ACRE-FOOT: A volume of water equal to one foot in depth covering an area of one acre, or 43,560 cubic feet; approximately 325,851 gallons.

AERATION: The addition of air to water or to the pores in soil.

AGRICULTURE: The science, art, and business of cultivating the soil, producing crops and raising livestock (farming).

AQUIFER: An underground layer of sand, gravel, or rock through which water can pass and is stored. Aquifers supply the water for wells and springs.

AUGMENTATION: The process of adding recycled/reclaimed water that has received advanced treatment to an existing raw water supply (such as a reservoir, lake, river, wetland, and/or groundwater basin) that could eventually be used for drinking water after further treatment.

BACKFLOW PREVENTION: Prevention of the flow of any foreign liquids, gases, or substances into the distribution pipelines of a potable water supply; accomplished by an air gap or mechanical backflow obstacle.

BACTERIA: Simple, one-celled microscopic organisms. Although some bacteria cause diseases (pathogenic bacteria), others are harmless and fill indispensable ecological roles such as decomposers.

BIOCHEMICAL OXYGEN DEMAND (BOD): The quantity of oxygen used in the biochemical oxidation of organic matter in a specified time, at a specific temperature, and under specific conditions; the BOD analysis is a standard test used in assessing wastewater strength. 

BIOFOULING: The formation of bacterial film (biofilm) on fragile reverse osmosis membrane surfaces.

BIOSOLIDS: The nutrient-rich organic materials resulting from the treatment of domestic sewage in a wastewater treatment facility. This organic material (sludge) that has been treated to reduce pathogens, organics, and odors, forms a reusable agricultural product. 

BRACKISH WATER: Water containing dissolved minerals in amounts that exceed normally acceptable standards for municipal, domestic, and irrigation uses. Considerably less saline than seawater.

CAPACITY: The ability of available water/wastewater utility resources to meet the quantity, quality, and peak loads of the various customers served.

CAPITAL IMPROVEMENT PLAN (CIP): A long-range plan of the Authority for the construction, rehabilitation and improvement of infrastructure and facilities. 

CLEAN WATER ACT: The federal law that establishes how the United States will restore and maintain the chemical, physical, and biological integrity of the country's waters (oceans, lakes, streams and rivers, groundwater, and wetlands).

CLIMATE: Meteorological conditions, including temperature, precipitation, condensation and wind.

CHLORINATION: The application of chlorine to water generally for the purpose of disinfection, but frequently for accomplishing chemicals such as iron, manganese or taste and odor removal.

CHLORINE: An element (Cl) ordinarily existing as a greenish-yellow gas (Cl2) about 2.5 times as heavy as air. It is commonly used as a disinfectant in water treatment.

CLARIFIER: A unit that separates particles of dirt from the water and deposits it in a sludge pile.

COLLECTION SYSTEM: A system of underground conduits/sewers collecting wastewater from a source and conveying it to the treatment facility. 

: Obtaining the benefits of water more efficiently, resulting in reduced demand for water. Sometimes called "end-use efficiency" or "demand management."

CRP: Acronym for Clean Rivers Program. 

CRWS: Acronym for Central Regional Wastewater System. 

CSG: Acronym for Collection System Group. 

DAM: A structure built to hold back water.

DCRWS: Acronym for Denton Creek Regional Wastewater System. 

DEWATERING: Water removal or concentration of solids by filtration, centrifugation, or drying. 

DISINFECTION: Water treatment that destroys potentially harmful bacteria.

DROUGHT: A long period of below-average precipitation.

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

EFFLUENT: The water leaving a water or wastewater treatment plant. If effluent has been treated to a high enough standard, it may be considered reclaimed or recycled.

ENDANGERED SPECIES ACT: The federal law that sets forth how the United States will protect and recover animal and plant species whose populations are in dangerous decline or close to extinction. The law protects not only threatened and endangered species but also the habitat upon which species depend.

ENDOCRINE DISRUPTING COMPOUNDS (EDCs): Chemicals that can interfere with the normal hormone function in humans and animals.

ENTERPRISE FUND: Enterprise funds are used to report the same functions presented as business-type activities. 

ENVIRONMENTAL IMPACT STATEMENT (EIS): Detailed analysis of the impacts of a project on all aspects of the natural environment required by the federal National Environmental Policy Act for federal permitting or use of federal funds.

EPA: Stands for the United States Environmental Protection Agency (USEPA or EPA). The Federal Agency created in 1970 that implements major environmental legislation. EPA's Office of Drinking Water is given the responsibility of establishing federal drinking water regulations and standards (levels of contaminants, which could be present in water without being harmful to man, when the water is consumed).

ESTUARY: The shallow water areas of bays or the mouths of rivers and creeks. This is the place where ocean tides meet and mix with fresh water.

ETEC: East Texas Electric Cooperative (ETEC), founded in 1987, is a private, independent electric cooperative owned by its members, seven destruction cooperatives and one generation and transmission cooperative. 

FASB: The Financial Accounting Standards Board is a private standard-setting body whose primary purpose is to establish and improve Generally Accepted Accounting Principles within the United States in the public's interest. 

FILTRATION: A process that separates small particles from water by using a porous barrier to trap the particles and allow the water through.

FINISHED WATER: Treated drinking water that is considered safe and suitable for delivery to consumers.

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.

FLOOD INFRASTRUCTURE FUND SPECIAL REVENUE FUND (FIF): This fund accounts for the activities of the Authority's Flood Infrastructure Fund, which is charged with conducting a regional flood planning study of the Trinity River mid-basin watersheds and developing hydraulic modeling under grant funding from the Texas Water Development Board (TWDB). 

FLOW: The measured amount of water or wastewater flowing by a particular point over some specified time. Flow is frequently expressed in millions of gallons per day (MGD). 

FLOW RATE: A measure of the volume of water moving past a given point in a given period of time.

GASB: The Governmental Accounting Standards Board (GASB), established in 1984, is the independent, private-sector organization, that establishes accounting and financial reporting standards for U.S. state and local governments that follow Generally Accepted Accounting Principles (GAAP). 

GFOA: The Government Finance Officers Association (GFOA), founded in 1906, is a membership organization that represents public finance officials throughout the United States and Canada. The association's more than 20,000 members are federal, state/provincial, and local finance officials involved in planning, financing, and implementing thousands of governmental operations in each of their jurisdictions. 

GIS: Acronym for Geographic Information Systems- a computerized mapping system that captures, stores, analyzes, manages and presents data that is linked to a location. 

GROUNDWATER: Water found below the surface of the earth.

HRWSS: Acronym for Huntsville Regional Water Supply System. 

HYDROLOGIC CYCLE: The movement of water as it evaporates from rivers, lakes or oceans, returns to the earth as precipitation, flows into rivers and evaporates again.

IMPORTED WATER: Water that has originated from one hydrologic region and is transferred to another hydrologic region.  

INDIRECT POTABLE REUSE (IPR): The blending of advanced treated recycled or reclaimed water into a natural water source (groundwater basin or reservoir) that could be used for drinking (potable) water after further treatment.

INFILTRATION/INFLOW: Infiltration is groundwater that leaks into the sewerage system through pipe joints and defects. Inflow refers to water that enters sewers from improperly connected catch basins, sump, and defective manholes. 

INFLUENT: Wastewater or other liquid flowing into a reservoir, basin or treatment plant. 

INFRASTRUCTURE: Physical means for meeting water and wastewater needs, such as dams, wells, conveyance systems and water or wastewater treatment plants. 

INTERCEPTOR: Large pipes that receive wastewater from collection systems and transport it to wastewater treatment plants. 

INTEGRATED RESOURCE PLANNING (IRP): A method for looking ahead using environmental, engineering, social, financial and economic considerations; includes using the same criteria to evaluate both supply and demand options while involving customers and other stakeholders in the process.

IRRIGATION: Diverting or moving water from its natural course in order to use it.

ITSS: Acronym for Information Technology Services Support. 

JPL: Acronym for Joe Pool Lake. 

LIFT STATION (LS): A facility designed and quipped to move sewage material or wastewater from a lower level to a higher elevation. A lift station may employ submersible pumps or other mechanical devices to deliver the wastewater and dischages into a pressure pipe called a force main. 

LRF: Acronym for Livingston Recreation Fund. 

LRWSS: Acronym for Livingston Regional Water Supply System. 

MAXIMUM CONTAMINANT LEVEL: The highest allowable amount of a constituent in water. Drinking water quality criteria are established by the U.S. Environmental Protection Agency as regulatory standards.

MCRWS: Acronym for Mountain Creek Regional Water Supply System. 

METER: An instrument for measuring the flow of water/wastewater. 

mg/L: Milligrams per liter; a measurement describing the amount of a substance (such as a mineral, chemical or contaminant) in a liter of water. One milligram per liter is equal to one part per million.

MGD: Acronym for million gallons per day. This term is used to describe the volume of water treated and discharged from a treatment plant.

MICROFILTRATION: A physical separation process where tiny, hollow, straw-like membranes separate particles from water. It is used as a pretreatment for reverse osmosis.

NATIONAL ASSOCIATION OF CLEAN WATER AGENCIES (NACWA): A national organization, involved in all facets of water quality protection, represents the collective interest of America's clean water utilities, and is the leading advocate for responsible national policies that advance clean water. 

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES): A permit issued by the EPA that governs effluent discharges into various rivers and waterways. 

NONPOTABLE: Water not suitable for drinking.

NONPOTABLE REUSE: Includes all recycled or reclaimed water-reuse applications except those related to drinking water.

NPDES: National Pollutant Discharge Elimination System. A federal permit authorized by the Clean Water Act, Title IV, which is required for discharge of pollutants to navigable waters of the United States, which includes any discharge to lakes, streams, rivers, bays, the ocean, wetlands, storm sewer, or any tributary to any surface water body.

NR: Acronym for Northern Region. 

NTU: Acronym for nephelometric turbidity units which is the measure of light shining through water to record turbidity. 

O&M: Acronym for Operations & Maintenance - relates to the Authority's day to day operational expenses, not funded by bond funds. 

PARTS PER BILLION: A unit frequently used to measure contamination concentration (parts of contamination per billion parts of water). One thousand parts per billion is equal to one part per million.

PARTS PER MILLION: A unit used to measure contamination concentration (parts of contamination per million parts of water). One part per million is equal to one milligram per liter. (This term is becoming obsolete as instruments measure smaller particles.)

PATHOGENS: Disease-causing organisms (generally viruses, bacteria, protozoa, or fungi).

PDCA: Acronym for Planning, Design and Construction Administration. 

PEAK FLOW: The maximum momentary quantity placed on a water/wastewater plant and/or pumping station. 

PERCOLATION POND: A pond that allows water to percolate (or seep) through layers of rock and gravel. The water is cleaned as it slowly travels downward and eventually reaches an underground aquifer. The purpose of man-made percolation ponds is both to clean the water and to keep the ground from sinking.

PFAS: Per- and Polyfluoroalkyl Substances (PFAS) are a groupd of manufactured chemicals that have been used in industry and consumer products since the 1940s because of their useful properties. One common characteristic of concern of PFAS is that many break down very slowly and can build up in people, animals, and the environment over time. 

pH: The quantitative measure of the acidity of basicity of aqueous or other liquid solutions. 

POTABLE WATER: Water that does not contain pollution, contamination, objectionable minerals or infective agents and is considered safe for domestic consumption; drinkable.

POTABLE REUSE: The addition of advanced treated recycled or reclaimed water (purified water) to augment a potable water distribution system.

PRETREATMENT: A process in wastewater treatment where metal screens are used to remove large objects and chunks of debris.

PRIMARY TREATMENT: The first process in wastewater treatment where solid matter is removed.

PUMP STATION: A facility designed and equipped to deliver water from one place to another to a higher elevation. The pump station can include pumps, motors, mother control centers, instrumentation and controls, piping, valves and other equipment used to move the water. 

RAW WATER: Untreated water, obtained from natural resources such as reservoirs. 

RECLAIMED WATER: Water that is used more than one time before it passes back into the natural water cycle. Wastewater that has been treated to a level that allows for its reuse for a beneficial purpose. Reclaimed water is sometimes another name for recycled water.

RECYCLED WATER: Water that is used more than one time before it passes back into the natural water cycle. Wastewater that has been treated to a level that allows for its reuse for a beneficial purpose. Recycled water is sometimes another name for reclaimed water.

RESERVOIR: A body of water used to collect and store water, or a tank or cistern used to store potable water.

RETROFIT: The process for constructing and separating new potable and recycled/reclaimed pipelines that allow recycled water to be used for nondrinking purposes. A retrofit system separates recycled water from drinking water pipelines.

REUSE: To use again; recycle; to intercept, either directly or by exchange, water that would otherwise return to the natural hydrologic (water) system, for subsequent beneficial use.

REVERSE OSMOSIS: A method of removing salts or other impurities from water by forcing water through a semi-permeable membrane.

RIGHT OF WAY (ROW): The legal right of passage over another person's property. 

ROCRWS: Acronym for Red Oak Creek Regional Wastewater System. 

SALINITY: Generally, the concentration of mineral salts dissolved in water. Salinity may be measured by weight (total dissolved solids - TDS), electrical conductivity, or osmotic pressure. Where seawater is known to be the major source of salt, salinity is often used to refer to the concentration of chlorides in the water.

SEAWATER INTRUSION: The movement of salt water into a body of fresh water. It can occur in either surface water or groundwater basins.

SECONDARY TREATMENT: Treatment of wastewater to a nonpotable level so that it may be discharged into the natural hydrologic system.

SLUDGE: The solid, semi-solid or liquid by-product of wastewater treatment. 

SOIL-AQUIFER TREATMENT: The process of water being purified by percolating through soil and into an underground aquifer.

SR: Acronym for Southern Region. 

SRSS: Acronym for Southern Region Support Services. 

STORAGE: Water held in a reservoir for later use.

SURFACE WATER: Water located on the earth's surface.

TCEQ: Acronym for the Texas Commission on Environmental Quality. 

TCRWSS: Acronym for Trinity County Regional Water Supply System. 

TCWSP: Acronym for Tarrant County Water Supply Project. 

TDS: Total dissolved solids. A quantitative measure of the residual minerals dissolved in water that remain after evaporation of a solution. Usually expressed in milligrams per liter.

TERTIARY TREATMENT: Treatment of wastewater to a level beyond Secondary Treatment but below Potable.

THERMAL HYDROLYSIS PROCESS (THP): A process that heats and pressurizes solids. The pressure cooking breaks down the solids and enhances the process of anaerobic digestion.

TMCRWS: Acronym for Ten Mile Creek Regional Wastewater System. 

TRA: Acronym for the Trinity River Authority of Texas. 

TREATED WATER: Raw water that has passed the purification process. 

TRWD: Acronym for Tarrant Regional Water District. 

TSBP: Acronym for Technical Services and Basin Planning.

TSS: Total suspended solids, a water quality measurement. 

TURBIDITY: A measure of suspended solids in water; cloudiness.

TWDB: Acronym for Texas Water Development Board. 

ULTRAFILTRATION (UF): A membrane filtration process that falls between reverse osmosis (RO) and microfiltration (MF) in terms of the size of particles removed.

ULTRAVIOLET TREATMENT (UV): The use of ultraviolet light for disinfection.

ULTRAVIOLET (UV) DISINFECTION SYSTEM: A UV disinfection system transfers electromagnetic energy to wastewater for the inactivation/destruction of pathogenic organisms to prevent the spread of waterborne diseases to downstream users and the environment. 

URBAN RUNOFF: Water from an urban area that neither infiltrates the soil nor is consumed, but flows into a storm sewer or open waterway.

U.S. ARMY CORPS OF ENGINEERS (USACE): The mission of the U.S. Army Corps of Engineers is to deliver vital public and military engineering services; partnering in peace and war to strengthen our nation's security, energize the economy and reduce risks from disasters. 

WASTEWATER: Water that has been previously used by a municipality, industry, or agriculture and has suffered a loss of quality as a result of use.

WATER CONSERVATION: Reducing the demand for water through activities that alter water use practices, e.g., improving efficiency in water use, and reducing losses of water from leaks. 

WATER CYCLE: The movement of water as it evaporates from rivers, lakes or oceans, returns to the earth as precipitation, flows into rivers and evaporates again.

WATER QUALITY: The chemical, physical and biological characteristics depending on its characteristics and the requirements for the particular use, of water with respect to its suitability for a particular purpose. The same water, may be of good quality for one purpose or use, and bad for another. 

WATER RIGHTS: A legally protected right, granted by law, to take possession of water occurring in a water supply and to guide the water and put it to beneficial use. 

WATERSHED: An area from which water drains and contributes to a given point on a stream or river.

WCB: Acronym for Walker-Calloway Branches.

WELL: A vertically drilled hole into an underground formation, usually to obtain a source of water, to monitor groundwater quality or to determine the position of the water table. 

WETLANDS: Areas with standing water or a high water table that under normal circumstances support vegetation typically adapted to saturated soil conditions; generally includes swamps, marshes, bogs and areas with vegetation that grows in or around water.

WSSRF: Acronym for Water Sales Special Revenue Fund. 

XERISCAPE: Landscaping concept that requires less water on vegetation that is suited to soils and climate.

µg/L (micrograms per liter): a measurement describing the amount of a substance (such as a mineral, chemical or contaminant) in a liter of water. It is expressed in terms of weight per volume. One µg/L is equal to one part per billion.