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Flow meter Directory

Flow meter Directory

Published: Friday, 18 October 2013 09:53
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Mining Terminology


Abutment - In coal mining, the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and the weight of the rocks over a long wall face is transferred to the front abutment, that is, the solid coal ahead of the face and the back abutment, that is, the settled packs behind the face

Acid deposition or acid rain – Referring loosely to mixtures of wet and dry deposited material from the atmosphere containing higher than normal amount of nitric and sulfuric acids. The precursors or chemical forerunners of acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur and nitrogen oxides resulting from fossil fuel combustion.

Acid mine water - Mine water that contains free sulfuric acid and mainly due to the weathering of iron pyrites.

Active workings - Any place in a mine where a miner is normally required to work or travel and which are ventilated and inspected regularly

Adit - A nearly horizontal passage from the surface by which a mine is entered and de-watered.

Advance - Mining in the same directions, or order of sequence

Air split - The division of a current of air into two or more parts.

Airway - Any passage through which air is carried.

Anemometer - Instrument for measuring air velocities

Angle of dip - The angle at which strata or mineral deposits are inclined to the horizontal plane.

Angle of repose - The maximum angle from horizontal at which a given material will rest on a given surface without sliding or rolling

Anticline - An upward fold or arch of rock strata.

Aquifer - A water-bearing bed of porous rock, often sandstone.

Arching - Fracture processes around a mine opening, leading to stabilization by an arching effect.

Area of an airway - Average width multiplied by average height of airway normally expressed in sq ft.

Auger - A rotary drill that uses a screw device to penetrate, break, and then transport the drilled material for example coal.

Auxiliary operations - All activities supportive of but not contributing directly to mining.

Auxiliary ventilation - Portion of main ventilating current directed to face of dead end entry by means of an auxiliary fan and tubing

Azimuth - A survey term that references the angle measured clockwise from any meridian . The bearing is used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line.


Back - The roof or upper part in any underground mining cavities

Backfill – Mine waste or rock used to support the roof after coal removal.

Barren - Said of rock or vein material containing no minerals of value, and of strata without coal, or containing coal in seams too thin to be workable.

Barricading - Enclosing part of a mine to prevent inflow of noxious gasses from a mine fire or an explosion.

Barrier - Something that bars or keeps out. Barrier pillars are solid blocks of coal left between two mines or sections of a mine to prevent accidents due to inrushes of water, gas, or from explosions or a mine fire.

Beam - A bar or straight girder used to support a span of roof between two support props or walls.

Beam building - The creation of a strong, inflexible beam by bolting or otherwise fastening together several weaker layers. In coal mining this is the intended basis for roof bolting.

Bearing – A surveying term used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line. The meridian is an established line of reference. Azimuths are angles measured clockwise from any meridian.

Bearing plate - A plate used to distribute a given load.

Bed - A stratum of coal or other deposit.

Belt conveyor - A looped belt on which coal or other materials can be carried and which is generally constructed of flame-resistant material

Belt idler - A roller usually of cylindrical shape which is supported on a frame and which in turn supports or guides a conveyor belt.

Bench - One of to or more divisions of a coal seam separated by slate or formed by the process of cutting the coal

Beneficiation - The treatment of mined material making it richer or more concentrated

Berm - A pile or mound of material capable of restraining a vehicle.

Binder - A streak of impurity in a coal seam.

Bit - The hardened and strengthened device at the end of a drill rod that transmits the energy of breakage to the rock. The size of the bit determines the size of the hole. A bit may be either detachable from or integral with its supporting drill rod.

Bituminous coal – A middle rank coal formed by additional pressure and heat on lignite. Usually has a high Btu value and may be referred to as soft coal

Black damp - A term generally applied to carbon dioxide. Strictly speaking, it is a mixture of carbon dioxide and nitrogen. It is also applied to an atmosphere depleted of oxygen, rather than having an excess of carbon dioxide.

Blasting agent - Any material consisting of a mixture of a fuel and an oxidizer.

Blasting cap - A detonator containing a charge of detonating compound, which is ignited by electric current or the spark of a fuse. Used for detonating explosives.

Blasting circuit - Electric circuits used to fire electric detonators or to ignite an igniter cord by means of an electric starter.

Bleeder or bleeder entries - Special air courses developed and maintained as part of the mine ventilation system and designed to continuously move air-methane mixtures emitted by the gob or at the active face away from the active workings and into mine-return air courses. Alt: Exhaust ventilation lateral.

Bolt torque - The turning force in foot-pounds applied to a roof bolt to achieve an installed tension.

Borehole - Any deep or long drill-hole, usually associated with a diamond drill.

Bottom - Floor or underlying surface of an underground excavation.

Boss - Any member of the managerial ranks who is directly in charge of miners (e.g., "shift-boss," "face-boss," "fire-boss," etc.).

Box-type magazine - A small, portable magazine used to store limited quantities of explosives or detonators for short periods of time at locations in the mine which are convenient to the blasting sites at which they will be used.

Brattice or brattice cloth - Fire-resistant fabric or plastic partition used in a mine passage to confine the air and force it into the working place. Also termed "line brattice," "line canvas," or "line curtain."

Break line - The line that roughly follows the rear edges of coal pillars that are being mined. The line along which the roof of a coal mine is expected to break.

Breakthrough - A passage for ventilation that is cut through the pillars between rooms.

Bridge carrier - A rubber-tire-mounted mobile conveyor, about 10 meters long, used as an intermediate unit to create a system of articulated conveyors between a mining machine and a room or entry conveyor.

Bridge conveyor - A short conveyor hung from the boom of mining or lading machine or haulage system with the other end attached to a receiving bin that dollies along a frame supported by the room or entry conveyor, tailpiece. Thus, as the machine boom moves, the bridge conveyor keeps it in constant connection with the tailpiece.

Brow - A low place in the roof of a mine, giving insufficient headroom.

Brushing - Digging up the bottom or taking down the top to give more headroom in roadways.

Btu – British thermal unit. A measure of the energy required to raise the temperature of one pound of water one degree Fahrenheit.

Bug dust - The fine particles of coal or other material resulting form the boring or cutting of the coal face by drill or machine.

Bump (or burst) - A violent dislocation of the mine workings which is attributed to severe stresses in the rock surrounding the workings.

Butt cleat - A short, poorly defined vertical cleavage plane in a coal seam, usually at right angles to the long face cleat.

Butt entry - A coal mining term that has different meanings in different locations. It can be synonymous with panel entry, submain entry, or in its older sense it refers to an entry that is "butt" onto the coal cleavage (that is, at right angles to the face).


Cage - In a mine shaft, the device, similar to an elevator car, that is used for hoisting personnel and materials.

Calorific value - The quantity of heat that can be liberated from one pound of coal or oil measured in BTU's.

Cannel coal - A massive, non-caking block coal with a fine, even grain and a conchoidal fracture which has a high percentage of hydrogen, burns with a long, yellow flame, and is extremely easy to ignite.

Canopy - A protective covering of a cab on a mining machine.

Cap - A miner's safety helmet. Also, a highly sensitive, encapsulated explosive that is used to detonate larger but less sensitive explosives.

Cap block - A flat piece of wood inserted between the top of the prop and the roof to provide bearing support.

Car - A railway wagon, especially any of the wagons adapted to carrying coal, ore, and waste underground.

Car-dump - The mechanism for unloading a loaded car.

Carbide bit - More correctly, cemented tungsten carbide. A cutting or drilling bit for rock or coal, made by fusing an insert of molded tungsten carbide to the cutting edge of a steel bit shank.

Cast - A directed throw; in strip-mining, the overburden is cast from the coal to the previously mined area.

Certified - Describes a person who has passed an examination to do a required job.

Chain conveyor - A conveyor on which the material is moved along solid pans (troughs) by the action of scraper crossbars attached to powered chains.

Chain pillar - The pillar of coal left to protect the gangway or entry and the parallel airways.

Check curtain - Sheet of brattice cloth hung across an airway to control the passage of the air current.

Chock - Large hydraulic jacks used to support roof in longwall and shortwall mining systems.

Clay vein - A body of clay-like material that fills a void in a coal bed.

Cleat - The vertical cleavage of coal seams. The main set of joints along which coal breaks when mined.

Clean Air Act Amendments of 1990 – A comprehensive set of amendments to the federal law governing the nation's air quality. The Clean Air Act was originally passed in 1970 to address significant air pollution problems in our cities. The 1990 amendments broadened and strengthened the original law to address specific problems such as acid deposition, urban smog, hazardous air pollutants and stratospheric ozone depletion.

Clean Coal Technologies – A number of innovative, new technologies designed to use coal in a more efficient and cost-effective manner while enhancing environmental protection. Several promising technologies include: fluidized-bed combustion, integrated gasification combined cycle, limestone injection multi-stage burner, enhanced flue gas desulfurization (or "scrubbing"), coal liquefaction and coal gasification.

Coal - A solid, brittle, more or less distinctly stratified combustible carbonaceous rock, formed by partial to complete decomposition of vegetation; varies in color from dark brown to black; not fusible without decomposition and very insoluble.

Coal dust - Particles of coal that can pass a No. 20 sieve.

Coal Gasification – The conversion of coal into a gaseous fuel.

Coal mine - An area of land and all structures, facilities, machinery, tools, equipment, shafts, slopes, tunnels, excavations, and other property, real or personal, placed upon, under, or above the surface of such land by any person, used in extracting coal from its natural deposits in the earth by any means or method, and the work of preparing the coal so extracted, including coal preparation facilities. British term is "colliery".

Coal reserves - Measured tonnages of coal that have been calculated to occur in a coal seam within a particular property.

Coal washing – The process of separating undesirable materials from coal based on differences in densities. Pyritic sulfur, or sulfur combined with iron, is heavier and sinks in water; coal is lighter and floats.

Coke – A hard, dry carbon substance produced by heating coal to a very high temperature in the absence of air.

Collar - The term applied to the timbering or concrete around the mouth or top of a shaft. The beginning point of a shaft or drill hole at the surface.

Colliery - British name for coal mine.

Column flotation – A precombustion coal cleaning technology in which coal particles attach to air bubbles rising in a vertical column. The coal is then removed at the top of the column.

Comminution - The breaking, crushing, or grinding of coal, ore, or rock.

Competent rock - Rock which, because of its physical and geological characteristics, is capable of sustaining openings without any structural support except pillars and walls left during mining (stalls, light props, and roof bolts are not considered structural support).

Contact - The place or surface where two different kinds of rocks meet. Applies to sedimentary rocks, as the contact between a limestone and a sandstone, for example, and to metamorphic rocks; and it is especially applicable between igneous intrusions and their walls.

Continuous miner - A machine that constantly extracts coal while it loads it. This is to be distinguished from a conventional, or cyclic, unit which must stop the extraction process in order for loading to commence.

Contour - An imaginary line that connects all points on a surface having the same elevation.

Conventional mining – The first fully-mechanized underground mining method involving the insertion of explosives in a coal seam, the blasting of the seam, and the removal of the coal onto a conveyor or shuttle car by a loading machine.

Conveyor - An apparatus for moving material from one point to another in a continuous fashion. This is accomplished with an endless (that is, looped) procession of hooks, buckets, wide rubber belt, etc.

Core sample – A cylinder sample generally 1-5" in diameter drilled out of an area to determine the geologic and chemical analysis of the overburden and coal.

Cover - The overburden of any deposit.

Creep - The forcing of pillars into soft bottom by the weight of a strong roof. In surface mining, a very slow movement of slopes downhill.

Crib - A roof support of prop timbers or ties, laid in alternate cross-layers, log-cabin style. It may or may not be filled with debris. Also may be called a chock or cog.

Cribbing - The construction of cribs or timbers laid at right angles to each other, sometimes filled with earth, as a roof support or as a support for machinery.

Crop coal - Coal at the outcrop of the seam. It is usually considered of inferior quality due to partial oxidation, although this is not always the case.

Crossbar - The horizontal member of a roof timber set supported by props located either on roadways or at the face.

Crosscut - A passageway driven between the entry and its parallel air course or air courses for ventilation purposes. Also, a tunnel driven from one seam to another through or across the intervening measures; sometimes called "crosscut tunnel", or "breakthrough". In vein mining, an entry perpendicular to the vein.

Cross entry - An entry running at an angle with the main entry.

Crusher - A machine for crushing rock or other materials. Among the various types of crushers are the ball mill, gyratory crusher, Handsel mill, hammer mill, jaw crusher, rod mill, rolls, stamp mill, and tube mill.

Cutter; Cutting machine - A machine, usually used in coal, that will cut a 10- to 15-cm slot. The slot allows room for expansion of the broken coal. Also applies to the man who operates the machine and to workers engaged in the cutting of coal by pick or drill.

Cycle mining - A system of mining in more than one working place at a time, that is, a miner takes a lift from the face and moves to another face while permanent roof support is established in the previous working face.


Demonstrated reserves – A collective term for the sum of coal in both measured and indicated resources and reserves.

Deposit - Mineral deposit or ore deposit is used to designate a natural occurrence of a useful mineral, or an ore, in sufficient extent and degree of concentration to invite exploitation.

Depth - The word alone generally denotes vertical depth below the surface. In the case of incline shafts and boreholes it may mean the distance reached from the beginning of the shaft or hole, the borehole depth, or the inclined depth.

Detectors - Specialized chemical or electronic instruments used to detect mine gases.

Detonator - A device containing a small detonating charge that is used for detonating an explosive, including, but not limited to, blasting caps, exploders, electric detonators, and delay electric blasting caps.

Development mining - Work undertaken to open up coal reserves as distinguished from the work of actual coal extraction.

Diffusion - Blending of a gas and air, resulting in a homogeneous mixture. Blending of two or more gases.

Diffuser fan - A fan mounted on a continuous miner to assist and direct air delivery from the machine to the face.

Dilute - To lower the concentration of a mixture; in this case the concentration of any hazardous gas in mine air by addition of fresh intake air.

Dilution - The contamination of ore with barren wall rock in stopping.

Dip - The inclination of a geologic structure (bed, vein, fault, etc.) from the horizontal; dip is always measured downwards at right angles to the strike.

Doppler Flow meter A Doppler flowmeter is a device used to measure flow rates or volumetric flow rates of liquid slurry normally a clamp on /strap on device or insert sensor type

Dragline – A large excavation machine used in surface mining to remove overburden (layers of rock and soil) covering a coal seam. The dragline casts a wire rope-hung bucket a considerable distance, collects the dug material by pulling the bucket toward itself on the ground with a second wire rope (or chain), elevates the bucket, and dumps the material on a spoil bank, in a hopper, or on a pile.

Drainage - The process of removing surplus ground or surface water either by artificial means or by gravity flow.

Draw slate - A soft slate, shale, or rock from approximately 1 cm to 10 cm thick and located immediately above certain coal seams, which falls quite easily when the coal support is withdrawn.

Drift - A horizontal passage underground. A drift follows the vein, as distinguished from a crosscut that intersects it, or a level or gallery, which may do either.

Drift mine – An underground coal mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into a coal seam.

Drill - A machine utilizing rotation, percussion (hammering), or a combination of both to make holes. If the hole is much over 0.4m in diameter, the machine is called a borer.

Drilling - The use of such a machine to create holes for exploration or for loading with explosives.

Dummy - A bag filled with sand, clay, etc., used for stemming a charged hole.

Dump - To unload; specifically, a load of coal or waste; the mechanism for unloading, e.g. a car dump (sometimes called tipple); or, the pile created by such unloading, e.g. a waste dump (also called heap, pile, tip, spoil pike, etc.).


Electrical grounding - To connect with the ground to make the earth part of the circuit.

Entry - An underground horizontal or near-horizontal passage used for haulage, ventilation, or as a mainway; a coal heading; a working place where the coal is extracted from the seam in the initial mining; same as "gate" and "roadway," both British terms.

Evaluation - The work involved in gaining a knowledge of the size, shape, position and value of coal.

Exploration - The search for mineral deposits and the work done to prove or establish the extent of a mineral deposit. Alt: Prospecting and subsequent evaluation.

Explosive - Any rapidly combustive or expanding substance. The energy released during this rapid combustion or expansion can be used to break rock.

Extraction - The process of mining and removal of cal or ore from a mine.


Face – The exposed area of a coal bed from which coal is being extracted.

Face cleat - The principal cleavage plane or joint at right angles to the stratification of the coal seam.

Face conveyor - Any conveyor used parallel to a working face which delivers coal into another conveyor or into a car.

Factor of safety - The ratio of the ultimate breaking strength of the material to the force exerted against it. If a rope will break under a load of 6000 lbs., and it is carrying a load of 2000 lbs., its factor of safety is 6000 divided by 2000 which equals 3.

Fall - A mass of roof rock or coal which has fallen in any part of a mine.

Fan, auxiliary - A small, portable fan used to supplement the ventilation of an individual working place.

Fan, booster - A large fan installed in the main air current, and thus in tandem with the main fan.

Fan signal - Automation device designed to give alarm if the main fan slows down or stops.

Fault - A slip-surface between two portions of the earth's surface that have moved relative to each other. A fault is a failure surface and is evidence of severe earth stresses.

Fault zone - A fault, instead of being a single clean fracture, may be a zone hundreds or thousands of feet wide. The fault zone consists of numerous interlacing small faults or a confused zone of gouge, breccia, or mylonite.

Feeder - A machine that feeds coal onto a conveyor belt evenly.

Fill - Any material that is put back in place of the extracted ore to provide ground support.

Fire damp - The combustible gas, methane, CH4. Also, the explosive methane-air mixtures with between 5% and 15% methane. A combustible gas formed in mines by decomposition of coal or other carbonaceous matter, and that consists chiefly of methane.

Fissure - An extensive crack, break, or fracture in the rocks.

Fixed carbon – The part of the carbon that remains behind when coal is heated in a closed vessel until all of the volatile matter is driven off.

Flat-lying - Said of deposits and coal seams with a dip up to 5 degrees.

Flight - The metal strap or crossbar attached to the drag chain-and-flight conveyor.

Float dust - Fine coal-dust particles carried in suspension by air currents and eventually deposited in return entries. Dust consisting of particles of coal that can pass through a No. 200 sieve.

Floor - That part of any underground working upon which a person walks or upon which haulage equipment travels; simply the bottom or underlying surface of an underground excavation.

Flue Gas Desulfurization – Any of several forms of chemical/physical processes that remove sulfur compounds formed during coal combustion. The devices, commonly called "scrubbers," combine the sulfur in gaseous emissions with another chemical medium to form inert "sludge" which must then be removed for disposal.

Fluidized Bed Combustion – A process with a high degree of ability to remove sulfur from coal during combustion. Crushed coal and limestone are suspended in the bottom of a boiler by an upward stream of hot air. The coal is burned in this bubbling, liquid-like (or "fluidized") mixture. Rather than released as emissions, sulfur from combustion gases combines with the limestone to form a solid compound recovered with the ash.

Fly ash – The finely divided particles of ash suspended in gases resulting from the combustion of fuel. Electrostatic precipitators are used to remove fly ash from the gases prior to the release from a power plant's smokestack.

Formation – Any assemblage of rocks which have some character in common, whether of origin, age, or composition. Often, the word is loosely used to indicate anything that has been formed or brought into its present shape.

Fossil fuel – Any naturally occurring fuel of an organic nature, such as coal, crude oil and natural gas.

Fracture - A general term to include any kind of discontinuity in a body of rock if produced by mechanical failure, whether by shear stress or tensile stress. Fractures include faults, shears, joints, and planes of fracture cleavage.

Friable - Easy to break, or crumbling naturally. Descriptive of certain rocks and minerals.

Fuse - A cord-like substance used in the ignition of explosives. Black powder is entrained in the cord and, when lit, burns along the cord at a set rate. A fuse can be safely used to ignite a cap, which is the primer for an explosive.


Gallery - A horizontal or a nearly horizontal underground passage, either natural or artificial.

Gasification – Any of various processes by which coal is turned into low, medium, or high Btu gases.

Gathering conveyor; gathering belt - Any conveyor which is used to gather coal from other conveyors and deliver it either into mine cars or onto another conveyor. The term is frequently used with belt conveyors placed in entries where a number of room conveyors deliver coal onto the belt.

Geologist - One who studies the constitution, structure, and history of the earth's crust, conducting research into the formation and dissolution of rock layers, analyzing fossil and mineral content of layers, and endeavoring to fix historical sequence of development by relating characteristics to known geological influences (historical geology).

Gob - The term applied to that part of the mine from which the coal has been removed and the space more or less filled up with waste. Also, the loose waste in a mine. Also called goaf.

Global climate change – This term usually refers to the gradual warming of the earth caused by the greenhouse effect. Many believe this is the result of man-made emissions of greenhouse gases such as carbon dioxide, chlorofluorocarbons (CFC) and methane.

Grain - In petrology, that factor of the texture of a rock composed of distinct particles or crystals which depends upon their absolute size.

Grizzly - Course screening or scalping device that prevents oversized bulk material form entering a material transfer system; constructed of rails, bars, beams, etc.

Ground control - The regulation and final arresting of the closure of the walls of a mined area. The term generally refers to measures taken to prevent roof falls or coal bursts.

Ground pressure - The pressure to which a rock formation is subjected by the weight of the superimposed rock and rock material or by diastrophic forces created by movements in the rocks forming the earth's crust. Such pressures may be great enough to cause rocks having a low compressional strength to deform and be squeezed into and close a borehole or other underground opening not adequately strengthened by an artificial support, such as casing or timber.

Gunite - A cement applied by spraying to the roof and sides of a mine passage.


Haulage - The horizontal transport of ore, coal, supplies, and waste. The vertical transport of the same is called hoisting.

Haulageway - Any underground entry or passageway that is designed for transport of mined material, personnel, or equipment, usually by the installation of track or belt conveyor.

Headframe - The structure surmounting the shaft which supports the hoist rope pulley, and often the hoist itself.

Heading - A vein above a drift. An interior level or airway driven in a mine. In longwall workings, a narrow passage driven upward from a gangway in starting a working in order to give a loose end.

Head section - A term used in both belt and chain conveyor work to designate that portion of the conveyor used for discharging material.

Heaving - Applied to the rising of the bottom after removal of the coal; a sharp rise in the floor is called a "hogsback".

Highwall – The unexcavated face of exposed overburden and coal in a surface mine or in a face or bank on the uphill side of a contour mine excavation.

Highwall miner – A highwall mining system consists of a remotely controlled continuous miner which extracts coal and conveys it via augers, belt or chain conveyors to the outside. The cut is typically a rectangular, horizontal cut from a highwall bench, reaching depths of several hundred feet or deeper.

Hogsback - A sharp rise in the floor of a seam.

Hoist - A drum on which hoisting rope is wound in the engine house, as the cage or skip is raised in the hoisting shaft.

Hoisting - The vertical transport coal or material.

Horizon - In geology, any given definite position or interval in the stratigraphic column or the scheme of stratigraphic classification; generally used in a relative sense.

Horseback - A mass of material with a slippery surface in the roof; shaped like a horse's back.

Hydraulic - Of or pertaining to fluids in motion. Hydraulic cement has a composition which permits it to set quickly under water. Hydraulic jacks lift through the force transmitted to the movable part of the jack by a liquid. Hydraulic control refers to the mechanical control of various parts of machines, such as coal cutters, loaders, etc., through the operation or action of hydraulic cylinders.

Hydrocarbon – A family of chemical compounds containing carbon and hydrogen atoms in various combinations, found especially in fossil fuels.


Inby - In the direction of the working face.

Incline - Any entry to a mine that is not vertical (shaft) or horizontal (adit). Often incline is reserved for those entries that are too steep for a belt conveyor (+17 degrees -18 degrees), in which case a hoist and guide rails are employed. A belt conveyor incline is termed a slope. Alt: Secondary inclined opening, driven upward to connect levels, sometimes on the dip of a deposit; also called "inclined shaft".

Incompetent - Applied to strata, a formation, a rock, or a rock structure not combining sufficient firmness and flexibility to transmit a thrust and to lift a load by bending.

Indicated coal resources – Coal for which estimates of the rank, quality, and quantity have been computed partly from sample analyses and measurements and partly from reasonable geologic projections. The points of observation are ? to 1 ? miles apart. Indicated coal is projected to extend as an ? mile wide belt that lies more than ? mile from the outcrop or points of observation or measurement.

Inferred coal resources – Coal in unexplored extensions of the demonstrated resources for which estimates of the quality and size are based on geologic evidence and projection. Quantitative estimates are based largely on broad knowledge of the geologic character of the deposit and for which there are few, if any, samples or measurements. The estimates are based on an assumed continuity or repletion of which there is geologic evidence; this evidence may include comparison with deposits of similar type. Bodies that are completely concealed may be included if there is specific geologic evidence of their presence. The points of observation are 1 ? to 6 miles apart.

In situ - In the natural or original position. Applied to a rock, soil, or fossil when occurring in the situation in which it was originally formed or deposited.

Intake - The passage through which fresh air is drawn or forced into a mine or to a section of a mine.

Intermediate section - A term used in belt and chain conveyor network to designate a section of the conveyor frame occupying a position between the head and foot sections.

Immediate roof - The roof strata immediately above the coalbed, requiring support during the excavation of coal.

Isopach - A line, on a map, drawn through points of equal thickness of a designated unit. Synonym for isopachous line; isopachyte.


Jackleg - A percussion drill used for drifting or stopping that is mounted on a telescopic leg which has an extension of about 2.5 m. The leg and machine are hinged so that the drill need not be in the same direction as the leg.

Jackrock – A caltrop or other object manufactured with one or more rounded or sharpened points, which when placed or thrown present at least one point at such an angle that it is peculiar to and designed for use in puncturing or damaging vehicle tires. Jackrocks are commonly used during labor disputes.

Job Safety Analysis (J.S.A.) - A job breakdown that gives a safe, efficient job procedure.

Joint - A divisional plane or surface that divides a rock and along which there has been no visible movement parallel to the plane or surface.


Kettle bottom - A smooth, rounded piece of rock, cylindrical in shape, which may drop out of the roof of a mine without warning. The origin of this feature is thought to be the remains of the stump of a tree that has been replaced by sediments so that the original form has been rather well preserved.

Kerf - The undercut of a coal face.


Lamp - The electric cap lamp worn for visibility. Also, the flame safety lamp used in coal mines to detect methane gas concentrations and oxygen deficiency.

Layout - The design or pattern of the main roadways and workings. The proper layout of mine workings is the responsibility of the manager aided by the planning department.

Lift - The amount of coal obtained from a continuous miner in one mining cycle.

Liquefaction – The process of converting coal into a synthetic fuel, similar in nature to crude oil and/or refined products, such as gasoline.

Lithology - The character of a rock described in terms of its structure, color, mineral composition, grain size, and arrangement of its component parts; all those visible features that in the aggregate impart individuality of the rock. Lithology is the basis of correlation in coal mines and commonly is reliable over a distance of a few miles.

Load - To place explosives in a drill hole. Also, to transfer broken material into a haulage device.

Loading machine - Any device for transferring excavated coal into the haulage equipment.

Loading pocket - Transfer point at a shaft where bulk material is loaded by bin, hopper, and chute into a skip.

Longwall Mining – One of three major underground coal mining methods currently in use. Employs a steal plow, or rotation drum, which is pulled mechanically back and forth across a face of coal that is usually several hundred feet long. The loosened coal falls onto a conveyor for removal from the mine.

Loose coal - Coal fragments larger in size than coal dust.

Low voltage - Up to and including 660 volts by federal standards.


Main entry - A main haulage road. Where the coal has cleats, main entries are driven at right angles to the face cleats.

Main fan - A mechanical ventilator installed at the surface; operates by either exhausting or blowing to induce airflow through the mine roadways and workings.

Manhole - A safety hole constructed in the side of a gangway, tunnel, or slope in which miner can be safe from passing locomotives and car. Also called a refuge hole.

Man trip - A carrier of mine personnel, by rail or rubber tire, to and from the work area.

Manway - An entry used exclusively for personnel to travel form the shaft bottom or drift mouth to the working section; it is always on the intake air side in gassy mines. Also, a small passage at one side or both sides of a breast, used as a traveling way for the miner, and sometimes, as an airway, or chute, or both.

Measured coal resources – Coal for which estimates of the rank, quality, and quantity have been computed from sample analyses and measurements from closely spaced and geologically well-known sample sites, such as outcrops, trenches, mine workings, and drill holes. The points of observation and measurement are so closely spaced and the thickness and extent of coals are so well defined that the tonnage is judged to be accurate within 20 percent of true tonnage. Although the spacing of the points of observation necessary to demonstrate continuity of the coal differs from region to region according to the character of the coal beds, the points of observation are no greater than ? mile apart. Measured coal is projected to extend as a ?-mile wide belt from the outcrop or points of observation or measurement.

Meridian -– A surveying term that establishes a line of reference. The bearing is used to designate direction. The bearing of a line is the acute horizontal angle between the meridian and the line. Azimuths are angles measured clockwise from any meridian.

Methane – A potentially explosive gas formed naturally from the decay of vegetative matter, similar to that which formed coal. Methane, which is the principal component of natural gas, is frequently encountered in underground coal mining operations and is kept within safe limits through the use of extensive mine ventilation systems.

Methane monitor - An electronic instrument often mounted on a piece of mining equipment, that detects and measures the methane content of mine air.

Mine development - The term employed to designate the operations involved in preparing a mine for ore extraction. These operations include tunneling, sinking, cross-cutting, drifting, and raising.

Mine mouth electric plant – A coal burning electric-generating plant built near a coal mine.

Miner - One who is engaged in the business or occupation of extracting ore, coal, precious substances, or other natural materials from the earth's crust.

Mineral - An inorganic compound occurring naturally in the earth's crust, with a distinctive set of physical properties, and a definite chemical composition.

Mining Engineer - A person qualified by education, training, and experience in mining engineering. A trained engineer with knowledge of the science, economics, and arts of mineral location, extraction, concentration and sale, and the administrative and financial problems of practical importance in connection with the profitable conduct of mining.

Misfire - The complete or partial failure of a blasting charge to explode as planned.

MSHA - Mine Safety and Health Administration; the federal agency which regulates coal mine health and safety.

Mud cap - A charge of high explosive fired in contact with the surface of a rock after being covered with a quantity of wet mud, wet earth, or sand, without any borehole being used. Also termed adobe, dobie, and sandblast (illegal in coal mining).


Natural ventilation - Ventilation of a mine without the aid of fans or furnaces.

Nip - Device at the end of the trailing cable of a mining machine used for connecting the trailing cable to the trolley wire and ground.


Open end pillaring - A method of mining pillars in which no stump is left; the pockets driven are open on the gob side and the roof is supported by timber.

Outby; outbye - Nearer to the shaft, and hence farther from the working face. Toward the mine entrance. The opposite of inby.

Outcrop – Coal that appears at or near the surface.

Overburden – Layers of soil and rock covering a coal seam. Overburden is removed prior to surface mining and replaced after the coal is taken from the seam.

Overcast (undercast) - Enclosed airway which permits one air current to pass over (under) another without interruption.


Panel - A coal mining block that generally comprises one operating unit.

Panic bar - A switch, in the shape of a bar, used to cut off power at the machine in case of an emergency.

Parting - (1) A small joint in coal or rock; (2) a layer of rock in a coal seam; (3) a side track or turnout in a haulage road.

Peat – The partially decayed plant matter found in swamps and bogs, one of the earliest stages of coal formation.

Percentage extraction - The proportion of a coal seam which is removed from the mine. The remainder may represent coal in pillars or coal which is too thin or inferior to mine or lost in mining. Shallow coal mines working under townships, reservoirs, etc., may extract 50%, or less, of the entire seam, the remainder being left as pillars to protect the surface. Under favorable conditions, longwall mining may extract from 80 to 95% of the entire seam. With pillar methods of working, the extraction ranges from 50 to 90% depending on local conditions.

Percussion drill - A drill, usually air powered, that delivers its energy through a pounding or hammering action.

Permissible - That which is allowable or permitted. It is most widely applied to mine equipment and explosives of all kinds which are similar in all respects to samples that have passed certain tests of the MSHA and can be used with safety in accordance with specified conditions where hazards from explosive gas or coal dust exist.

Permit – As it pertains to mining, a document issued by a regulatory agency that gives approval for mining operations to take place.

Piggy-back - A bridge conveyor.

Pillar - An area of coal left to support the overlying strata in a mine; sometimes left permanently to support surface structures.

Pillar robbing - The systematic removal of the coal pillars between rooms or chambers to regulate the subsidence of the roof. Also termed "bridging back" the pillar, "drawing" the pillar, or "pulling" the pillar.

Pinch - A compression of the walls of a vein or the roof and floor of a coal seam so as to "squeeze" out the coal.

Pinch – A compression of the roof and floor of a coal seam so as to "squeeze" out the coal.

Pinning - Roof bolting.

Pitch - The inclination of a seam; the rise of a seam.

Plan - A map showing features such as mine workings or geological structures on a horizontal plane.

Pneumoconiosis - A chronic disease of the lung arising from breathing coal dust.

Portal - The structure surrounding the immediate entrance to a mine; the mouth of an adit or tunnel.

Portal bus - Track-mounted, self-propelled personnel carrier that holds 8 to 12 people.

Post - The vertical member of a timber set.

Preparation plant - A place where coal is cleaned, sized, and prepared for market.

Primary roof - The main roof above the immediate top. Its thickness may vary from a few to several thousand feet.

Primer (booster) - A package or cartridge of explosive which is designed specifically to transmit detonation to other explosives and which does not contain a detonator.

Prop - Coal mining term for any single post used as roof support. Props may be timber or steel; if steel--screwed, yieldable, or hydraulic.

Proximate analysis - A physical, or non-chemical, test of the constitution of coal. Not precise, but very useful for determining the commercial value. Using the same sample (1 gram) under controlled heating at fixed temperatures and time periods, moisture, volatile matter, fixed carbon and ash content are successfully determined. Sulfur and Btu content are also generally reported with a proximate analysis.

Pyrite - A hard, heavy, shiny, yellow mineral, FeS2 or iron disulfide, generally in cubic crystals. Also called iron pyrites, fool's gold, sulfur balls. Iron pyrite is the most common sulfide found in coal mines.


Raise - A secondary or tertiary inclined opening, vertical or near-vertical opening driven upward form a level to connect with the level above, or to explore the ground for a limited distance above one level.

Ramp - A secondary or tertiary inclined opening, driven to connect levels, usually driven in a downward direction, and used for haulage.

Ranks of coal – The classification of coal by degree of hardness, moisture and heat content. "Anthracite" is hard coal, almost pure carbon, used mainly for heating homes. "Bituminous" is soft coal. It is the most common coal found in the United States and is used to generate electricity and to make coke for the steel industry. "Subbituminous" is a coal with a heating value between bituminous and lignite. It has low fixed carbon and high percentages of volatile matter and moisture. "Lignite" is the softest coal and has the highest moisture content. It is used for generating electricity and for conversion into synthetic gas. In terms of Btu or "heating" content, anthracite has the highest value, followed by bituminous, subbituminous and lignite.

Reclamation – The restoration of land and environmental values to a surface mine site after the coal is extracted. Reclamation operations are usually underway as soon as the coal has been removed from a mine site. The process includes restoring the land to its approximate original appearance by restoring topsoil and planting native grasses and ground covers.

Recovery - The proportion or percentage of coal or ore mined from the original seam or deposit.

Red dog - A nonvolatile combustion product of the oxidation of coal or coal refuse. Most commonly applied to material resulting from in situ, uncontrolled burning of coal or coal refuse piles. It is similar to coal ash.

Regulator - Device (wall, door) used to control the volume of air in an air split.

Reserve – That portion of the identified coal resource that can be economically mined at the time of determination. The reserve is derived by applying a recovery factor to that component of the identified coal resource designated as the reserve base.

Resin bolting - A method of permanent roof support in which steel rods are grouted with resin.

Resources – Concentrations of coal in such forms that economic extraction is currently or may become feasible. Coal resources broken down by identified and undiscovered resources. Identified coal resources are classified as demonstrated and inferred. Demonstrated resources are further broken down as measured and indicated. Undiscovered resources are broken down as hypothetical and speculative.

Respirable dust - Dust particles 5 microns or less in size.

Respirable dust sample - A sample collected with an approved coal mine dust sampler unit attached to a miner, or so positioned as to measure the concentration of respirable dust to which the miner is exposed, and operated continuously over an entire work shift of such miner.

Retreat mining - A system of robbing pillars in which the robbing line, or line through the faces of the pillars being extracted, retreats from the boundary toward the shaft or mine mouth.

Return - The air or ventilation that has passed through all the working faces of a split.

Return idler - The idler or roller underneath the cover or cover plates on which the conveyor belt rides after the load which it was carrying has been dumped at the head section and starts the return trip toward the foot section.

Rib - The side of a pillar or the wall of an entry. The solid coal on the side of any underground passage. Same as rib pillar.

Rider - A thin seam of coal overlying a thicker one.

Ripper - A coal extraction machine that works by tearing the coal from the face.

Rob - To extract pillars of coal previously left for support.

Robbed out area - Describes that part of a mine from which the pillars have been removed.

Roll - (1) A high place in the bottom or a low place in the top of a mine passage, (2) a local thickening of roof or floor strata, causing thinning of a coal seam.

Roll protection - A framework, safety canopy, or similar protection for the operator when equipment overturns.

Roof - The stratum of rock or other material above a coal seam; the overhead surface of a coal working place. Same as "back" or "top."

Roof bolt - A long steel bolt driven into the roof of underground excavations to support the roof, preventing and limiting the extent of roof falls. The unit consists of the bolt (up to 4 feet long), steel plate, expansion shell, and pal nut. The use of roof bolts eliminates the need for timbering by fastening together, or "laminating," several weaker layers of roof strata to build a "beam."

Roof fall - A coal mine cave-in especially in permanent areas such as entries.

Roof jack - A screw- or pump-type hydraulic extension post made of steel and used as temporary roof support.

Roof sag - The sinking, bending, or curving of the roof, especially in the middle, from weight or pressure.

Roof stress - Unbalanced internal forces in the roof or sides, created when coal is extracted.

Roof support – Posts, jacks, roof bolts and beams used to support the rock overlying a coal seam in an underground mine. A good roof support plan is part of mine safety and coal extraction.

Roof trusses - A combination of steel rods anchored into the roof to create zones of compression and tension forces and provide better support for weak roof and roof over wide areas.

Room and pillar mining – A method of underground mining in which approximately half of the coal is left in place to support the roof of the active mining area. Large "pillars" are left while "rooms" of coal are extracted.

Room neck - The short passage from the entry into a room.

Round - Planned pattern of drill holes fired in sequence in tunneling, shaft sinking, or stopping. First the cut holes are fired, followed by relief, lifter, and rib holes.

Royalty - The payment of a certain stipulated sum on the mineral produced.

Rubbing surface - The total area (top, bottom, and sides) of an airway.

Run-of-mine - Raw material as it exists in the mine; average grade or quality.


Safety fuse - A train of powder enclosed in cotton, jute yarn, or waterproofing compounds, which burns at a uniform rate; used for firing a cap containing the detonation compound which in turn sets off the explosive charge.

Safety lamp - A lamp with steel wire gauze covering every opening from the inside to the outside so as to prevent the passage of flame should explosive gas be encountered.

Sampling - Cutting a representative part of an ore (or coal) deposit, which should truly represent its average value.

Sandstone - A sedimentary rock consisting of quartz sand united by some cementing material, such as iron oxide or calcium carbonate.

Scaling - Removal of loose rock from the roof or walls. This work is dangerous and a long bar (called a scaling bar)is often used.

Scoop - A rubber tired-, battery- or diesel-powered piece of equipment designed for cleaning runways and hauling supplies.

Scrubber – Any of several forms of chemical/physical devices that remove sulfur compounds formed during coal combustion. These devices, technically know as flue gas de-sulfurization systems, combine the sulfur in gaseous emissions with another chemical medium to form inert "sludge," which must then be removed for disposal.

Seam - A stratum or bed of coal.

Secondary roof - The roof strata immediately above the coal bed requiring support during the excavating of coal.

Section - A portion of the working area of a mine.

Selective mining - The object of selective mining is to obtain a relatively high-grade mine product; this usually entails the use of a much more expensive stopping system and high exploration and development costs in searching for and developing the separate bunches, stringers, lenses, and bands of ore.

Self-contained breathing apparatus - A self-contained supply of oxygen used during rescue work from coal mine fires and explosions; same as SCSR (self-contained self rescuer).

Self-rescuer – A small filtering device carried by a coal miner underground, either on his belt or in his pocket, to provide him with immediate protection against carbon monoxide and smoke in case of a mine fire or explosion. It is a small canister with a mouthpiece directly attached to it. The wearer breathes through the mouth, the nose being closed by a clip. The canister contains a layer of fused calcium chloride that absorbs water vapor from the mine air. The device is used for escape purposes only because it does not sustain life in atmospheres containing deficient oxygen. The length of time a self-rescuer can be used is governed mainly by the humidity in the mine air, usually between 30 minutes and one hour.

Severance – The separation of a mineral interest from other interests in the land by grant or reservation. A mineral dead or grant of the land reserving a mineral interest, by the landowner before leasing, accomplishes a severance as does his execution of a mineral lease.

Shaft - A primary vertical or non-vertical opening through mine strata used for ventilation or drainage and/or for hoisting of personnel or materials; connects the surface with underground workings.

Shaft mine – An underground mine in which the main entry or access is by means of a vertical shaft.

Shale - A rock formed by consolidation of clay, mud, or silt, having a laminated structure and composed of minerals essentially unaltered since deposition.

Shearer - A mining machine for longwall faces that uses a rotating action to "shear" the material from the face as it progresses along the face.

Shift - The number of hours or the part of any day worked.

Shortwall – An underground mining method in which small areas are worked (15 to 150 feet) by a continuous miner in conjunction with the use of hydraulic roof supports.

Shuttle car – A self-discharging truck, generally with rubber tires or caterpillar-type treads, used for receiving coal from the loading or mining machine and transferring it to an underground loading point, mine railway or belt conveyor system.

Sinking - The process by which a shaft is driven.

Skid - A track-mounted vehicle used to hold trips or cars from running out of control. Also it is a flat-bottom personnel or equipment carrier used in low coal.

Skip - A car being hoisted from a slope or shaft.

Slack - Small coal; the finest-sized soft coal, usually less than one inch in diameter.

Slag - The waste product of the process of smelting.

Slate - A miner's term for any shale or slate accompanying coal. Geologically, it is a dense, fine-textured, metamorphic rock, which has excellent parallel cleavage so that it breaks into thin plates or pencil-like shapes.

Slate bar - The proper long-handled tool used to pry down loose and hazardous material from roof, face, and ribs.

Slickenside - A smooth, striated, polished surface produced on rock by friction.

Slip - A fault. A smooth joint or crack where the strata have moved on each other.

Slope - Primary inclined opening, connection the surface with the underground workings.

Slope mine – An underground mine with an opening that slopes upward or downward to the coal seam.

Sloughing - The slow crumbling and falling away of material from roof, rib, and face.

Solid - Mineral that has not been undermined, sheared out, or otherwise prepared for blasting.

Sounding - Knocking on a roof to see whether it is sound and safe to work under.

Spad – A spad is a flat spike hammered into a wooden plug anchored in a hole drilled into the mine ceiling from which is threaded a plumbline. The spad is an underground survey station similar to the use of stakes in marking survey points on the surface. A pointer spad, or sight spad, is a station that allows a mine foreman to visually align entries or breaks from the main spad.

Span - The horizontal distance between the side supports or solid abutments along sides of a roadway.

Specific gravity - The weight of a substance compared with the weight of an equal volume of pure water at 4 degrees Celsius.

Split - Any division or branch of the ventilating current. Also, the workings ventilated by one branch. Also, to divide a pillar by driving one or more roads through it.

Squeeze - The settling, without breaking, of the roof and the gradual upheaval of the floor of a mine due to the weight of the overlying strata.

Steeply inclined - Said of deposits and coal seams with a dip of from 0.7 to 1 rad (40 degrees to 60 degrees).

Stemming - The noncombustible material used on top or in front of a charge or explosive.

Strike - The direction of the line of intersection of a bed or vein with the horizontal plane. The strike of a bed is the direction of a straight line that connects two points of equal elevation on the bed.

Stripping ratio – The unit amount of overburden that must be removed to gain access to a similar unit amount of coal or mineral material.

Stump - Any small pillar.

Subbituminous – Coal of a rank intermediate between lignite and bituminous.

Subsidence – The gradual sinking, or sometimes abrupt collapse, of the rock and soil layers into an underground mine. Structures and surface features above the subsidence area can be affected.

Sump - The bottom of a shaft, or any other place in a mine, that is used as a collecting point for drainage water.

Sumping - To force the cutter bar of a machine into or under the coal. Also called a sumping cut, or sumping in.

Support - The all-important function of keeping the mine workings open. As a verb, it refers to this function; as a noun it refers to all the equipment and materials--timber, roof bolts, concrete, steel, etc.--that are used to carry out this function.

Surface mine – A mine in which the coal lies near the surface and can be extracted by removing the covering layers of rock and soil.

Suspension - Weaker strata hanging from stronger, overlying strata by means of roof bolts.

Syncline - A fold in rock in which the strata dip inward from both sides toward the axis. The opposite of anticline.


Tailgate - A subsidiary gate road to a conveyor face as opposed to a main gate. The tailgate commonly acts as the return airway and supplies road to the face.

Tailpiece - Also known as foot section pulley. The pulley or roller in the tail or foot section of a belt conveyor around which the belt runs.

Tail section - A term used in both belt and chain conveyor work to designate that portion of the conveyor at the extreme opposite end from the delivery point. In either type of conveyor it consists of a frame and either a sprocket or a drum on which the chain or belt travels, plus such other devices as may be required for adjusting belt or chain tension.

Tension - The act of stretching.

Tertiary - Lateral or panel openings (e.g., ramp, crosscut).

Through-steel - A system of dust collection from rock or roof drilling. The drill steel is hollow, and a vacuum is applied at the base, pulling the dust through the steel and into a receptacle on the machine.

Timber - A collective term for underground wooden supports.

Timbering - The setting of timber supports in mine workings or shafts for protection against falls from roof, face, or rib.

Timber set - A timber frame to support the roof, sides, and sometimes the floor of mine roadways or shafts.

Tipple - Originally the place where the mine cars were tipped and emptied of their coal, and still used in that same sense, although now more generally applied to the surface structures of a mine, including the preparation plant and loading tracks.

Ton – A short or net ton is equal to 2,000 pounds; a long or British ton is 2,240 pounds; a metric ton is approximately 2,205 pounds.

Top - A mine roof; same as "back."

Torque wrench - A wrench that indicates, as on a dial, the amount of torque (in units of foot-pounds) exerted in tightening a roof bolt.

Tractor - A battery-operated piece of equipment that pulls trailers, skids, or personnel carriers. Also used for supplies.

Tram - Used in connection with moving self-propelled mining equipment. A tramming motor may refer to an electric locomotive used for hauling loaded trips or it may refer to the motor in a cutting machine that supplies the power for moving or tramming the machine.

Transfer - A vertical or inclined connection between two or more levels and used as an ore pass.

Transfer point - Location in the materials handling system, either haulage or hoisting, where bulk material is transferred between conveyances.

Trip - A train of mine cars.

Troughing idlers - The idlers, located on the upper framework of a belt conveyor, which support the loaded belt. They are so mounted that the loaded belt forms a trough in the direction of travel, which reduces spillage and increases the carrying capacity of a belt for a given width.

Tunnel - A horizontal, or near-horizontal, underground passage, entry, or haulageway, that is open to the surface at both ends. A tunnel (as opposed to an adit) must pass completely through a hill or mountain.


Ultimate analysis - Precise determination, by chemical means, of the elements and compounds in coal.

Undercut - To cut below or undermine the coal face by chipping away the coal by pick or mining machine. In some localities the terms "undermine" or "underhole" are used.

Underground mine – Also known as a "deep" mine. Usually located several hundred feet below the earth's surface, an underground mine's coal is removed mechanically and transferred by shuttle car or conveyor to the surface.

Underground station - An enlargement of an entry, drift, or level at a shaft at which cages stop to receive and discharge cars, personnel, and material. An underground station is any location where stationary electrical equipment is installed. This includes pump rooms, compressor rooms, hoist rooms, battery-charging rooms, etc.

Unit train – A long train of between 60 and 150 or more hopper cars, carrying only coal between a single mine and destination.

Universal coal cutter - A type of coal cutting machine which is designed to make horizontal cuts in a coal face at any point between the bottom and top or to make shearing cuts at any point between the two ribs of the place. The cutter bar can be twisted to make cuts at any angle to the horizontal or vertical.

Upcast shaft - A shaft through which air leaves the mine.


Valuation - The act or process of valuing or of estimating the value or worth; appraisal.

Velocity - Rate of airflow in lineal feet per minute.

Ventilation - The provision of a directed flow of fresh and return air along all underground roadways, traveling roads, workings, and service parts.

Violation - The breaking of any state or federal mining law.

Virgin - Unworked; untouched; often said of areas where there has been no coal mining.

Void - A general term for pore space or other reopenings in rock. In addition to pore space, the term includes vesicles, solution cavities, or any openings either primary or secondary.

Volatile matter - The gaseous part, mostly hydrocarbons, of coal.


Waste - That rock or mineral which must be removed from a mine to keep the mining scheme practical, but which has no value.

Water Gauge (standard U-tube) - Instrument that measures differential pressures in inches of water.

Wedge - A piece of wood tapering to a thin edge and used for tightening in conventional timbering.

Weight - Fracturing and lowering of the roof strata at the face as a result of mining operations, as in "taking weight".

White damp - Carbon monoxide, CO. A gas that may be present in the afterdamp of a gas- or coal-dust explosion, or in the gases given off by a mine fire; also one of the constituents of the gases produced by blasting. Rarely found in mines under other circumstances. It is absorbed by the hemoglobin of the blood to the exclusion of oxygen. One-tenth of 1% (.001) may be fatal in 10 minutes.

Width - The thickness of a lode measured at right angles to the dip.

Winning - The excavation, loading, and removal of coal or ore from the ground; winning follows development.

Winze - Secondary or tertiary vertical or near-vertical opening sunk from a point inside a mine for the purpose of connecting with a lower level or of exploring the ground for a limited depth below a level.

Wire rope - A steel wire rope used for winding in shafts and underground haulages. Wire ropes are made from medium carbon steels. Various constructions of wire rope are designated by the number of strands in the rope and the number of wires in each strand. The following are some common terms encountered: airplane strand; cablelaid rope; cane rope; elevator rope; extra-flexible hoisting rope; flat rope; flattened-strand rope; guy rope; guy strand; hand rope; haulage rope; hawser; hoisting rope; lang lay rope; lay; left lay rope; left twist; nonspinning rope; regular lay; reverse-laid rope; rheostat rope; right lay; right twist; running rope; special flexible hoisting rope; standing rope; towing hawser; transmission rope.

Working - When a coal seam is being squeezed by pressure from roof and floor, it emits creaking noises and is said to be "working". This often serves as a warning to the miners that additional support is needed.

Working face - Any place in a mine where material is extracted during a mining cycle.

Working place - From the outby side of the last open crosscut to the face.

Workings - The entire system of openings in a mine for the purpose of exploitation.

Working section - From the faces to the point where coal is loaded onto belts or rail cars to begin its trip to the outside.

Published: Friday, 18 October 2013 09:52
Hits: 1959


absolute humidity: the ratio of the mass of water vapor to the volume of air in which it is present.(g/m^3)

acid rain: rain that has become acidic after contact with certain atmospheric gases (primarily sulfur dioxide, carbondioxide, and nitrogen oxides)

afforestation: process of establishing a forest.

air mass: a large body of air all of similar temperature and humidity.

air pressure: barometric pressure; weight of the atmosphere at a particular point of interest. Some Meteorologists use hPa – hectopascal for atmospheric air pressure. The hectopascal is equivalent to the mbar (millibar)

Anemometer: Wind Meter . A gage for recording the speed and direction of wind, see Anemometer

anomaly 1: unusual temperature or precipitation for a given region over a specified period. Also see anomaly 2 (Orbital Mechanics section).

anticyclone: high pressure area with counterclockwise winds in the Southern Hemisphere and clockwise winds in the Northern Hemisphere.

Atmospheric Infrared Sounder: advanced sounding instrument designed to retrieve vertical temperature and moisture profiles in the troposphere and stratosphere achieving a temperature retrieval accuracy of 1 degree C with a 1 km vertical resolution. It has been selected to be onboard the EOS-PM1 a remote sensing satellite to take orbit in the year 2000.

atmospheric pressure: force exerted on a surface area, created by the weight of air above it.


barometer: tool for measuring atmospheric pressure.

blizzard: severe weather in which there is low temperatures, strong winds and heavy amounts of snow falling or blowing.


climate: average meteorological conditions in a certain area over a certain period.

clouds: a suspended mass of water vapor in the atmosphere. Clouds can be categorized into two general groups: cumulus clouds (tall, cotton ball) and stratus clouds (layered); these can be divided even further to 4 sub-groups describing altitude: 20,000 ft and above are the cirrus or cirro clouds (cirrocumulus, cirrostratus), composed of mostly ice crystals; from 6,500 to 20,000ft are the alto clouds (altostratus, altocumulus); Low clouds develop up to 6,500ft (stratocumulus, nimbostratus) ,can contact the ground and when they do so, are called fog; existing at many heights, extending far from their bases are the Vertical clouds, such as the cumulus (Cumulonimbus clouds, can have their base near the ground yet reach heights of 75,000ft.)

convection:the process in which cool air delves down, while warmer air rises to the top. The warm air usually cools in the cooler, higher sections of the atmosphere and again begins to return back down. Local breezes, wind and even thunderstorms are a result of convection.

cryosphere: a component of the Earth's system that is frozen water; the forms include: snow, permafrost, floating ice, and glaciers. The cryosphere component is directly related to ocean sea-level, therefore is indirectly related to changes in the atmosphere and biosphere.


dew: condensed moisture (water vapor), appearing as small drops on a cool surface; usually occurs after or during a very warm day.

dew point: the certain temperature at which dew begins to form and water vapor chages to liquid form.

doldrums: area near equator that experiences low pressures and light shifting winds.

Doppler radar: weather radar system that employs the apparent shift in frequency of radio waves to perceive air motion and consequently predict tornadoes and precipitation sooner than previous radars, as well as measure the speed and direction of rain and ice.


eclipse: solar=partial to total darkening of sun due to moon coming between Earth and sun, lunar=partial to total darkening due to Earth casting its shadow on a full moon.

El Ni–o: warming of surface waters in the eastern equatorial Pacific that brings about strange anomolous weather patterns to the coastal regions. Certain economical and ecological disasters can be linked to this phenomena.

evaporation: the process by which an element changes phase from a liquid to a gas; the opposite of condensation.

exosphere: the outer-most layer of the Earth's atmosphere (500 to 1000km above surface); the only part of the atmosphere where an appreciable amount of atmospheric gases escape the Earth.


Fahrenheit: temperature scale in which water boils at 212 ?F and freezes at 32 ?F under standard atmospheric pressure; named after the designer of the scale, the German scientist Gabriel Fahrenheit.

front: boundary that defines two separate air masses; where two different air masses collide, sometimes resulting in severe weather changes.

frost: water that has condensed at a temperature below the freezing point, thus has turned to


glacier: a large mass of ice (at least .1km^2) set in motion by the Earth's gravity, which is a result of accumulated snowfall with little snow melt.

green house effect:process in which green house gases, like carbon dioxide in the Earth's atmosphere, cause thermal radiation emitted by the Earth's surface to be reflected back down, therefore causing the climate to warm. This natural process is enhanced by man's added pollutants and can reach proportions at which a number of animal and plant species can be threatened with extinction, not to mention cause drastic changes in the Earth's natural weather patterns.

gulf stream: ocean current flowing along the coast of the Eastern United States to Ireland, Great Britain, and the Scandivanian countries, making the latter three warmer than they otherwise would be.


hail: precipitation composed of chunks of ice that form atop cumulonimbus clouds and fall as soon as they become too heavy for the cloud updrafts to hold.

haze: a concentration near the surface of the Earth, of fine particles (wet or dry dust, salt, etc.,) .

Haze Meter: An instrument that measures visibility or light transmission. Also known as a Transmissometer

humidity: is the quantity of water vapor in the air. Relative humidity is the ration between the actual quantity of watervapor and the amount of watervapor that the air can hold at a given temperature.

hurricanes: tropical storms with winds exceeding 74 mph originating over the North Atlantic and North Pacific oceans near high humidity and light winds. One well known characteristic of a hurricane is it's eye, which is generally about 5 to 25 miles in diameter and in which are present calm conditions, with clear skies and light winds. Hurricanes can move rather quickly losing intensity as soon as land is encountered, but not without having created very high tides and possibly massive destruction.

hydrosphere: all the components of water present on the Earth, including bodies of water, water vapor, ice, etc.

Hygrometer – Hygrometers are instruments designed to measure relative humidity (RH)


jet stream: high speed air flow in the atmosphere forming air rivers several hundred miles across that generally move west to east and mark the boundary that separates two global air masses with significant differences in temperature.


low (low pressure system): area with lower atmospheric pressure than its surrounding areas; this makes air from surrounding areas to flow into the low, the end result of which is probably cloudiness and precipitation.


mesopause:the uppermost boundary of the mesosphere with the lowest temperature in the atmosphere.

mesosphere: atmospheric layer above the stratosphere (50-85 km altitude).

Meter - See

Metric Conversion Online See

monsoon: season of wind originating from the Indian Ocean and southern Asia, these winds are usually accompanied by heavy rains.


ozone: gaseous form of oxygen that constitutes less than one part per million of the gases in the atmosphere, yet absorbs most of the ultraviolet radiation which has been proven to be harmful to humans as well as other life forms on Earth.


precipitation: rain, drizzle and other forms of moisture falling from clouds. Raindrops form around particles of dust or salt, join other water droplets or ice droplets and fall when sufficently heavy in the from of liquid or ice, depending on the quantity of collected ice crystals.


sea breeze: wind blowing from the ocean to land at the coast, due to the cool air replacing the warmer air that has moved up on the coastline.

sea level: the imaginary line from which sea depth and land elevation are measured.

stratosphere: region between the troposphere and mesosphere, extending from 10 to 30 miles above the Earth's surface.


temperature: measure of the quantity of thermal energy in a substance. High temperature indicates more heat energy than low temperature.


Weather Station: Weather Stations gather , record and send out meteorological data . Some may also analyze meteorological data and patterns. Typical weather stations use several types of measuring instruments which might included thermometers, barometers, hygrometers, anemometers, wind vanes, rain gauges . Weather stations supporting airports usually have instruments for measuring rain drop size distribution or Disdrometers , transmissmeters for measuring cloud visibility and ceiling projectors for cloud ceiling


Published: Friday, 18 October 2013 09:51
Hits: 1877

Some Water and Waste Terminology


Activated Carbon Filter: Water treatment process to remove taste, odor, some organic compounds, and radon.

Adsorption: retention of a substance by soil particles.

Aerobic: in the presence of or requiring oxygen.

Agri-chemical: chemicals (fertilizers and pesticides) used in agricultural production.

Algal Bloom: large, visible masses of algae found in bodies of water during warm water.

Alkalinity: capacity of water to neutralize acids by its content of bicarbonates, carbonates, or hydroxides.

Ambient Monitoring: performed to determine existing environmental conditions or contaminant levels in the environment, against which future conditions can be compared.

Anaerobic (Anoxic): in the absence of oxygen.

Aquifer: water-bearing formation of rock or soil that will yield useable supplies of water. May be classified as confined or unconfined.

Artesian (Flowing) Aquifer: aquifer in which water is held under pressure by confining layers, forcing water to rise in wells above the top of the aquifer.

Assimilative Capacity: natural ability of soil and water to use and decompose potential pollutants without harmful effects to the environment.

Available Nitrogen: amount of nitrogen present as either nitrate or ammonium, forms which can be readily taken up by plants.

Available Water: the portion of water in soil that can be readily absorbed by plant roots.

Background Level: amount of a substance which occurs naturally in the environment.

Bacteria: microscopic one-celled organisms which live everywhere and perform a variety of functions. While decomposing organic matter in water, bacteria can greatly reduce the amount of oxygen in the water.

Baler: machine used to compress and bind recyclables, such as aluminum, paper, corrugated cardboard and plastics.

Bentonite: highly plastic clay consisting of the minerals montmorillonite and beidellite that swells when wet and is often used as a lining material to seal landfills and lagoons.

Best Management Practice (BMP): structural or managerial technique recognized as the most effective and practical means of controlling pollution for an agricultural, urban, forested, or mining area.

Biochemical Oxygen Demand (BOD): laboratory measurement of the amount of oxygen consumed by microorganisms while decomposing organic matter in a product. BOD levels are indicative of the effect of the waste on fish or other aquatic life which require oxygen to live, and though not a specific compound, it is defined as a conventional pollutant under the federal Clean Water Act.

Biodegradeable: capable of being broken down (decomposed) by microorganisms.

Black Water: liquid and solid human body waste and the carriage water generated by toilet use.

Bottle Bill: law requiring deposits on beverage containers (see Container Deposit Legislation).

BTX: a test for benzene, toluene, and xylene, three organic compounds characteristically present in gasoline.

Buffer Zone: neutral area which acts as a protective barrier separating two conflicting forces. An area which acts to minimize the impact of pollutants on the environment or public welfare. For example, a buffer zone is established between a compositing facility and neighboring residents to minimize odor problems.

Bulky Waste: large items of refuse including, but not limited to, appliances, furniture, large auto parts, non-hazardous construction and demolition material, trees, branches and stumps which cannot be handled by normal solid waste processing, collection and disposal methods.

Buy-Back Center: facility where individuals bring recyclables in exchange for payment.

Carcinogen: substance which causes cancer.

Chemical Oxygen Demand (COD): laboratory measurement of the amount of oxygen used in chemical reactions that occur in water as a result of the addition of wastes. A major objective of conventional wastewater treatment is to reduce the chemical and biochemical oxygen demand.

Chlorination: addition of chlorine as a means of disinfecting drinking water or wastewater.

Co-compositing: simultaneous composting of two or more diverse waste streams.

Coliform Bacteria: microorganisms which typically inhabit the intestines of warm-blooded animals. They are commonly measured in drinking water analyses to indicate pollution by human or animal waste.

Commercial Waste: materials originating in wholesale, retail, institutional or service establishments such as offices, stores, markets, theaters, hotels and warehouses.

Commingled Recyclables : mixture of several recyclable materials in one container.

Compactor: power-driven device used to compress materials to smaller volume.

Composting: controlled microbial degradation of organic waste yielding an environmentally sound product with value as a soil ammendment.

Comprehensive Environmental Response, Compensation and Liability Act (CERCLA): See Superfund.

Confined Aquifer: water-bearing formation whose upper boundary is a layer which does not transmit water readily.

Contaminant: any physical, chemical, biological, or radiological substance causing an impurity in the environment.

Corrosive: capable of eating away materials and destroying living tissue on contact.

Corrugated: structural paper or cardboard shaped in parallel furrows and ridges for rigidity.

Curbside Collection: program where recyclable materials are collected at the curb, often from special containers, to be taken to various processing facilities.

Deactivation: process in which a pesticide adheres to a soil particle or some organic material so tightly that it is no longer biologically available.

Decomposition: breaking down into component parts or basic elements.

Decomposition: breaking down into component parts or basic elements.

Decomposition Gases: produced in the breakdown of garbage or other material. Some, such as methane, are flammable.

Degradable: capable of being chemically reduced or broken down.

Denitrification: biochemical conversion of nitrate (NO3) to nitrite (NO2), ammonia (NH3), and free nitrogen (N), as in soil by microorganisms.

Dioxins: heterocyclic hydrocarbons that occur as toxic impurities, especially in pesticides.

Discharge: flow of surface water in a stream or the flow of ground water from a spring, ditch, or flowing artesion well.

Disposable: manufactured to be used for a short time and then thrown away; not durable or repairable.

Dissolved Oxygen (DO): oxygen dissolved in water and readily available to fish and other aquatic organisms.

Diversion Rate: measure of the amount of waste material being diverted for recycling compared with the total amount previously thrown away.

Drawdown: vertical drop of the water level in a well during pumping.

Drop-off Center: method of collecting recyclable or compostible materials in which materials are taken by individuals to collection sites and deposited into designated containers.

Ecosystem: community of animals and plants and the physical environment in which they live.

Effluent: discharge or emission of a liquid or gas.

Energy Recovery: conversion of waste energy, generally through the combustion of processed or raw refuse (incineration), to produce steam.

Erosion: natural breakdown and movement of soil and rock by water, wind, or ice. The process may be accelerated by human activities.

Escherichia coli (E. coli): species of coliform bacteria that inhabit intestines of people and animals.

Eutrophication: degradation of water quality due enrichment by nutrients, primarily nitrogen (N) and phosphorus (P), which results in excessive plant (principally algae) growth and decay. Low dissolved oxygen (DO) in the water is a common consequence.

Evapotranspiration (ET): loss of water to the atmosphere from the earth's surface by evaporation and by transpiration through plants.

Explosive / Reactive: capable of causing an explosion or releasing poisonous fumes when exposed to air, water, or other chemicals.

Formulation: the combination of active and inactive (inert) ingredients which make up a pesticide.

Fumigant: gaseous material used to destroy insects, pathogens, or other pests in soil or grain bins.

Fungicide: substance that kills fungi.

Garbage: waste food that is thrown away, generally defined as wet food waste. The term is also used to describe all products discarded, regardless of their reusability or recyclability.

Geographic Information System: computerized database system containing natural resources and land use data that can be used to analyze and display information in spatial, or map, format.

Giardiasis: presence of the Giardia lamblia protozoan in the human small intestine which can cause diarrhea.

Grey Water: wastewater other than sewage, such as sink or washing machine drainage.

Ground Water: water in the saturated zone (below the water table).

Half-life: time required for one-half of a specified substance to decompose.

Hammermill: type of crusher or shredder used to break up waste materials into smaller pieces.

Hardness: characteristic of water which describes the presence of dissolved minerals. Carbonate hardness is caused by calcium and magnesium bicarbonate; noncarbonate hardness is caused by calcium sulfate, calcium chloride, magnesium sulfate, and magnesium chloride.

Hazardous Waste: solid, liquid, or gaseous substance which, because of its source or measurable characteristics, is classified under state or federal law as potentially dangerous and is subject to special handling, shipping, and disposal requirements.

Head: the height of a column of water above a standard datum such as mean sea level.

Health Advisory (HA): non-regulatory, health-based reference level of drinking water contaminants at which adverse health effects are believed to be minimal. HA levels are established for 1-day, 10-day, longer-term, and lifetime exposure periods, and they include large safety margins.

Heavy Metals: those metals (elements with high density, malleability, and electrical and thermal conductivity) that have high specific gravity and high atomic mass, such as lead, cadmium, zinc, copper, silver, and mercury. These may be found in the waste stream as part of discarded items such as batteries, lighting fixtures, colorants and inks.

Herbicide: chemical used to destroy or inhibit undesirable plant growth.

High Grade Paper: relatively valuable paper such as computer printout, white ledger, and tab cards. Also used to refer to industrial trimmings at paper mills that are recycled.

Household Hazardous Waste: discarded or usused portions of home cleaning products, workshop and outdoor chemicals, automotive fluids, and personal care products that contain toxic chemicals. Products labeled WARNING, CAUTION, POISONOUS, TOXIC, FLAMMABLE, REACTIVE, or EXPLOSIVE are considered hazardous.

Humus: organic materials resulting from decay or plant or animal matter. Also referred to as compost.

Hydrologic Cycle: the movement of water in and on the earth and atmosphere through processes such as precipitation, evaporation, runoff, and infiltration.Hydrology: science dealing with the properties, distribution, and flow of water on or in the earth.

Hydrolysis: reaction of a water molecule with another larger molecule, resulting in the splitting of the larger molecule.

Ignitable: capable of burning or causing a fire.

In-vessel Composting: method in which the compost material is continuously and mechanically mixed and aerated in a large, contained area.

Incinerator: facility in which the combustion of solid waste takes place.

Industrial Waste: materials discarded from industrial operations or derived from manufacturing processes.

Infiltration: entry of water from precipitation, irrigation, or runoff into the soil profile.

Inorganic Chemicals: natural or synthetic chemicals that contain no carbon.

Insecticide: substance that kills insects.

Institutional Waste: material originating in schools, hospitals, prisons, research institutions, and other public buildings.

Integrated Solid Waste Management: practice of using several alternative waste management techniques to manage and dispose of specific components of the municipal waste stream. Waste management alternatives include source reduction, recycling, composting, energy recovery, and landfilling.

Intermediate Processing Center (IPC): type of materials recovery facility (MRF) that processes residentially collected mixed recyclables into new products available for market; often used interchangeably with MRF.

Landfill: see Sanitary Landfill.

Leaching: movement through soil of dissolved or suspended substances in water.

Lethal Dose (LD): amount of a substance required to cause death in an organism.

Loading: amount of a substance entering the environment (soil, water, or air).

Manual Separation: sorting of recyclables or compositable materials from waste by hand sorting.

Mass Burn: municipal waste combustion technology in which solid waste is burned in a controlled system without prior sorting or processing.

Materials Market: combination of manufacturing interests which buy recyclable materials and process them for reuse. The demand for goods made of recycled materials determines the economic feasibility of recycling and resource recovery.

Materials Recovery Facility (MRF): facility that separates and processes recyclable materials for sale to an end user.

Maximum Contaminant Level (MCL): enforceable EPA standard for the maximum permissible concentration of a contaminant in public water supplies. An MCL is set after considering health effects as well as the feasibility and cost of analysis and treatment of the regulated contaminant.

Maximum Contaminant Level Goal (MCLG): preliminary standard based entirely on health effects which is used by EPA to establish the MCL for a contaminant. For a chemical believed to cause cancer, the MCLG is zero.

Mechanical Separation: sorting of waste into various components using mechanical means, such as cyclones, trommels, and screens.

Metabolites: breakdown chemical products resulting when a pesticide passes through a biological system.

Methane: odorless, colorless, flammable and explosive gas produced by municipal solid waste undergoing anaerobic decomposition. Methane is emitted from municipal solid waste landfills.

Mineral Water: contains large amounts of dissolved minerals such as calcium, sodium, magnesium, and iron. Some tap waters contain as many or more minerals than some commercial mineral waters. There is no scientific evidence that either high or low mineral content water is beneficial to humans.

Mineralization: microbial conversion of an element from an organic (containing carbon) to an inorganic (not containing carbon) state.

Modular Incinerator: small-scale waste combustion units prefabricated at a manufacturing facility and transported to the MWC facility site.

Most Probable Number (MPN): statistical expression for estimating the number of microorganisms in a culture or a volume of water.

Mulch: natural or artificial layer of plant residue pr pther material covering the land surface which conserves soil moisture, holds soil in place, aids in establishing plant cover, and minimizes temperature fluctuations.

Municipal Solid Waste (MSW): non-hazardous discarded material generated in residential, commercial, institutional, and light industrial settings. It is defined by local governments, and in general does not include automobile oil, tires, lead-acid batteries, hazardous or infectious wastes, demolition debris, etc.

NIMBY: acronym for "Not In My Back Yard" which is an expression of resident opposition to the siting of a solid waste facility based on the particular location proposed.

Nitrification: biochemical oxidation of ammonia (NH3), ammonium (NH4), or atmospheric nitrogen (N) to nitrate (NO3) or nitrite (NO2).

No Observeable Adverse Effect Level (NOAEL): chemical exposure dose or level producing no observeable adverse effect in long-term toxicity studies. This level is used to establish a tolerance for human consumption.

Nondischarge Systems : wastewater disposal systems that do not discharge to surface waters, such as spray irrigation, land application, or conventional septic systems.

Nonpoint Source (NPS) Contamination: : water contamination derived from diffuse sources such as construction sites, agricultural fields, and urban runoff.

Nuisance Contaminant: constituents in water which are not normally harmful to health but may cause offensive taste, odor, color, corrosion, foaming, or staining.

Nutrient: element essential for plant or animal growth. Major nutrients include nitrogen, phosphorus, carbon, oxygen, sulfur, and potassium.

Organic Compound: any carbon-based substance, including some petroleum products, solvents, pesticides, and halomethanes. Volatile organic compounds (VOCs) are those which are readily vaporized; a number of these are known or probable carcinogens.

Oxygen Demand: materials such as food waste and dead plant or animal tissue that use up dissolved oxygen in the water when they are degraded through chemical or biological processes. Chemical and biochemical oxygen demand (COD and BOD) are measures of the amount of oxygen consumed when a substance degrades.

Package Treatment Plant: prefabricated, small-scale wastewater treatment system used in subdivisions or trailer parks.

Pathogen: disease-causing biological agent such as a bacterium, virus, or fungus.

Percolation: movement of water through soil or rock.

Permeability: capacity of soil, sediment, or porous rock to transmit water.

Persistence: resistance to degradation as measured by the period of time required for complete breakdown of a material. Depends on temperature, pH, soil type, light intensity, etc.

Pesticide: substance used for controlling, destroying, or repelling a specific pest. Includes fungicides, herbicides, insecticides, nematicides, rodenticides, defoliants, and plant growth regulators.

Photodegradeable: capable of being broken down (decomposed) by a chemical reaction initiated by direct exposure to the sun's ultraviolet radiation.

pH: numerical measure of acidity, with a scale of 0 to 14. Neutral is pH 7, values below 7 are acidic, and values above 7 are alkaline.

Point-of-entry(POE): water treatment system located at the entry point to the home which treats all water used in the home.

Point-of-use: water treatment system located at the tap which treats only water used from the tap.

Point Source Contamination: water contamination from specific sources such as leaking underground storage tanks, landfills, industrial waste discharge points, or chemical mixing sites.

Pollution: presence of a contaminant to such a degree that the environment (land, water, or air) is not suitable for a particular use.

Polychlorinated Byphenyl (PCB): hazardous compound (suspected carcinogen) used for electrical insulation and heating/cooling equipment which has been found in air, soil, water, and fish across the country.

Polyethylene Terephthalate (PET): recyclable plastic used to make bottles such as soda bottles. Recycled PET is used in car bumpers, furniture, skis, surfboards, carpet yarn, polyester fiber, films and sheets, and molded parts.

Polyvinyl Chloride (PVC): common plastic material which releases hydrochloric acid when burned.

Post-Consumer Recycling: reuse of materials generated from residential and commercial waste; excludes recycling of material from industrial processes that has not reached the consumer, such as glass broken in the manufacturing process.

Post-Consumer Waste: material discarded by a business or residence that has fulfilled its useful life.

Potable: suitable for drinking.

Primary Drinking Water Standards: enforceable EPA standards which establish MCLs for drinking water contaminants after considering health effects and the feasibility and cost of analysis and treatment of regulated contaminants.

Publicly Owned Treatment Works (POTW): wastewater treatment facility supported by public funding.

Pyrolysis: chemical decomposition of a material by heat in the absence of oxygen.

Radon: colorless, odorless, tasteless, radioactive gas.

Receiving Waters : bodies of water that receive runoff or wastewater discharges, such as rivers, streams, lakes, estuaries, and ground water.

Recharge: downward movement of water through soil to ground water.

Recharge Area: land area over which precipitation infiltrates into soil and percolates downward to replenish an aquifer.

Recyclables: materials that still have useful physical or chemical properties after serving their original purpose and that can be reused or remanufactured into additional products, thereby serving as substitutes for raw materials.

Recycling: process by which materials otherwise destined for disposal are collected, reprocessed or remanufactured, and reused. Mandatory recycling programs require by law that consumers separate trash so that some or all recyclable materials are not burned or dumped in landfills.

Refractory: material able to withstand dramatic heat variations which may be used to construct conventional combustion chambers in incinerators.

Refuse Derived Fuel (RDF): product of a mixed waste processing system in which certain recyclable and non-combustible materials are removed, and the remaining combustible material is converted for use as a fuel to create energy. Densified Refuse Derived Fuel (d-RDF) results when the fuel is processed to form briquettes, pellets, or cubes.

Residential Waste: materials generated in single and multiple-family homes.

Residue: materials remaining after processing, incineration, composting, or recycling have been completed; normally disposed of in landfills.

Resource Conservation and Recovery Act (RCRA): federal legislation related to hazardous waste (Subtitle C), solid, non-hazardous waste (Subtitle D), and the recovery and use of recycled materials and energy (Subtitle F).

Resource Recovery: extraction and utilization of materials and energy from the waste stream.

Reuse: use of a product, such as a softdrink bottle, in its original form more than once for the same purpose.

Reverse Osmosis (RO):water treatment process in which contaminants are removed by forcing water through a membrane having microscopic holes that allow water molecules, but not larger compounds, to pass through. RO units do not remove all chemicals, and they generally discharge more than half of the total water as waste.

Roll-off Container: large waste container that fits onto a tractor trailer and can be loaded and unloaded hydraulically.

Runoff: the portion of precipitation, snow melt, or irrigation which flows over and through soil, eventually reaching surface water (streams, rivers, lakes).

Safe Drinking Water Act(SDWA): passed by Congress in 1974, and ammended in 1986, to insure safe drinking water. It directs the EPA to establish and enforce water quality standards to protect public health.

Salinity: quality of water based on its salt content; seawater contains approximately 18,000 parts per million of salt.

Sanitary Landfill: solid waste disposal site where waste is spread in layers, compacted, and covered with soil or other cover materials each day to minimize pest, aesthetic, disease, air pollution, and water pollution problems. Modern sanitary landfills are equipped with leachate collection and monitoring systems and methane gas controls and are operated in accordance with environmental protection standards.

Saturated Zone: portion of the soil or rock profile in which all pores are filled with water.

Scavenger: one who illegally removes materials at any point in the solid waste management system.

Scrap: discarded or rejected industrial waste material often suitable for recycling.

Scrubber: anti-pollution device that uses a liquid or slurry spray to remove acid gases and particulates from municipal waste combustion facility flue gases.

Secondary Drinking Water Standards: EPA guidelines for establishing Secondary Maximum Contaminant Levels (SMCLs), non-enforceable standards for nuisance contaminants that cause offensive taste, odor, color, corrosion, foaming, and staining.

Secondary Material: used in place of a primary or raw material in manufacturing a product.

Sediment: eroded soil and rock material, and plant debris, transported and deposited by water.

Septic Tank: sewage disposal tank in which a continuous flow of waste material is decomposed by anaerobic (in the absence of oxygen) bacteria.

Signal Word: warning required by the Federal Hazardous Substances Act of 1960 to be used on the label of a hazardous substance. Examples include DANGER, WARNING, CAUTION, and POISON.

Sludge: heavy, slimy residue remaining from the treatment of municipal and industrial water and wastewater. Digested sewage sludge remains after decomposition under controlled temperature, pH, and mixing in a digester tank.

Softening: process of removing hardness caused by calcium and magnesium minerals from water.

Soil Liner: landfill liner composed of compacted soil or synthetic material designed to assist in containment of leachate.

Solid Waste Management: related to storage, collection, transportation, treatment, utilization, processing, and final disposal of solid waste or resource recovery, and facilities necessary for such activities.

Solubility: amount of a substance that will dissolve in a given amount of another substance, typically water.

Soluble: capable of being dissolved easily.

Solvent: liquid capable of dissolving another substance.

Source Reduction: design, nanufacture, acquisition, and reuse of materials so as to minimize the quantity and/or toxicity of waste produced. Waste is eliminated by redesigning products or by otherwise changing societal patterns of consumption, use, and waste generation.

Source Separation: segregation of specific recyclable materials at the point of generation for separate collection; often part of a curbside recycling program.

Special Waste: items that require special or separate handling, such as household hazardous waste, bulky waste, tires, and used oil.

Static Water Level: water level in a well before pumping.

Superfund: common name for the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) designed to clean up abandoned or inactive hazardous waste dump sites.

Tipping Fee: Charge, usually in dollars per ton, for the unloading or dumping of waste at a landfill, transfer station, recycling center, or waste-to-energy facility, also called a disposal or service fee.

Total Dissolved Solids (TDS): concentration of all substances dissolved in water (solids remaining after evaporation of a water sample).

Toxic Substance (Toxicant): harmful to plant or animal life, either immediately (acute toxicity) or over a long time period (chronic toxicity).

Transfer Station: site where waste materials are taken and temporarily stored after collection, pending shipment to a disposal site or resource recovery facility. Recycling and some processing may also take place at transfer stations.

Transmissivity: rate at which water passes through a unit width of an aquifer.

Trash: Material considered worthless, unnecessary or offensive that is usually thrown away. In common usage, it is a synonym for garbage, rubbish or refuge.

Tub Grinder: Machine to grind or chip wood wastes for mulching, composting or size reduction.

Turbidity: measure of water cloudiness due to suspended solids.

Unconfined (Water Table) Aquifer: water-bearing formation whose upper boundary is the water table (as opposed to a confining layer).

Unsaturated Zone: portion of the soil profile which contains both air and water. Water in this zone cannot enter a well.

Vector: a carrier, typically an insect or rodent, capable of transmitting a disease.

Virgin Material: raw materials which have never been processed in a manufacturing system, usually requiring more energy to produce than when substituted for by recyclable materials.

Volatilization: conversion of substance to gaseous form.

Volume Reduction: the processing of waste materials so as to decrease the amount of space the materials occupy, usually by compacting or shredding (mechanical), incineration (thermal), or composting (biological).

Waste Exchange: a computer and catalog network that redirects waste materials back into the manufacturing or reuse process by matching companies generating specific waste with companies that use those wastes as manufacturing inputs.

Waste Stream: the total waste generated by all contributors (households, industry, government) in a particular area (city, county, state).

Wastewater Treatment Plant (WWTP): facility that treats wastewater (and sometimes runoff) from domestic and/or industrial sources by a combination of physical, chemical, and biological processes.

Water Table: top of an unconfined aquifer, below which the pore spaces are saturated with water.

Watershed (Drainage Basin): all land and water that drains runoff to a stream or other surface water body.

Waterwall Incinerator: waste combustion facility using lined steel tubes filled with circulating water for cooling. Heat from the combustion gases is transferred to the water, and the resultant steam is sold or used to generate electricity.

Wetlands: areas that are regularly wet or flooded and have a water table that stands at or above the land surface for at least part of the year. Coastal wetlands extend back from estuaries and include salt marshes, tidal basins, marshes, and mangrove swamps. Inland freshwater wetlands consist of swamps, marshes, and bogs.

White Goods: Large household appliances such as refrigerators, stoves, air conditioners and washing machines.

Windrow: A large, elongated pile of composting material. Yard Waste: Leaves, grass clippings, prunings, and other natural organic matter discarded from yards and gardens.

Zoning: designation by ordinances of areas of land reserved and regulated for different land uses; a type of regulatory ordinance based on a land use plan.

Published: Friday, 18 October 2013 09:51
Hits: 2141


acid - a substance that has a pH value between 0 and 7 
acid deposition ("acid rain") - water that falls to or condenses on the Earth's surface as rain, drizzle, snow, sleet, hail, dew, frost, or fog with a pH of less than 5.6 
acre-foot - the amount of water needed to cover one acre of land one foot deep; about 326,000 gallons 
adhesion - the attraction between molecules that causes matter to cling to or stick to other matter 
adjudication - a court determination of water rights for a groundwater basin or a stream; adjudication sets priorities during shortages 
aeration - the addition of air to water or to the pores in soil 
aesthetic - sensitive to beauty 
alkaline - the quality of being bitter due to alkaline content (pH is greater than 7) 
alluvial - sediment deposited by flowing water, such as in a riverbed 
alum - aluminum sulfate: a chemical, which is mixed into water to cause particles in the water to clump together so they can be removed 
anadramous - any fish which spends a portion of its life cycle in freshwater and a portion in the sea 
aquifer - an underground layer of rock, sediment or soil that is filled or saturated with water 
aquifer system - a heterogeneous body of introduced permeable and less permeable material that acts as a water-yielding hydraulic unit of regional extent 
aqueduct - man-made canal or pipeline used to transport water 


bacteria - any of a number of one-celled organisms, some of which cause disease 
base - a substance that has a pH value between 7 and 14 
basin - a groundwater reservoir defined by the overlying land surface and underlying aquifiers that contain water stored in the reservoir 
benefit - an advantage to be gained in a trade-off 
benefit/cost analysis - a process of evaluating the advantages and disadvantages of a proposed purchase or project 
BMPs (Best Management Practices) - structural or management practices which are implemented to reduce pollution (e.g., using a permeable material for parking lots to reduce urban runoff) 
boiler scale - mineral deposits from water, such as those found inside pipes or teakettles 
bond - a promise to repay money borrowed, plus interest, over a specified period of time 
bond issue - a means of raising large amounts of money for major projects by selling bonds 
brackish - water containing too much salt to be useful to people but less salt than ocean water
by-products - something produced in addition to the principal product 


capillarity - the process by which water rises through rock, sediment or soil caused by the cohesion between water molecules and an adhesion between water and other materials that "pulls" the water upward 
capital cost - all the implements, equipment, machinery and inventory used in the production of goods and services 
cesspool - a covered hole or pit for receiving sewage 
chloramination - the treatment of a substance, such as drinking water, with chlorine and ammonia (chloramines) in order to kill disease-causing organisms 
chlorination - the treatment of a substance, such as drinking water, with chlorine in order to kill disease-causing organisms 
cloud - a mass of suspended water droplets and/or ice crystals in the atmosphere 
cloud droplets - the tiny liquid pieces of water that many clouds are made of. When cloud droplets join together and become heavy enough they form raindrops. 
coagulation - the process, such as in treatment of drinking water, by which dirt and other suspended particles become chemically "stuck together" so they can be removed from water 
cohesion - the ability of a substance to stick to itself and pull itself together 
coliform - a group of bacteria used as indicators of microbiological contamination 
colloidal suspension - a method of sediment transport in which water turbulence (movement) supports the weight of the sediment particles, thereby keeping them from settling out or being deposited 
condensation - water vapor changing back into liquid 
condensation surfaces - small particles of matter, such as dust and salt suspended in the atmosphere, which aid the condensation of water vapor in forming clouds 
confined aquifer - an aquifer that is bound above and below by dense layers of rock and contains water under pressure 
conjunctive use - the planned use of groundwater in conjunction with surface water to optimize total water resources 
conservation - saving; not wasting; using water wisely 
constituents - parts of a whole; components 
consumer - one who consumes or uses economic goods or services 
contaminate - to make unfit for use; to pollute 
contractor - a water agency that signs a contract to acquire given amounts of water from another agency, usually under specified conditions 
contour plowing - plowing done in accordance with the natural outline or shape of the land by keeping the furrows or ditches at the same elevation as much as possible to reduce runoff and erosion 
cost - the outlay or expenditure (as of money, effort or sacrifice) made to achieve an object or advantage 
cost-effective - able at least to pay for itself or make a profit 
county water authority - a public water district serving a county-wide area 
cubic foot of water - the amount of water needed to fill a cube that is one foot on all sides; about 7.5 gallons 


dam - a structure built to hold back a flow of water 
debt service - the repayment of borrowed money, plus interest 
deficit - the amount by which a sum of money falls short of an expected amount 
delta - fan-shaped area at the mouth of a river (where seas are relatively calm) 
demand - the quantity of goods or services that consumers are willing and able to buy at a given price 
deposition - the process of dropping or getting rid of sediments by an erosional agent such as a river or glacier; also called sedimentation 
desalination - the process of removing salt from seawater or brackish water 
dew - moisture in the air that condenses on solid surfaces when the air is saturated with water vapor 
dew point - the temperature at which the air becomes saturated with water vapor 
discharge - the amount of water flowing past a location in a stream/river in a certain amount of time - usually expressed in liters per second or gallons per minute 
disinfect - to destroy harmful microorganisms 
dissolve - to enter into a solution 
divert - to direct a flow away from its natural course 
divide - a ridge or high area of land that separates one drainage basin from another 
drainage basin - all of the area drained by a river system 
drought - a prolonged period of below-average precipitation 


economic benefit - a gain that can be measured in dollars 
economic cost - a cost involved in a trade-off that requires spending money 
ecosystem - an interacting network of groups of organisms together with their non-living or physical environment 
efficiency - effective operation as measured by a comparison of production with cost 
endangered species - a species of animal or plant threatened with extinction 
environment - the surroundings that affect the growth and development of an organism 
environmental impacts - factors that affect organisms and the surroundings of organisms 
Environmental Impact Report (EIR) - a state-mandated written summary of the positive and negative effects on the environment caused by the construction and operation of a project 
erosion - the processes (including soil erosion) of picking up sediments, moving sediments, shaping sediments, and depositing sediments by various agents; erosional agents include streams, glaciers, wind and gravity 
Escherichia coli (E. coli) - a common bacterium found in fecal matter; member of the coliform group 
evaporation - water changing into vapor and rising into the air 
exchange - the act of trading goods or services for those produced by people who are located elsewhere 
expense - something spent (such as money, time or effort) to secure a benefit or bring about a result 


factors of production - the resource inputs involved in the production of goods and services: for example, labor, land and capital 
feces - waste excreted from the bowels of humans and animals 
filtration - passing water through coal, sand and gravel to remove particles 
filtration plant - place where water is cleaned and made safe to drink 
financing cost - the fees charged by financial specialists and the interest charged on money borrowed to pay for a project 
fish ladder - a device to help fish swim around a dam 
fishery - the aquatic region in which a certain species of fish lives 
floc - clumps of impurities removed from water during the purification process; formed when alum is added to impure water 
flocculation - a step in water filtration in which alum is added to cause particles to clump together 
floodplain - area formed by fine sediments spreading out in the drainage basin on either side of the channel of a river as a result of the river's fluctuating water volume and velocity 
fog - clouds that form at the Earth's surface 
frost - the ice that forms on surfaces as a result of the temperature of that surface reaching freezing before the air becomes saturated with water 


gallon - a unit of measure equal to four quarts or 128 fluid ounces 
geyser - a thermal spring that erupts intermittently and to different heights above the surface of the Earth; eruptions occur when water deep in the spring is heated enough to turn into steam, which forces the liquid water above it out into the air 
glacial striations - lines carved into rock by overriding ice, showing the direction of glacial movement 
glacier - a large mass of ice formed on land by the compacting and recrystallization of snow; glaciers survive from year to year, and creep downslope or outward due to the stress of their own weight 
groundwater - water under ground, such as in wells, springs and aquifiers 
gullying - small-scale stream erosion 


habitat - the place or type of site where a plant or animal naturally or normally lives and grows 
hail - transparent or layered (ice and snow) balls or irregular lumps of solid water 
hardness - a characteristic of water determined by the levels of calcium and magnesium 
hatcheries - a place for hatching fish eggs 
humus - decomposed bits of plant and animal matter in the soil 
hydroelectric plant - a power plant that produces electricity from the power of rushing water turning turbine-generators 
hydrologic cycle - the natural recycling process powered by the sun that causes water to evaporate into the atmosphere, condense and return to earth as precipitation 
hydrology - the scientific study of the behavior of water in the atmosphere, on the Earth's surface and underground 


iceberg - large chunks of ice that break off of coastal glaciers and float away 
igneous - rock solidified from a molten state, such as lava and obsidian 
impermeable - having a texture that does not permit water to move through quickly 
imported water - water brought into an area from a distant source, such as from one part of a state to another via an aqueduct 
impound - to confine in an enclosure, such as impounding water in a reservoir 
impurity - any component which causes another substance to become contaminated 
indicator - a device or substance used to show the presence of another substance 
infiltration (also called percolation) - the entrance or flow of water into the soil, sediment or rocks of the Earth's surface 
inorganic - chemicals not containing the element carbon 
interest - payments made to an investor for the use of borrowed money 
intrusion - the entrance of an unwanted element, such as saltwater, into freshwater supplies 
inundation - covering over or flooding, such as flood waters covering a valley 
irrigation - supplying water to agriculture by artificial means, such as pumping water onto crops in an area where rainfall is insufficient 


labor - the mental and/or physical talents contributed by people for the production of goods or services 
lactose - a white organic substance made from milk that is used in infant foods, bakery products and confections; also used as a "culture" in laboratories 
landfill - an open area where trash is buried 
leach - to remove components from the soil by the action of water trickling through 
levees - dikes or other embankments which contain water within a given course 
local runoff - water running off a local area, such as rainfall draining into a nearby creek 


manufacturer - one who makes a product 
marginal land - land which, in its natural state, is not well suited for a particular purpose, such as raising crops 
member agency - one of 27 member public water providers associated with the Metropolitan Water District of Southern California, from which it purchases water and on whose board it is represented 
Meter - See
microorganism - an organism of microscopic size, such as bacterium 
migratory - moving from one area to another on a seasonal basis 
mitigation - a way in which an agency may offset negative environmental impacts of a project or make the impacts less serious 
mulch - material spread on the ground to reduce soil erosion and evaporation of water; include hay, plastic sheeting and wood chips 
municipal water district - a public water provider, owned and operated by more than one city government, which supplies water to its member cities 


natural environment - all living and nonliving things that occur naturally on the earth; not made 
nomad - a wanderer, a person or animal which moves from place to place 
non-economic benefit - a gain resulting from a trade-off that cannot be measured in dollars 
nonpoint source pollution - pollution which comes from diffuse sources such as urban and agricultural runoff 
NPDES (National Pollutant Discharge Elimination System) permits - permits issued to point sources for the purpose of limiting pollution in discharges 


organic - any chemical containing the element carbon 
overdraft - condition that occurs in a groundwater basin when pumping exceeds the amount of replenishment over a period of years 
ozone - a gas that is bubbled through water to kill germs 


pathogenic - capable of causing disease 
percolation - water soaking into the ground 
perennial yield - maximum quantity of water that can be annually withdrawn from a groundwater basin over a long period of time (during which water supply conditions approximate average conditions) without developing an overdraft condition 
permeability - the capacity or ability of a porous rock, sediment, or soil to allow the movement of water through its pores 
PEROXONE - a combination of peroxide and ozone used to kill germs in water 
pH - a relative scale of how acidic or basic (alkaline) a material is; the scale goes from 0 to 14; 7 is neutral, acids have pH values less than 7 and bases have pH values higher than 7 
photosynthesis - process in which chlorophyll-containing cells convert light into chemical energy, forming organic compounds from inorganic compounds 
pipeline - carries water underground to homes and businesses 
plankton - minute plants and animals floating in bodies of water; often a major source of nutrition for larger aquatic life forms 
pollutant - any inorganic or organic substance that contaminates air, water or soil 
point source pollution - pollution which comes from a well-defined source such as sewage treatment plant effluent from industrial dischargers. . .for purposes of the Clean Water Act, agricultural return flows are not regulated as a point source 
pore spaces - the open areas, or spaces, in soil, sediments, and rocks that are filled by air or water 
porosity - a measure of the ratio of open space within a rock or soil to its total volume 
POTWs (Public Owned Treatment Works) - sewage treatment plants 
precipitation - water falling toward the Earth's surface in the form of rain, drizzle, hail, sleet, or snow 
pumping lift - distance water must be lifted in a well from the pumping level to the ground surface 
pumping plant - facility that lifts water up and over hills 


reclaimed water - wastewater that has been cleaned so that it can be reused for most purposes except drinking 
recharge - increases in groundwater storage from precipitation, infiltration from streams, or human activity (artificial recharge), such as putting surface water into spreading basins 
relative humidity - the ratio of the amount of moisture in the air to the maximum amount of moisture the air could hold under the same conditions; usually expressed as a percentage 
reservoir - a pond or lake where water is collected and stored until it is needed 
rills - small grooves, furrows, or channels in soil made by water flowing down over its surface; also another name for a stream - usually a small stream 
runoff - liquid water that travels over the surface of the Earth, moving downward due to the law of gravity; runoff is one way in which water that falls as precipitation returns to the ocean 


saltation - the movement of sand or fine sediment by short jumps above a streambed under the influence of a water current too weak to keep it permanently suspended in the moving water 
salinity - saltiness 
saturation - the condition of being filled to capacity 
sea ice - solid water that forms when ocean or sea water freezes 
section 319 grants - grants for nonpoint source pollution programs 
sediments - fragments of material produced by weathering and erosion of rocks 
sedimentation - the process of particles in water settling to the bottom of a tank 
selenium - a non-metallic element in the same chemical group as sulfur; its compounds are harmful to wildlife or people when found above certain levels in water 
septic tank - a sewage disposal tank in which bacteria decompose waste 
sheet wash - a flow of rainwater that covers the entire ground surface with a thin film and is not concentrated into streams 
sleet - precipitation that consists of clear pellets of ice; sleet is formed when raindrops fall through a layer of cold air and freeze 
snow - precipitation that consists of frozen flakes formed when water vapor accumulates on ice crystals, going directly to the ice phase 
soil - sediment on or near the Earth's surface that is formed by the chemical and physical weathering of rocks as well as the decay of living matter 
soil subsidence - the lowering of the normal level of the ground, usually due to overpumping of water or oil from wells 
spawn - to produce or deposit eggs, as those of aquatic animals 
spring - groundwater seeping or flowing out of the Earth's surface; springs occur where the water table reaches the surface 
SRF (State Revolving Fund) - funding, in the form of loans, available for the control of point and nonpoint source pollution 
steam - water vapor that rises from boiling water 
stream - the type of runoff where water flows in a channel downhill because of the pull of gravity
sublimation - formation of a gas from a solid, or vice-versa, without passing through the liquid phase 
subsidence - sinking of the land surface due to a number of factors, of which groundwater extraction is one 
subsurface water - all water - solid, liquid or gaseous - that occurs beneath the Earth's surface; located below the water table in the zone of saturation 
surface runoff - water flowing along the ground into rivers, lakes, and oceans 
surface water - all water, fresh and salty, on the Earth's surface 
suspended - the state of floating in water rather than being dissolved in it 
suspension - a method of sediment transport in which air or water turbulence supports the weight of the sediment particles, thereby keeping them from settling out or being deposited 


thermal spring - a warm or hot water spring; many occur in regions of recent volcanic activity and are fed by water heated by contact with hot rocks far below Earth's surface 
till - a deposit of sediment formed under a glacier, consisting of an unlayered mixture of clay, silt, sand, and gravel ranging widely in size and shape 
topsoil - the top layer of soil; topsoil can grow better crops partly because it has more organic matter (humus), allowing it to hold more water than lower soil layers 
toxic - poisonous; harmful to living organisms 
transpiration - evaporation of water through the leaves of plants 
trihalomethanes, trichloroethylene, perchloroethylene - organic compounds which may be harmful to health at certain levels in drinking water 
turbidity - the state of having sediment or foreign particles suspended or stirred up in water 


unconfined aquifer - an aquifer that discharges and recharges with an upper surface that is the water table 
unsaturated zone - the subsurface zone, usually starting at the land surface and ending at the water table, that includes both water and air in spaces between rocks 
usable storage capacity - the quantity of groundwater of acceptable quality that can be economically withdrawn from storage 


wastewater - water that has waste material in it 
wastewater treatment - cleaning wastewater 
water cycle - the movement of water from the air to and below the Earth's surface and back into the air 
water quality - the condition of water as it relates to impurities 
water reclamation - treating wastewater so that it can be used again 
water table - (1) the boundary in the ground between where the ground is saturated with water (zone of saturation) and where the ground is filled with water and air (zone of aeration); (2) the upper surface of the saturated zone that determines the water level in a well in an unconfined aquifer 
water vapor - the gaseous state of water 
watershed - a geographical portion of the Earth's surface from which water drains or runs off to a single place like a river; also called a drainage area 
well - a hole or shaft drilled into the earth to get water or other underground substances 


xeriscape - landscaping that doesn't require a lot of water 


zanja - Spanish word for ditch 
zone of aeration - the portion of the ground from the Earth's surface down to the water table - the zone of aeration is not saturated with water because its pores are filled partly by air and partly by water 
zone of saturation - the portion of the ground below the water table where all the pores in rock, sediment, and soil are filled with water
Published: Friday, 18 October 2013 09:50
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Activated Sludge
The term "activated sludge" refers to a brownish flocculent culture of organisms developed in aeration tanks under controlled conditions. It is also Sludge floc produced in raw or settled waste water by the growth of zoological bacteria and other organisms in the presence of dissolved oxygen. Activated sludge is normally brown in colour. 

The capacity of water to neutralize acids, a property imparted by the water's content of carbonates, bicarbonates, hydroxides, and occasionally borates, silicates, and phosphates. Alkaline fluids have a pH value over 7

A biological environment that is deficient in all forms of oxygen, especially molecular oxygen, nitrates and nitrites. The decomposition by microorganisms of waste organic matter in wastewater in the absence of dissolved oxygen is classed as anaerobic.

A biological environment that is deficient in molecular oxygen, but may contain chemically bound oxygen, such as nitrates and nitrites.

Bacteria are microscopic living organisms They are a group of universally distributed, rigid, essentially unicellular, microscopic organisms lacking chlorophyll. They are characterized as spheroids, rod-like, or curved entities, but occasionally appearing as sheets, chains, or branched filaments.

Biochemical Oxygen Demand (BOD)
The BOD test is used to measure the strength of wastewater. The BOD of wastewater determines the milligrams per liter of oxygen required during stabilization of decomposable organic matter by aerobic bacteria action. Also, the total milligrams of oxygen required over a five-day test period to biologically assimilate the organic contaminants in one liter of wastewater maintained at 20 degrees Centigrade. 

Bulking Sludge
A phenomenon that occurs in activated sludge plants whereby the sludge occupies excessive volumes and will not concentrate readily. This condition refers to a decrease in the ability of the sludge to settle and consequent loss over the settling tank weir. Bulking in activated sludge aeration tanks is caused mainly by excess suspended solids (SS) content. Sludge bulking in the final settling tank of an activated sludge plant may be caused by improper balance of the BOD load, SS concentration in the mixed liquor, or the amount of air used in aeration.

Chemical Oxygen Demand (COD)
The milligrams of oxygen required to chemically oxidize the organic contaminants in one liter of wastewater. 

Composite Sample
To have significant meaning, samples for laboratory tests on wastewater should be representative of the wastewater. The best method of sampling is proportional composite sampling over several hours during the day. Composite samples are collected because the flow and characteristics of the wastewater are continually changing. A composite sample will give a representative analysis of the wastewater conditions. 

A biological process by which nitrate is converted to nitrogen gas.

The biological decomposition of organic matter in sludge resulting in partial gasification, liquefaction, and mineralization of putrescible and offensive solids.

The killing of pathogenic organisms is called disinfection.

Dissolved Oxygen (DO)
The oxygen dissolved in water, wastewater, or other liquid. DO is measured in milligrams per liter. If the DO of a sample of water is 2 mg/L, it means that there are 2lbs of oxygen in 1 mil lb of water.

Dissolved Solids
Solids that cannot be removed by filtering are dissolved solids.

Extended Aeration
A modification of the activated sludge process which provides for aerobic sludge digestion within the aeration system. 

Clumps of bacteria and particles that have come together to form clusters, or small gelatinous masses. The floc mass in an activated sludge aeration tank generally consists of microorganisms. 

In wastewater, a group of substances, including fats, waxes, free fatty acids, calcium and magnesium soaps, mineral oils, and certain other non-fatty materials. 

Meter - See

Milligrams per Liter (mg/L)
A unit of concentration of water or wastewater constituent. It is 0.001 g of the constituent in 1000 ml of water. The unit parts per million is identical to milligrams per liter. 

Mixed Liquor (ML)
The mixture of activated sludge, wastewater, and oxygen, wherein biological assimilation occurs.

Mixed Liquor Suspended Solids (MLSS)
The milligrams of suspended solids per liter of mixed liquor that are combustible at 550 degrees Centigrade. An estimate of the quantity of MLSS to be wasted from the aeration tank of an extended aeration plant may be determined by the rate of settling and centrifuge tests on the sludge solids.

The conversion of nitrogen matter into nitrates by bacteria.

Nitrogen is present in wastewater in many forms: total Kjeldahl nitrogen, ammonia nitrogen, organic nitrogen.

Nitrogen Cycle
The cycle of life, death, and decay involving organic nitrogenous matter is known as the nitrogen cycle. In the nitrogen cycle ammonia is produced from proteins.

A simple compound of phosphorous and oxygen that is soluble in water.

A biological environment which is aerobic

A large compound formed of several orthophosphate molecules connected by phosphate-storing microorganisms. 

Raw Wastewater
Wastewater before it receives any treatment.

A tank where a wastewater stream is mixed with bacterial sludge and biochemical reactions occur.

Return Sludge
Settled activated sludge returned to mix with incoming raw or primary settled wastewater. When the return sludge rate in the activated sludge process is too low, there will be insufficient organisms to meet the waste load entering the aerator. 

Return Activated Sludge
Activated return sludge is normally returned continuously to the aeration tank. Recycling of activated sludge back to the aeration tank provides bacteria for incoming wastewater. Its should be brown in color with no obnoxious odor and is often also returned in small portions to the primary settling tanks to aid sedimentation. Settled activated sludge is generally thinner than raw sludge. Some activated sludge will be wasted to prevent excessive solids build up. 

Sludge Age
In the activated sludge process, a measure of the length of time a particle of suspended solids has been undergoing aeration, expressed in day. It is usually computed by dividing the weight of the suspended solids in the aeration tank by the weight of excess activated sludge discharged from the system per day. 

Sludge Digestion
The purpose of sludge digestion is to separate the liquid from the solids to facilitate drying. The proper pH range for digested sludge is 6.8 - 7.2.

Sludge Index
Properly called sludge volume index (SVI). It is the volume in millimeters occupied by 1 g of activated sludge after settling of the aerated liquid for 30 minutes.

Sludge Reaeration
The continuous aeration of sludge after initial aeration for the purpose of improving or maintaining its condition.

Splitter Box
A division box that splits the incoming flow into two or more streams. A device for splitting and directing discharge from the head box to two separate points of application. 

Domestic wastewater is 99.9% water and 0.1% solids. Fresh wastewater is usually slightly alkaline. If the pH of the raw wastewater is 8.0, it indicates that the sample is alkaline. If wastewater has a pH value of 6.5, it means that it is acid. Wastwater is said to be septic when it is undergoing decomposition.