DOCUMENT RESUME

ED 134 459 SE 021 936

AUTHOR Studdard, Gloria J., Comp.TITLE Common Environmental Terms: A Glossary. Revised

Edition.-INSTITUTION Environmental Protection Agency, Washington, D. C.PUB DATE Nov 74NOTE 27p.; For 1973 edition, see ED 103 217

EDRS PRICEDESCRIPTORS

MF-$0.83 HC-$2.06 Plus Postage.Conservation (Environment); *Environment;*Environmental Education; *Glossaries; NaturalResources; Pollution; *Reference Books; ScienceEducation; Secondary Edacation

ABSTRACTThis glossary is designed for students studying about

the environment. The document is not intended for scientists andtechnicians. Several hundred terms are included in the glossary.(RH)

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U S DEPARTMENT OF HEALTH,EDUCATION II WELFARENATIONAL INSTITUTE OF

EDUCATION

THiS (DOCUMENT HAS BEEN REPRO.DUCE() EXACTLY AS RECEIVEO FROMTHE PERSON OR ORGANIZATION ORIGIN-ATING ,T POINTS OF VIEW OR OPINIONSSTATEO DO NOT NECESSARILY REPRE-SENT OFFICIAL NATIONAL INSTITUTE OFEOLICATION POSITION OR POLICY

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A Glossary

2

ammon EmAronmentalTerms

A Glossary

Compiled by

GLORIA J. STuDDARDEPA Region IV

Atlanta, Ga.

U.S. Environmental Protection AgencyWashington, D.C.

Revised November 1974

3

Fore\,vord

The w olds and tetins included in this glossary are used in discussing andibout the en\ iionment We have excepted household words generally

understood And defined els.,,,vhere. such as water or air. but havL includedcertain common words \vhidi. whde not peculiar to the environment, occurfregaently in environmental literature and are important to a student's under-standing of pollution problemswords like adsorption or rodenticide. The

ssary also explains the moaning of words such as dust and abatement asthey apply to the cm ironmont ceil though definitions of such words arefound us ordinal y dictionaries.

In sum, we }we endeavored in a single listing to compile and define themost common words and rerms essential to the study, understanding andsolution of environmental problems. Where so many' words and terms areconcerned. it is sometimes difficult to settle upon definitions acceptable tousers w.lio represent a great variety of pursuits and interests. This is particu-lark true of chc newer words generated by science and technology. It may berec.dled that Dr. Samuel Johnson once described a compiler of dictionariesI. .1 "harmless drudge.' and observed: "Dictionaries are like watches; theworst is better dun none, and the best eannot be expected to go quite true."

We do not expect thk glossary to he used extensively by technicians andprofessionals in environmental control. It was not designed for that purpose.Rather, it is our hope that it will stimulate and improve a student's under-st.inJing of man's emironment and the interrelationship of the forces andelements that comprise it.

AcknowledgementsSo many good people helped compile this glossary it would be impossible

to list them all. but sincac thanks go to each. Employees of EPA's RegionIV deserve special mention for contributing words for inclusion.

Specific credit should be given to my major sources: Paul Sarnoff'sdelifhtful The Vew York Times Encyclopedic Dictionary of the Environ->nent, Herbert Hanson's Dicti(mary of Ecology. the American Society of CivilEngineers' Glossary---ll'atcr _and Sewage Control Engineering, Veatch andHumphrys' Water and Water Use Terminology and a myriad of other equallygood, bin untraceable sources.

My especial thanks go to Charles Pou for his patience and moral support,to Dr. Walter Bishop, my mentor, and to Daisy Sawicki for her beautifultyping and for uncomplainingly correcting my misspelling of "eutrophication"all the way through.

4 G. J. S.

abatement: The method of reducing thedegree or intensity of pollution, alsothe use of such a method.

absorption: The penetration of a sub-stance into or through another. Forexample. in air pollution control, ab-sorption is the dissolving of a solublegas, present in an emission, in a liquidwhich can be extracted.

accelerator: In radiology, a device forimparting high velocity to chargedparticles such as electrons or protons.These fast particles can penetratematter and are known as radiation.

acclimation: The physiological and be-havioral adjustments of an organismto changes in its immediate environ-ment.

acclimatizadon: The acclimation or adap-tation of a particular species overseveral generations to a markedchange in the environment.

activated carbon: A highly adsorbentform of carbon, used to remove odorsand toxic substances from gaseousemissions. In advanced waste treat-ment, activated carbon is used toremove dissolved organic matterfrom waste water.

activated sludge: Sludge that has beenaerated and subjected to bacterialaction, used to remove organic matterfrom sewage.

activated sludge process: The process ofusing biologically active sewage sludgeto hasten breakdown of organic mat-ter in raw sewage during secondarywaste treatment.

acute toxicity: Any poisonous effect pro-duced within a short period of time,usually up to 24-96 houis, resultingin severe biological harm and oftendeath.

ak curtsks

adaptation: A cllange in structure orhabit of an organism that producesbetter adjustment to the environment.

adsorption: The adhesion of a substanceto the surface of a solid or liquid.Adsorption is often used to extractpollutants by causing them to be at-tached to such adsorbents as activatedcarbon or silica gel. Hydrophobic, orwater-repulsing adsol bents, are usedto extract oil from waterways in oilspills.

adulterants: Chemicals or substances thatby law do not belong in a food, plant,animal or pesticide formulation. Adul-terated products are subject to seizureby the Food and Drug Administration.

advanced waste treatment: Waste watertreatment beyond the secondary orbiological stage that includes removalof nutrients such as phosphorus andnitrogen and a high percentage of sus-pended solids. Advanced waste treat-ment, known as tertiary treatment, isthe "polishing stage" of waste watertreatment and produces a high qualityeffluent.

aeration: The process of being suppliedor impregnated with air. Aeration isused in waste water treatment tofoster biological and chemical puri-fication.

aerobic: This refers to life or processesthat can occur only in the presenceof oxygen.

aerosol: A suspension of liquid or solidparticles in the air.

afterburner: An atr pollution abatementdevice that removes undesirable or-ganic gases through incineration.

agricultural polludon: The liquid andsolid wastes from all tyr. :If farm-ing, including runoff :.c., oesticides,fertilizers and feedk., *ion anddust from plowing .^. il manureand carcasses and iidues anddebris. It has beeli .,ated thatagricultural pollution in the U.S. hasamounted to more than 21/2 billiontons per year.

air curtain: A method for mechanicalcontainment of oil spills. Air isbubbled through a perforated pipe

5

air mass

causing an upward water flow thatretards the spreading of oil. Air cur-tains arc also used as barriers to pre-vent fish from entering a pollutedbody of water.

air mass: A widespread body of air withproperties that were established whilethe air was situated over a particularregion of the earth's surface and thatundergoes specific modifications whilein transit away from that region.

air monitoring: See monitoring.

air pollution: The presence of contami-nants in the air in concentrations thatprevent the normal dispersive abilityof the air and that interfere directlyor indirectly with man's health, safetyor comfort or with the full use andenjoyment of his property.

air pollution episode: The occurrence ofabnormally high concentrations of airpollutants usually due to low windsand temperature inversion and accom-panied by an increase in illness anddeath. See inversion.

air quality control region: An area desig-nated by the Federal governmentwhere two or more communitieseither in the same or different statesshare a common air pollution prob-lem.

air quality criteria: The levels of Pollu-tion and lengths of exposure at whichadverse effects on health and welfareoccur.

air quality standards: The prescribedlevel of pollutants in the outside airthat cannot be exceeded legally dur-ing a specified time in a specifiedgeographical area.

algal bloom: A proliferation of livingalgae on the surface of lakes, streamsor ponds. Algal blooms are stimulatedby phosphate enrichment.

alpha particle: A positively charged par-ticle emitted by certain radioactivematerials. It is the least penetratingof the three common types of radi-ation (alpha, beta and gamma) andusually not dangerous to plants, ani-mals or man.

ambient air: Any unconfined portion ofthe atmosphere: the outside air.

anadromous: Type of fish that ascendrivers from the sea to spawn.

26

- _- - ..anaerobic: Refers to life or processes

that occur in the absence of oxygen.

anticoagulant: A chemical that interfereswith blood clotting, often used as arodenticide.

anti-degradation clause: A provision inair quality and water quality lawsthat prohibits deterioration of air orwater quality in aieas where the pol-lution levels are presently belowthose allowed.

aquaculture project: A controlled dis-charge of pollutant, to enhance growthor propagation of harvestable fresh-water. estuarine, or marine life plantor animal species.

aquifer: An underground bed or stratumof earth, gravel or porous stone thatcontains water.

aquatic plants: Plants that grow in watereither floating on the surface, growingup from the bottom of the body ofwater or growing under the surfaceof the water.

area source: In air pollution, any smallindividual fuel combustion source, in-cluding any transportation sources.This is a general definition; areasource is legally and precisely definedin Federal regulations. See pointsource.

asbestos: A mineral fiber with countlessindustrial uses: a hazardous air pol-lutant when inhaled: its effects as awater pollutant are under scrutiny.

A-Scale sound level: The measurement ofsound approximating the auditorysensitivity of the human ear. TheA-Scale sound level is used to meas-ure the relative noisiness or annoy-ance of common sounds.

assimilation: Conversion or incorpora-tion of absorbed nutrients into proto-plasm. Also refers to tbe ability of abody of water to purify itself of or-ganic pollution.

atmosphere: The layer of air surroundingthe earth.

atomic pile: A nuclear reactor.

attractant: A chemical or agent that luresinsects or other pests by olfactorystimulation.

tributing processes of air pollution,the others are vaporization and com-bustion.

audiometer: An instrument for measur-ing hearing sensitivity.

autotrophic: Self-nourkhing; denotingthose organisms capable of construct-ing organic matter from inorganicsubstances.

backfill: The material used toditch or other excavation,process of doing so.

background level: With respect to airpollution, amounts of pollutants pres-ent in the ambient air due to naturalsources.

refill aor the

background radiation: Normal radiationpresent in the lower atmosphere fromcosmic rays and from earth sources.

bacteria: Single-celled micre nganismsthat lack chlorophyll. Some bacteriaare capable of causing human, animalor plant diseases, others are essentialin pollution control because theybreak down organic matter in the airand in the water.

baffle: Any deflector device used tochange the direction of flow or thevelocity of water, sewage or productsof combustion such as fly ash orcoarse particulate matter. Also usedin deadening sound.

baghouse: An air pollution abatementdevice used to trap particulates byfiltering gas streams through largefabric bags, usually made of glassfibers.

baling: A means of reducing the volumeof solid waste by compaction.

ballistic separator: A machine that sep-

biological control

arates inorganic from organic matterin a composting process.

band application: With respect to pesti-cides, the application of the chemicalover or next to each row of plantsin a field.

bar screen: In waste water treatment, ascreen that removes large floating andsuspended solids.

basal application: With respect to pesti-cides, the application of the pesticideformulation on stems or trunks ofplants just above the soil line.

basin: See river basin.

benthic region: The bottom of a bodyof water. This region supports thebenthos, a type of life that not onlylives upon, but contributes to thecharacter of the bottom.

benthos: The plant and animal life whosehabitat is the bottom of a sea, lakeor river.

beryllium: A metal that when airbornehas adverse effects on human health;it has been declared a hazardous airpollutant. It is primarily dischareedby operations such as machine shops,ceramic and propellant plants andfoundries.

beta particle: An elementary particleemitted by radioactive decay that maycause skin burns. It is easily stoppedby a thin sheet of metal.

bioassay: The employment of living or-ganisms to determine the biologicaleffect of some substance, factor orcondition.

biochemical oxygen demand (BOD): Ameasure of the amount of oxygenconsumed in the biological rrocessesthat break down organic matter inwater. Large amounts of organicwaste use up large amounts of dis-solved oxygen, thus the greater thedegree of pollution, the greater theBOD.

biodegradable: The process of decompos-ing quickly as a result of the actionof microorganisms.

biological control: A method of con-trolling pests by means of introduced

73

biological oxidation

or naturally occurring predatory orga-nisms, sterilization or the use of in-hibiting hormones, etc., rather thanby mechanical or chemical means.

biological oxidation: The proeess bywhich bacterial and other microorga-nisms feed on complex organic mate-rials and decompose them. Self-purification of waterways and acti-vated shidge and trickling filter wastewater treatment processes depend onthis principle. The process is alsocalled biochemical oxidation.

blomonitoring: The use of living orga-nisms to test the suitability of effluentfor discharge into receiving watersand to test the quality of such watersdownstream from a discharge.

biosphere: The portion of the earth andits atmosphere capable of supportinglife.

biostabilizer: A machine used to convertsolid waste into compost by grindingand aeration.

biota: All the species of plants and ani-mals occurring within a certain area.

bloom: .A proliferation of living algaeand/or other aquatic plants on thesurface of lakes or ponds. Bloomsare frequently stimulated by phos-phate enrichment.

ROD: See biochemical oxygen demand.

ROD.: The amount of dissolved oxygenconsumed in five days by biologicalprocesses breaking down organic mat-ter in an effluent. See biochemicaloxygen demand.

bog: Wet, spongy land usually poorlydrained, highly acid and rich in plantresidue.

boom: A floating device that is used tocontain oil on a body of water.

botanical pesticide: A plant-producedchemical used to control pests: for ex-ample, nicotine, strychnine or orpyre-thrun.

brackish water: A mixture of fresh andsalt water.

breeder: A nuclear reactor that producesmore fuel than it consumes.

4

broadcast application: With respect topesticides. the application of a chem-ical over an entire field, lawn orother area.

burial ground (graveyard): A place forburying unwanted radioactive mate-rials to prevent radiation escape, theearth or water acting as a shield.Such materials must be placed inwater-tight, noncorrodible containersso the radioactive mate:ial cannotleach out and invade undergroundwater supplies.

cadmium: See heavy metals.

carbon dioxide (CO..): A colorkss, odor-less. nonpoisonous vas that is a nor-mal part of the amb...nt air. CO2 is aproduct of fossil fuel cmnbustion, andsome researchers have theorized thatexcess CO., raises atmospheric tem-peratures.

carbon monoxide (CO): A colorless,odorless, highly toxic gas that is anormal byproduct of incomplete fossilfuel combustion. CO, one of themajor air pollutants, can be harmfulin small amounts if breathed over acertain period of time.

carcinogenic: Cancer producing.

catalytic converter: An air pollutionabatement device that removes organ-ic contaminants by oxidizing theminto carbon dioxide and water throughchemical reaction. Can be used toreduce nitrogen oxide emissions frommotor vehicles.

caustic soda: Sodium hydroxide (Na0H),a strongly alkaline, caustic substanceused as the cleaning agent in somedetergents.

cells: With respect to solid waste dis-

posal, earthen compartments in whichsolid wastes are duruNd, compactedand covered over daily with layersof earth.

centrifugal collector: Any of severalmechanical systems using centrifugalforce to remove aerosols from a gasstream.

cfs: Cubi, feet per second, a measure ofthe amount of w,ater passing a givenpoint.

channelizafion: The straightening anddeepening of streams to permit waterto move faster, to reduce flooding orto drain marshy acreage for farming.However, channelization reduces theorganic waste assimilation capacity ofthe stream and may disturb fishbreeding and destroy the stream'snatural beauty.

chemical oxygen demand (COD): Ameasure of the amount of oxygenrequired to oxidize organic and oxi-dizable inorganic compounds inwater. The COD test, like the BODtest, is used to determine the degreeof pollution in an effluent.

chemosterilant: A pesticide chemicalthat controls pests by destroyingtheir ability to reproduce.

chilling effect: The lowering of the earth'stemperature due to the increase ofatmospheric particulates that inhibitpenetration of the sun's energy.

chlorinated hydrocarbons: A class ofgenerally long-lasting, broad-spectruminsecticides of which the best knownis DDT, first used for insect controlduring World War II. Other similarcompounds include aldrin, dieldrin,heptachlor, chlordane, lindane, endrin,mirex, benzene hexachloride (BHC),and toxaphene. The qualities of per-sistence and effectiveness against awide variety of insect pests were longregarded as highly desirable in agri-culture, public health and home uses.But later research has revealed thatthese same qualities may represent apotential hazard through accumulationin the food chain and persistence inthe environment.

chlorination: The application of chlorine

coliform organism

to drinking water, sewage or indus-trial waste for disinfection or oxida-tion of undesirable compounds.

chlorinator: A dcvicc fur adding achlorine-containing gas or liquid todrinking or waste water.

chlorine-contact chamber: In a wastetreatment plant, a chamber in whicheffluent is disinfected by chlorine be-fore it is discharged to the receivingwaters,

chlorosis: Yellniying or whitening of nor-mally green plant parts. It can becaused by glisease organisms, lack ofoxygen or nutrients in the soil or byvarious air .pollutants.

chromium: See heavy metals.

chronk: Marked by long duration orfrequent recurrence, as a disease.

clarification: In waste water treatment,the removal of turbidity and sus-pended solids by settling, often aidedby centrifugal action and chemicallyinduced coagulation.

clarifier: In waste water treatment, asettling tank which mechanically re-moves settleable solids from wastes.

coagulafion: The clumping of particles inorder to settle out impurities; ofteninduced by chemicals such as lime oralum.

coastal zone: Coastal waters and adja-cent lands that exert a measurableinfluence on the uses of the sea andits ecology.

COD: See chemical oxygen demand.

coefficient of haze (COH): A measure-ment of visibility interference in theatmosphere.

coffin: A thick-walled container (usuallylead) used for transporting radioactivematerials.

COH: See coefficient of haze.

coliform index: An index of the purityof water based on a count of its coli-form bacteria.

coliform organism: Any of a number oforganisms common to the intestinaltract of man and animals whose

95

combined sewers

presence in waste water is an indi-cator of pollution and of potentiallydangerous bacterial contamination.

combinod sewers: A sewerage systemthat carries both sanitary sewage andstorm water runoff. During dryweather, combined sewers carry allwaste water to the treatment plant.During a storm, only part of the flowis intercepted because of plant over-loading; the remainder goes untreated

,to the receiving stream.

combustion: Burning. Technically. a rapidoxidation accomoanied by the releaseof energy in the form of heat andlight. It is one of the :hree basic con-tributing factors causing air pollution,the others are attrition and vaporiza-tion.

comminution: Mechanical shredding orpulverizing of waste, a process thatconverts it into a homogeneous andmore manageable material. Used insolid waste management and in theprimary stage of waste water treat-ment.

comminutor: A device that grinds solidsto make them easier to treat.

compaction: Reducing the bulk of solidwaste by rolling and tamping.

compost: Relatively stable decomposedorganic material.

composting: A controlled process of de-grading organic matter by microorga-nisms. ( I ) mechaticala method inwhich the compost is continuouslyand mechanically mixed and aerated.(2) ventilated cellcompost is mixedand aerated by being dropped througha vertical series of ventilated cells.(3) windrowan open-air method inwhich compostable material is placedin windrows, piles or ventilated binsor pits and occasionally turned ormixed. The process may be anaerobicor aerobic.

contact pesticide: A chemical that killspests on contact with the body, ratherthan by ingestion (stomach poison).

contrails: Long narrow clouds caused bythe disturbance of the atmosphereduring passage of high-flying jets.Proliferation of contrails may cause

6

10

changes in the weather.

Coolant: A substance, usually liquid orgas, uscd for cooling any part of areactor in which heat is generated,including the core, the reflector, shieldand other elements that may beheated by absorption of radiation.

cooling tower:Nib fromoperations.generation.

A device to remove excesswater used in industrialnotably in electric power

core: The heart of a nuclear reactorwhere energy is released.

cover material: Soil that is used to covercompacted solid waste in a sanitarylandfill.

cultural eutrophication: Acceleration byman of the natural aging process ofbodies of water.

curie: A measure of radioactivity.

cutie-pie: A portable instrument equippedwith a direct reading meter used todetermine the level of radiation inan area.

cyclone collector: A device used to col-lect large-size particulates from pol-luted air by centrifugal force.

DDT: The first of the modern chlori-nated hydrocarbon insecticides whosechemical name is 1,I,I-tricholoro-2,2-bis (p-chloripheny1)-ethane. It has ahalf-life of l5 years. and its residuescan become concentrated in the fattytissues of certain organisms, especiallyfish. Because of its persistence in theenvironment and its ability to accu-mulate and magnify in the foodchain. EPA has banned the registra-tion and interstate sale of DDT fornearly all uses in the United Stateseffective December 31, 1972.

decibel (dB): A unit of sound measure-ment.

decomposition: Reduction of the netenergy level and change in chemicalcomposition of organic matter be-cause of the actions of aerobic oranaerobic microorganisms.

dermal toxicity: The ability of a pesti-cide chemical to poison an animal orhuman by skin absorption.

desalinization: Salt removal from sea orbrackish water.

desiccant: A chemical agent that may beused to remove moisture from plantsor insects causing them to wither anddie.

detergent: Synthetic washing agent that,like soap, lowers the surface tensionof water, emulsifies oils and holdsdirt in suspension. Environmentalistshave criticized detergents becausemost contain large amounts of phos-phorus-containing compounds thatcontribute to the eutrophication ofwaterways.

diatomaceous earth (diatomite): A finesiliceous material resembling chalkused in waste water treatment plantsto filter sewage effluent to removesolids. May also be used as inactiveingredients in pesticide formulationsapplied as dust or pow'. .r.

diffused air: A type of sewage aeration.Air is pumped into the sewage througha perforated pipe.

digester: In a waste wa:er treatmentplant, a closed tank that decreasesthe volume of solids and stabilizesraw sludge by bacterial action.

digestion: The biochemical decompositionof organic matter. Digestion of sew-age sludge takes place in tanks wherethe sludge decomposes, resulting inpartial gasification, liquefaction andmineralization of pollutants.

dilution ratio: The ratio of the volumeof water of a stream to the volumeof incoming waste. The capacity of astream to assimilate waste is partial-ly dependent upon the dilution ratio.

disinfection: Effective killing by chemicalor physical processes of all organisms

^

dry limestone process

capable of causing infectious disease.Chlorination is the disinfection meth-od commonly employed in sewagetreatment processes.

dispersant: A chemict.1 agent used tobreak up concentrations of organicmaterial. In cleaning oil spills, dis-persants are used to disperse oil fromthe water surface.

dissoll.ed oxygen (DO): The oxygen dis-solved in water or sewage. Adequate-ly Lissolved oxygen is necessary forthe life of fish and other aquaticorganisms and for the prevention ofoffensive odors. Low dissolved oxy-gen concentrations generally are dueto discharge of excessive organicsolids having high BOD, the result ofinadequate'waste-treatMent.

dissolved solids: The total amount ofdissolved material, organic and inor-ganic, contained in water or wastes.Excessive dissolved solids make waterunpalatable for drinking and unsuit-able for industrial uses.

distillation: The removal of impuritiesfrom liquids by boiling. The steam,condensed back into liquid, is almostpure water; the pollutants remain inthe concentrated residue.

(Ince: In radiology, the quantity of en-ergy or radiation absorbed.

dosimeter (dosemeter): An instrumentused to measure the amount of radi-ation a person has received.

dredging: A method for deepeningstreams, swamps or coastal waters byscraping ar d removing solids from thebottom. The resulting mud is usuallydeposited in marshes in a processcalled filling. Dredging and filling candisturb natural ecological cycles. Forexample, dredging can destroy oysterbeds and other aquatic life; filling candestroy the feeding and breedinggrounds for many fish species.

dry limestone process: A method of con-trolling air pollution caused by sulfuroxides. The polluted gases are exposedto limestone which combines withoxides of sulfur to form manageableresidues.

1 17

dump

dump: A land site where solid waste isdisposed of in a manner that doesnot protect the environment,

dust: Fine-grain particulate matter thatis capable of being suspended in air.

dustfall jar: An open-mouthed containerused to collect large particles that MIout of the air. The particles are mea-sured and analyzed.

dystrophic lakes: Lakes between .eutro-phic and swamp stages of aging. Suchbkes are shallow and have high hu-mus content, high organic matter con-tent, low nutrient availability andhigh BOD.

ecological impact: The total effect of an^nvironmental change, either naturalor man-made, on the ecology of thearca.

ecology: The interrelationships of livingthings to one another and to their en-vironment or the study of such inter-relationships.

economic poisons: Those chemicals usedto control insects, rodents, plant dis-eases. weeds and other pests, and alsoto defoliate economic crops such ascotton.

ecosphere: See biosphere.

ecosystim: The interacting sy.'m ar 3biological community andliving environment.

effluent: A discharge of pollutants intothe environment, partially or com-pletely treated or in its natural state.Generally used in regard to dischargesinto waters.

electrodialysis: A process that useselectrical current and an arrangement

8

of permeabb membranes to separatesoluble minerals from water. OftenusiM to desalinize salt or brackishwater.

electrostatic precipitator:An air pollutioncontrol device that removes particulatematter by imparting an electricalcharge to particles in a gas stream formechanical collection on an electrode.

emergency episode: See air pollutionepisode.

emission: See effluent. (Generally usedin regard to discharges into air.)

emission factor: The average amount ofa pollutant emitted from each type ofpolluting source in relation to aspecific amount of material processed.For example, an emission factor fora blast furnace (used to make iron)would be a number of pounds of par-ticulates per ton of raw materials.

emission inventory: A Hit of air pollu-tants emitted into a community's at-mosphere, in amounts (usually tons)per day, by type of source. The emis-sion inventory is basic to the establish-ment of emisJion standards.

emission standard:The maximum amountof a pollutant legally permitted to bedischarged from a single source, eithermobile or stationary.

enrichment: The addition of nitrogen,phosphorus and carbon compounds orother nutrients into a lake or otherwaterway that greatly increases thegrowth potential for algae and otheraquatic plants. Most frequently, en-richment results from the inflow ofsewage effluent or from agriculturalrunoff.

environment: The sum of all externalconditions and influences affecting thelife, development and, ultimately, thesurvival of an organism.

environmental impact statement: A docu-ment prepared by a Federal agencyon the environmental impact of itsproposals for legislation and othermajor actions significantly affectingthe quality of the human environment.Environmental impact statements areused as tools for decision making andare required by the National Environ-mental Policy Act.

1 2

epidemiology: The study of diseases asthey affect populations.

erosion: The wearing away of the landsurface by wind or water. Erosionoccurs naturally from weather or run-off but is often intensified by man'sland-clearing practices.

estuaries: Areas where the fresh watermeets salt water. For example, bays,mouths of rivers, salt marshes andlagoons. Estuaries are delicate eco-systems; they serve as nurseries,spawning and feeding grounds for alarge group of marine life and provideshelter and food for birds and wildlife.

eutrophkation: The normally slow agingprocess by which a lake evolves intoa bog or marsh and ultimately as-sumes a completely terrestrial stateand disappears. During eutrophicationthe lake becomes so rich in nutritivecompounds, especially nitrogen andphosphorus, that algae and othermicroscopic plant life become super-abundant, thereby "choking" the lake,and causing It eventually to dry up.Eutrophication may be accelerated bymany human activities.

eutrophic lakes: Shallow lakes, weed-choked at the edges and very rich Innutrients. The water is characterizedby large amounts of algae, low watertransparency, low dissolved oxygenand high SOD.

evaporation ponds: Shallow, artificialponds where sewage sludge is pumped,permitted to dry and either removedor buried by more sludge.

fabric filters: A device for removing dustand particulate matter from Industrialemissions much like a home vacuum

flue gas

cleaner bag. The most common useof fatiric filters is the baghouse.

fecal coliform bacteria: A group of orga-nisms common to the intestinal tractsof man and of animals. The presenceof fecal coliform bacteria in water isan indicator of pollution and of po-ten tially dangerous bacterial contami-nation.

feedlot: A relatively small, confined landarea for raising cattle. Although aneconomical method of fattening beef,feedlots concentrate a large amountof animal wastes in a small area. Thisexcrement cannot be handled by thesoil as it could be if the cattle werescattered on open range. In addition,runoff from feedlots contributes ex-cessive quantities of nitrogen, phos-phorus and potassium to nearbywaterways, thus contributing to eutro-phication.

fen: A low-lying land area partly coveredby water.

filling: The process of depositing dirt andmud in marshy areas to create moreland for real estate development. Fill-ing can disturb natural ecologicalcycles. See dredging.

film badge: A piece of masked photo-graphic film worn like a badge bynuclear workers to monitor an expo-sure to radiation, Nuclear radiationdarkens the film.

filtration: in waste water treatment, themechanical process that removes par-ticulate matter by separating waterfrom solid material usually by passingit through sand.

floc: A clump of solids formed In sewageby biological or chemical action.

flocculation: in waste water treatment,the process of separating suspendedsolids by chemical creation of clumpsor flocs.

flowmeter: In waste water treatment, ameter that Indicates the rate at whichwaste water flows through the plant.

flue gas: A mixture of gases resultingfrom combustion and emerging froma chimney, Flue gas Includes nitrogen

13 9

fluorides

oxides. carbon oxides, water vaporand often sulfur oxides or particu-lates.

fluorides: Gaseous, solid or dissolvedcompounds containing fluorine,emitted into the air or water from anumber of industrial processes. Fluo-rides in the air are a cause of vege-tation damage and, indirectly, oflivestock damage.

flume: A channel, either natural or man-made, which carries water.

fly ash: All solids, including ash, charredpaper, cinders, dust, soot or otherpartially incinerated matter, that arecarried in a gas stream.

fog: Liquid particles formed by conden-sation of ;iporized liquids.

fogging: The pplication of a pestiddeby rapidly heating the liquid chemi-cal, thus forming very fine dropletswith the appearance of smoke. Fog-ging is often used to destroy mos-quitoes and blackflies,

food wastes Animal and szgetable wasteresulting from the handling, storage,sale, preparation, cooking and servingof foods; commonly called garbage.

fossil fuels: Coal, oil and natural gas;so-calkd hccause they are derivedfrom the remains of ancient plantand animal life.

fume: Tiny solid particles commonlyformed ty thc condensation of vaporsof solid matter.

fumigants pesticide that is burned orevaporated to form a gas or vaporthat dcstroys pests, Fumigants areoften used in buildings or green-houses.

fungi: Small, often microscopic plantswithout chlorophyll. Some fungi in-fect and cause disease in plants oranimak; other fungi are useful Instahiliting sewage or in breakingdown wastes for compost.

fungicides pesticide chemical that killsfungi or prevents them from causingdiseases, usually on plants of econom-ic importance. See pesticide.

10

`game fish:. Those species of fish soughtby sports fishermen; for example,salmon, trout, black bass, striped bass,etc. Game fish are usually more sen-sitive to environmental changes andwater quality degradation than"rough" fish.

gamma ray: Waves of radiant nuclearenergy. Gamma rays are the mostpenetrating of the three types of radi-ation and are best stopped by densematerials such as lead.

garbage: See food waste.

garbage grinding: A method of grindingfood waste by a household disposal,for example, and washing it into thesewer system. Ground garbage thenmust be disposed of as sewage sludge.

Geiger counters An electrical device thatdetects the presence of radioactivity.

'generator: A device that converts me-chanical energy into electrical energy.

germicide: A chemical or agent that killsmicroorganisms such as bacteria andprevents thcm from causing disease.Such compounds must be registered115 pesticides with EPA,

grains A unit of weight equivalent to 65milligrams or 2/1,000 of an ounce,

grain loadings The rate of emission ofparticulate matter from a pollutingsource. Measurement is made ingrains of particulate matter per cubicfoot of gas emitted.

green belts: Certain areas restricted fromtieing used for buildings and houses;thcy often serve as separating buffershetween pollution sources and con-centrations of population,

greenhouse effect: The heating effect ofthe atmosphere upon the earth. Lightwaves from the sun pass through the

14

air and are absorbed by the earth.The earth then reradiates this energyas heat waves that are absorbed bythe air, specifically by carbon dioxide.The air thus behaves like glass in agreenhouse, allowing the passage oflight but not of heat. Thus manyscientists theorize that an increase inthe atmospheric concentration of CO,can eventually cause an increase inthe earth's surface temperature.

ground cover: Grasses or other plantsgrown to keep soil from being blownor washed away.

groundwater: The supply of freshwaterunder the earth's surface in an aqui-fer or soil that forms the naturalreservoir for man's use.(See surface waler)

groundwater runoff: Groundwater that isdischarged into a stream channel asspring or seepage water.

habitat: The sum total of environmentalconditions of a specific place that isoccupied by an organism, a popula-tion or a community.

half-life: The time it takes certain mate-rials, such as persistent pesticides orradioactive isotopes, to lose half theirstrength. For example, the half-lifeof DDT is 15 years; the half-life ofradium is 1,580 years.

hammermill: A broad category of high-speed equipment that uses pivoted orfixed hammers or cutters to crush,grind, chip or shred solid wastes.

hard water: Water containing dissolvedminerals such as calcium, iron andmagnesium. The most notable char-acteristic of hard water Is its inabilityto lather soap. Some pesticide chem-icals will curdle or settle out whenadded to hard water.

humus

hazardous air pollutant: According tolaw, a pollutant to which no ambientair quality standard is applicable andthat may cause or contribute to anincrease in mortality or in seriousillness. For example, asbestos, beryl-lium and mercury have been declaredhazardous air pollutants.

'heat island effect. An air circulationproblem peculiar to cities. Tall build-ings, heat from pavements and con-centrations of pollutants create a hazedome that prevents rising hot airfrom being cooled at its normal rate.A self-contained circulation system isput in motion that can be broken byrelatively strong winds. If such windsare absent; the heat island can traphigh concentrations of pollutants andpresent a serious health problem.

heating season: The coldest months ofthe year when pollution emissions arehigher in some areas because of in-creased fossil-fuel consumption.

heavy metals: Metallic elements withhigh molecular weights, generallyWk. in low concentrations to plantand animal life. Such metals are oftenresidual in the environment and ex-hibit biological accumulation. Ex-amples include mercury, chromium,cadmium, arsenic and lead.

herbicide: A pesticide chemical used todestroy or control the growth ofweeds, bush and other undesirableplants. See pesticide.

herbivore: An organism that feeds onvegetation.

heterotrophic organism: Organisms de-pendent on organic matter for food.

high density polyethylene: A materialoften used in the manufacture of plas-tic bottles that produces toxic fumesif incinerated.

hi-volume sampler: A device used in themeasurement and analysis of sus-pended particulate pollution. Alsocalled a Hi-Vol.

hot: A colloquial term meaning highlyradioactive.

humus: Decomposed organic material.

1511

hydrocarbons

hydrocarbons: A vast family of com-pounds containing carbon and hydro-gen in various combinations, foundespecially in fossil fuels. Some hydro-carbons are major air pollutants,some may be carcinogenic and otherscontribute to photochemical smog.

hydrogen sulfide (KS): A malodorousgas made up of hydrogen and sulfurwith the characteristic odor of .rotteneggs. It is emitted in the natural de-composition of organic matter and isalso the natural accompaniment ofadvanced stages of eutrophication.I-12S is also a -byproduct of refineryactivity and the combustion of oilduring power plant operations. Inheavy concentrations, it can causeillness.

hydrology: The science dealing with theproperties, distribution and circulationof water and snow.

Impedance: The rate at which a sub-stance can absorb and transmit sound.

implementation plan: A document of thesteps to be taken to ensure attainmentof environmental quality standardswithin a specified time period. Imple-mentation plans are required by vari-ous laws.

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

Incineration: The controlled process bywhich solid, liquid or gaseous com-bustible wastes are burned andchanged into gases; the residue pro-duced contains little or no combus-tible material.

Incinerator: An engineered apparatusused to burn waste substances and inwhich all the combustion factorstemperature, retention time, turbu-lence and combustion aircan becontrolled.

1216

inert gas: A gas that does not react wimother substances under ordinary con-ditions.

inertial separator: An air pollution con-trol device that uses the principle ofinertia to remove particulate matterfrom a stream of air or gas.

infiltration: The flow of a fluid into asubstance through pores or smallopenings. Commonly used in hydrol-ogy to denote the flow of water intosoil material.

infiltration/inflow: Total quantity ofwater entering a sewer system. Infil-tration means entry through suchsources as defective pipes. pipe joints,connections, or manhole walls. Inflowsignifies discharge into the sewer systemthrough service connections from suchsources as area or, foundation drainage.springs and swamps, storm waters,street wash waters. or %ewers.

inoculum: Material such as bacteriaplaced in compost or other mediumto initiate biological action.

integrated pest control: A system of man-aging pests by using biological, cul-tural and chemical means.

interceptor sewers: Sewers used to collectthe flows from main and trunk sewersand carry them to a central point fortreatment and discharge. In a com-bined sewer system, where street run-off from rains is allowed to enter thesystem along with sewage, interceptorsewers allow some of the sewage toflow untreated directly into the receiv-ing stream, to prevent the plant frombeing overloaded.

interstate carrier water supply: A watersupply whosb water may be used fordrinking or cooking purposes aboardcommon carriers (planes, trains, busesand ships) operating interstate. Inter-state carrier water supplies are regu-lated by the Federal government.

Interstate waters: According to law,waters defined as: (I) rivers, lakes andother waters that flow across orform a part of State or internationalboundaries: (2) waters of the GreatLakes; (3) coastal waters whosescope has ,been defined to includeocean waters seaward to the territoriallimits and waters along the coast-line (including inland streams) in-fluenced by the tide.

inversion: An atmospheric conditionwhere a layer of cool air is trappedby a layer of warm air so that itcannot rise. Inversions spread pol-luted air horizontally rather than ver-tically so that contaminating sub-stances cannot be widely dispersed.An inversion of several days cancause an ajr pollution episode.

ionization chamber: A device roughlysimilar jo a Geiger counter that re-veals the presence of ionizing radia-tion.

isotope: A variation of an element havingthe same atomic number as the ele-ment itself, but having a differentatomic weight bcause of a differentnumber of neutrons. Different iso-topes of the same element have dif-ferent radioactive behavior.

lagoon: In waste water treatment, a shal-low pond usually man-made wheresunlight, bacterial action and oxygeninteract to restore waste water to areasonable state of purity.

landfill: (See Sanitary Landfill).

lateral sewers: Pipes running underneathcity streets that collect sewage fromhomes or businesses.

LC50: Median lethal concentration, astandard measure of toxicity. LC50indicates the concentration of a sub-stance that will kill 50 percent of agroup of experimental insects or ani-mals.

Imitate: Liquid that has percolatedthrough solid waste or other mediumsand has extracted dissolved or sus-mnded materials from it.

leaching: The process by which solublematerials in the soil, such as nutrients,pesticide chemicals or contaminants,are washed into a lower layer of soil

methane

or are dissolved and carried away bywater.

lead: A heavy metal that may be haz-ardous to human health if breathedor ingested.

life cycle: The phases, changes or stagesan organism passes through duringits lifetime.

lilt: In a sanitary landfill, a compactedlayer of solid waste and the top layerof cover material.

limnology: The study of the physical,chemical, meteorological and biologi-cal. aspects of fresh waters.

marsh: A low-tying tract of soft, wetland that pruvides an important eco-system for a variety of plant andanimal life but often is destroyed bydredging and filling.

masking: Covering over of one sound orelement by another. Quantitatively,masking is the amount the audibilitythreshold of one sound is raised bythe presence of a second maskingsound. Also used in regard to odors.

mechanical turbulence: The erratic move-ment of air caused by local obstruc-tions such as buildings.

mercury: A heavy metal, highly toxic ifbreathed or ingested. Mercury is re-sidual in the environment, showingbiological accumulation in all aquaticorganisms, especially fish and shellfish. Chronic exposure to airbornemercury can have serious effects onthe central nervous system.

methane: Colorless, nonpoisonous andflammable gaseous hydrocarbon. Meth-ane, (CA,), is emitted by marshes andby dumps undergoing anaerobic de-composition.

1713

mgd^

mgd: Millions of gallons per day. Mgdis commonly used to express rate offlow.

microbes: Minute plant or animal life.Some disease-causing microbes existin sewage.

mist: Liquid particles in air formed bycondensation of vaporized liquids.Mist particles vary from 500 to 40microns in size. By comparison, fogparticles are miller than 40 micronsin size.

mixed liquor: A mixture of activatedsludge and water .:ontaining organicmatter undergoing act...ated sludgetreatment in the aeration tank.

mobile source: A moving source of airpollution such as an automobile.

monitoring: Periodic or continuous deter-mination of the amount of pollutantsor radioactive contamination presentin the environment.

muck soils: Soils made from decayingplant materials.

mulch: A layer of W ood chips, dryleaves, straw, hay, plastic strips orother material placed on the soilaround plants to retain moisture, toprevent weeds from growing and toenrich soil.

natural gas: A fuel gas occurring nat-urally in certain geologic formation.Natural gas is usually a combustiblemixture of methane and hydro-carbons.

natural selection: The natural process bywhich the organisms best adapted totheir environment survive and thoseless well adapted are eliminated.

necrosis: Death of plant cells resulting

14

in a discolored, sunken area or deathof the entire plant.

nitric oxide (NO): A gas formed in greatpart from atmospheric nitrogen andoxygen when combustion takes placeunder high temperature and high pres-sure, us in internal combustion en-gines. NO is not itself a pollutant;however, in the ambient air, it con-verts to nitrogen dioxide, a majorcontributor to photochemical smog.

nitrogen dioxide (NO2): A compoundproduced by the oxidation of nitricoxide in the omosphere; a majorcontributor to photochemical smog.

nitrogenous wastes: Wastes of animal orplant origin that contain a significantconcentration of nitrogen.

NO: A notation meaning oxides of nitro-gen. See nitric oxide.

noise: Any undesired audible signal.Thus, in acoustics, noise is any un-desired sound.

NTA: Nitrilotriacetic acid, a compoundonce used to replace phosphates indetergents.

nuclear power plant: Any device, ma-chine or assembly that converts nu-clear energy into some form of usefulpower, such as mechanical or elec-trical power. In a nuclear electricpower plant, heat produced by a

reactor is generally used to makesteam to drive a turbine that in turndrives an electric generator.

nutrients: Elements or compounds essen-tial as raw materials for organismgrowth and development; for example,carbon, oxygen, nitrogen and phos-phorus.

oil spill: The accidental discharge of oilInto oceans. bays or inland water-

18

PCB's

ways. Methods of oil spill controlinclude chemical dispersion, combus-tion, mechanical containment andabsorption.

oligotrophic lakes: Deep lakes that havea low supply of nutrients and thuscontain little organic matter. Suchlakes are characterized by high watertransparency and high dissolvedoxygen.

opadty: Degree of obscuration of light.For example, a window has zeroopacity; a wall is 100 percent opaque.The Ringelmann system of evaluatingsmoke density is based on opacity.

open burning: Uncontrolled burning ofwastes in an open dump.

open dump: See dump.

organic: Referring to or derived fromliving organisms. In chemistry, anycompound containing carbon.

organism: Any living human, plant oranimal.

organophosphates: A group of pesticidechemicals containing phosphorus, suchas malathion and parathion, intendedto control insects. These compoundsare short-lived and, therefore, do notnormally contaminate the environ-ment. However, some organophos-phates, such as parathion,. are ex-tremely toxic when initially appliedand exposure to them can interferewith the normal processes of the ner-vous system, causing convulsions andeventually death. Malathion, on theother hand, is low in toxicity andrelatively safe for humans and ani-mals; it is a common ingredient inhousehold insecticide products.

outfall: The mouth of a sewer, drain orconduit where an effluent is dis-charged into the receiving waters.

overfire ain Air forced into the top ofan incinerator to fah the flame.

oxidant: Any oxygen containing substancethat reacts chemically in the air toproduce new substances. Oxidants arethe primary contributors to photo-chemical smog.

oxidation: A chemical reaction in which

oxygen unites or combines with otherelements. Organic matter is oxidizedby the action of aerobic bacteria; thusoxidation is used in waste water treat-ment to break down organic wastes.

oxidation pond: A man-macle lake orpond in which organic wastes arereduced by bacterial action. Oftenoxygen is bubbled through the pondto speed the process.

ozone (Os): A pungent, colorless, toxicgas. Ozone is one component ofphotochemical smog and is consid-ered a major air pollutant.

package plant: A prefabricated or pre-built waste water treatment plant.

packed tower: An air pollution controldevice in which polluted air is forcedupward through a tower packed withcrushed rock or wood chips while aliquid is sprayed downward on thepacking material. The pollutants inthe air stream either dissolve or chem-ically react with the liquid.

PAN: Peroxyacetyl nitrate, a pollutantcreated by the action of sunlight onhydrocarbons and nitrogen oxides inthe alr. PANS are an integral part ofphotochemical smog.

particulates: Finely divided solid orliquid particles in 'the air or in anemission. Particulates include dust,smoke, fumes, mist, spray and fog.

particulate loading: The introductionof particulates into the ambient air.

pathogenic: Causing or capable of caus-ing disease.

PCBs: Polychlorinated biphenyls, a groupof organic compounds used in themanufacture of plastics. In the en-

r 19 15

peat

vironment, PCBs exhibit many of thesame characteristics as DDT and may,therefore, be confused with that pesti-cide. PCBs are highly toxic to aquaticlife, they persist in -the environmentfor long periods of time, and they arebiologically accumulative.

peat: Partially decomposed organic mate-rial.

percolation: Downward flow Or infiltra-tion of water through the pores orspaces of a rock or soil.

persistent pesticides: Pesticides that willbe present in the environment forlonger than one growing season orone year after application.

pesticide: An agent used to control pests.This includes insecticides for useagainst harmful insects; herbicides forweed control; fungicides for controlof plant diseases; rodenticides forkilling rats, mice, etc.; and germicidesused in disinfectant products, algae-cides, slimicides, etc. Some pesticidescan contaminate water, air or soil andaccumulate in man, animals and theenvironment, particularly if they aremisused. Certain of these chemicalshave been shown to interfere withthe reproductive processes of Preda-tory birds and possibly other animals.

pesticide tolerance: A scientifically andlegally established limit for theamount of chemical residue that canbe permitted to remain in or on aharvested food or feed crop as aresult of the application of a chemi-cal for pest-control purposes. Suchtolerances or safety levels, establishedfederally by EPA, are set well belowthe point at which residues might beharmful to consumers.

pH: A measure of the acidity or alka-linity of a material, liquid or solid.pH is represented on a scale of 0 to14 with 7 representing a neutralstale, 0 representing the most acidand 14, the most alkaline.

pheaols: A group of orAanic compoundsthat in very low concentrations pro-duce a taste and odor problem ;IIwater. In higher concentrations, theyare toxic to aquatic life. Phenols arebyproducts of pelroleum refining,tanning and textile, dye and resinman ufacture.

16

phosphates; The salt or ester of a phos-phoric acid.

phosphorus: An element that while essen-tial to life, contributes to the eutro-phication of lakes and other bodiesof water.

photochemical oxidants: Secondary pol-lutants formed by the action of sun-light on the oxides of nitrogen andhydrocarbons in the air; they are theprimary contributors to photochemi-cal smog.

photochemical smog: Air pollution as-sociated with oxidants rather thanwith sulfur oxides, particulates, etc.Produces necrosis, chlorosis andgrowth alterations in plants and isan eye and respiratory irritant inhumans.

phytoplankton: The plant portion ofplankton.

phytotoxic: Injurious to plants.pig: A container usually made of lead

used to ship or store radioactivematerials.

pile: A nuclear reactor.plankton: The floating or weakly swim-

ming plant and animal life in a bodyof water, often microscopic in size.

plume: The visible emission from a flueor chimney.

point source: In air pollution, a stationarysource of a large individual emission,generally of an industrial nature. Thisis a general definition; point source islegally and precisely defined in Fed-eral regulations. See area source.

pollen: A fine dust produced by plants;a natural or background air pollutant.

pollutant: Any introduced gas, liquid orsolid that makes a resource unfit fora specific purpose.

pollution: The presence of matter oror energy whose nature, location orquantity produces undesired environ-mental effects.

polyelectrolytes: Synthetic chemicals usedto speed flocculation of solids insewage.

polyvinyl chloride: (PVC). A commonplastic material that releases hydro-chloric acid when burned.

20

potable water: Water suitable for drink-ing or cooking purposes from bothhealth and aesthetic considerations.

ppm: Parts per miflion. The unit com-monly used to represent the degree ofpollutant concentration where theconcentrations are small. Larger con-centrations are given in percentages.Thus BOD is represented in ppmwhile suspended solids in water areexpressed in percentages. In air, ppmis usually a volume/volume ratio; inwater, a weight/volume ratio.

precipitateA solid that separates froma solution because of some chemicalor physical change or the formationof such a solid.

precipitators: In pollution control work,any of a number of air pollution con-trol devices usually using mechanical/electrical means to collect particulatesfrom an emission.

pretreatment: In waste water treatment,any process used to reduce pollutionload before the waste water is intro-duced into a main sewer system ordelivered to a treatment plant forsubstantial reduction of the pollutionload.

primary treatment: The first stage inwaste water treatment in which sub-stantially all floating or settleablesolids are mechanically removed byscreening and sedimentation.

process weight: The total weight of allmaterials, including fuels, introducedinto a manufacturing process. Theprocess weight is used to calculatethe allowable rate of emission ofpollutant matter from the process.

pulverization: The crushing or grindingof material into small pieces.

pumping station: A station at whichsewage is pumped to a higher level.In most sewer systems pumping isunnecessary; waste water flows bygravity to the treatment plant.

putrescible: Capable of being decom-posed by microorganisms with suffi-cient rapidity to cause nuisances fromodors, gases, etc. For example, kitchenwastes or dead animals.

Pyrolysis: Chemical decomposition byextreme heat,

raw sewage

quench tank: A water-filled tank usedto cool incinerator residues.

rad: A unit of measurement of any kindof radiation absorbed by man.

radiation: The emission of fast atomicparticles or rays by the nucleus ofan atom. Some elements are naturallyradioactive while others become radio-active after bombardment with neu-trons or other particles. The threemajor forms of radiation are alpha,beta and gamma.

radiation staneards: Regulations that in-clude exposure standards, permissibleconcentrations and regulation: fortransportation.

radiohiology: The study of the principles,mechanisms and effects of radiationon living matter.

radleecology: The study of the effects ofradiation on species of plants andanimals in natural communities.

radioisotopes: Radioactive isotopes. Ra-dioisotopes such as cobalt-60 are usedin the treatment of disease.

rasP: A device used to grate solid wasteinto a more manageable material,ridding it of much of its odor.

raw sewage: Untreated domestic or com-mercial waste water.

21 17

receiving waters

receiving waters: Rivers, lakes, oceans al.other bodies that receive treated oruntreated waste waters.

recycling: The process by which wastematerials are transformed into newproducts in such a manner that theoriginal products may lose theiridentity.

red tide: A proliferation or bloom of acertain type of plankton with red-to-orange coloration, that often causesmassive fish kills. Though they are anatural phenomenon. blooms are be-lieved to be stimulated by phosphorusand other nutrients discharged intowaterways by man.

refuse: See solid waste.

refuse reclamation: The process of con-verting solid waste to saleable prod-ucts. For example, the composting oforganic solid waste yields a saleablesoil conditioner.

rem: A measurement of radiation doseto the internal tissue of man. (Acronymfor roentgen equivalent man.)

rep: A unit of measurement of any kindof radiation absorbed by man.

reservoir; A pond. lake, tank or basin,natural or man-made, used for thestorage, regulation and control ofwater.

resource recovery: The process of obtain-ing materials or energy, particularlyfrom solid waste.

reverberation: The persistence of soundin an enclosed space after the soundsource has stopped.

reverse osmosis: An advanced method ofwaste treatment relying on a semi-permeable membrane to keparatewaters from pollutants.

Ringelmann chart: A series of illustra-tions ranging from light grey to blackused to measure the opacity of smokeemitted from stacks and other sources.The shades of grey simulate varioussmoke densities and are assigned num-bers ranging from one to five. Ringel-mann No. I is equivalent to 20 per-ccnt dense: No. 5 is 100 percentdense, Ringclmann charts are used inthe setting and enforcement of emis-sion standards.

riparian rights: Rights of a land ownerto the water on or bordering his prop-

18

_-erty, including the right to preventdiversion or misuse of upstream water.

river basin: The total area drained bya river and its tributaries.

rodenticide: A chemical or agent used todestroy or prevent damage by rats orother rodent pests. See pesticide.

rough fish: Those fish species consideredto be of poor fighting quality whentaken on tackle or of poor eatingquality: for example, gar. suckers,etc. Most rough fish are more tolerantof widely changing environmentalconditions than are game fish.

rubbish: A general term for solid wasteexcluding food waste and ashestaken from residences, commercial es-tablishments and institutions.

rimoff: The portion of rainfall, meltedsnow or irrigation water that flowsacross ground surface and eventuallyis returned to streams. Runoff canpick up pollutants from the air orthe land and carry them to the re-ceiving waters.

salinity: The degree of salt in water.

salt water intrusion: The invasion of saltwater into a body of fresh water, oc-curring in either surface or ground-water bodies. When this invasion iscaused by oceanic waters, it is calledsea water intrusion.

salvage: The utilization of waste mate-rials.

sanitation: The control of all the factorsin man's physical environment thatexercise or can exercise a deleteriouseffect on his physical development,health and survival.

sanitary landfill: A sitc for solid wastedisposal using sanitary landfillingtechniques.

sanitary landfilling: An engineered meth-od of solid waste disposal on,lund in

2 63

sewerage

a manner that protects the cnviron-ment; waste is spread in thin layers,compacted to the smallest practicalvolume and covered with soil at theend of each working day.

unitary sewers: Sewers that carry onlydomestic or commercial sewage.Storm water runoff is carried in aseparate system. See sewer.

scrap: Discarded or rejected materialsthat result from manufacturing orfabricating operations and are suit-able for reprocessing.

screening: The removal of relativelycoarse floating and suspended solidsby straining through racks or screens.

scrubber: An air pollution control devicethat uses a liquid spray to removepollutants from a gas stream by ab-sorption or chemical reaction. Scrub-bers also reduce the temperature ofthe emission.

secondary treatment: Waste water treat-ment, beyond the primary stage, inwhich bacteria consume the organicparts of the wastes. This biochemicalaction is accomplished by use oftrickling filters or the activated sludgeprocess. Effective secondary treatmentremoves virtually all floating and set-tleable solids and approximately 90percent of both BOD, and suspendedsolids. Customarily, disinfection bychlorination is the final stage of thesecondary treatment process.

sedbnentadon: In waste water treatment,the settling out of solids by gravity.

sedimentation tanks: In waste water treat-ment, tanks where the solids are al-lowed to settle or to float as scum.Scum is skimmed off; settled solidsare pumped to Ancinerators, digesters,filters or other means of disposal.

seepage: Water that flows through thesoil.

segment: A portion of a river basin, thesurface waters of which have commonhydrologic characteristic (or flow regu-lation patterns); common natural.physical, chemical, and biologicalprocesses and common reactions toexternal stresses such as dischargingof pollutants.

selective herbkide A pesticide intendedto kill only certain types of plants,

especially broad-leafed weeds, and notharm other plants such as farm cropsor lawn grasses. The leading herbicidein the United States is 2,4-D. A re-lated but stronger chemical used most-ly for brush control on range, pas-ture, and forest lands and on utilityor highway rights-of-way is 2,4,5-T.Uses of the latter chemical have beensomewhat restricted because of labora-tory evidence that it or a dioxin con-taminant in 2,4,5-T can cause birthdefects in test animals.

senescence: The process of growing old.Sometimes used to refer to lakes near-ing extinction.

septic tank: An underground tank usedfor the deposition of domestic wastes.Bacteria in the wastes decompose theorganic matter, and the sludge settlesto the bottom. The effluent flowsthrough drains into the ground. Sludgeis pumped out at regular intervals.

settleable solids: Bits of debris and finematter heavy enough to settle out ofwaste water.

settling chamber In air pollution control,a low-cost device used to reduce thevelocity of flue gases usually by meansof baffles, promoting the settling offly ash.

settling tank: in waste water treatment, atank or basin in which settleablesolids are removed by gravity.

sewage: The total of organic waste andwaste water generated by residentialand commercial establishments.

sewage lagoon: See lagoon.sewer Any pipe or conduit used to col-

lect and carry away sewage or storm-water runoff from the generatingsource to treatment plants or receiv-ing streams. A sewer that conveyshousehold and commercial sewage iscalled a sanitary sewer. If it trans-ports runoff from rain or snow, it iscalled a storm sewer. Often stormwater runoff and sewage are trans-ported in the same system or com-bined sewers.

sewerage: The entire system of sewagecollection, treatment and disposal.Also applies to all effluent carried bysewers whether it is sanitary sewage,industrial wastes or storm water run-off.

23 19

shield

shield: A wall that protects workers fromharmful radiation released by radio-active materials.

silt: Finely divided particles of soil orrock. Often carried in cloudy suspen-sion in water and eventually depositedas sediment.

sinking: A method of controlling oil spillsthat employs an agent to entrap oildroplets and sink them to the bottomof the body of water. The oil andsinking agent are eventually biologi-cally degraded.

skimming. The mechanical removal ofoil or scum from the surface ofwater.

sludge: The construction of solids re-moved from sewage during wastewater treatment. Sludge disposal isthen handled by incineration, dump-ing or burial.

smog: Generally used as an equivalent ofair pollution, particularly associatedwith oxidants.

smoke: Solid particles generated as a re-sult of the incomplete combustion ofmaterials containing carbon.

SOK: A symbol meaning oxides of sulfur.

soft detergents: Biodegradable detergents.

soil conditioner: A biologically stable or-ganic material such as humus or com-post that makes soil more amenableto the passage of water and to thedistribution of fertilizing material, pro-viding a better medium for necessarysoil bacteria growth.

solid waste: Useless, unwanted or dis-carded material with insufficient liquidcontent to be free flowing. Also seewaste. ( I ) agriculturalsolid wastethat results from the raising andslaughtering of animals, and theprocessing of animal products and or-chard and field crops. (2) commercialwaste generated by stores, officesand other activities that do not ac-tually turn out a product. (3) indus-trialwaste that results from indus-trial processes and manufacturing.(4) institutional waste originatingfrom educational, health care and re-search facilities. (5) municipalresi-

20

dential and commercial solid wastegenerated within a community. (6)pesticidethe residue from the manu-facturing, handling or use of chemi-cals intended for killing plant andanimal pests. (7) residentialwastethat normally originates in a residen-tial environment. Sometimes called do-mestic solid waste.

solid waste disposal: The ultimate dispo-sition of refuse that cannot be sal-vaged or recycled.

solid waste management: The purposeful,systematic control of the generation,storage, collection, transport, separa-tion, processing, recycling, recoveryand disposal of solid wastes.

sonic boom: The tremendous boomingsound produced as a vehicle, usually asupersonic jet airplane, exceeds thespeed of sound, and the shock wavereaches the ground.

soot: Agglomerations of tar-impregnatedcarbon particles that form whencarbonaceous-material does not under-go complete combustion.

sorption: A term including both adsorb-tion and absorption. Sorption is basicto many processes used to removegaseous and particulate pollutantsfrom an emission and to clean up oilspills.

spoil: Dirt or rock that has been removedfrom its original location, specificallymaterials that have been dredged fromthe bottoms of waterways.

stabilization: The process of convertingactive organic matter in sewagesludge or solid wastes into inert,harmless material,

stabilization ponds: See lagoon, oxidationpond.

stable air: An air mass that remains inthe same position rather than movingin its normal horizontal and verticaldirections. Stable air does not dispersepollutants and can lead to high build-ups of air pollution.

stack: A smokestack; a vertical pipe orflue designed Itto exhaust gases andsuspended particulate matter.

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perature difference between the gasesand the atmosphere.stagnation: Lack of wind in an air massor lack of motion in water. Both .cases tend to entrap and concentratepollutants.

stationary source: A pollution emitterthat is fixed rather than moving asan automobile.

storm sewer: A conduit that collects andtransports rain and snow runoff backto the ground water. In a separatesewerage system, storm sewers areentirely separate from those carryingdomestic and commercial waste water.stratification: Separating into layers.strip milling: A process in which rock andtop soil strata overlying ore or fueldeposits are scraped away by me-chanical shovels. Also known as sur-face mining.

sulfur dioxide (SO2) A heavy, pungent,colorless gas formed primarily by thecombustion of fossil fuels. SO, dam-ages the respiratory tract as well asvegetation and materials and is con-sidered a major air pollutant.sump: A depression or tank that servesas a drain or receptacle for liquids forsalvage or disposal.surface water: Water on the earth's sur-face exposed to the atmosphere asrivers, lakes. streams, the oceans, (Seegroundwater.)

surfactant: An agent used in detergentsto cause lathering.Composed of sev-eral phosphate

compounds, surfactantsare a source ofexternal enrichmentthought to speed the eutrophicationof our lakes.

surveillance system: A monitoring systemto determine environmental quality.Surveillance systems should be estab-lished to monitor all aspects of prog-ress toward attainment of environ-mental standards and to identify po-tential episodes of high pollutantconcentrations in time to take pre-ventive action.suspended solids (SS): Small particles ofsolid pollutants in sewage that con-tribute to turbidity and that resistseparation by conventional means.The examination of suspended solids

tolerance

and the BOD test constitute the twomain determinations for water qual-ity performed at waste water treat-ment facilities.

synergism: The cooperative action of sep-arate substances so that the totaleffect is greater than the sum of theeffects of the substances acting inde-pendently.

systemic pesticide: A pesticide chemicalthat is carried to other parts of aplant or animal after it is injected ortaken up from the soil or body sur-face.

tailings: Second grade or waste materialderived when raw material is screenedor processed.

tertiary treatment: Waste water treatmentbeyond the secondary, or biologicalstage that includesremoval of nutri-ents such as phosphorus and nitrogen,and a high percentage of suspendedsolids. Tertiary treatment, also knownas advanced waste treatment, pro-duces a high quality effluent.

thermal pollution: Degradation of waterquality by the introduction of aheated effluent. Primarily a result ofthe discharge of cooling waters fromindustrial processes, particularly fromelectrical power generation. Evensmall deviations from norrgal watertemperatures can affect aquatic life.Thermal pollution usually can becontrolled by cooling towers.threshold dose: The minimum dose of agiven substance necessary to producea measurable

physiological or psy-chological effect.

tolerance: The relative capability of anorganism to endure an unfavorableenvironmental factor, The amount of

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topography

a chemical considered safe on anyfood to be eaten by man or animals.Also see pesticide tolerance.

topography: The configuration of a sur-face area including its relief, or rela-tive elevations, and the position of itsnatural and man-made features.

toxicant: A substance that kills or injuresan organism through its chemical orphysical action or by altering its en-vironment; for example, cyanides,phenols, pesticides or heavy metals.Especially used for insect control.

toxicity: The quality or degree of beingpoisonous or harmful to plant oranimal life.

toxic pollutants: A combination of pol-lutants including disease-carryingagents which, after discharge andUpon exposure. ingestion, inhalation.or assimilation into any organism cancause death or disease", mutations, de-formities.. or malfunctions in suchorganisms or th1 offspring.

trace metals: Metak Torrid in smallquantities or traces. usually due totheir ir

trickling filter: A device for the biologi-cal or secondary treatment of wastewater consisting of a bed of rocks orstones that support bacterial growth.Sewage is trickled over the bed en-abling the bacteria to break downorganic wastes.

troposphere: The layer of the atmosphereextending seven to ten miles abovethe earth. Vital to life on earth, itcontains clouds and moisture thatreach earth as rain or snow,

turbiditneter: A device used to measurethe amount of suspended solids in aliquid.

turbidity: A thick, hazy condition of airdue to the presence of particulates orother pollutants, or the similar cloudycondition in water due to the suspen-sion of silt or fnely divided organicmatter.

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urban runoff: Storm water from citystreets and gutters that usually con-tains a great deal of litter and organicand bacterial wastes.

vapor: The gaseous phase of substancesthat normally are either liquids orsolids at atmospheric temperature andpressure; for example, steam and phe-nolic compounds.

vapor plume: The stack effluent consist-ing of flue gas made visible by con-densed water droplets or mist.

vaporization: The change of a substancefrom the liquid to the gaseous state.One of three basic contributing fac-tors to air pollution, the others areattrition and combustion.

variance: Sanction granted by a govern-ing body for delay or exception inthe application of a given law, ordi-nance or regulation.

vector: Disease vectora carrier, usuallyan arthropod, that is capable of trans-mitting a pathogen from one orga-nism to another.

yinyl chloride (V('): A gaseous chemicalsuspected of causing angiosarcoma. arare form of cancer of the liver.

volatile: Evaporating readily at a rela-tively low temperature.

waste: Also see solid waste. (I) bulkywasteitems whose large size pre-cludes or complicates their handlingby normal collection, processing ordisposal methods. (2) constructionand demolition wastebuilding ma-terials and rubble resulting from con-struction, remodeling, repair anddemolition operations. (3) hazardouswaste wastes that require specialhandling to avoid illness or injury topersons or damage to property.(4) special wastethose wastes thatrequire extraordinary management.(5) wood pulp waste -- wood orpaper fiber residue resulting from amanufacturing process. (6) yardwasteplant clippings, prunings andother discarded material fr)m yardsand gardens. Also known as yardrubbish.

waste water: Water carrying wastes fromhomes, businesses and industries thatis a mixture of water and dissolvedor susmnded solids.

water pollution: The addition of sewage,industrial wastes or other harmful orobjectionable material to water inconcentrations or in sufficient quan-tities to tesult in measurable degrada-tion of water quality.

water quality criteria: The levels of pol-lutants that affect the suitability of

zooplantoa

water for a given use. Generally,water use classification includes: pub-lic water supply; recreation; propaga-tion of fish and other aquatic life;agricultural use and industrial use.

water quality standard: A plan for waterquality management containing fourmajor elements: the use (recreation,drinking water, fish and wildlife prop-agation, industrial or agricultural) tobe made of the water; criteria toprotect those uses; implementationplans (for needed industrial-municipalwaste treatment improvements) andenforcement plans, and an anti-degra-dation statement to protect existinghigh quality waters.

watershed: The area drained by a givenstream.

water supply system: The system for thecollection, treatment, storage and dis-tribution of potable water from thesources of supply to the consumer.

water table: The upper level of groundwater.

wetlands: Swamps or marshes. especiallyas areas preserved for wildlife.

zooplaoktou: Planktonic animals thatsupply food for fish.

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