Glossary Draft – Jan 14, 2010

Aerobic biological reactor – A tank in which material is converted from an unwanted form into a desired form by microorganisms in the presence of free oxygen

.

Air heater ash – The ash taken from hoppers below the air heater.

Air heater cleaning wash water – Any water or liquid cleaning solution used for or generated from cleaning the air heater.

Anaerobic biological reactor – A tank in which material is converted from an unwanted form into a desired form by microorganisms not in the presence of free oxygen

.

Background concentration

– The concentration of a substance in an environmental media (air, water, or soil) th at occurs naturally or is not the result of human activities.

Base load unit – A unit normally operated to produ ce electricity at an essentially constant rate and runs continuously.

Best Management Practice (BMP)

– Pollution prevention practices that help to avoid

contact between pollutants and water media that may include good housekeeping measures, good management techniques, pr oduct modifications, operational changes, materials substitution, materials and wate r conservation, and other measures.

Boiler blowdown – The minimum amount of liquid removed from the boiler/steam generator for the purpose of preventing buildup of materials that exceed limits established by best engineering practices.

Boiler fireside cleaning wash water – Any water or liquid cleaning solution used for or generated from cleaning the boiler fireside.

Boiler tube cleaning wash water – Any water or liquid cleaning solution used for or generated from cleaning the boiler tubes.

Bottom ash – The heavier ash particles that are not carried out of the boi ler with the flue gas, and which settle in the furnace or are dislodged from furnace walls. Includes boiler slag collected in wet-bottom furnaces. Economizer ash is included when it is collected

with bottom ash.

Bottom ash sluice

– Process wastewater generated from a wet bottom ash handling

system that is formed by combining bottom ash with the bottom ash transport water. Bottom ash sluice is typically transferred to a pond/impoundment or a dewatering bin.Carbon capture system – An air pollution control system intended to reduce emissions of carbon dioxide. Includes both post- combustion and pre-combustion carbon capture/reduction technologies.

Carbon capture wastewater – Any process wastewater generated from the carbon

capture system.

Chemical precipitation/flocculation

– Process involving the addi tion of chemicals to alter the physical state of disso lved and suspended solids and facilitate their removal by

sedimentation.

Clarification

– A sedimentation process to remove so lid particles from a liquid stream by gravitational force.

Clean Water Act (CWA) – Federal legislation enacted by Congress to “restore and maintain the chemical, physical, and biological integrity of the Nati on’s waters” (Federal Water Pollution Control Act of 1972, as amended, 33 U.S.C. 1251 et seq.).

Coal pile runoff – The runoff from or through any coal storage pile.

Coal washing – Coal washing, also known as co al cleaning, entails separating out foreign material from coal in a liquid medium and may also include processes to remove ash, sulfur and moisture. The liquid medi um may be combined with finely ground heavier minerals, such as magnetite, in a dense medium fluid, better to effect separation of unwanted rock and mineral matter from coal particles.

Cogeneration plant – A plant that produces electric ity and another form of useful thermal energy (such as heat or steam), us ed for industrial, co mmercial, heating, or cooling purposes.

Combustion turbine cleaning wash water – Any water or liquid cleaning solution used for or generated from cleaning a combustion turbine, including the air compressor section

of the turbine.

Cost of service – A ratemaking concept used for the design and development of rate

schedules to ensure that the filed rate schedules recover on ly the cost of providing the

electric service at issue. This concept attempts to correlate the utility 's costs and revenue with the service provided to each of the various customer classes.

Cycling unit – A unit used in a constant and specific cycle. For example, a unit that runs daily, but reduces capacity or shuts off at night would be a cycling unit.

Deep (or shallow) well injection – Disposal of fluids underground through any bored, drilled, or driven shaft or a dug hole, improve d sinkhole, or a subsur face fluid distribution system where the depth is greater than the largest surface dimension.Design storm – The storm for which a drainage syst em or hydraulic structure such as an impoundment is designed.

Detection limit – The minimum result which can be re liably discriminated from a blank (for example, with a 99% confidence level).

Discharge – The conveyance of process wastewater to: (1) surface waters ; or (2) a publicly owned, privately owned, federally ow ned, combined, or other treatment works.

Dry bottom ash handling system – A system that does not use water to convey bottom ash away from the boiler. It includes systems that collect and convey the ash without any use of water, as well as systems in which bot tom ash is quenched in a water bath and then mechanically or pneumatically conveyed away from the boiler.

Dry FGD system – Dry FGD system, also referred to as semi-dry FGD system, captures sulfur dioxide from flue gas by a spray drye r absorption process th at produces calcium

sulfite with low moisture content.

Dry fly ash handling system – A system that does not use water to convey fly ash as a dry material away from part iculate collection equipment.

DUNS Number – Unique nine-digit numeric se quence (“Data Universal Numbering System”) assigned to a corporat e entity by Dun and Bradstreet.

Economizer ash – The ash taken from hoppers below the economizer.

Evaporation – The process by which water or other liquid becomes a gas.

FGD scrubber absorber – As depicted in Figure B-1, th e FGD scrubber absorber is the module where contact between flue gas and so rbent occurs, which results in the capture of sulfur dioxide from the flue gas.

FGD scrubber purge

– Process wastewater that exits an FGD scrubber system (typically from a solids separation pro cess) and that is transferred to a wastewater
treatment system or discharged . Note: The scrubber purge stream may be the same as

the FGD slurry blowdown stream if the plant does not operate a solids separation system prior to wastewater treatment

.

FGD scrubber system – As shown in Figure B-1, a system that captures sulfur dioxide from flue gas. An FGD scrubber system may be wet or dry. For wet FGD systems , the solids separation and solids dewatering processes are part of this system.

FGD slurry blowdown – Slurry water that exits an FGD scrubber absorber to control

the solids/chlorides levels in the FGD scrubber absorber . FGD slurry blowdown is typically transferred to a solids separation process.FGD slurry preparation process water –Water used for the preparation of FGD slurry

water (e.g., water that is added to ball mills for limestone slurry preparation).

FGD slurry water – All water that enters into, is used within, or recycles through the

FGD scrubber absorber . FGD slurry water is replenis hed by make-up water and the solids level is controlled by FGD slurry blowdown

.

FGD solids – Any solid material generated by the FGD scrubber system . This may also be called FGD sludge (e.g., calcium sulfite and calcium sulfate).

FGD solids separation – The process that separates FGD slurry blowdown into two separate streams: the solids-rich st ream (i.e. underflow) that contains FGD solids and the solids-lean stream (i.e. overflow) that contains water and fines.

FGD solids separation recycle – The FGD wastewater that is returned to the FGD

scrubber absorber following the FGD solids separation process.

FGD wastewater

– Process wastewater generated specifically from the FGD scrubber

system.

Filter – An apparatus using woven, granular, or ot her material to remove solid particles

from wastewater or water.

Filter backwash – Any water generated from reversi ng the direction of flow through a filterfor the purpose of washing and/or eliminating solids from the filter

.

Filter press – An apparatus used in solids dewatering that forces sludge through a filter

to remove water and form a cake.

Floor drain wastewater – Liquid collected in any of th e floor drains at the plant.

Flue gas mercury control system – An air pollution control system installed or operated for the purpose of removing mercury from flue gas. In this questi onnaire, do not include FGD or SCR/SNCR systems as flue gas mercury control systems.

Flue gas mercury control system wastewater – Any process wastewater generated

from the flue gas mercury control system

.

Fly ash – The ash that is carried out of the furnace by the gas stream and collected by mechanical precipitators, electrostatic pr ecipitators, and/or fabric filters. Economizer ash is included when it is collected with fly ash.

Fly ash sluice

– Process wastewater generated from a wet fly ash handling system that is formed by combining fly ash with the fly ash tr ansport water. The fly ash sluice water is typically transferred to an ash pond/impoundment

.Forced generator outage – The hours for any failure, misoperation, or malfunction

that results in the immediate automatic or manual removal of a generating unit from connection to the transmission system, or th at prevents such connection from being accomplished when desired.

Gross generation – Amount of power produced by an elec tric power plant, measured at the terminals of the plant (i.e., prior to the poi nt at which the power leaves the station and is available to the system). This amount includes electric power generated at a power plant that is used to opera te equipment at the plant.

Gypsum pile – A temporary storage pile on site containing gypsum.

Gypsum pile runoff – The runoff from or through any gypsum pile

.

Gypsum stacking – For plants that sluice gypsum to a pond/impoundment, the process used to dig out the gypsum from the pond/impoundment and stack it alo ng the sides of

the pond/impoundment or in separate piles for dewatering.

Gypsum wash water – Process wastewater generated during the solids dewatering operation of gypsum or gypsum solids.

IGCC generating unit – An integrated gasification combined cycle generating unit.

Immediate parent firm – The first entity in the facility’s ownership structure responsible for facility’s expenses associated with steam electric generating units . Note that for the purpose of Part I of the questionnaire, if a pl ant that has multiple owners, detailed financial and economic data are reque sted of the immediate parent firm that holds the largest equity share in the plant.

Independent power producer – A corporation, person, agenc y, authority, or other legal entity or instrumentality that owns or opera tes facilities for the generation of electricity for use primarily by the public, and that is not a utility

.

Intake water – Water from public utilities, stre ams, rivers, lakes, or underground aquifers that is used to supply or feed pr ocess unit operations or treatment processes.

Intermediate unit – A unit that not used in a constant and specific cycle. The unit is instead used more sporadically on an as n eeded basis when energy requirements are less than peak load but more than base load.

Ion exchange

– Reversible exchange of ions adsorbed on a mineral or synthetic polymer

surface with ions in solution in contact with the surface.

Landfill – A disposal facility or part of a facility where solid waste, sludges , or other

process residuals are placed in or on any natural or manmade formation in the earth for disposal and which is not a storage pile, a la nd treatment facility, a surface impoundment,an underground injection well, a salt dome or salt bed formation, an underground mine, a cave, or a corrective ac tion management unit.

Leachate - Liquid, including any suspended or dissolved constituents in the liquid that has percolated through or drained from waste or other materials emplaced in a landfill , or that pass through the containmen t structure (e.g., bottom, di kes, berms) of a surface impoundment. Leachate also includes the term s seepage, leak, and leakage, which are generally used in reference to leachate from an impoundment.

Leachate collection system - A system that gathers leachate and conveys it to a collection area for treatment, discharge, or other use.

Leak detection system - A system whose primary purpose is to monitor performance of

the containment structure of a pond/impoundment or landfill by collecting fluid which flows through the liner.

Liner – A continuous layer of natural or man-made materials, beneath or on the sides of

a pond/impoundment

, landfill , or landfill cell, which restricts the downward or lateral escape of the wastes placed therein or leachate

.

Mill reject sluice – Water stream that is generated by combining mill rejects with water to aid in transport and/or disposal

.

Mill rejects – Material such as stone, slate and iron pyrite that is rejected by coal pulverizers because it could not be ground.

Nameplate capacity –The full-load continuous rating of a generator, prime mover, or other electric power production equipment under specific conditions as designated by the manufacturer. Installed generator nameplate rating is usually indicated on a nameplate physically attached to the generator.

Natural wetlands

– An area created naturally, not man- made, that is saturated by surface or ground water with vegetation adapted for life under those soil cond itions, as swamps, bogs, fens, marshes, and estuaries.

Non-contact cooling water

– Water used for cooling which does not come into direct contact with any raw material, product, byproduct , or waste.

Non-pond wastewater treatment unit – A wastewater treatment unit that is not a pond/impoundment . Non-pond wastewater treatment units include, but are not limited to: chemical precipitation/flocculation

, pH adjustment

, clarification

, anaerobic/aerobic biological reactor

, thickeners , and filters

.

Nonutility – A corporation, person, agency, auth ority, or other legal entity or instrumentality that owns or operates facili ties for electric generation and is not an

electric utility . These entities are not owned by a governmental unit or the consumers thatthe entity serves and do not ope rate within the traditional cost-of-service price regulation. Nonutility power producers include qualifying cogenerators

, qualifying small power producers , and other nonutility generators (including independent power producers ). Nonutility power producers are without a designated franchised service area and do not

file forms listed in the Code of Fe deral Regulations, Title 18, Part 141.

NO

x control system – An air pollution control system that removes NO

x from air emissions. Types of NO

x control systems include, but ar e not limited to, the following: selective catalytic reducti on (SCR), selective non-catalyt ic reduction (SNCR), overfire air, and low NO

x burners.

NPDES permit – Permits issued under the National Pollutant Discharge Elimination System (NPDES) program authorized by Sections 307, 318, 402, and 405 of the Clean

Water Act that applies to plants that discharge wastewater directly to United States surface waters

.

On site – Property and equipment under the opera tional control of the plant, including landfills, ponds/impoundments, and outfall structures located on non-contiguous

property.

Particulate matter control system – An air pollution control system that removes particulates from the flue gas. Particulat e matter control system s include, but are not limited to, the following: electrostatic prec ipitators (ESP), fabric filters/baghouses, mechanical collectors, and venturi scrubbers.

Peaking unit – A unit normally used only during peak-load periods of electricity

demand.

pH Adjustment

– Decreasing the acidity or alkalinity of a substance by adding alkaline or acidic materials, respectively.

Plant – Includes all contiguous and non-adjoin ing property and equipment that is under operational control of the facility, including non-adjoining landfills, surface impoundments, and outfall structures.

Pollutant – Dredged spoil, solid waste, incine rator residue, filter backwash, sewage, garbage, sewage sludge , munitions, chemical wastes, bi ological materials, radioactive materials (except those regulated under the Atomic Energy Act of 1954, as amended (42 U.S.C. 2011 et seq.)), heat, wrecked or disc arded equipment, rock, sand, cellar dirt and industrial, municipal, and ag ricultural waste discharged in to water. (See 40 CFR 122.2)

Pollution prevention – The use of materials, processe s, or practices that reduce or

eliminate the creation of pollutants or wastes. It in cludes practices that reduce the use of hazardous and nonhazardous materials, energy, wate r, or other resources, as well as those practices that protect natural resources th rough conservation or more efficient use.Pollution prevention includes but is not limited to source reduction, in-process recycle/reuse , and water conservation practices.

Pond/impoundment – A natural topographic depressi on, man-made excavation, or diked area formed from earthen materials or man-made materials or a combination of them, which is designed to hold an accumulation of liquid process wastes or process wastes containing free liquids, and which is not an injection well. Examples of ponds/impoundments include holding, storage, settling, and aera tion pits, ponds, and lagoons.

Pond/impoundment system – A treatment system consisting of one or more ponds/impoundments

.

Pond outlet – The point at which the pond/impoundment releases water to another pond/impoundment, surface water

, or other process

Power marketers – Business entities engaged in buyi ng and selling electricity. Power marketers do not usually own generating or tr ansmission facilities. Power marketers, as opposed to brokers, take ownership of the electr icity and are involved in interstate trade.

These entities file with th e Federal Energy Regulatory Commi ssion (FERC) for status as a power marketer.

Primary purpose – Provides the predominant sour ce of revenue for the plant. The principal reason for which the plant operates.

Priority pollutant – Priority pollutants are a set of 126 chemical po llutants listed at 40 CFR part 423, Appendix A.

Privately Owned Treatment Works (PrOTW) – Any device or system which is (a) used to treat wastes from any facility whos e operator is not the ope rator of the treatment works and (b) not a “POTW.”

Process operation – One or more pieces of process equipment used to change the physical or chemical characteristics of one or more process streams. Process operations include, but are not limited to, boilers, scrubbe rs, SCR/SNCR systems, air heaters, EMC systems, and cooling towers.

Process wastewater – Any water which comes into dir ect contact with or results from the storage, production, or use of any raw material, intermediate product, finished product, byproduct, or waste product. Exampl es of process wastew ater include, but are not limited to, wastewater from ash handling, equipment cleaning, air pollution control devices, rinse water, coal pile runoff or other contaminated stormwater, and cooling water are considered process wastewater. Pr ocess wastewater can be treated, recycled, discharged, or hauled offsite for disposal. Sanitary wastewater, non-contact cooling

water, potable water, sewage, fire protection, car washes, and uncontaminatedstormwater are not considered process wastewater for the purpose of this information collection request.

Publicly Owned Treatment Works (POTW) – In general terms, any device or system owned by a state or municipality that is used to recycle, reclaim, or treat liquid municipal sewage and/or liquid industrial wastes. See 40 CFR part 403.3 for an expanded definition

of this term.

Qualifying Cogenerator and Qualif ying Small Power Producer (QF) – A cogeneration or small power production faci lity, respectively, that meets certain ownership, operating, and efficiency crit eria established by the Federal Energy Regulatory Commission (FERC) pursuant to the Public Util ity Regulatory Policies Act (PURPA).

Raw intake water – Intake water prior to any treatment or use.

Recycle/reuse – To return a stream or a portion of a stream to an earlier step in the process/treatment process or to an other process at the plant.

Residue

– Amount of a pollutant remaining in the environment after a natural or technological process has taken place; e.g., the sludge remaining after initial wastewater treatment, or particulates remaining in air after it passes through a scrubbing or other

process.

Reverse Osmosis (RO)

– A filtration process designed to separate particulate, colloidal, and dissolved matter from a liquid using a se mi-permeable membrane, where pressure in excess of the osmotic pressure is applied to the concentrated side of the membrane.

RO reject water – Waste water released from the reverse osmosis process.

Rural Electric Cooperatives – For the purpose of this ques tionnaire, rural electric cooperatives are electric utilities that are legally establ ished to be owned by and operated for the benefit of those using its service. This entity will generate, transmit, and/or distribute supplies of electric energy to a specified area no t being serviced by another utility. Such ventures are generally exempt from Federal income ta x laws. Most electric cooperatives have been initially financed by the Rural Utilities Service (prior Rural Electrification Administration), U.S. Department of Agriculture.

Sanitary wastewater – Wastewater that is generate d from restrooms, cafeterias, showers, and domestic (ver sus industrial) activities.

Scheduled generator outage – The hours during which the generating unit is offline due to planned, scheduled repairs, maintenance, or upgrades, such as routine repetitive maintenance and repair that have been programmed into the power schedule,

Semi-dry FGD systems – Refer to dry FGD system

.SCR catalyst regeneration wastewater – Any water generated from the SCR catalyst regeneration process.

SCR catalyst washing wastewater – Any water generated from the SCR catalyst washing process.

SCR catalyst regeneration – Process by which catalysts used in the SCR system are regenerated after a period of time because the catalysts ha ve become less reactive through

use.

SCR catalyst washing – Process by which catalysts used in the SCR system are washed to remove fly ash and/or other particulates.

Settling pond

– A pond used to remove solid particles from a liquid stream by gravitational force (i.e., sedimentation process).

Settling tank – A tank that uses a sedimentation pro cess to remove solid particles from a liquid stream by gravitational force.

Sludge – Any solid, semi-solid, or liquid waste generated from a municipal, commercial,

or industrial wastewater treat ment plant, water supply treatment plant, or air pollution control facility exclusive of the treated effl uent from a wastewater treatment plant.

Solids dewatering – The process that removes water from the solids-rich stream generated in the solids separation process. Typically a vacuum belt filter or a vacuum drum filter is used in this process. FGD solids such as gypsum are produced by this

process.

Steam turbine cleaning wash water –Any water or liquid cleaning solution used for or generated from cleaning the steam turbine.

Stormwater runoff

– Runoff generated when precipitation from rain and snowmelt events flows over land or impervious surfaces and does not percolate into the ground.

Sulfur dioxide control systems – An air pollution control sy stem that removes sulfur dioxide from flue gas. Sulfur dioxide cont rol systems include, but are not limited to: wet FGD systems, dry FGD systems, and lime/limestone addition to the boiler.

Thickener – A sedimentation process to remove so lid particles from a liquid stream by gravitational force. In contrast to clarifi cation, the primary purpose of the thickener is to

increase the concentration of su spended solids of the feed stre am (i.e., to remove liquids), thereby increasing the concentration of solids in sludge . Note that thickening should not

be confused with solids dewatering; the cake formed from solids dewatering is handled as a solid and not a liquid.Treated (water or process wastewater ) – Water that has been processed by physical, chemical, biological, or other means to remove specific constituents of the water stream or to alter the physical or chemical state of specific constituents of the water stream.

Treated intake water – Water that is acquired from a source and treated prior to use by physical, chemical, biological, or other means to remove specific constituents of the water stream or to alter the physical or chemi cal state of specific c onstituents of the water

stream.

Ultimate parent firm – The highest level domestic business entity in the facility’s ownership structure. A firm that is owned by another U.S. firm is not an ultimate domestic parent firm. In contrast, a U.S. fi rm that is owned by a foreign firm is an ultimate domestic parent firm.

Uncontaminated stormwater

– Stormwater runoff that has not come into contact with raw materials, byproducts , or waste products from the electricity generation process.

Utility – Any entity that generates, transmits, or distributes electric ity and recovers the cost of its generation, transmissi on or distribution asse ts and operations, ei ther directly or indirectly, through cost-based rates set by a separate regu latory authority (e.g., State Public Service Commission), or is owned by a governmental unit or the consumers that the entity serves. Examples of these enti ties include: investor-owned entities, public power districts, public utility districts, municipalities, rural electric cooperatives, and State and Federal agencies. Electric u tilities may have Federal Energy Regulatory Commission approval for interconnection ag reements and wholesale trade tariffs covering either cost-of-service and/or mark et-based rates under the authority of the

Federal Power Act.

Vacuum drum filter – A system that consists of a tank containing a rotating drum

covered with a cloth filter. A vacuum is us ed to pull water thr ough the cloth filter to

dewater the solids. Also referre d to as a rotary drum filter.

Vacuum filter belt – An apparatus used in dewatering that uses a vacuum to remove water by pulling it through a revolving filter belt.

Variable O&M costs – Operation and maintenance costs that vary directly in proportion

to the amount of electric ity generated by a plant.

Wastewater treatment – The processing of wastew ater by physical, chemical, biological, or other means to remove specific pollutants from the wastewater stream or to alter the physical or chemical state of specific pollutants in the wastewater stream. Treatment is performed to allow for discharge of wastewater or recycle/reuse of

wastewater.

Wastewater treatment system – A combination of one or more wastewater treatment
units , other than ponds/impoundments, designed to achieve wastewater treatment

.Wastewater treatment unit – A unit operation used to remove pollutants from process

wastewater . Wastewater treatment units include, but are not limited to: primary settling ponds, chemical precipitation, pH adjustment, cl arification, biological reactor, thickeners, filters, and constructed wetlands.

Waste coal

– Usable material that is a byproduct of previous coal processing operations. Waste coal is usually composed of mixed coal, soil, and rock (mine waste). Most waste

coal is burned as-is in unconventional fluidi zed-bed combustors. For some uses, waste coal may be partially cleaned by rem oving some extraneous noncombustible constituents. Examples of waste coal include fine coal, coal obtai ned from a refuse bank or slurry dam, anthracite culm, bituminous gob, and lignite waste.

Wet bottom ash handling system – A system in which bottom ash is conveyed away from the boiler using water as the transpor t medium. Wet bottom ash systems typically send the ash slurry to dewatering bins or a pond/impoundment

.

Wet FGD system – Wet FGD systems capture sulfur dioxide from the flue gas using a

sorbent that has mixed with water to form a wet slurry, and that generates a water stream

that exits the FGD scrubber absorber.

Wet fly ash handling system – A system that conveys fly ash away from particulate removal equipment using water as the transp ort medium. Wet fly ash systems typically dispose of the ash slurry in a pond/impoundment

.

Zero discharge

– Disposal of process and/or non- process wastewaters other than by

direct discharge to surface water or by indirect discharge to a POTW . Examples include evaporation

, deep-well injection , hauling, and/or offsite recycle/ recovery

.