IMF Protector™ Drinking water treatment system by Smith & Loveless, Inc. Imhoff cone Cone-shaped container used to determine the volume of settleable solids in a specific volume of water. Imhoff tank A two-story wastewater treatment tank developed by Karl Imhoff in which sedimentation occurs in the upper compartment and anaerobic digestion occurs in the lower compartment. Also called an “Emscher fountain.” immediately dangerous to life or health (IDLH) The maximum environmental concentration of a substance from which one could escape from a 30 minute exposure without irreversible adverse health effects. immiscible Incapable of being mixed. immunoassay The identification of a substance based on its capacity to act as an antigen. immunodeficiency A lack of one or more immune functions. Impac™ Packing media for air stripping towers by Lantec Products, Inc. Impact™ Ion exchange resins by Sybron Chemicals, Inc. impact fee Fee assessed new connections to a water or sewer system intended to recover a portion of the capital cost of the system. impeller The rotating set of vanes in a turbine, blower, or centrifugal pump designed to cause rotation of a fluid mass. Imperial gallon See “gallon, Imperial.” impermeable strata Layers of clay or dense stone in the earth through which water cannot penetrate in measurable quantities. impervious Not allowing the passage of water at ordinary hydrostatic pressure. impingement (1) The entrapment of fish and other marine life on the surface of an intake screen when a high water velocity prevents escape. (2) The striking of a surface by a moving fluid. impoundment A pond, lake, or reservoir created through the use of a structural barrier such as a dam, levee, or dike. impressed voltage cathodic protection The use of an impressed current to pre- vent or reduce the rate of corrosion of a metal in an electrolyte by making the metal the cathode for the impressed current. Impulse ® Counter-current water softeners by USFilter/Lowell. impulse turbine An energy recovery device used to recover pressure energy from reverse osmosis brine streams. impurity A chemical substance which is unintentionally present with another chemical substance or mixture. IMR Infant mortality rate. IMS See “Ion Mobility Spectrometry (IMS).” IMS ® Filter media support cap for sand filters by F.B. Leopold Co., Inc. in situ Treatment or disposal methods that do not require movement of contami- nated material. in vitro study A laboratory study conducted in glassware. in vivo study A study conducted in a living organism. in-channel storage The water storage volume in a channel or canal above the minimum water level required for conveyance. © 2001 by CRC Press LLC incidence of illness The rate of occurrence of new cases of disease in a defined population over a specified period of time. incidental recharge Groundwater recharge occurring as a result of human activ- ities such as irrigation which are unrelated to a recharge project. incineration The process of reducing the volume of a solid by burning of organic matter. incinerator A furnace or device for incineration. inclined plate separator A series of parallel inclined plates that can be used to increase the efficiency of clarifiers and gravity thickeners. incompatible waste A hazardous waste that may cause corrosion or decay of containment materials or is unsuitable for comingling with another waste under uncontrolled conditions because of the hazardous reactions that may result. incrustant Solids formed as a crust on the inside wall of a pipe. incubate To maintain optimum environmental conditions for growth and repro- duction of viable microbes. Incutrol Biochemical oxidation measuring and temperature control apparatus for BOD incubation by Hach Co. index organism See “indicator organism.” indicator organism Microbes that indicate the absence or presence of a specific pollutant. indirect discharger Water treatment plants that discharge pollutants to publicly owned treatment works. indirect reuse The beneficial use of reclaimed water after releasing it for storage or dilution into natural surface waters or groundwater. indirect source Any facility, building, property, road, or parking facility that attracts motor vehicle traffic and, indirectly, causes pollution. induced air flotation (IAF) The clarification of suspended material using dis- persed air bubbles that attach to hydrophobic surfaces causing materials to collect as a froth on the surface. induced draft cooling tower A cooling tower in which the air flow through the tower is induced by means of an electrically operated fan. industrial waste Waste generated by manufacturing or industrial practices that is not a hazardous waste regulated under Subtitle C of RCRA. industrial wastewater Liquid wastes resulting from industrial practices or processes. inert Lacking active properties and unable to react with other substances. inertial separator A device that uses centrifugal force to separate waste particles. infectious agent Any organism that is capable of being communicated in body tissues and causing disease or adverse health impacts in humans. infectious dose 50 (ID 50 ) The microbe dose that will infect 50% of a population to which it is applied. infectious waste Equipment, instruments, pathological specimens, or other dis- posable wastes that may be contaminated from persons who are suspected to have a communicable disease or have been diagnosed with a communicable disease. © 2001 by CRC Press LLC infiltration (1) Water entering a sewer system through broken or defective sewer pipes, service connections, or manhole walls. (2) Wind-induced air movement into a building through openings in walls, doors, or windows. infiltration gallery A horizontal underground conduit of screens, perforated pipes, or porous material which collects percolating water, often under a river bed. Infinity™ Continuous later filter underdrain by Roberts Filter Group. inflammable Easily set on fire. inflow Surface and subsurface water or stormwater discharged into a sewer system. inflow/infiltration (I/I) The total quantity of water from inflow and infiltration without distinguishing the source. influent Water or wastewater flowing into a basin or treatment plant. Information Collection Rule (ICR) An EPA rule requiring water utilities serving more than 10,000 customers to conduct monitoring which will aid in the gathering of data for use in developing the D/DPB Rule and ESWTR. infrared furnace A furnace using infrared radiant heat emitted from silicon car- bide resistance heating elements to rapidly heat organic wastes to combustion temperatures. infrared radiation Low energy radiation with wavelengths longer than visible light and shorter than radio waves. infrastructure The fundamental network of facilities, installations, and utility systems serving a community. infuse (1) To pour a liquid into or upon. (2) To steep in water or liquid without boiling so as to extract soluble constituents. inhalable diameter The diameter of a particle considered to be less than 15 micro- meters for humans which are capable of being inhaled and deposited anywhere within the respiratory tract. inhalation LC 50 The concentration of a substance expressed as milligrams per liter of air which is lethal for 50% of the test population. inhibitor A chemical that interferes with a chemical reaction. Inipol™ Oil slick dispersant by Elf Atochem North America, Inc. initiator A chemical that can cause the initial step in the carcinogenesis process. injection well A hole drilled below the ground surface into which wastewater or treated effluent is discharged. inlet (1) A surface connection to a drain pipe. (2) A structure at the diversion end of a conduit. (3) The upstream end of any structure through which water may flow. (4) A form of connection between the surface of the ground and a drain or sewer for the admission of surface or storm water. (5) An intake. innovative technology A process or technique which has not been fully proven under the circumstances of its contemplated use and which represents an advancement over the state of the art. inoculum (1) Bacterium placed in compost to start biological action. (2) A medium containing organisms that is introduced into cultures or living organisms. inorganic carbon The carbon present in an inorganic compound such as carbon dioxide or calcium carbonate. inorganic compound Compounds that contain no carbon or contain only carbon bound to elements other than hydrogen. © 2001 by CRC Press LLC inorganic contaminant (IOC) An inorganic substance regulated by the EPA for compliance with drinking water requirements. inorganic matter Substances of mineral origin that do not contain hydrocarbons and are not subject to decay. insecticide A pesticide compound specifically used to kill or prevent the growth of insects. In-Situ Oxygenator™ Mechanical floating aerator by Praxair, Inc. insoluble A compound that has very low solubility. InSpectra™ UV analyzer by Azur Enviromental. Instant Ocean ® Mineral concentrate used to simulate seawater salinity by Aquar- ium Systems. InstoMix In-line and in-channel mixers by Walker Process Equipment. instrument detection limit (IDL) Lowest concentration of a chemical that can be detected by an instrument without correction for the effects of a sample matrix or method-specific parameters. instrumentation Use of technology to control, monitor, or analyze physical, chemical, or biological parameters. intake (1) The works or structures at the head of a conduit into which water is diverted. (2) The process or operation by which water is absorbed into the ground and added to the saturation zone. (3) The flow or rate of flow into a canal, conduit, pump, stack, tank, or treatment process before treatment. Integra ® Bladder pumps by Solinst Canada Ltd. integrated exposure assessment Cumulative summation (over time) of the mag- nitude of exposure to a toxic chemical in all media. Intellisieve Rotary fine screen filter by Smith & Loveless, Inc. IntensAer Radial surface aerator formerly offered by Walker Process Equipment. inter- Prefix meaning between or among. interceptor sewer A sewer that receives flow from a number of other sewers or outlets for disposal or conveyance to a treatment plant. intercondenser A condenser used between stages to reduce steam consumption in the steam jet vacuum system in an evaporator system. interconnecting piping Piping, usually field-installed, that connects equipment skids or unit processes to one another. interface The common boundary between two substances such as water and a solid and water and a gas, or between two liquids such as water and oil. interfacial tension The tension that occurs at the interface between two fluids or a liquid and a solid. intergranular corrosion Corrosion at or near the grain boundaries. Inter-Mix ® Slow speed mixer by Air-O-Lator Corp. Internalift ® Enclosed screw pump by USFilter/CPC. International Process System Former supplier acquired by USFilter/CPC. International Shredder Sewage shredder by ZMI/Portec Chemical Processing. Interox America Former name of Solvay America. Inter-Sep™ Rotary screen by Dontech, Inc. interstate waters Waters that flow across or form part of state or international boundaries, or coastal waters. © 2001 by CRC Press LLC interstice An open space in granular material that is not occupied by solid material. interstitial monitoring The continuous surveillance of the space between the walls of an underground storage tank. interstitial water (1) Water contained in the interstices of rocks. (2) Extracellular water between cells. intra- Prefix meaning within or inside. Intracid ® Water tracing dye by Crompton & Knowles Colors, Inc. inverse solubility The characteristic attributed to a substance that becomes less soluble with increasing temperature. inversion The abnormal atmospheric condition that occurs when the air tempera- ture increases with elevation. invert The lowest point of the internal surface of a drain, sewer, or channel at any cross section. inverted siphon A u-shaped pipe used to convey flow under a river, road, or other obstruction. Also called a “sag line.” in-vessel composting Composting system with integral material handling and in- vessel mixing and aeration. IOC (1) See “inorganic contaminant (IOC).” (2) Inorganic chemicals. iodinator A mechanical device used to introduce iodine into water for sanitization purposes. iodine A nonmetallic element in the halogen group sometimes used as a disinfectant. iodine number A surrogate value indicating an activated carbon’s ability to adsorb low molecular weight organics. iodometric titration See “Winkler titration.” ion An electrically charged atom, molecule or radical. ion chromatography (IC) A technique for separating and measuring the quanti- ties of different ions present in a sample based on their affinity for an adsorption medium. ion exchange (IX or IE) A chemical process involving the reversible exchange of ions between a liquid and a solid. Ion Grabber Electrolytic purification unit by Hoffland Environmental Inc. Ion Mobility Spectrometry (IMS) Continuous emissions analyzer used to mea- sure pollutants in gases. Ion Stick ® Electrostatic water treater for prevention of scale and fouling by York Energy Conservation. Ionac ® Ion exchange resins by Sybron Chemicals, Inc. ionic strength A measure of solution strength based on both the concentrations and valences of the ions present. ionization The process by which an atom or molecule acquires a positive or negative electrical charge through the loss or gain of electrons. ionization chamber A device that measures the intensity of ionizing radiation. ionizing radiation Radiation that can strip electrons from atoms. ionosphere The upper level of the earth’s atmosphere beginning at an altitude of approximately 80 km. Ionpure ® High purity water treatment products and services by USFilter/Lowell. © 2001 by CRC Press LLC Iopor Low pressure ultrafiltration system formerly offered by GL&V/Dorr-Oliver, Inc. IP Inhalable particulates. IPA Isopropyl alcohol. IPCC Intergovernmental Panel on Climate Change. IPLP ® Double-pass reverse osmosis system by USFilter Corp. IPP Independent power producer. IPS Composting System In-vessel composting system by USFilter/CPC. IQS/3™ Programmable controller used to operate and monitor water treatment systems by Culligan International, Corp. iron A common naturally occurring metallic element found in dissolved form in most water supplies. Chemical formula is Fe. iron bacteria Bacteria capable of metabolizing ferrous iron often from water or steel pipes. See also “crenothrix polyspora.” Iron Humate ® An iron source for agricultural soils and turf grasses produced from water treatment plant sludges by Kemiron. Iron Remover Contact bed type iron removal system by Walker Process Equipment. iron salt An iron-based coagulant used in water and wastewater treatment. irradiated food Food subject to brief radioactivity, usually gamma rays, to kill insects, bacteria, and mold, and to permit storage without refrigeration. irradiation Exposure to radiation of wavelengths shorter than those of visible light for medical purposes, to sterilize foodstuffs, or to induce polymerization of monomers or vulcanization of rubber. irreversible effect An effect characterized by the inability of the body to partially or fully repair injury caused by a toxic agent. irrigation The artificial application of water to meet the requirements of growing plants or grass that are not met by rainfall alone. irrigation efficiency The amount of water stored in the crop root zone compared to the amount of irrigation water applied. irritant A substance that can cause irritation of the skin, eyes, or respiratory system. Effects may be acute from a single high level of exposure or chronic from repeated low-level exposures to such compounds as chlorine, nitrogen dioxide, and nitric acid. ISA Instrument Society of America. ISCO In-situ chemical oxidation. ISEP ® Ion exchange systems by Advanced Separation Technologies. ISF™ Induced air flotation unit by Baker Hughes Process Systems. ISO International Organization for Standardization. ISO 9000 Certification conferred to a manufacturer that has demonstrated the capa- bility of running an integrated business from initial design through manufacture. ISO 14000 A series of guidance standards to provide businesses with a structure for managing varied environmental concerns. ISO 14001 Environmental management system standards for manufacturing and service industries. isobar A line on a weather map that joins all points of equal barometric pressure. © 2001 by CRC Press LLC isobath A line on a map connecting all points of equal depth above the surface of a water-bearing formation or aquifer. isochrone A line on a map connecting all points having the same time of travel for contaminants to move through the saturated zone and reach a well. isohaline A line on a map connecting points having equal amounts of salinity. isohyet A line on a map connecting points that receive equal average amounts of precipitation. isomer A chemical compound that has the same molecular formula but different molecular structure, as another compound. isopleth A line on a map connecting points at which a certain variable has the same value. isotherm A line on a weather map connecting points that have the same temperature. isothiazalon A high molecular weight non-oxidizing biocide used to control mem- brane biofouling. isotopes Atoms with the same atomic number but different atomic weights. isthmus A narrow strip of land bounded by water on both sides and connecting two large land masses. ITT Marlow Former name of ITT A-C Pump. IU Industrial user. IWEM See “CIWEM.” IWPF Industrial wastewater pretreatment facility. IWS USFilter/Industrial Wastewater Systems. IWT ® Illinois Water Treatment product line of USFilter/Rockford. IX See “ion exchange (IX or IE).” IXPER ® Calcium peroxide by Solvay America. J J See “joule (J).” J&A Jones and Attwood product division of Waste-Tech, Inc. JAC Oxyditch Oxidation ditch treatment system formerly offered by Chemineer, Inc. Jackbolt™ Aluminum clarifier cover by Enviroquip, Inc. jacking A method of installing pipe by forcing it into a horizontal opening with horizontal jacks. JackKnife Pivoting air header and drop pipe arrangement by Walker Process Equipment. Jackson turbidity unit (JTU) An obsolete unit of measure used to quantify the water turbidity by observing the outline of a candle flame viewed through a water sample. Replaced by “NTU.” Jacquelyn™ Corrosion and zebra mussel resistant coating by Cook Screen Tech- nologies, Inc. JAPCA Journal of Air Pollution Control Association. © 2001 by CRC Press LLC jar test A test procedure using laboratory glassware for evaluating coagulation, flocculation, and sedimentation in a series of parallel comparisons. Jayfloc Polyelectrolyte used to enhance liquid/solid separation by Vulcan Perfor- mance Chemicals. J-Belt Belt filter press by USFilter/Dewatering Systems. Jeffrey Screening equipment product line offered by Jones & Attwood, Inc. Jeffrey ® Chain, sprocket, and related component products by Jeffrey Chain Corp. JelClear™ Granular filtration media having a coagulant bonded directly to the media grains by BetzDearborn-Argo District. jet A stream of pressurized liquid or vapor from a nozzle or orifice. jet aeration Wastewater aeration system using floor-mounted nozzle aerators that combine liquid pumping with air diffusion. Jet Breaker™ Screenings washer/compactor by Headworks, Inc. Jet Plant Package wastewater treatment plant by Jet, Inc. Jet Shear Continuous mixing system using jet nozzles by Flo Trend Systems, Inc. jet stream A strong, thermally driven, high altitude wind. Jet Tech Former name of USFilter/Jet Tech. Jet Tray Deaerator by Cochrane Inc. Jet VIP™ Pulsed fabric filter by Wheelabrator Air Pollution Control, Inc. JETA Vortex type grit collector by Waste-Tech, Inc. Jeta-Matic Spray jet pressure leaf filter cleaning system by USFilter/Whittier. Jet-Chlor ® Tablet chlorine disinfection system by Jet, Inc. JETIII ® Fabric filter by Wheelabrator Air Pollution Control, Inc. JetMix™ Vortex mixing system for sludge storage basins by Liquid Dynamics Corp. jetsam Floating jettisoned material. Jet-Tex Leach bed filter fabric by Jet, Inc. jetty A structure that extends into an open body of water to influence currents or tides or protect a harbor. Jet-Wet™ Dry polymer feeding system by Fluid Dynamics, Inc. and Ciba Specialty Chemicals. J-Flow Gravity belt thickener by USFilter/Dewatering Systems. JH™ Series of air scrubbers for odor control by USFilter/Davis Process. Jigrit Screw-type grit washer by Jeffrey Chain Corp. J-Mate ® Sludge volume reduction system by USFilter/Dewatering Systems. Johnson Filter Former name of USFilter/Johnson Screens. Johnson Screen Wedgewire screen media by USFilter/Johnson Screens. Jones and Attwood Environmental product division of Waste-Tech, Inc. joule (J) An SI unit of energy or work equal to the work done by the application of 1 newton acting through a distance of 1 meter. Joule™ Electrochemical flocculation system by Ecoloquip Inc. journal bearing A cylindrical bearing that supports a rotating shaft. J-Press ® Plate and frame filter press by USFilter/Dewatering Systems. J-Spin Centrifuge by USFilter/Dewatering Systems. J-Track™ Nonmetallic return track for chain and flight sludge collectors by USFil- ter/Envirex. © 2001 by CRC Press LLC JTU See “Jackson turbidity unit.” JUD Belt tracking system for belt filter press by Klein America, Inc. junction box An enclosure within which electrical cables are connected and/or terminated. J-Vap™ Mechanical sludge dewatering and drying system by USFilter/Dewatering Systems. JWI Dewatering equipment product line by USFilter/Dewatering Systems. K K soil horizon A soil horizon in which the grains are cemented with CaCO 3 to form a hardpan layer. K wastes A class of hazardous wastes categorized from specific sources as estab- lished by the EPA and identified in 40 CFR 261.32. K 2 Modular™ Volumetric screw feeder by K-Tron North America. Kaldnes System Biological wastewater treatment system by Waterlink Biological Systems. kame A ridge or hill of stratified drift deposited by glacial meltwater. KAMET Municipal effluent treatment system by Krofta Engineering Corp. Kan-Floc™ Wastewater flocculant/coagulant by Kem-Tron. kaolin A type of fine white clay material. karst A geologic formation of irregular limestone deposits with sinks, under- ground streams, and caverns. katabatic wind A localized wind that flows down valley or mountainous slopes — usually at night — caused by the descent of cold air as the valley slopes undergo rapid nocturnal cooling. Katec ® Thermal oxidizer by Megtec Systems, Inc. Kat-Floc™ Wastewater flocculant/coagulant by Kem-Tron. Katox Catalytic oxidizer by Adwest Technologies, Inc. KD-HF™ Deionization system by Kinetico Engineered Systems, Inc. Kebab™ Disc-type oil skimmer by Vikoma International Ltd. Keene Former equipment manufacturer acquired by Amwell, Inc. Kenics ® Static mixer product line by Chemineer, Inc. Kenite ® Diatomite material by Celite Corp. Ketema Product group of Baker Process/Ketema. Key-Pac Package water/wastewater treatment plants by Pacific Keystone Technol- ogies. Keystone Former name of Pacific Keystone Technologies. K-Floc™ Wastewater flocculant/coagulant by Kem-Tron. K-Floor Suspended monolithic filter floor by the former PWT Americas. kg See “kilogram (kg).” kiln A heated enclosure for processing a substance by drying or burning. kiln dust See “cement kiln dust.” © 2001 by CRC Press LLC kilocalorie See “calorie.” kilogram (kg) A unit of mass equivalent to 1000 grams or approximately 2.205 pounds. kilopascal (kPa) A unit of pressure equal to 1000 pascals, 0.3346 feet of hydraulic head, or 0.145 psi. kilowatt (kW) A measure of power equal to 1000 watts; 1 hp equals 0.746 kilowatts. kilowatt-hour (kWh) A unit of energy equal to that expended by 1 kilowatt in 1 hour. kinematic viscosity A fluid’s absolute viscosity divided by its mass density. kinesis An organism’s involuntary movement or reaction to an environmental stimulus. kinetic energy Energy that is possessed by a body of matter as a result of its motion. kinetic head The theoretical vertical height that a liquid may reach due to its kinetic energy. KIWA Netherlands Waterworks Testing and Research Institute. Kiwi Centrifuge conveyor by Alfa Laval Separation, Inc. Kjeldahl nitrogen The sum of the organic plus ammonia nitrogen in a water sample. KL Series™ Cleaning powders for removal of membrane foulants by King Lee Technologies. Klampress ® Belt filter press by Ashbrook Corp. (U.S.) and Simon-Hartley, Ltd. (U.K.). Kleer Flow Spiral wound reverse osmosis membranes by Great Lakes Interna- tional, Inc. Klenphos-300 Zinc phosphate corrosion inhibitor by Klenzoid, Inc. Klensorb Oil and grease absorbent by Calgon Carbon Corp. Knight-Botec Auger compost mixer by Knight Manufacturing Corp. knot A unit of speed equal to one nautical mile per hour (approximately 1.15 mph) used to describe the speed of winds or ships. Koagulator Solids contact clarifier by USFilter/Zimpro. Koch Corrosion Control Former name of KCC Corrosion Control Co. KochKleen ® Reverse osmosis cleaning chemicals by Koch Membrane Systems, Inc. KochTreat ® Antiscalants, stabilizers, and anti-microbial chemicals by Koch Mem- brane Systems, Inc. Koflo ® In-line static mixers by Koflo Corp. Komara™ Floating oil skimmer by Vikoma International Ltd. Kompakt Tubular block media by NSW Corp. Kompress ® Belt filter press by Komline-Sanderson, Engineering Corp. Komprimat Fish/screenings separation system by Brackett Geiger. Konsolidator Wet scrubber solids filter by CMI-Schneible Co. Kopcke Former name of REKO Industrial Equipment B.V. Koppers Former manufacturer of traveling bridge filters whose product line was acquired by Infilco Degremont, Inc. Koro-Z PVC biological filter media formerly offered by B.F. Goodrich Co. kPa See “kilopascal (kPa).” kraft An alkaline chemical pulping process using salt cake as makeup. © 2001 by CRC Press LLC [...]... disposal to minimize environmental hazards and protect the quality of surface and subsurface waters Landox™ Aeration system by WesTech Engineering Inc (North America) and Landustrie Sneek BV landscaping The enhancement of the appearance of land by changing its contours and planting decorative vegetation Landy™ Surface aerator product line by WesTech Engineering Inc (North America) and Landustrie Sneek BV... applicable treatment standards land disposal Application of municipal wastewater solids to the soil without production of usable agricultural products Land Disposal Restrictions (LDR) EPA-promulgated rules implementing the land ban landfarming Application of organic waste onto surface soil for the purpose of controlled biodegradation landfill (LF) A land disposal site that employs an engineering method... Denver Blower Division Lanco Environmental Equipment product line of Waterlink Separations, Inc Lancom™ Flue gas monitoring system by Land Combustion Lancy™ Wastewater treatment product line offered by USFilter/Industrial Wastewater Systems land application The disposal of wastewater or municipal solids onto land under controlled conditions land ban RCRA provisions prohibiting land disposal of specific... (U.S.) and Copa Group (U.K.) malodor An odor which causes annoyance or discomfort to the public and which has been determined to be objectionable Mammoth® Brush aerator by USFilter/Zimpro mandatory recycling Programs which by law require consumers to separate trash so that some or all recyclable materials are recovered for recycling rather than going to landfills manganese greensand See “greensand.”... utilizing two or more types of filter media of different sizes and specific gravities, usually silica sand, anthracite and ilmenite, or garnet Mixflo™ Aeration injection and dissolution system by Praxair, Inc mixing zone Limited area where initial dilution of a discharge takes place, water quality changes may occur, and certain water quality standards may be exceeded Mix-Mate® Multistage polymer mixing... detection, collection, and removal system LDR See “Land Disposal Restrictions (LDR).” LDS Leak detection system leach field The area of land into which a septic tank drains or wastewater is discharged leachate Fluid which percolates through solid materials or wastes and contains suspended or dissolved materials or products of the solids leachate collection system A system that gathers leachate and pumps it to... specified percentage of the population, usually expressed at the 50 % level as LC50 lethal dose (LD) The quantity of a substance which is fatal to a specified percentage of the population, usually expressed at the 50 % level as LD50 LEV Low emissions vehicle levee A dike or embankment along a river built to prevent flooding of the surrounding land Level Bed Agitator Agitator used in composting system by USFilter/CPC... microorganisms lime -and- settle Common term for treatment technologies that utilize chemical precipitation and sedimentation processes lime-soda softening The addition of sufficient lime and soda ash to raw water to achieve a reduction of carbonate and noncarbonate hardness limestone A sedimentary rock composed primarily of calcium carbonate limestone scrubbing Use of a limestone and water solution to... whose height 15 meters or more; or whose height is between 10- 15 meters with a crest length of at least 50 0 meters with a reservoir volume of at least 1 million cubic meters large quantity generator Person or facility generating more than 1000 kilos (2200 pounds) of hazardous waste per month and subject to all RCRA requirements large water system A water system that serves more than 50 ,000 persons... of organic matter in wetland areas Also called “swamp gas.” marshland An area of soft wet land vegetated by reeds and grasses masking The blocking out or covering of a sound or smell with another Maspac® Plastic packing media by Clarkson Controls & Equipment Co mass balance An analysis that delineates changes that take place in a reactor or system by quantifying system inputs and outputs Also known as . minimize environmental hazards and protect the quality of surface and subsurface waters. Landox™ Aeration system by WesTech Engineering Inc. (North America) and Landustrie Sneek BV. landscaping. the appearance of land by changing its contours and planting decorative vegetation. Landy™ Surface aerator product line by WesTech Engineering Inc. (North Amer- ica) and Landustrie Sneek BV. Langelier. implementing the land ban. landfarming Application of organic waste onto surface soil for the purpose of controlled biodegradation. landfill (LF) A land disposal site that employs an engineering method