a public water
   system to evaluate the adequacy of those
  elements for producing and distributing
  safe drinking water.

  Sanitary Water (Also  known  as  gray
  water): Water discharged from sinks, sho-
.  wers, kitchens,  or  other nonindustrial
  operations,  but not from commodes.  '

  Sanitation:  Control of physical factors in
  the human  environment that could harm
  development, health, or survival.

  Saturated Zone: A subsurface  area in
  which all pores and cracks are filled with
  water under pressure equal  to or greater
  than that of the atmosphere.

  Scrap: Materials discarded from manufac-
  turing operations that may be suitable for

  Screening: Use of screens to remove coarse
  floating and suspended  solids from sew-

  Science Advisory Board (SAB): A group
  of external scientists who,advise EPA on
 science, and policy..
    Scrubber An air pollution device that uses
    a spray of water or reactant or a dry pro-
    cess to trap pollutants in emissions.

    Secondary drinking Water Regulations:
    Non-enforceable regulations applying to
    public water  systems and specifying the
    maximum contamination levels that, in the
   judgment of EPA, are required to protect
   the public welfare. These regulations apply
   to any contaminants that may adversely
   affect the odor  or appearance of  such
   water and consequently may cause people
   served by the system to discontinue its

   Secondary Materials: Materials that have
   been manufactured and used at least once
   and are to be  used again.

   Secondary Treatment: The second step in
   most  publicly owned  waste  treatment
   systems  in  which bacteria consume the
   organic parts  of the waste. It is accom-
   plished by bringing together waste, bacte-
   ria, and oxygen in trickling filters or in the
   activated  sludge process. This treatment
   removes floating and settleable solids and
   about 90 percent of the oxygen-demanding
   substances and suspended solids. Disinfec-
   tion is the final stage of secondary treat-
  ment. (See: primary, tertiary treatment.)

  Secure Chemical Landfill: (See: landfills.)

  Secure Maximum  Contaminant Level:
  Maximum permissible level of a contami-
  nant in water delivered to the free flowing
  outlet of the ultimate user, or of contami-
  nation resulting from corrosion of piping
  and plumbing caused by water quality.

  Sedimentation Tanks: Wastewater tanks
  in which floating wastes are skimmed off
  and settled solids are removed for
  disposal.  •

  Sedimentation: Letting solids settle out of
  wastewater by gravity during treatment.

  Sediments: Soil,  sand,  and  minerals
  washed from land into water, usually after
  rain. They pile up in reservoirs, rivers and
  harbors, destroying fish and wildlife habfc
  tat, and clouding the water so that sunlight
 cannot reach aquatic plants. Careless farm-
 ing,  mining, and building activities will
 expose sediment materials, allowing them
 to wash off the land after rainfall.

 Seed Protectanfc A chemical applied before
 planting to protect  seeds  and seedlings
 from disease or insects.

 Seepage: Percolation of water through the
 soil from unlined canals, ditches, laterals,
. watercourses, or water storage facilities.

 Selective Pesticide: A chemical designed
 to affect only certain types of pests, leaving
 other plants and animals  unharmed.

 Semi-Confined Aquifer An aquifer par-
 tially confined by soil layers of low perme-
ability through which recharge and dis-
charge can still occur.

    Senescence: The aging process. Sometimes
    used to describe lakes or other bodies of
    water in advanced stages of eutrophica-

    Septic Tank: An underground storage tank
    for wastes from homes not connected to a
    sewer line. Waste goes directly from the
    home to the tank, where it is decomposed
    by bacteria.  The sludge settles to the bot-
    tom and is pumped out periodically, but
   effluent flows into  the  ground  through

   Service Connector The pipe that carries
   tap water from a public water main to a

   Settleable Solids: Material heavy enough
   to  sink to the  bottom of a wastewater
   treatment tank.

   Settling Chamber. A series of  screens
   placed in the way of flue gases to slow the
   stream of air, thus helping gravity to pull
   particles into a collection device.

   Settling Tank: A holding  area fo/ivaste-
   water, where heavier particles sink to the
   bottom for removal and disposal.

   7Q10:  Seven-day, consecutive low flow
   with a ten year return frequency; the low-
   est stream flow for seven consecutive-days
   that would be expected to occur once in
  ten years.

  Sewage: The waste and wastewater pro-
  duced by residential and commercial sour-
  ces and discharged into sewers.
  Sewage Lagoon: (See: lagoon.)

  Sewage Sludge: Sludge produced at a
  Publicly Owned Treatment  Works,  the
  disposal of which is regulated under  the
  dean Water Act.

  Sewer: A channel or conduit that carries
  wastewater and storm-water runoff from
  the source to a treatment plant or receiving
  stream. "Sanitary "sewers carry household,
  industrial, and commercial waste. "Storm"
  sewers  carry runoff from  rain or  snow.
  "Combined" sewers handle both.
  Sewerage:  The entire system  of sewage
 collection, treatment, and disposal
 Sharps:  Hypodermic  needles, syringes
 (with or without  the  attached  needle)
 pasteur  pipettes,  scalpel blades,  blood
 vials, needles with attached tubing, and
 culture dishes  used in animal  or human
 patient care or treatment, or in medical,
 research or industrial laboratories. Also
 included are  other types  of  broken or
 unbroken glassware that were in contact
 with infectious agents, such as used slides
 and cover slips, and unused hypodermic
 and suture needles, syringes, and scalpel

 Signal:   The  volume  or  product-level
 change produced by a leak in a  tank.
 Signal Words: The words used on a pesti-
cide label-Danger, Warning, Caution-to
indicate level of toxicity.  •

 Significant Deterioration: Pollution result-
 ing from a new  source in previously
 "dean" areas. (See: prevention of significant
 Significant Municipal Facilities: Those
 publicly owned sewage treatment plants
 that discharge a million gallons per day or
 more  and are  therefore considered by
 states to have the potential for to substan-
 tially effect the quality of receiving waters.
 Significant Non-Compliance: (See Signifi-
 cant Violations.)
 Significant Violations: Violations by point
 source dischargers of sufficient magnitude
 or duration to be a regulatory priority.
 Silviculture: Management of forest land
 for timber. Sometimes contributes to water
 pollution, as in clear-cutting.
 Sinking: Controlling oil spills by using an
 agent  to trap the oil and sink it  to  the
 bottom of the body of water where  the
 agent and the oil are biodegraded.
 Site Assessment Program: A means of
 evaluating hazardous waste sites through
 preliminary assessments and site inspec-
 tions to develop a Hazard Ranking System

 Site Inspection: The collection of informa-
 tion from a Superfund  site to determine
 the extent and severity  of hazards posed
 by the site. It follows and is more  exten-
 sive than a preliminary assessment The
 purpose is to gather information necessary
 to score the site, using the Hazard Ranking
 System, and to determine if it presents an
 immediate threat requiring prompt

 Site Safety Flan: A cruciaL element in all
 removal actions, it includes information on
 equipment being used, precautions to be
 taken, and steps to take in the event of an
 on-site emergency.
 Siting: The process of choosing a location
 for a facility.
 Skimming: Using a machine to remove oil
 or scum from the surface of the water.
 Slow Sand Filtration:  Passage of raw
water through a bed of sand at low veloci-
 ty,  resulting  in substantial removal of
chemical and biological contaminants.   •
Sludge: A semi-solid residue from any of
a number of air or water treatment pro-
cesses; can be a hazardous waste.
Sludge Digester Tank in which complex
organic substances like sewage sludges are
biologically dredged. During these reac-
 tions, energy is released and much of the
sewage is converted to  methane, carbon
dioxide, and water.
Slurry:  A watery mixture of insoluble
matter resulting from some pollution con-
trol techniques.
 Small Quantity Generator (SQG-someti-
 me» referred to as "Squeegee"); Persons or
 enterprises that produce 220-2200 pounds
 per month of hazardous waste; are re-
 quired to keep more records than condi-
 tionally exempt  generators. The  largest
 category of hazardous  waste generators,
 SQGs include automotive shops, dry clean-
 ers, photographic developers, and a host of
 other small businesses. (See: conditionally
 exempt generators).

 Smelter: A facility that melts or fuses ore,
 often with  an accompanying  chemical
 change, to separate its metal content. Emis-
 sions cause pollution. "Smelting" is the pro-
 cess involved.

 Smog: Air pollution associated with oxi-
 dants. (See: photochemical smog.)

 Smoke: Particles suspended in air after in-
 complete combustion.

 Soft Detergents:  Cleaning  agents  that
 break down in nature.

 Soft Water: Any water that does not con-
 tain  a  significant amount  of  dissolved
 minerals such as salts of calcium or mag-

 Soil Adsorption Field: A sub-surface area
 containing a  trench  or  bed with clean
 stones and a system of piping through
 which treated sewage may seep into the
 surrounding soil for further treatment and

 Soil and Water Conservation  Practices:
 Control measures consisting of managerial,
 vegetative, and  structural  practices to
 reduce the loss of soil and water.

 Soil Conditioner An organic material like
 humus or compost that  helps soil absorb
 water, build  a bacterial community,  and
 take up mineral nutrients.

 Soil Erodibility: An indicator of a soil's
 susceptibility to raindrop impact, runoff,
 and other erosive processes.

 Soil  Gas:  Gaseous  elements  and com-
 pounds in the small spaces between parti-
 cles of the earth and soil. Such gases can
 be moved or driven out under pressure.

 Soil Sterilant:: A chemical that temporarily
 or permanently prevents the growth of all
 plants and animals,  depending on  the

 Sole-Source Aquifer An aquifer that sup-
plies 50-percent or more of the drinking"
water of an area.

 Solid  Waste:  Non-liquid,  non-soluble
materials ranging from municipal garbage
 to industrial wastes that contain complex
and sometimes hazardous   substances.
Solid wastes also include sewage sludge,
agricultural refuse, demolition wastes, and
mining residues. Technically, solid  waste
also refers to liquids and gases in contain-
 Solid Waste Disposal: The final placement
 of refuse that is not salvaged or recycled.

 Solid  Waste  Management:  Supervised
 handling of waste materials from  their
 source  through recovery processes to dis-

 Solidification and Stabilization: Removal
 of wastewater from a waste or changing it
 chemically to make it less permeable and
 susceptible to transport  by water.

 Soot: Carbon dust formed by incomplete

 Sorption: The action of soaking up  or
 attracting  substances;  process  used  in
 many pollution control systems.

 Source  Reduction:  Reducing the  amount
 of materials entering the waste stream by
 redesigning products or patterns of  pro-
 duction or consumption (e.g., using return-
 able beverage containers).  Synonymous
 with waste reduction.

 Source  Separation:  Segregating  various
 wastes  at the  point of generation (e.g.,
 separation of paper, metal and glass from
 other wastes  to make recycling  simpler
 and more efficient.)

 Special Review: Formerly known as Re-
 buttable Presumption Against Registration
 (RPAR), this  is the  regulatory  process
 through which existing pesticides suspect-
 ed of posing unreasonable risks to human
 health,  non-target organisms, or the envi-
 ronment are referred for review by EPA.
 Such   review   requires  ah   intensive
 risk/benefit analysis with opportunity for
 public comment. If risk is found  to out-
 weigh social and economic benefits, regula-
 tory actions ranging from label revisions
 and use-restriction to cancellation or sus-
 pended registration can be initiated.

 Special Waste: Items such as household
 hazardous waste, bulky wastes (refrigera-
 tors, pieces  of furniture, etc.) tires, and
 used oil.

 Species: A reproductively isolated aggre-
 gate of interbreeding organisms.

 Spill Prevention Control and Counter-
 measures Plan (SPCP): Plan  covering the
 release of hazardous substances as defined
 in the Clean Water Act.

 Spoil: Dirt or rock removed from its origi-
 nal location-destroying the composition of
 the soil  in the process-as in strip-mining,
 dredging, or construction.

 Sprawl: Unplanned development of open

 Spray Tower Scrubber. A  device  that
 sprays   alkaline water into  a  chamber
where acid gases present to aid  in  the
neutralizing of the gas.

Stable Air A motionless mass of air that
holds instead of dispersing pollutants.

Stabilization:  Conversion of the active
organic  matter in sludge into inert, harm-
less material.  •

 Stack: A chimney, smokestack, or vertical
 pipe that discharges used air.

 Stabilization Ponds: (See: lagoon.)

 Stack Effect: Air, as in a chimney, that
 moves upward because it is warmer than
 the ambient atmosphere.

 Stack Gas: (See: flue gas.)

 Stage II Controls:  Systems  placed on
 service station gasoline pumps to control
 and capture gasoline vapors during refuel-

 Stagnation: Lack of motion in a mass of
 air or water that holds pollutants in place.

 Standards: Norms that impose limits on
 the amount  of  pollutants  or emissions
 produced. EPA establishes minimum stan-
 dards, but states are allowed to be stricter.

 Start of a Response Action: The point in
 time when there is a guarantee or set-aside
 of° funding either by EPA, other federal
 agencies, states or Principal Responsible
 Parties in order to begin response actions
 at a Superfund site.

 State Emergency Response Commission
 (SERC): Commission appointed by each
 state  governor according to the require-
 ments of SARA Title in. The SERCs desig-
 nate emergency planning districts, appoint
 local emergency planning committees, and
 supervise and coordinate their activities.

 State Implementation Plans (SIP): EPA -
 approved state plans for the establishment,
 regulation, and enforcement of air pollu-
 tion standards.

 Stationary Source: A fixed-site producer of
 pollution, mainly  power plants and other
 facilities using industrial combustion pro-

 Storage: Temporary  holding  of  waste
 pending treatment or disposal, as in con-
 tainers, tanks, waste piles, and surface.

 Storm Sewer A system of pipes (separate
 from  sanitary sewers) that carries only
 water  runoff  from buildings  and land

 Stratification: Separating into layers.

 Stratosphere:  The portion of  the  atmo-
 sphere 10-to-25 miles above the earth's

 Strip-Cropping: Growing crops in  a sys-
 tematic arrangement of strips or bands that
 serve  as barriers to wind and  water ero-

 Strip-Mining; A  process that  uses ma-
chines to scrape soil or rock away from
 mineral deposits  just under the earth's

 Structural  Deformation: Distortion  in
walls of a tank after liquid has been added
or removed.

Sulfur Dioxide (SOj): A pungent, colorless,
 gaseous pollutant formed primarily by the
 Sump: A pit or tank that catches liquid
 runoff for drainage or disposal.

 Supercritical Water A type" of thermal
 treatment using moderate temperatures
 and high pressures to enhance the ability
 of water  to  break  down large organic
 molecules into smaller, less  toxic ones.
 Oxygen injected during this process com-
 bines  with simple organic compounds to
 form carbon dioxide and water.

 Superfund: The program operated under
 the legislative authority of CERCLA and
 SARA that funds and carries out EPA solid
 waste emergency and long-term removal
 and remedial activities. These  activities
 include establishing the National Priorities
 List, investigating sites for inclusion on the
 list, determining their priority, and con-
 ducting  and/or supervising  the cleanup
 and other remedial actions.

 Superfund Innovative Technology Evalu-
 ation: EPA program to promote develop-
 ment  and use of  innovative  treatment
 technologies in Superfund site cleanups.

 Surface  Impoundment:  Treatment, stor-
 age, or disposal of liquid hazardous wastes
 in ponds.

 Surface  Uranium Mines: Strip mining
 operations for removal of uranium-bearing

 Surface Water All water naturally open to
 the atmosphere (rivers, lakes, reservoirs,
 ponds,  streams,  impoundments,  seas,
 estuaries, etc.) and all springs, wells, or
 other  collectors directly  influenced  by
 surface water.

 Surfacing  ACM:   Asbestos-containing
 material that is sprayed or troweled on or
 otherwise  applied to  surfaces,  such as
 acoustical  plaster  on  ceilings and fire-
 proofing materials on structural members.

 Surfacing Material:  Material sprayed or
 troweled onto structural members (beams,
 columns, or decking) for fire protection; or
 on ceilings or walls for fireproof ing, acous-
 tical  or   decorative  purposes.  Includes
 textured plaster, and other textured wall
 and ceiling surfaces.

 Surfactant: A  detergent compound that
 promotes lathering.

 Surveillance System: A series of monitor-
 ing devices designed to check on environ-
 mental conditions.

 Suspect  Material: Building material sus-
 pected of containing asbestos, e.g., surfac-
 ing material, floor tile, ceiling tile, thermal
 system insulation, and miscellaneous other

 Suspended Loads:    Sediment particles
 maintained in the water column by turbu-
 lence and carried with the flow of water.

 Suspended Solids: Small particles of solid
pollutants that float on the surface of, or
are suspended in, sewage or other liquids.
They.  resist . removal  by  conventional
 Suspension: Suspending the .use  of a
 pesticide when EPA deems it necessary to
 prevent an imminent hazard resulting from
 its continued use. An emergency suspen-
 sion takes effect immediately; under an
 ordinary suspension  a registrant can re-
 quest a hearing before the suspension goes
 into effect. Such a hearing process might
 take six months.

 Suspension Culture: Cells growing in a
 liquid nutrient medium.

 Swamp: A type of wetland dominated by
 woody vegetation but without appreciable
 peat deposits. Swamps may be fresh or salt
 water and tidal or non-tidal.  (See: wetlan-

 Synthetic  Organic .Chemicals (SOCs):
 Man-made organic chemicals. Some SOCs
 are  volatile, others tend to stay dissolved
 in water instead of evaporating.

 Systemic Pesticide: A chemical absorbed
 by an organism that makes the organism
 toxic to .pests.                 . X *  •

 Tailings: Residue of raw material or waste
 separated  out during the processing of
 crops or mineral ores.

 Tail Water The runoff of irrigation water
 from the lower end of an irrigated field.
 Technical  Assistance Grant (TAG): As
 part of the Superfund program. Technical
 Assistance Grants of up to $50,000 are
 provided to citizens'  groups  to  obtain
 assistance  in  interpreting  information
 related to cleanups at Superfund sites or
 those proposed for the National Priorities
 List. Grants are used by such  groups to
 hire technical advisors to help them under-
 stand the site-related technical information
 for the duration of response activities.
 Technology-Based Limitations: Industry-
 specific effluent limitations applied  to a
 discharge when it will not cause a viola-
 tion of water quality standards at  low
 stream flows. Usually applied to discharg-
 es into large rivers.

 Technology-Based  Standards:  Effluent
 limitations applicable to direct and indirect
 sources which are developed on a categor-
 y-by-category basis using statutory factors,
 not including water-quality effects.
 Terracing: Dikes built along the contour of
 sloping farm land that hold runoff  and
 sediment to reduce erosion.
Tertiary Treatment: Advanced cleaning of
 wastewater that goes beyond the second-
 ary or biological stage, removing nutrients
 such as phosphorus, nitrogen, and most
 BOD and suspended solids.
Thermal  Pollution: Discharge of heated
water from industrial processes  that  can
kill or injure aquatic 'organisms.

 Thermal System InrnUHoa (TSI): Asbes-
 tos-containing material applied to pipes,
 fitting*, boiler*, breeching, tank*, ducts, or
 other interior structural components to
 prevent heat los« or g»ia or waier conden-
 Thtrmal Treatment: Use of elevated tem-
 peratures to treat hazardous wastes. (See:
 incineration; pyrolysia.)
 Threshold Limit Value (TLV): The concen-
 tration of an airborne substance that an
 average person can be repeatedly exposed
 to without adverse effects. TLVs may be
 expressed in three ways: TLV-TWA-Time
 weighted avenge, based on an allowable
 exposure averaged over a normal 8-hour
 workday or 40-hour workweek; TLV-STE-
 L-Short-term exposure limit or maximum
 concentration for a brief specified period of
 time,  depending on a specific chemical
 (TWA must still be met);  and TLV-C-
 Cciling  Exposure  Limit  or  maximum
 exposure concentration not to be exceeded
 under any circumstances. (TWA must still
 be met.)
 Threshold Planning Quantity: A quantity
 designated for each chemical on the list of
 extremely hazardous substances that trig-
 gers notification  by facilities to the State
 Emergency  Response  Commission  that
 such facilities are subject to emergency
 planning requirements under SARA Title
 Tidal  Marsh: Low,  flat  marshlands tra-
 versed by channels and tidal  hollows,
 subject to tidal inundation; normally, the
 only  vegetation  present is salt-tolerant
 bushes and grasses. (See: wetlands.)
 Time-weighted Average  (TWA):  In air
 sampling, the average air concentration of.
 contaminants during a given period.
 Tolerances: Permissible residue levels for
 pesticides in raw agricultural produce and
 processed foods. Whenever a pesticide is
 registered for use on a food or a feed crop,
 a tolerance (or exemption from-the toler-
 ance requirement) must be established.
 EPA establishes the tolerance levels, which
 are enforced  by the Food and Drug Ad-
 ministration and the Department of Agri-
 Tonnage: The  amount of waste that a
 landfill accepts, usually expressed in tons
 per month. The rate at which a landfill
 accepts waste is limited by the landfill's
 Topography: The physical features of a
 surface area including  relative elevations
 and the position of natural and man-made
Total Dissolved Phosphorous: The total
phosphorous  content o all material that
will pass through a filter, which is  deter-
mined  as orthophosphate without prior
digestion or hydrolysis. Also called soluble
P. or ortho P.
  Total Dissolved Solids (TDS): All material
  that passes the standard glass river filter;
  now called total  filtrable reside. Term is
  used, to reflect salinity.

  Total Suspended Solids (TSS): A measure
  of the suspended solids in wastewater,
  effluent, or water bodies, determined by
  tests  for "total suspended  non-filterable
  solids." (See: suspended solids.) •

  Toxic Chemical Release Form: Informa-
  tion form required of facilities that manu-
  facture, process, or use (in quantities above
  a specific amount) chemicals listed  under
  SARA Title ffl.

  Toxic Chemical:  Any chemical listed in
  EPA rules as "Toxic Chemicals Subject to
  Section 313 of the Emergency Planning and
  Community Right-to-Know  Act of 1986."

  Toxic Chemical Use Substitution: Replac-
  ing toxic chemicals with  less  harmful
 chemicals in industrial processes.

 Toxic Cloud: Airborne plume of gases,
 vapors, fumes, or aerosols containing toxic

 Toxic Pollutants: Materials  that  cause
 death, disease, or birth defects in organ-
 isms that ingest or absorb them. The quan-
 tities and exposures necessary  to  cause
 these effects can vary widely.

 Toxic Release Inventory: Database of toxic
 releases in the United States compiled from
 SARA Title in section 313 reports.

 Toxic Substance:  A chemical or mixture
 that may present an unreasonable risk of
 injury to health or the environment.

 Toxic Waste: A waste that  can produce
 injury if inhaled, swallowed, or absorbed
 through the skin.

 Toxicity Testing: Biological testing (usual-
 ly with  an invertebrate,  fish, or small
 mammal) to determine the adverse effects
 of a compound or effluent.

 Toxicologicil Profile: An  examination,
 summary, and interpretation of a hazard-
 ous substance to determine levels of expo-
 sure and associated health effects.

 Transpiration: The process by which water
 vapor is lost to the atmosphere from living
 plants. The term can also be applied to the
 quantity of water thus dissipated.

 Transportation Control Measures (TCMs):
 Steps taken by a locality to  adjust traffic
 patterns (e.g., bus lanes, turnout, right turn
 on red) or reduce vehicle use (ride sharing,
 high-occupancy vehicle lanes) to cut vehic-
 ular emissions.

 Trash: Material considered  worthless or
 offensive that is thrown away. Generally
 defined as dry waste material, but in com-
 mon usage it is a  synonym  for garbage,
 rubbish, or refuse.

 Treatability Studies: Tests  of potential
 cleanup technologies conducted in a labo-
 ratory (See: bench-scale tests.)

Trash-tO'Energy  Plan:  Burning trash to
 orodiice enerev  •
  Treated Regulated Medical Waste: Medi-
  cal waste treated to substantially reduce or
  eliminate its pathogenkity, but that has not
  yet been destroyed.

  Treatment Plant: A structure built to treat
  wastewater before  discharging it into the

  Treatment, Storage, and Disposal Facility:
  Site where a hazardous substance is treat-
  ed, stored, or disposed of. TSD faculties
  are regulated by EPA and states under

  Treatment: (1) Any method, technique, or
  process designed to remove solids and/or
  pollutants from solid waste, wastestreams,
  effluents, and air emissions. (2)  methods
  used to change the biological character or
  composition  of  any regulated  medical
  waste so as to  substantially reduce or
  eliminate its potential for causing disease.

  Trial Burn: An incinerator test in which
  emissions are monitored for the presence
  of specific organic compounds, particula-
  tes, and hydrogen chloride.      . jjT

  Trichloroethylene (TCE): A stable,  low
  boiling-point colorless liquid, toxic if in-
•  haled. Used as a solvent or metal decreas-
  ing agent, and in  other industrial applica-

  Trickling Filter: A coarse treatment system
  in which wastewater is trickled over a bed
  of stones or other material covered  with
  bacteria that break down the organic waste
  and produce clean water.

  Trickle Irrigation: Method in which water
  drips to the soil from perforated tubes or

  Trihalomethane (THM): One of a family
  of organic compounds named as derivative
  of methane. THMs are generally by-prod-
  ucts of chlorinalion of drinking water that
  contains organic material.

 Trust Fund (CERCLA): A fund set up
 under the Comprehensive Environmental
 Response, Compensation and Liability Act
 (CERCLA)  to help  pay for cleanup of
 hazardous waste sites and for legal action
 to force those responsible for the sites to
 clean them up.

 Tundra: A type of ecosystem dominated
 by lichens,  mosses, grasses,  and woody
 plants. Tundra is found at high latitudes
 (arctic tundra) and high altitudes (alpine
 tundra). Arctic  tundra is  underlain by
 permafrost and is usually saturated. (See:

 Turbidimeten A device that measures the
 density of suspended solids in a liquid.

 Turbidity: 1. Haziness in air caused by the
 presence of particles and pollutants. 2. A
 cloudy condition in water due to suspend-
 ed silt or organic matter.

    Ultra Clean Coal  (UCQ: Coal  that  is
    washed, ground into fine particles, then
    chemically treated to remove sulfur, ash,
    silicone, and other  substances; usually
    briquetted and coated with a sealant made
    from coal.

    Ultraviolet Rays: Radiation from the sun
    that can be useful or potentially harmful.
    UV rays from one part of the spectrum
    (UV-A) enhance plant life and are useful in
    some medical and dental procedures; UV
    rays from other parts of the spectrum (UV-
    B)  can cause skin cancer or other tissue
    damage. The ozone layer in  the atmo-
    sphere partly shields us from ultraviolet
    rays reaching the earth's surface.

    Underground Injection Control (UIC): The
   program under the "Safe Drinking Water
   Act that regulates the use of wells to pump
   fluids into the ground.

   Underground Sources of Drinking Water
   Aquifers currently being used as a source
   of  drinking water or  those capable of
   supplying a  public  water  system. They
   have a total  dissolved  solids  content of
   10,000 milligrams per liter or less, and are
   not  "exempted aquifers." (See:  exempted

   Underground  Storage Tank: A tank locat-
   ed  at least  partially underground and
   designed to hold gasoline or other petro-
   leum products or chemicals.

   Unreasonable  Risk: Under the Federal
  Insecticide, Fungicide, and Rodenticide Act
  (FIFRA), "unreasonable adverse effects"
  means any unreasonable risk to man or the
  environment, taking into account the medi-
  cal,  economic,  social, and environmental
  costs and benefits of any pesticide.

  Unsaturated  Zone: The area above the
  water table where soil pores are not fully
  saturated, although some water may be
  present.       •
    Vapor Capture System: Any combination
    of hoods and ventilation system that cap-
    tures or contains organic vapors so they
    may be directed to an abatement or recov-
    ery device.

    Vapor  Dispersion:  The movement  of
    vapor clouds in air due to wind, thermal
    action, gravity spreading, and mixing.

    Vapor Plumes: Rue gases visible because
    they contain water droplets.

    Variance: Government  permission for a
    delay or exception in the application of a
    given law, ordinance, or regulation.

    Vector  1. An organism, often an insect or
    rodent,  that carries disease. 2.  Plasmids,
    viruses,  or bacteria used to transport genes
   into a host cell.  A gene is  placed in the
   vector; the vector then "infects" the bacteri-
    Vulnerable Zone: An area over which the
    airborne concentration of a chemical acci-
    dentally released could reach the level of

    Vulnerability Analysis:  Assessment of
    elements in the community that  are sus-
    ceptible to damage should a release of
    hazardous materials occur.
   Vehicle Miles Travelled (VMT): A mea-
   sure of the extent of motor vehicle opera-
   tion; the total number of vehicle miles
   travelled within a specific geographic area
   over a given period of time.

   Ventilation/Suction: The act of admitting
   fresh air into a space in order to replace
   stale or contaminated, air; achieved by
   blowing air into the space. Similarly, suc-
   tion represents  the admission of fresh air
   into an  interior space by  lowering the
  pressure outside  of the space,  thereby
  drawing the contaminated air outward.

  Venturi Scrubbers: Air pollution control
  devices that use water to remove particu-
  late matter from emissions.

  Vinyl Chloride: A chemical compound,
  used in  producing some plastics, that is
  believed to be oncogenic.

  Virgin Materials: Resources extracted from
  nature in their raw form, such as timber or
  metal ore.
 Uranium Mill  Tailings  Piles:  Former
 uranium ore processing sites that contain
 leftover  radioactive materials  (wastes),
 including radium and unrecpvered urani-'

 Uranium Mill-Tailings Waste Piles- Li-
 censed active mills with tailings piles and
 evaporation  ponds  created  by  acid  or
 alkaline leaching processes.

 Urban Runoff: Storm water from city
 streets and adjacent domestic or commer-
 cial properties  that  carries pollutants  of
 various kinds into the sewer systems and
 receiving waters.

 Utility Load: The total electricity demand
.for a utility district.             •
 Volatile: Any substance that evaporates
 readily.                       . r

 Volatile Organic Compound (VOC): Any
 organic compound that participates  in
 atmospheric photochemical reactions ex-
 cept those designated by EPA as having
 negligible photochemical reactivity.

 Volatile Synthetic  Organic Chemicals:
 Chemicals that tend to volatilize or evapo-

 Volume  Reduction:  Processing  waste
 materials to decrease the amount of space
 they occupy,  usually by  compacting or
 shredding, incineration, or composting.

 Volumetric Tank Test: One of several tests
 to determine the physical integrity of  a
 storage tank; the volume of fluid in the
 tank is measured  directly  or  calculated
from product-level changes.  A  marked
drop in volume indicates a leak.

    Waste: 1. Unwanted materials left over
    from a manufacturing process. 2. Refuse
    from places of human or animal habitation.

    Waste Characterization: Identification of
    chemical and microbiological constituents
    of a waste material.

   Waste Exchange: Arrangement in which
   companies exchange their wastes for the
   benefit of both parties.

   Waste Feed: The continuous or intermit-
   tent flow .of wastes into an incinerator.

   Waste  Load Allocation: The  maximum
   load of pollutants each discharger of waste
   is allowed  to  release into a  particular
   waterway. Discharge limits are usually
   required for each specific water quality
   criterion being, or expected to be, violated.
   The portion of a stream's total assimilative
  capacity assigned to an individual  dis-

  Waste Minimization: Measures or tech-
  niques that reduce the amount of wastes
  generated during  industrial production
  processes; term is also applied to recycling
  and other efforts to reduce the amount of
  waste going into the waste stream.
  Waste Reduction: Using source reduction
  recycling,  or  composting to prevent or
  reduce waste generation.

  Waste  Stream: The  total  flow  of solid
  waste from homes, businesses, institutions,
  and manufacturing plants that  are recy-
 cled, burned, or disposed of in landfills, or
 segments  thereof such as the "residential
 waste  stream" or  the "recyclable waste

 Waste Treatment Lagoon: Impoundment
 made by excavation or earth fill for biolog-
 ical treatment of wastewater.

 Waste Treatment Plant: A facility contain-
 ing a series of tanks, screens, filters and
 other processes by which  pollutants are
 removed from water.

 Waste Treatment Stream: The continuous
 movement of waste  from  generator   to
 treater and disposer.

Wastewaten The spent or used water from
a home, community, farm, or industry that
contains dissolved or suspended matter.

 Wutewcter Infractroctai*: Hie plan or
 network foe the collection, treatment, and
 disposal of sewag* in a community. The
 level of treatment wiB depend on the size
 of the community, tfae type of discharge,
 and/or the designated use of the receiving

 Wastewater Operation* and Maintenance:
 Actions taken after construction to assure
 that facilities constructed to treat wastewa-
 ter will be operated, maintained, and man-
 aged to reach prescribed effluent levels in
 an optimum manner.

 Water Pollution: The presence in water of
 enough harmful or objectionable material
 to damage the water's quality.

 Water Purveyor A public utility, mutual
 water company, county water district, or
 municipality that delivers drinking water
 to customers.

 Water Quality Criteria: Levels of water
 quality expected to render a body of water
 suitable for its designated use. Criteria are
 based on Specific levels of pollutants that
 would make the water harmful if used for
 drinking, swimming, farming, fish produc-
 tion, or industrial processes.

 Water Quality Standards: State-adopted
 and EPA-approved ambient standards for
 water bodies. The standards prescribe the
 use of the water body and establish the
 water quality criteria that must be met to
 protect  designated uses.

 Water Quality-Based Limitations: Effluent
 limitations applied  to dischargers when
 mere technology-based limitations would
 cause violations of water quality standards.
 Usually applied  to discharges  into small

 Water Quality-Based Permit:'A permit
 with an effluent limit more stringent than
 one  based on  technology performance.
 Such limits may be necessary to protect the
 designated use of receiving waters (Le.,
 recreation, irrigation, industry or water

 Water Solubility: The maximum possible
 concentration of  a  chemical compound
 dissolved in water. If a substance is water
 soluble  it can  very  readily disperse
 through the environment.

Water Supplier: One who owns or oper-
 ates a public water system.

Water Supply  System:  The  collection,
 treatment,  storage,  and  distribution  of
 potable  water from source to consumer.

Water Table: The level of groundwater.

Watershed: The land area that drains into
a stream.

Well Injection: The subsurface emplace-
ment of fluids into a welL

Well Monitoring: Measurement by on-site
instruments or laboratory methods of well
water quality.
 Well Flog: A watertight, gastight  seal
 installed in a bore hole or well to prevent
 movement of fluids.

 Wellhead  Protection Area: A  protected
 surface and subsurface zone surrounding
 a well or wellfield supplying a public
 Water system to keep contaminants from
 reaching the well water.

 Wetlands: An  area that is saturated by
 surface or  ground water with vegetation
 adapted for life under  those soil condi-
 tions, as swamps, bogs, fens, marshes, and

 Wildlife Refuge: An area designated for
 the  protection  of wild animals, within
 which hunting and fishing are either pro-
 hibited or strictly controlled.

 Wood-Buming-Stove Pollution: Air pollu-
 tion caused by emissions of particulate
 matter, carbon monoxide, total suspended
 participates, and polycyclic organic matter
 from wood-burning stoves.

 Wood Treatment Facility: An industrial
 facility that treats lumber and other wood
 products' for outdoor use. The process
 employs chromated copper arsenate, which
 is regulated as a hazardous material

Working Level Month (WLM): A unit of
measure used to determine  cumulative
exposure to radon.

Working Level (WL): A unit of measure
for documenting exposure to radon decay
products, the so-called "daughters".. One
working level is equal to approximately
200 picocuries per liter.

Xenobiote: Any biotum displaced from its
normal habitat; a chemical foreign to a
biological system.

Yard Waste: The part of solid waste com-
posed  of grass dippings, leaves, twigs,
branches, and garden refuse.

Yellow-Boy: Iron oxide flocculent (clumps
of solids in waste or water);  usually ob-
served as orange-yellow deposits in sur-
face streams with excess iron content. (See:
floe, flocculation.)

Z-lisfc OSHA's tables of toxic and hazard-
ous air contaminants.

Zone of Saturation: (See: saturated zone.)

Zooplanktoiu Tiny aquatic animals  eaten
by fish.


   Abbreviations  And   Acronyms
    A&I: Alternative and Innovative
      (Wastewater Treatment System)
    AA: Accountable Area
    AA: Adverse Action
    AA: Advices of Allowance
    AA: Assistant Administrator
    AA: Associate Administrator
    AA: Atomic Absorption
    AAEE: American Academy of  •
      Environmental Engineers
    AANWR: Alaskan Arctic National
      Wildlife Refuge
    AAP: Asbestos Action Program
    AAPCO: American Association of
      Pesticide Control Officials
    AARO Alliance for Acid Rain
   ABEL: EPA's computer model for
      analyzing a violator's ability to
      pay a civil penalty.
   ABES: Alliance for Balanced
     Environmental Solutions
   AC Actual Commitment.
     Advisory Circular
   A&C: Abatement and Control
   ACA: American Conservation

   ACBM: Asbestos-Containing
     Building Material
   ACE: Alliance for dean Energy
   ACEEE: American Council for an
     Energy Efficient Economy
   ACFM: Actual Cubk Feet Per
   ACL: Alternate Concentration
     Limit Analytical Chemistry

  ACM: Asbestos-Containing
    Material            *
  ACP: Agriculture Control
    Program (Water Quality
  ACP: Air Carcinogen Policy
  ACQUIRE: Aquatic Information
  ACQR: Air Quality Control
  ACS: American Chemical Society
  ACT: Action
  ACTS: Asbestos Contractor-
    Tracking System
 ACWA: American Clean Water
 ACWM: Asbestos-Containing
    Waste Material
 ADABA: Acceptable Data Base
 ADB: Applications Data Base
 ADI: Acceptable Daily Intake
 ADP: Automated Data Processing
 ADP: AHERA Designated Person
 ADQ: Audits of Data Quality

 ADR: Alternate Dispute

 ADSS: Air Data Screening System
 ADT: Average Daily Traffic
 AEA: Atomic Energy Act
 AEC: Associate Enforcement

 AEE: Alliance for Environmental
    AEM: Acoustic Emission
    AERE: Association of
      Environmental and Resource
    AES: Auger Electron Spectrometry
    AFA: American Forestry
    AFCA: Area Fuel Consumption
    AFRCE: Air Force Regional Civil
    APS: AIRS Facility Subsystem
    AFUG: AIRS Facility Users Group
    AH: Allowance Holders
    AHERA: Asbestos Hazard
     Emergency Response Act
   AIC Active to Inert Conversion
   AICUZ: Air Installation
     Compatible Use Zones
   AID: Agency for International
   AIHC: American Industrial Health
   AIP: Auto Ignition Point
   AIRS: Aerometric Information
     Retrieval System
   AL: Acceptable Level
   ALA: Delta-Aminolevulinic Acid
   ALA-Cfc Delta-Aminolevulinic
     Acid Dehydrates
   ALAPO: Association of Local Air
     Pollution Control Officers
  ALARA: As Low As Reasonably
  ALO Application Limiting

  ALJ: Administrative Law Judge
  ALMS: Atomic Line Molecular
  ALR: Action Leakage Rate
  AMBIENS: Atmospheric Mass
    Balance of Industrially Emitted
    and Natural Sulfur
  AMOS: Air Management
    Oversight System
  AMPS: Automatic Mapping and
    Planning System
  AMSA: Association of Metropoli-
    tan Sewer Agencies
  ANPR: Advance Notice of
    Proposed Rulemaking
  ANRHRD'/Air, Noise, &
    Radiation Health Research
 ANSS: American Nature Study
   Society                 '
 AOC Abnormal Operating
 AOD: Argon-Oxygen
AEERL: Air and Energy Engineer-
  ing Research Laboratory
'AOML: Atlantic Oceanographic
   and Meteorological Laboratory
AP: Accounting Point
APA: Administrative Procedures
APCA: Air Pollution Control
APCD: Air Pollution Control
APDS: Automated Procurement
   Documentation System
APHA:' American Public Health
  Association                ,
  APRAC: Urban Diffusion Model
    for Carbon Monoxide from
    Motor Vehicle Traffic
  APTI: Air Pollution Training
  APWA: American Public Works
  AQ-7: Non-reactive Pollutant
  AQCCT: Air-Quality Criteria and
    Control Techniques
  AQCP: Air Quality Control
  AQCR: Air-Quality Control'
 AQD: Air-Quality'Digest
 AQDHS: Air-Quality Data
    Handling System
 AQDM: Air-Quality Display

 AQMA: Air-Quality Maintenance

 AQMP: Air-Quality Maintenance

 AQMP: Air-Quality Management

 AQSM: Air-Quality Simulation

 AQTAD: Air-Quality Technical
   Assistance Demonstration
 AR Administrative Record
 A&R: Air and Radiation
 ARA: Assistant Regional
ARA: Associate Regional
ARAR: Applicable or Relevant
   and Appropriate Standards,
   Limitations, Criteria
    	««»«»Mw«ip, Criteria, and
  ARB: Air Resources Board
  ARC Agency Ranking Committee
  ARCC American Rivers
    Conservation Council
  ARCS: Alternative Remedial
    Contract Strategy
  ARC: American Resources Group
  ARIP: Accidental Release
    Information Program
  ARL: Air Resources Laboratory
  ARM: Air Resources Management
  ARO: Alternate Regulatory Option
 ARRP: Acid Rain Research
 ARRPA: Air Resources Regional
   Pollution Assessment Model
 ARS: Agricultural Research
 ARZ: Auto Restricted Zone
 AS: Area Source
 ASC Area Source Category
 ASDWA: Association of State
   Drinking Water Administrators
 ASHAA: Asbestos in Schools
   Hazard Abatement Act
 ASIWCPA: Association of State
   and Interstate Water Pollution
   Control Administrators
 ASMDHS: Airshed Model Data
   Handling System
ASRL: Atmospheric Sciences
   Research Laboratory
AST: Advanced Secondary
   (Wastewater) Treatment
   ASTHO: Associatioh of State and
     Territorial Health Officers
   ASTM: American Society for
     Testing and Materials
   ASTSWMO: Association of State
     and Territorial Solid Waste
     Management Officials
   AT: Advanced Treatment. Alpha
     Track Detection •
   ATERIS: Air Toxics Exposure and
     Ruk Information System
   ATS: Action Tracking System
   ATSDR: Agency for Toxic Sub-
     stances and Disease Registry
   ATTF: Air Toxics Task Force
   AUSM: Advanced Utility
     Simulation Model
  A/WPR: Air/Water Pollution
  AWRA: American Water
     Resources Association   „
  AWT: Advanced WastewaMr
  AWWA: American Water Works
  AWWARF: American Water
    Works Association Research


  BAA: Board of Assistance  Appeals
  BAG Biotechnology Advisory
 BACM: Best Available Control
 BACT: Best Available Control
 BADT: Best Available
    Demonstrated Technology
 BaK Benzo(a)Pyrene
 BAP: Benefit* Analysis Program
 BART: Best Available Retrofit
 BASIS: Battefle's Automated
   Search Information System
 BAT: Best Available Technology
 BATEA: Bert Available Treatment
   Economically Achievable
 BCT: Bert Control Technology
 BCPCT: Bert Conventional
   Pollutant Control Technology
 BOAT: Bert Demonstrated
   Achievable Technology
BDCT: Bert Demonstrated Control
BDT: Bert Demonrtrated
                                           T      u
                                     Expert Judgment
                               BF: Bonifide Notice of Intent to
                                 Manufacture or Import
                                 OMD/OTS)       ^
                               BID: Background Information'
                                 Document Buoyancy Induced
                               BIOPLUME Model to Predict the
                                 Maximum Extent of Existing
                               BMP: Bert Management Practice(s)
                               BMR: Baseline Monitoring Report
                               BO: Budget Obligation*

BOD: Biochemical Oxygen
  Demand. Biological Oxygen
EOF: Buic Oxygen Furnace
BOP: Basic Oxygen PTOCCM
BOPR Baric Oxygen Proc*«»
BOYSNG Beginning of Year
BP: Boiling Point
BPJ: Beit Professional Judgment
BPT: Beit Practicable Technology.
  Pert Practicable Treatment
BPWTT: Beit Practical Wattewater
  Treatment Technology
BRS: Bibliographic Retrieval
BSl: British Standards Institute
BSD: Beniene Soluble Organic*
BTZ: Below the Treatment Zone
BUN: Blood Urea Nitrogen
CA: Citizen Act Competition
  Advocate. Cooperative
  Agreement*. Collective Action
CAA: dean Air Act
CAA: Compliance AMurance
CAAA: dean Air Act
CAER: Community AwareneM
  and Emergency Respome
CAFE: Corporate Average Fuel
CAPO: Consent Agreement/Final
CAG: Carcinogenic Assessment
CA1R4 Comprehensive Assessment
  of Information Rule
CAUNE California Line Source
CAMP: Continuous Air
  Monitoring Program
CAN; Common Account Number
CAO: Corrective Action Order
CAP: Corrective Action Plan. Coot
  Allocation Procedure. Criteria
  Air Pollutant
CAR: Corrective Action Report
CAS: Ccnler for Automotive
CAS: Chemical Abstract Service
CASAC dean Air Scientific
  Advisory Committee
CASLP: Conference on Alternative
  State and Local Practice*
CATS: Corrective Action Tracking
CAU: Carbon Adsorption Unit
CAU: Command Arithmetic Unit
CB: Continuous Bubbler
CB A: Chesapeake- Bay Agreement
  Coot Benefit Analysis
CBD: Central Business District
CB1: Compliance Biomonitoring
CBI: Confidential Business
CBOD: Carbonaceou* Biochemical
  Oxygen Demand
CBP: Chesapeake Bay Program
CBP: County Business Patterns
CCA: Competition in Contracting
CCAA: Canadian dean Air Act
CCAP: Center for dean Air Policy
CCEA: Conventional Combustion
  Environmental Assessment
CCHW: Citizens Clearinghouse
 , for Hazardous Wastes
CdEh Confidential Chemicals
  Identification System
CCMS/NATO: Committee on
  Challenges of a Modem
  Society/Narth Atlantic Treaty
CCP: Composite Correction Flan
CC/RTS:Chemical Collection/
  Request Tracking System
CCTP: dean Coal Technology
CD: dimatological Data
CDB: Consolidated Data Base
CDBA: Central Data Base
CDBG: Community Development
  Block Grant
CDD: Chlorinated
CDF: Chlorinated dibenzofuran
CDHS: Comprehensive Data
  Handling System
GDI: Case Development
COM: dimatological Dispersion
COM: Comprehensive Data
CDMQO dimatological
  Dispersion Model with
  Calibration and Source
CDN& dimatological Data
  National Summary
CDP: Census Designated Places
CDS: Compliance Data System
CE Categorical Exclusion.
  Conditionally Exempt
CEA: Cooperative Enforcement
CEA: Cost and Economic
CEAT: Contractor Evidence Audit
CEARC Canadian Environmental
  Assessment Research Council
CEB: Chemical Element Balance
CECATS: CSB Existing Chemicals
  Assessment Tracking System
fEB? Center for Environmental
CEEM: Center for Energy and
  Environmental Management
CEI: Compliance Evaluation
CELRF: Canadian Environmental
  Law Research Foundation
CEM: Continuous Emission
CEMS: Continuous Emission
  Monitoring System
CEPP: Chemical Emergency
  Preparedness Flan
CEO/. Council' on Environmental
CERCLA: Comprehensive
  Environmental Response,
  Compensation, and Liability
  Act (1980)
CERCUS: Comprehensive
  Environmental Response,
  Compensation, and Liability
  Information System
CERT: Certificate of Eligibility
CF: Conservation Foundation
CFG Chlorofluorocaibons
CFM: Chlorofluoromethanes
CFR: Code of Federal Regulations
CHABA: Committee on Hearing
  and Bio-Acoustics
CHAMP: Community Health Air
  Monitoring Program
CHEMNET: Chemical Industry
  Emergency Mutual Aid
CHESS: Community Health and
  Environmental Surveillance
CHIP: Chemical Hazard
  Information Profiles
d: Compression Ignition.
  Confidence Interval
OAQ: Council on Indoor Air
dBL: Convective Internal
  Boundary Layer
dCA: Competition in Contracting
ddS: Chemicals in Commerce
  Information System
dDRS: Cascade Impactor Data
  Reduction System
CDvQ: Committee on Integrity and
  Management Improvement
dS: Chemical Information
  System.  Contracts Information
CLC: Capacity Limiting
CLEANS: Qi«i«il Laboratory for
  Evaluation and Assessment of
 Toxic Substances
CLEVER: Clinical Laboratory for
  Evaluation and Validation of
   Epidemiologk Research
CLF: Conservation Law
CLIPS: Chemical List Index and
  Processing System
CLP: Contract Laboratory
CM: Corrective Measure
CMA: Chemical Manufacturers
CMB: Chemical Mas* Balance
CME: Comprehensive Monitoring
CMEL: Comprehensive Moni-
  toring Evaluation Log
CMEP: Critical Mass Energy
COCO: Contractor-Owned/
COD: Chemical Oxygen Demand
COH: Coefficient Of Haze
CPF: Carcinogenic Potency Factor
CPO: Certified Project Officer
CQA: Construction Quality
CR: Continuous Radon
CROP: Consolidated Rules of
CRP: Conservation Reserve
CRR: Center for Renewable
CKSl'tK: Single Source Dispersion
CSI: Compliance Sampling
CSIN: Chemical Substances
  Information Network
CSO: Combined Sewer Overflow
CSPA: Council of State Planning
CSRL: Center for the Study of
  Responsive Law
CTARC Chemical Testing and
  Assessment Research
CTG: •Control Techniques
 . Guidelines
CV: Chemical Vocabulary
CW: Continuous working-level
OVA: dean Water Act (aka
CWAP: dean Water Action
CWTC Chemical Waste
  Transportation Council
CZMA: Coastal Zone
  Management Act
CZARA: Coastal Zone
  Management Act
  Reaumorization Amendments
DAPSS: Document and Personnel
  Security System (IMD)
Dd: Data Call-In
DCO: Delayed Compliance Order
DCO: Document Control Officer
DDT: DichlbroDiphehyl-
DERs: Data Evaluation Records
DES: Diethylstilbesterol
DI: Diagnostic Inspection
DMR: Discharge Monitoring
  Report                f
DNA: Deoxyribonuclek add*
DO: Dissolved Oxygen
DOW: Defenders Of Wildlife
DPA: Deepwater Ports Act
DQO: Data Quality Objective
DRE: Destruction and Removal
DRES: Dietary Risk Evaluation
DRMS: Defense Reutilization and
  Marketing Servke
DRR: Data Review Record
DS: Dichotomous Sampler
DSAP: Data Self Auditing
DSCF: Dry Standard Cubic Feet
DSCM: Dry Standard Cubic Meter
DSS: Decision Support System
DSS: Domestic Sewage Study
DT: Detention Time
DT: Detectors (radon) damaged or
DU: Decision Unit Ducks
DUC Decision Unit Coordinator
DWEL: Drinking Water
  Equivalent Level
DWS: Drinking Water Standard
EA: Endangerment Assessment
   Enforcement Agreement
   Environmental Action.
   Environmental Assessment
   Environmental Audit
EAF: Electric Arc Furnaces
EAG: Exposure Assessment Group
EAP: Environmental Action Plan
EAR: Environmental Auditing
EB: Emissions Balancing
EC Emulsifiable Concentrate
EC Environment Canada
EC Effective Concentration
EGA: Economic Community for
ECAP: Employee Counselling and
   Assistance Program
ECD: Electron Capture Detector
ECHH: Electro-Catalytic Hyper-
   Heaters         •  •

   ECL: Environmental Chemical
   ECR: Enforcement Cage Review
   ECRA: Economic Cleanup
     Responsibility Act
   ED: Effective Doae
   EDA: Emergency Declaration Area
   EDB: Ethylene Dibromide
   EDO Ethylene Dichloride
   EDD: Enforcement Decision
   EDF: Environmental Defense Fund
   EDRS: Enforcement Document
     Retrieval System
   EDS: Electronic Data System
   EDS: Energy Data System
   EDTA: Ethylene Diamine Triacetic
     Acid   .
   EDX: Electronic Data Exchange
   EDZ: Emission Density Zoning
   EEA: Energy and Environmental
   EECs: Estimated Environmental
  HER: Excess Emission Report
  EERL: Eastern Environmental
     Radiation Laboratory
  EERU: Environmental Emergency
     Response Unit
  EESI: Environment and Energy
    Study Institute
  EESL: Environmental Ecological
    and Support Laboratory
  EETFC Environmental Effects,
    Transport, and Fate Committee
  EF: Emission Factor
  EFO: Equivalent Field Office
  EFTC European Fhiorocarbon
    Technical Committee
  EGR: Exhaust Gas Recalculation
  EH: Redox Potential
  EHC Environmental Health
  EH& Extremely Hazardous
  H: Emissions Inventory
  HA: Environmental Impact
    Assessment Economic Impact
 .EIL: Enwonmental Impairment
 PR: Endangerment Information
 EIR: Environmental Impact Report
 EIS: Environmental Impact
 EIS: Environmental Inventory '
 EIS/AS: Emissions Inventory
   System/Area Source
 E1S/P& Emissions Inventory
   System/Point Source
 EKMA: Empirical Kinetic
   Modeling Approach
 EL: Exposure Level
 ELI: Environmental Law Institute
 ELR: Environmental Law Reporter
 EM: Electromagnetic Conductivity
 EMAS: Enforcement Management
   and Accountability System
 EMR: Environmental Management
 EMS: Enforcement Management
 EMSL: Environmental Monitoring
   Support Laboratory
EMSL: Environmental Monitoring
   Systems Laboratory
EMTS: Environmental Monitoring
   Testine Site               *
  EMTS: Exposure Monitoring Test
     Site                    \
  EO: Ethylene Oxide       >
  EOC Emergency Operating * i-~
     Center                  ;
  EOF: Emergency Operations
     Facility (RTF)
  EOF: End Of Pipe
  EOT: Emergency Operations Team
  EP: Earth Protectors
  EP: Environmental Profile. End-
     use Product. Experimental
     Product Extraction Procedure
  EPAA: Environmental Programs
     Assistance Act
  EPAAR EPA Acquisition
  EPCRA: Emergency Preparedness
    and Community Right to Know
  EPACASR EPA Chemical
    Activities Status Report
  EPCA: Energy Policy and
    Conservation Act
  EPD: Emergency Planning District
  EPI: Environmental Policy
  EPIC Environmental Photo-
    graphic Interpretation Center
  EPNL: Effective Perceived Noise
  EPRI: Electric Power Research
  EFTC Extraction Procedure
    Toxitity Characteristic
  ER: Electrical Resistivity
  ERA: Economic Regulatory
 ERAMS: Environmental Radiation
    Ambient Monitoring System
 ERC Emergency Response
 ERC Emissions Reduction Credit
 ERC Environmental Research
 ERC& Emergency Response
   Cleanup Services
 ERDA: Energy Research and
   Development Administration
 ERDtDAA: Environmental
   Research, Development and
   Demonstration Authorization
 ERL: Environmental Research
 ERNS: EmergencyResponse
  Notification System
 ERP: Enforcement Response
 ERT: Emergency Response Team
 ERTAQ: ERT Air Quality Model
 ES: Enforcement Strategy
 ESA: Endangered Species Act
  Environmentally Sensitive Area
ESC Endangered Species
ESCA: Electron Spectroscopy for
  Chemical Analysis
ESCAP: Economic and Social
  Commission for Asia and the
   Environmental <
EStt Environmental Safety and

ESP: Electrostatic Precipitators
ET: Emissions Trading
ETP: Emissions Trading Policy
ETS: Environmental Tobacco
                                    EUP: Experimental Use Permit
                                    EWCC Environmental Workforce
                                      Coordinating Committee
                                    EXAMS: Exposure Analysis
                                      Modeling System
                                    ExEx: Expected Exceedance
   FACA: Federal Advisory
     Committee Act
   FAN: Fixed Account Number
     Enforcement System
   FBC Fhiidized Bed Combustion
   FCC Fluid Catalytic Converter
   FCCU: Fluid Catalytic Crackine
     Unit                   *
   FCO: Federal Coordinating, Officer
     (in disaster areas)
   FCO: Forms Control Officer
   FDF: Fundamentally Different
  FDL: Final Determination Letter
  FDO: Fee Determination Official
  FE: Fugitive Emissions
  FEDS: Federal Energy Data  .
  FEFx: Forced Expiratory Flow
  FEIS: Fugitive Emissions In-
    formation System
  FEL: Frank Effect Level
  FEPCA: Federal Environmental
    Pesticide Control Act; enacted
  '  as amendments to FIFRA.
  FERC Federal Energy Regulatory
  FES: Factor Evaluation System
  FEV: Forced Expiratory Volume
  FEV1: Forced Expiratory
    Volume—one second
  FEVI: Front End Volatility Index
  FF: Federal Facilities
  FFAfe.Fuel  and Fad Additive
  FFDCA: Federal Food, Drufc and
    Cosmetic Act
  FFF: Firm Financial FaciKty
  FFFSGFoosil-Fuel-Hred Steam
  FFIS: Federal Facilities
    Information System
 FFP: Firm Fixed Price
 FGD: Flue-Gas Desulfurization
 FID: Flame lonization Detector
 FIFRA: Federal Insecticide,
   Fungicide, and Rodentitide Act
 FIM: Friable Insulation Material
 FINDS: Facility Index System
 FTP: Final Implementation Plan
 FIPS: Federal Information
   Procedures System
 FIT: Field Investigation Team
 FLETO Federal Law Enforcement
   Training Center
 FLM: Federal Land Manager
 FLP: Flash Point
 FLPMA: Federal Land Policy and
   Management Act
 FMAP: Financial Management
   Assistance Project
 F/M: Food to Microorganism
FML: Flexible Membrane Liner
FMP: Facility Management Flan
FMP: Financial Management Flan
FM& Financial Management
                                             FOE: Friends Of the Earth
                                             FOIA:  Freedom Of Information
                                            . FOISD: Fiber Optic Isolated
                                               Spherical Dipole Antenna   ,
                                             FONSI: Finding Of No Significant
                                             FORAST: Forest Response to
                                               Anthropogenic Stress
                                            FP: Fine Particulate
                                            FPA: Federal Pesticide Act
                                            FPAS: Foreign Purchase Ac-
                                               knowledgement Statements
                                            FPD: Flame Photometric Detector
                                            FPEIS: Fine Particulate Emissions
                                               Information System
                                            FPM: Federal Personnel Manual
                                            FPPA:  Federal Pollution
                                               Prevention Act
                                            FFR Federal Procurement
                                            FPRS: Federal Program Resources
                                            FPRS: Formal Planning and
                                               Supporting System
                                            FR: Federal Register. Final
                                               Rulemaking         . *
                                            FRA: Federal Register Act
                                            FREDS: Flexible Regional
                                               Emissions Data System
                                            FRES: Forest Range
                                               Environmental Study
                                            FRM: Federal Reference Methods
                                            FRN: Federal Register Notice.
                                              Final Rulemaking Notice
                                            FRS: Formal Reporting System
                                            FS: Feasibility Study
                                            PSA: Food Security Act
                                            FS& Faculty Status Sheet
                                            FS& Federal Supply Schedule
                                            FTP: Federal Test Procedure (for
                                              motor vehicles)
                                            FT&Ffle Transfer Service
                                            FTT& FffRA/TSCA Tracking
                                            FUA: Fuel Use Act
                                            FURS: Federal Underground
                                              Injection Control Reporting
                                            FVMP: Federal Visibility
                                              Monitoring Program
                                            FWCA: Fish and Wildlife
                                              Coordination Act
                                           FWPCA: Federal Water Poflution
                                             and Control Act (aka CWA).
                                             Federal Water Po&ution and
                                             Control Administration
                                                                  GAAP: Generally Accepted
                                                                    Accounting Principles
                                                                  GAC Granular Activated Carbon
                                                                  GACT: Granular Activated
                                                                    Carbon Treatment
GCWR: Gross Combination
  Weight Rating
GDE: Generic Data Exemption
GEt Geographic Enforcement
GEMS: Gtobal Environmental
  Monitoring System
GEM& Graphical Expomre
                                                                 •FMVCP- Federal Motor Vehicle   •
                                          GEft Good Engmcermg Practice
                                          GFR Osjss Fiber Filter
                                          GFCh Grant Funding Order
                                          GFP: Govemment-Fumbhed

 GXCS: Grant Information uid
   Control System
 OS: Geographic Information
 Q& Global Indexing System
 GLO GSJI Uquld Cnromatography
 GLERU Gnat Lake* Environ-
   mental Research Laboratory
 GLNPO: Greet Lake* National
   Pjogiam Office
 GLP: Good Laboratory Practice*
 GLWQA: Great Lake* Water
   Quality Agreement
 CM CO Global Monitoring for
   Climatic Change
 G/MI: Gram* per mile
 COCO: Government-Owned/
   Contractor-Operated  '
 GOGO. Government-Owned/
 GOP: General Operating
 GOPO: Government-Owned/
 GPAD: GaOonff-per-acre per-day
 GFG: Grams-per-Gallon
 GPR: Ground-Penetrating Radar
 GPS: Groundwater Protection
 GR: Grab Radon Sampling
 GRCDA: Government Refute
   Collection and Di«po»al
 GRGL- Groundwater Residue
   Guidance Level
 GIN: Global Trend Network
 GTR:  Government Transportation
 GVP;  Gasoline Vapor Pressure
 GVW: Grow Vehicle Weight
 GVWR: Grooa Vehicle Weight
 GW: Grab Working-Level
   Sampling. Groundwater
 GWM: Groundwater Monitoring
 GWPS: Groundwater Protection
 GWPS: Groundwater Protection

 H    :•
 HA: Health Advisory
 HAD: Health Assessment
 HAP: Hazardous Air Pollutant
 HAPEMS: Hazardous Air
   Pollutant Enforcement
   Management System
 HAPPS: Hazardous Air Pollutant
   Prioritization System
 HATREMS: Hazardous and Trace
   Emissions System
 HAZMAT: Hazardous Materials
 HAZOP: Hazard and Operability

 HO Hazardous Constituents
 HO Hydrocarbon
 HCCPD: Hexachlorocyclo-
 HCP: Hypothermal Coal Process
 HDD: He*vy-Duty Diesel
HDE;  Heavy-Duty Engine
HDG: Heavy-Duty GasoEne-
  Powered Vehicle
HOPE High Density Polyethylene
HOT: Highest Dose Tested in a
  study. Heavy-Duty Truck
HDV: Heavy-Dury Vehicle
HEAL: Human Exposure
  Assessment Location
 HECO House Energy and
   Commerce Committee
 HEI: Health Effects Institute
 HEM: Human Exposure Modeling
 HEPA: High-Efficiency Particulate
 HERS: Hyperion Energy Recovery
 HHE: Human Health and the
 HHV: Higher Heating Value
 HI: Hazard Index
 HI-VOL: High-Volume Sampler
 HIWAY: A Line Source Model for
   Gaseouf Pollutants
 HLRW: High Level Radioactive
 HMIS: Hazardous Materials
   Informabon System
 HMS: Highway Mobile Source
 HMTA: Hazardous Materials
   Transportation Act
 HMTR: Hazardous Materials
   Transportation Regulations
 HOC Halogenated Organic
 HON: Hazardous Organic
 HOV: High-Occupancy Vehicle
 HP:  Horse Power
 HPLQ High-Performance Liquid
   Chroma tography
 HPV: High Priority Violator
 HQCDO: Headquarters Case
   Development Officer
 HRS: Hazardous Ranking System
 HRUP: High-Risk Urban Problem
 HSDB: Hazardous  Substance Data
 HSL: Hazardous Substance List
 HSWA: Hazardous and Solid
   Waste Amendments
 HT: Hypothermally Treated
 HTP: High Temperature and
 HVIO: High Volume Industrial
 HW: Hazardous Waste
 HWDMS: Hazardous Waste Data
   Management System
 HWGTF: Hazardous Waste
   Groundwater Task Force
 HWGTF: Hazardous Waste
  •Groundwater Test Facility
 HWLT: Hazardous Waste Land
 HWM: Hazardous  Waste
 HWRTF: Hazardous Waste
   Restrictions Task Force
 HWTO Hazardous Waste
   Treatment Council

 I/A: Innovative/Alternative
 IA: Interagency Agreement
 IAAO Interagency  Assessment
   Advisory Committee
 LAG: Interagency Agreement
 LAP:  Incentive Awards Program.
   Indoor Air Pollution
 IARO International Agency for
   Research on Cancer
IATDB: Interim Air Toxics Data
IBT: Industrial Biotest Laboratory
ICAIR: Interdisciplinary Planning
   and Information Research
ICAP: Inductively Coupled Argon
 ICB: Information Collection
 ICBN: International Commission
   on the Biological Effects of
 ICE: Industrial Combustion
   Emissions Model Internal
   Combustion Engine
 ICP: Inductively Coupled Plasma
 ICR: Information Collection
 ICRE: IgnitabiHty, Corrosivity,
   Reactivity, Extraction
 ICRP: International Commission
   on Radiological Protection
 ICS: Incident Command System.
   Institute for Chemical Studies.
   Intermittent Control Strategies.
   Intermittent Control System
 ICWM: Institute for Chemical
   Waste Management
 IDLH: Immediately Dangerous to
   Life and Health
 IEB: International Environment
 IEMP: Integrated Environmental
   Management Project
 IES: Institute for Environmental
 IFB: Invitation for Bid
 IFCAM: Industrial Fuel Choice
   Analysis Model
 IFIS: Industry File Information
   System              •
 IFPP: Industrial Fugitive Process
 IFMS: Integrated Financial
   Management System
 IGO: Industrial Gas Cleaning
 IRLG: Interagency Regulatory
   Liaison Group (Composed of
   EPA, CPSC, FDA, and OSHA)
 nS: Inflationary Impact Statement
 IJO International Joint Com-
   mission (on Great Lakes)
 I/M: Inspection/Maintenance
 IMM: Intersection Midblock
 IMPACT: Integrated Model of
   Plumes ana Atmosphere in
   Complex Terrain
 IMPROVE: Interagency
   Monitoring of Protected Visual
 INPUFF: Gaussian Puff Dispersion
 INT: Intermittent
 IOB: Iron Ore Benefication
 IOU: Input/Output Unit
 IP: Inhalable Particles
 IPM: Inhalable Particulate Matter.
   Integrated  Pest Management
 IPP: Implementation Planning
   Program. Integrated Plotting
   Package. Inter-media Priority
   Pollutant (document)
 IPCS: International Program on
   Chemical Safety
IPP: Independent Power Producer
 IRG: Interagency Review Group
IRIS: Instructional Resources
   Information System. Integrated
   Risk Information System
IRM: Intermediate Remedial
IRMO Inter-Regulatory Risk
   Management Council
IRP: Installation Restoration
IRPTO International Register of
   Potentially Toxic Chemicals
 IRR: Institute of Resource
 IRS: International Referral Systems
 IS: Interim Status
 ISAM: Indexed Sequential File
   Access Method
 ISO Industrial Source Complex
 ISCL: Interim Status Compliance
 ECLT: Industrial Source Complex
   Long Term Model
 ISCST: Industrial Source Complex
 •  Short Term Model
 ISO: Interim Status Document
 ISE: Icn-specific electrode
 ISMAP. Indirect Source Model for
   Air Pollution
 EPF: (IBM) Interactive System
   Productivity Facility
 I5S: Interim Status Standards
 ITO Interagency Testing
 IUR: Inventory Update Rule
 IWO uvStream Waste
 IWS: Ionizing Wet Scrubber
JAPCA: Journal of Air Pollution
   Control Association
JCL: Job Control Language
JEO Joint Economic Committee
JECFA: Joint Expert Committee of
   Food Additives
JLO Justification for Limited
JMPR: Joint Meeting on Pesticide
JNCP: Justification for Non-
   Competitive Procurement
JOFOO Justification for Other
   Than Full and Open
JPA: Joint Permitting Agreement
JSD: Jackson Structured Design
JSP: Jackson Structured
JTU: Jackson Turbidity Unit
LAA: Lead Agency Attorney
LADD: Lowest Acceptable Daily
LAER Lowest Achievable
  Emission Rate
LAI: Laboratory Audit Inspection
LAMP: Lake Acidification
  Mitigation Project
LO Lethal Concentration. Liquid
LCD: Local dimatological Data
LCL: Lower Control Limit
LCM: Life Cycle Management
LCRS: Leachate Collection and
  Removal System
LD: Land Disposal Light Duty
LD LO: The lowest dosage of a
  toxic substance that kuls test
LOG London Dumping
LDCRS: Leachate Detection,
  Collection, and Removal
LDD: Light-Duty Diesel
LDIP: Laboratory Data Integrity
LDR: Land Disposal Restrictions

 LDRTF: Land Disposal
   Restrictions Task Force
 LDS: Leak Detection System
 LOT: Lowest Dose Tested. Light-
   Duty Truck
 LDV: Light-Duty Vehicle
 LEL: Lowest Effect Level. Lower
   Explosive Limit
 LEP: Laboratory Evaluation
  • Program
 LEPC: Local Emergency Planning
 LERC Local Emergency Response
 LFL: Lower  Flammability Limit
 LGR: Local Governments
   Reimbursement Program
 UDAR: Light Detection and
 LIMB:  Limestone-Injection Multi-
   stage Burner
 LLRW: Low Level Radioactive
 LMFBR: Liquid Metal Fast Breeder
 LUIS: Label  Use Information

 MAPSIM: Mesoscale Air Pollution
   Simulation Model
 MEP: Multiple Extraction
 MOE: Margin Of Exposure
 MP: Manufacturing-use Product
   Melting Point
 MRF: Materials Recovery Facility
 MRID: Master Record
   Identification number
 MRL: Maximum-Residue Limit
   (Pesticide  Tolerance)
 MSW: Municipal Solid Waste
 MUF: Manufacturing-Use Product
 MUTA: Mutagenkity

 NFRAP: No  Further Remedial
   Action Planned
 NICT: National Incident
   Coordination Team
 NISAC National Industrial
   Security Advisory Committee  .
 NOA: Notice of Arrival
 NOAC Nature of Action Code
 NPHAP: National Pesticide,
   Hazard Assessment Program
 NSDWR: National Secondary
   Drinking Water Regulations
 NSEC:  National  System for
   Emergency Coordination
 NSEP: National System for
   Emergency Preparedness
OCD: Offshore and Coastal
OF: Optional Form
OLTS: On Line Tracking System
O&M: Operations and
ORM: Other Regulated Material
ORP: Oxidation-Reduction
PA1: Performance Audit
  Inspection (CWA)
• PAI: Pure Active Ingredient
 PAM: Pesticide Analytical Manual
 PAT: Permit Assistance Team^:'
   (RCRA)                 -;,
 PATS: Pesticide Action Tracking
 PATS: Pesticides Analytical
   Transport Solution
 PBA: Preliminary Benefit Analysis
 PCA: Principle Component
 PCM: Phase Contrast Microscopy
 PCN: Policy Criteria Notice
 PCO: Pest Control Operator
 PDd: Product Data Call-In
 PFCRA: Program Fraud Civil
   Remedies Act
 PHO Principal Hazardous
 PHSA: Public Health Service Act
 PI: Preliminary Injunction.
   Program Information
 PIG Products  of Incomplete
 PIGS: Pesticides in Groundwater
 PIMS: Pesticide Incident Mon-
   itoring System
 PIN: Pesticide  Information
 PIN: Procurement Information
PIP: Public Involvement Program
PIPQUIC: Program Integration
   Project Queries Used in
   Interactive Command
PIRG: Public Interest Research
PIRT: Pretreabnent Implemen-
   tation Review Task Force
PITS: Project Information Tracking
PURRA: Pollution Liability
   Insurance and Risk Retention
PLM: Polarized Light Microscopy
PLUVUE: Flume Visibility Model
PM: Paniculate Matter
PMlft Particulate Matter
   (nominally 10m and less)
PM15: Particulate Matter
   (nominally 15m and less)
PMEL: Pacific Marine Envi-
   ronmental Laboratory
PMN: Premanufacture Notifi-
PMNF: Premanufacture Noti-
   fication Form
PMR: Pollutant Mass Rate
PMRS: Performance Management
   and Recognition System
PMS: Program  Management
PNA: Polynuclear Aromatic
PO: Project Officer
POO Point Of  Compliance
POE: Point Of Exposure
POGO: Privately-Owned/
POHC: Principal Organic
   Hazardous Constituent
POt Point Of Interception
POLREP:Pollution Report
POM: Particulate Organic Matter.
   Polycyclic  Organic Matter
FOR: Program of Requirements
POJW: Publicly Owned
 POV: Privately Owned Vehicle
 PP: Program Planning
 PPA: Planned Program
 PPB: Parts Per Billion
 PPIC: Pesticide Programs
   Information Center
 PPIS: Pesticide Product Infor-
   mation System
 PPM/PPB: Parts per million/
   parts per billion
 PPMAP: Power Planning
   Modeling Application
 PPSP: Power Plant Siting Program
 PPT: Parts Per Trillion
 PPTH: Parts Per Thousand
 PQUA: Preliminary Quantitative
   Usage Analysis
 PR: Preliminary Review   '
 PRA: Paperwork Reduction Act
 PRA: Planned Regulatory Action
 PRATS: Pesticides Regulatory
   Action Tracking System
 PRC: Planning Research Cor-
 PRI: Periodic Reinvestigation
 PRM: Prevention Reference
 PRN: Pesticide Registration Notice
 PRP: Potentially Responsible Party
 PRZM: Pesticide Root Zone Model
 PS: Point Source
 PSAM: Point Source Ambient
 PSO Program Sate Coordinator
 PSD: Prevention of Significant
 PSES: Pretreabnent Standard* for
   Existing Sources
 PSI: Pollutant Standards Index
 PSI: Pounds Per Square Inch
 PSI: Pressure Per Square Inch
 PSIG: Pressure Per Square Inch
 PSM: Point Source Monitoring
 PSNS: Pretreabnent Standards for
   New Sources
 PSU: Primary Sampling Unit
 PTDIS: Single Stack Meteoro-
   logical Model in EPA
   UNAMAP Series
 PTE: Potential to Emit
 FIFE: Polytetrafluoroethylene
 PTMAX: Single Stack
   Meteorological Model in EPA
   UNAMAP series
 PTPLU: Point Source Gaussian
   Diffusion Model
 PUC: Public  Utility Commission
 PV: Project Verification
 PVO Polyvinyl Chloride
 PWS: Public  Water Supply/
 PWSS: Public Water Supply
QAC: Quality Assurance
QA/QO Quality Assistance/
  Quality Control
QAMIS: Quality Assurance
  Management and Information
QAO: Quality Assurance Officer
QAPP: Quality Assurance
  'Program lor Project) Plan •
 QBTU: Quadrillion British
   Thermal Units
 QO Quality Control
 QCA: Quiet Communities Act
 Qd: Quality Control Index
 QCP: Quiet Community Program
 QNCR: Quarterly Noncompliance
 QUA: Qualitative Use Assessment
 QUIPE: Quarterly Update for
   Inspector in Pesticide
 RA: Reasonable Alternative.
   Regulatory Alternatives.
   Regulatory Analysis. Remedial
   Action. Resource Allocation.
   Risk Analysis. Risk Assessment
 RAATS: RCRA Administrate
   Action Tracking System
 RAC.Radiation Advisory
 RAO Regional Asbestos Coor-
 RAO Response Action Coor-
   dinator               „
 RACM: Reasonably Available
   Control Measures
 RACT: Reasonably Available
   Control Technology
 RAD: Radiation Adsorbed Dose
   (unit of measurement of
   radiation absorbed by humans)
 RADM: Random Walk Advection
   and Dispersion Model
 RADM: Regional Acid Deposition
 RAM: Urban Air Quality Model
   for Point and Area Source in
   EPA UNAMAP Series
 RAMP: Rural Abandoned Mine
 RAMS: Regional Air Monitoring
 RAP: Radon Action Program
 RAP: Reregisbation AMeannent
 RAP: Remedial Accomplishment
 RAP: Response Action Plan
 RAPS: Regional Air Pollution
 RARG: Regulatory Analysis
 RAS: Routine Analytical Service
 RAT: Relative Accuracy Test
 RB: Request for Bid
 RO Responsibility Center
 RCO Radiation Coordinatine
 RCDO: Regional Case
   Development Officer
 RCP: Research Centers Program
 RCRA: Resource Conservation
   and Recovery Act
 RCRIS: Resource Conservation
   and Recovery Information
 RD/RA: Remedial Design/
   Remedial Action
 R&D: Research and Development
 KDJcD: Research, Development
   and Demonstration
 RDF: Refuse-Derived Fuel
 rDNA: Recombinant DNA
 RDU: Regional Decision Units
RDV: Reference Dow Values
RE: Reasonable Efforts
RE Reportable Event

  REAP: X*fknal
  REE: Rut Earth Etaatab
  KEEP: Review of Enriroasnsntel
    Effects of PoBuiis*   .  •
  REM (RiMntfM Eqpdntal tte4
    InvesrlgtHon T
    Management System
  REP: Rsesonable Efforts Program
  REPS: Regional Enr»«»«M
    Project iiMi System
  RESOLVE: Center for Envi-
    ronmental Conflict Resolution
  RF: Response Factor
  RFA: Regulatory Flexibility Art
  RFB: Request for Bid
  RFD: Reference DOM Value*
  RFt Remedial Held Investigation
  RFP: Reasonable Further Pro-
    grams. Reque** for Proposal
  RHRS: Revised Hazard Ranking
  RI: Reconnaissance Inspection
  RI: Remedial Investigation
  RIA: Regulatory Impact Analysis
  RIA: Regulatory Impart
  RIO Radon Information Center
  RICC Retirement Information and
    Counseling Cento
  RICO Racketeer Influenced and
    Corrupt Organization Art
  R1/P5: Remedial Information/
    Feasibility Study
  RIM: Regulatory Interpretation
  RIN: Regulatory Identifier
 RIP: RCRA Implementation Flan
 RISC Regulatory Information
   Service Center
 RJE: Remote Job Entry
 RLL: Rapid and Large Leakage
    (Ralef         ^     ^
 RMCLs Recommended Maximum
   Contaminant Level (mis phrase
   being discontinued in favor of
 RMDHS: Ragjonal Model Data
   Handling System
 RM1S: Resources Management
   Information System
 RNA: Ribonudek Acid
 ROADCHEM: Roadway Version
   that Includes Chemical
   Reactions of BL NO, and O,
 ROADWAY: A Model to Predict
   Pollutant Concentrations Near «
 ROO Record Of Communication
 RODS: Records Of Decision
 ROC: Reactive Organic Cases
 ROLLBACK: A Proportional
   Reduction Model
 ROM: Regional Oxidant Model
 ROMCOE- Rocky Mountain
   Center on Environment
 ROft Regional Oversight Policy
 ROPA: Record Of Procurement
RP: Radon Progeny Integrated
   Sampling. ReapiraHe
   Partfculates. Responsible Party
RPAR: RebuttaMe Presumption
   Againit Registration
RPMs Reactive Plume Model.
   Remedial Project Manager
RQ: Reportabie Quantities
  RHC Regional Resporve Center
  RRT: Regional Rssporae Team
  RRT: Requisite Remedial
  R& RegMtration Standard
  RSCO Regional Sample Control
  RSD: Rfak-Spedfk Done
  RSE: Removal Site Evaluation
  RTCM: Reasonable Transportation
     Control Measure
  RTDM: Rough Terrain Diffusion
  RTECS: Registry of Toxic Effects
     of Chemical Substances
  RTM: Regional Transport Model
  RUP: Restricted Use Pesticide
  RVP: Reid Vapor Preseure
  RWC Residential Wood
  S&A: Sampling and Analysis.
    Surveillance and Analysis
  SAB: Science Advisory Board
  SAO Suspended and Cancelled
  SAEWG: Standing Air Emissions
    vVoxx Group
  SAIO Special-Agents-In-Charge
  SAIP: Systems Acquisition and
    Implementation Program
  SAMWG: Standing Air Moni-
    toring Work Group
  SANE: Sulfur and Nitrogen
  SANSS: Structure and Nomen-
    clature Search System
  SAP: Scientific Advisory Panel
  SAR Start Action Request
    Structural Activity Relationship
    (of a qualitative assessment)
 SARA: Superfund Amendments
    and Reauthorization Art of
 SAROAD: Storage and Retrieval
    Of Aeromeuic Data
 SAS: Special Analytical Service.
   Statistical Analysis System
 SASS: Source Assessment
   Sampling System
 SC Sierra dub
 SCAR Superfund Consolidated
   AccompUshmenis Plan
 SCBA: Self-Contained Breaming
 SCC'Source Classification Code
 SCFM: Standard Cubic Feet Per
  ' Minute
 SCLDF: Sierra dub Legal Defense
 SCR: Selective Catalytic Reduction
 SCRAM:  State Consolidated
   RCRA Authorization Manual
 SCRC Superfund Community
   Relations Coordinator
 SCS: Supplementary Control
 SCSA: Soil Conservation Society
   of America
 SCSP: Storm and Combined Sewer
 SCW: Supercritical Water
 SDO Systems Decision Plan
SDWA: Safe Drinking Water Art
SEAz State Enforcement
SEA: State/EPA Agreement
SEAM: Surface, Environment, and
  SEAS: StratsgfcJEnviroiiiiieiUal

  SEIA: Sodoeconomic Impart
  SEM: Standard Error of the Means
  SEP: Standard Evaluation
  SEPWC Senate Environment and
     Public Work* Committee
  SERC State Emergency Planning
  SES: Secondary Emissions
  SETSjSite Enforcement Tracking
  SF: Standard Form. Superfund
  SFA: Spectral Flame Analyzers
  SFDS: Sanitary Facility Data
  SFFAS: Superfund Financial
    Assessment System      ,
  SFTREG: State FIFRA Issues
    Research and Evahiation Group
  SPS: State Funding Study
  SHORTZ: Short Term Terrain
  SHWL: Seasonal High Water
  SI: International System of Units.
    Site Inspection. Surveillance
    Index.  Spark Ignition
  SIC Standard Industrial
  SICEA: Steel Industry Compliance
    Extension Art
  SIMaSecondary Ion-Mass
    Lfpcc ii'uu letiy
  SIP: State Implementation Plan
  SITE: Superfund Innovative
    Technology Evaluation
  SLAMS: State/Local Air
    Monitoring Station
  SLSM: Simple Line Source Model
 SMART: Simple Maintenance of
 SMCRA; Surface Mining Control
    and Reclamation Art
 SME: Subject Matter Expert
 SMO: Sample Management Office
 SMOA: Superfund Memorandum
    of Agreement
 SMSA: Standard Metropolitan
   Statistical Area
 SNA: System Network
 SNAAQS:  Secondary National
   Ambient Air Quality Standards
 SNAP: Significant Noncompliance
   Action jrrogram
 SNARL: Suggested No Adverse
 SNC: Significant Noncompliers
 SNUR: Significant New Use Rule
 SOC Synthetic Orgardc Chemicals
 SOCMI: Synthetic Organk
  Chemicals Manufacturing
 SOTDAT: Source Test Data
 SOW: Scope Of Work",
 SPAR: Status of Permit
  Application Report
 SPCC Spill Prevention, Con-
  tainment, and Countenneasure
 SPE: Secondary Particulate
 SPF: Structured Programming
SPI: Strategic Planning Initiative
SPLMD: Soil-pore Liquid
  Monitoring Device
SPMS: Special Purpose Monitoring
  SPMS: Strategic Planning and
     Management System
  SPOC Single Point Of Contact
  SPS: State Permit System
  SPSS: Statistical Package for the
  SPUR: SoftwarePackage for
     Unique Reports
  SQBR- Small Quantity Burner
  SQG: Small Quantity Generator
  SRAP: Superfund Remedial
     Accomplishment Plan
  SRC Solvent-Refined Coal
  SRM: Standard Reference Method
  SRP: Special Review Procedure
  SRR: Second Round Review.
    Submission Review Record
  SRT5: Service Request Tracking
  SS: Settieable Solids. Superfund
    Surcharge. Suspended Solids
  SSA: Sole Source Aquifer
  SSAC Soil Site Assimilated
  SSO State Superfund Contracts
  SSD: Standards Support
  SSHS: Standard Support andT
    Environmental Impact*
    Statement Stationary Source
    Emissions and Inventory
  SSI: Size Selective Inlet
  SSMS: Spark Source Mass
    tj pec 11*011 te uy
  SSO: Source Selection Official
  SSTS^Section Seven Tracking
  SSURCh Stop Sale, Use and
    Removal Order
  STAPPA: State and Territorial Air
  STALAPCO: State and Local Air-
    PoQution Control Officials
 STAR: Stability Wind Rose. State
    Acid Rain Projects
 STEL: Short Term Exposure Limit
 STEM: Scanning Transmission-
    Electron Microscope
 STN: Scientific and Technical
    Information Network
 STORET: Storage and Retrieval of
   Water-Related Data
 STP: Sewage Treatment Plant.
   Standard Temperature  and
 SUP: Standard Unit of Processing
 SURE: Sulfate Regional
   Experiment Program
 SV: Sampling Visit
 SW: Slow Wave
 SWC Settlement With Conditions
 SWDA: Solid Waste Disposal Act
 SWIE: Southern Waste Infor-
   mation Exchange
 SWMU: Solid Waste Management
 SWTR Surface Water Treatment
 SYSOP: Systems Operator
TAG: Technical Assistance Grant
TALM& Tunable Atomic Line
  Molecular Spectroscopy
TAMS: Toxic Air Monitoring
TAMTAC Toxic Air Monitoring
 ' System Advisory Committee

     TAP: Technical Assistance
     T^DS: Toxk Air Ponutant Dtta
     TAS; Tolerance AaMaoacRt
     TBT: Tributyltin
     TC: Target Concentration.
       Technical Center. Tenacity
       Characteristics. Toxic
    TCDD: Dioxin (Tetrachlorodi-
    TCDF: Tetrachlorodi-benzofurans
    TCE: Trichloroethylene
    TCLP: Total Concentrate Leachate
      Procedure. Toxicity
      Characteristic Leachate
    TCM: Transportation Control
    TCP: Transportation Control Plan.
    TCRI: Toxic Chemical Release
    TD: Toxic Dose
    TDS: Total Dissolved Solids
    TEAM: Total .Exposure
      Assessment Model
   TEC Technical Evaluation
   TEG: Tetraethylene Qycol
   TEGD: Technical Enforcement
     Guidance Document
   TEM: Texas Episodic Model
   TEP: Typical End-use Product
     Technical Evaluation Panel
   TERA: TSCA Environmental
     Release Application
   TES: Technical Enforcement
   TEXIN: Texas Intersection Air
     Quality Model
  TGO: Total Gross Output
  TGAI: Technical Grade of the
    Active Ingredient
  TCP: Technical Grade Product
  THC: Total Hydrocarbons
  THM: Trihaloroethane
  TI: Temporary Intermittent
  TI: Therapeutic Index
  TIBL: Thermal Internal Boundary

  TIC: Technical Information
    Coordinator. Tentatively
    Identified Compounds   •
  TIM: Technical Information
  TIP: Transportation Improvement
  TIS: Tolerance Index System
  TEE: Take It Somewhere Else
 TTTC: Toxic Substance Control Act
    Interagency Testing Committee
 TLV: Threshold Limit Value