GLOSSARY OF WATER AND WASTEWATER TERMS (Source: Operator Basics, Montana State University, 2005 http://watercenter.montana.edu/training/ob2005/default.htm) Absorption : The uptake of water or dissolved chemicals by a cell, organism, or other absorbing material (as tree roots absorb dissolved nutrients in the soil).

Access Hatch : An entry way into a storage tank that facilitates inspection and maintenance.

Acid : A substance that tends to lose a proton, dissolves in water with the formation of hydrogen ions, contains hydrogen that may be replaced by metals to form salts, and is highly corrosive.

Acidic : The condition of water or soil which contains a sufficient amount of acid substances to lower the pH below 7.0.

Acre-Foot : A volume of water that covers one acre to a depth of one foot, or 43,560 cubic feet.

Action Level : acronym: AL The concentration of lead or copper in water which determines, in some cases, the treatment requirements for source water or corrosion control.

Activated Carbon : Adsorptive particles or granules of carbon usually obtained by heating carbon (such as wood). These particles or granules have a high capacity to selectively remove certain trace and soluble materials from water.

Activated Sludge : Sludge containing many living microorganisms, including bacteria, fungi and protozoa, that are sustained by dissolved oxygen and can feed on incoming wastewater.

Acute : Occurring over a short period of time; used to describe brief exposures and effects which appear promptly after exposure.

Acute Health Effect : An impact on health which occurs over a short period of time after exposure to a contaminant.

Acute Illness : An illness occuring over a short period of time; used to describe brief exposures and effects which appear promptly after exposure.

Adsorption : The collection of a gas, liquid, or dissolved substance on the surface or interface zone of another material.

Aeration : 1: The process of adding air to water either by passing water through air or passing air through water. 2: The process of adding air to wastewater in order to provide dissolved oxygen for 1 aerobic bacterial treatment, freshen wastewater, and keep solids in suspension. 3: A mechanical transfer of atmospheric oxygen from the air to the wastewater to supply the needs of aerobic and facultative microorganisms.

Aerobic : The condition in which free oxygen is dissolved in the water. Aerobic bacteria need free dissolved oxygen to live and multiply.

Air Binding : The clogging of a filter, or pipe, or pump due to the presence of air released from water. Air entering the filter media is harmful to both the filtration and backwash processes. Air can prevent the passage of water during the filtration process and can cause the loss of filter media during the backwash process.

Air Gap : An open vertical drop, or vertical empty space, that separates a drinking water supply to be protected from another water system in a water treatment plant or other location. This open gap prevents the contamination of drinking water by backsiphonage or backflow because there is no way raw water or any other water can reach the drinking water.

Air Release/vacuum Breaker Valve : acronym: AVB Valves used to release trapped air or vacuums created in water pipelines.

Air Relief Valve : Valve used to release air trapped in water pipelines to prevent excessively high pressure.

Air Vent : A screened opening on the top of a gravity tank that lets the tank "breathe" as the tank is filled and emptied.

Alarm System : Detects unacceptable low and/or high water levels in a gravity storage tank and sends a signal to operators.

Algae : Microscopic plants that contain chlorophyll, live floating (suspended) in water or are attached to rocks, walls and other surfaces, and grow and multiply through photosynthesis. Algae produce oxygen during sunlight hours, use oxygen during darkness, and affect the pH and dissolved oxygen levels in waster.

Algal Bloom : A sudden massive growth of algae in a wastewater lagoon, lake or reservoir.

Alkali : Any of certain soluble salts, principally of sodium, potassium, magnesium, and calcium. It has the property of combining with acids to form neutral salts and may be used in a chemical water treatment process.

Alkaline : The condition of water or soil which contains a sufficient amount of alkali substances to raise the pH above 7.0.

2 Alkalinity : The capacity of water to neutralize acids, imparted primarily by the water's content of carbonates, bicarbonates, and hydroxides. A characteristic of substances with a pH greater than 7.

Alluvial Deposit : Relating to mud and/or sand deposited by flowing water. Alluvial deposits may occur after a heavy rain storm.

Alluvium : Mud and/or sand deposited by flowing water, commonly formed in river valleys and deltas from materials washed down the river after a heavy rain storm.

Altitude Valve : A valve that automatically shuts off the flow into an elevated tank when the water level in the tank reaches a predetermined level. It automatically opens when the pressure in the distribution system drops below the pressure in the tank. The valve is often used to fill a second tank.

Amoebic Dysentery : An inflammation of the colon causing diarrhea of varying degrees of severity due to infection by the amoeba Entamoeba histolytica.

Anaerobic : The condition in which there is no, or very little, free dissolved oxygen in the water. Anaerobic bacteria live in the absence of free oxygen and obtain energy through the fermentation process.

Annular Space : The ring-shaped space located between the bore-hole of a well and the well casing.

Anode : The positive pole or electrode of an electrolytic system, such as a battery. The anode attracts negatively charged particles or ions (anions).

Apparent Color : Color of water caused by suspended and dissolved particles in the water.

Aquifer : A natural underground layer of porous, water-bearing materials (sand, gravel), usually capable of yielding a large amount of water.

Artesian : Water held under pressure in porous rock or soil confined by impermeable geologic formations. Also, see confined aquifer.

Artesian Well : Water held under pressure in porous rock or soil confined by impermeable geologic formations; a free flowing well.

Aseptic : Free from the living germs of disease, fermentation or putrefaction; sterile.

Assembly : A group of mechanical parts that fit together to form a self-contained unit.

3 Autotrophic Bacteria : Bacteria that utilize carbon dioxide for their carbon source to synthesize all the organic molecules of the cell.

Available Chlorine : The amount of chlorine available in compound chlorine sources compared with that of elemental (liquid or gaseous) chlorine.

Average Daily Flow : The average of the highest and lowest measured flows entering into a wastewater treatment facility in a day.

Back-Pressure : Occurs when normal flow in the distribution system is reversed due to an increase in the downstream pressure above the supply pressure.

Back-Siphonage : Occurs when a negative pressure (below atmospheric pressure, or a vacuum) develops in the distribution system which can allow pollutants or contaminants to be siphoned into the water system.

Backflow : The unwanted reverse flow of water in a public water supply system.

Backwash : The process of reversing the flow of water back through the filter media to remove the entrapped solids.

Backwashing : The process of reversing the flow of water back through the filter media to remove the entrapped solids.

Bacteria : 1: Single-celled microorganisms that can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Examples are Acidophilus, found in yogurt, E. coli, found in the colon, and Streptococcus, the cause of strep throat. 2: Microorganisms that use organic material for food (heterotrophs) or carbon dioxide (autotrophs) for building blocks of cellular molecules and energy, and produce waste products. The three main types of bacteria are: aerobic, anaerobic and facultative anaerobic.

Baffle : A flat board or plate, deflector, guide, or similar device constructed or placed in flowing water or slurry systems to cause more uniform flow velocities, to absorb energy, and divert, guide, or agitate liquids (water, chemical solutions, slurry, etc.).

Ball Valve : A valve with a ball resting in a cylindrical seat. A hole is bored through the ball to allow water to flow when the valve is open. When the ball is rotated 90 degrees, the valve is closed.

Barrel : The body of a fire hydrant. It can be classified as wet or dry.

4 Base : A substance that takes up or accepts protons, dissociates in water to produce hydroxyl (OH-) ions, reacts with metals, and is corrosive.

Basic : The condition of water or soil which contains a sufficient amount of alkaline substances to raise the pH about 7.0.

Bentonite : A light-colored valuable clay that expands with the addition of water and is used as a sealant in water wells, as oil-well drilling mud, as a liner in wastewater lagoons, and as a filler in the building, paper, soap, and pharmaceutical industries.

Best Available Technology : acronym: BAT After examination for efficacy under field conditions and not solely under laboratory conditions, the best technology treatment techniques or other means which the Administrator finds are available (taking cost into consideration).

Biochemical Oxygen Demand : acronym: BOD or BOD5 The amount of oxygen used by a population of microorganisms to aerobically decompose organic matter present in a sample in five days. BOD5 is used as a measure of the organic strength of wastewater.

Biosolids : Organic wastewater solids that can be used for beneficial purposes after stabilization by such methods as composting or digestion.

Blue-Green Algae : Varieties of algae characterized by their bluish-green color; also known as cyanobacteria. The presence of blue-green algae indicates unhealthy conditions in wastewater lagoon cells or surface waters such as lakes, reservoirs, streams. They are often associated with organic overloading and lack of adequate dissolved oxygen.

Brake Horsepower : (1) The horsepower required at the top or end of a pump shaft (input to a pump). (2) The energy provided by a motor or other power source.

Breakpoint Chlorination : Addition of chlorine to water until the chlorine demand has been satisfied. At this point, further additions of chlorine will result in a free residual chlorine which is directly proportional to the amount of chlorine added beyond the breakpoint.

Breakthrough : A crack or break in a filter bed allowing the passage of floc or particulate matter through the filter. This will cause an increase in filter effluent turbidity. A breakthrough can occur (1) when a filter is first placed in service, (2) when the effluent valve suddenly opens or closes, and (3) during periods of excessive head loss through the filter.

Brine : Subsurface water with a high content of dissolved salts.

5 Burette : A measuring instrument consisting of a graduated glass tube with a tap at the bottom; used for titration.

By-Product : Something usually produced in an industrial or biological process in addition to the principal product.

Calcium Hypochlorite : acronym: Ca(OCl)2 A dry material, of about 65% available chlorine, that comes as a powder, granular or tablet form.

Capacity : 1.(design) - Volume of water per unit time. 2.(viability) - The financial, managerial and technical ability of a public water supply system to meet the requirements of the Safe Drinking Water Act.

Capillary Fringe : The porous material just above the water table which may hold water by capillarity (a property of surface tension that draws water upwards) in the smaller void spaces.

Capital : Infrastructure items such as buildings, equipment, etc.

Carbon Dioxide : acronym: CO2 A common gas, abundant in air, produced by bacterial respiration, and used by algae in photosynthesis.

Carbon Monoxide : acronym: CO A colorless, odorless, poisonous gas generated by the burning of natural gas in furnaces, hot water heaters, stoves, etc.

Carbonaceous BOD5 : acronym: CBOD5 A measure of the oxygen used by a population of microorganisms to aerobically degrade only carbon-based organic matter present in a sample after five days.

Carcinogen : Any substance which tends to produce cancer in an organism.

Casing : 1) The enclosure surrounding the pump, where the suction and discharge ports operate. 2) An impervious, durable pipe placed in a bore-hole to prevent the walls of the bore-hole from caving, and to seal off surface drainage or undesirable water, gas, or other fluids and prevent their entrance into the well.

Cavitation : The formation and collapse of a gas pocket or bubble on the blade of an impeller or the gate of a valve. The collapse of the pocket or bubble drives water into the valve or impeller with enough force to cause pitting. It is accompanied by loud noises which sound like someone pounding on the impeller or gate with a hammer.

6 Cell : 1) A term used for individual lagoon basins. A primary cell is the first in the series of cells in a lagoon. 2) The simplest entities that have all the properties of life. They are the least complicated units that we can say are truly alive.

Centrifugal Force : A force exerted on an object moving in a circular path which is directed away from the center of rotation.

Centrifugal Pump : A pump consisting of an impeller on a rotating shaft enclosed by a casing that has suction and discharge connections. The spinning impeller throws water outward at high velocity, and the casing shape converts this high velocity to a high pressure.

Check Valve : A special valve with a hinged disc or flap that opens in the direction of normal flow and is forced shut when the flow attempts to go in the reverse or opposite direction of normal flow.

Chemical Compatibility : The ability of pipe, valve or tank materials to be in contact with certain chemicals without losing strength or integrity. Corrosive chemicals in particular need compatible materials used for their storage and application.

Chemical Containment : Berms, walls or other means by which potential chemical spills are limited to a controlled area.

Chemical Oxygen Demand : acronym: COD An indirect measure of the amount of oxygen used by inorganic and organic matter in water. The measure is a laboratory test based on a chemical oxidant and therefore does not ecessarily correlate with biochemical oxygen demand.

Chloramines : Compounds formed by the reaction of hypochlorous acid (or aqueous chlorine) with ammonia.

Chlorination : The addition of chlorine to water for the disinfection or oxidation of undesirable constituents. Chlorine compounds are gas, liquids or solids (hypochlorites or chloramines).

Chlorinator : A metering device that is used to add chlorine to water.

Chlorine : acronym: Cl2 A chemical which destroys small organisms in water.

Chlorine Contact Basin : A baffled basin designed to provide sufficient time for disinfection to occur.

Chlorine Demand : The difference between the amount of chlorine added to water and the amount of residual chlorine remaining after a given contact time.

7 Chlorine Dioxide : acronym: ClO2 A powerful oxidant used to treat raw water high in humic and fulvic substances to reduce the formation of trihalomethanes.

Chlorine Gas : acronym: Cl2 A greenish-yellow gas with a penetrating and distinctive odor used for disinfection. Chlorine gas is 100% available chlorine and is highly toxic in pure form.

Chlorine Residual : The amount of free chlorine remaining after meeting chlorine demand under given conditions; positive value is necessary to complete disinfection. (see free chlorine residual)

Chlorophyll : A pigment found in plants and algae which absorbs energy from light.

Chlororganic : Organic compounds combined with chlorine. These compounds generally originate from, or are associated with, life processes such as those of algae in water.

Cholera : A devastating and sometimes lethal disease caused by infection with Vibrio cholera. A comma- shaped bacteria, which thrives in damp, moist places and stools of infected patients. Symptoms include intense vomiting and diarrhea leading to dehydration which, unless immediately treated, may be fatal.

Chronic : Occurring over a long period of time, either continuously or intermittently; used to describe ongoing exposures and effects that develop only after a long exposure.

Chronic Health Effect : Impacts on health which occur over a long period of time, either continuously or intermittently, generally caused after long-term and low-level exposure to a contaminant.

Chronic Illness : Illness occurring over a long period of time, either continuously or intermittently; used to describe ongoing exposures and effects that develop only after a long exposure.

Circle of Influence : The circular outer edge of a depression produced in the water table by the pumping of water from a well.

Clarification : A settling process used to reduce the concentration of suspended solids in wastewater or water. In facultative lagoons this process occurs in each cell; in aerated lagoons it happens in the non- aerated cells; and in water systems it happens in the sedimentation basin.

Clean Water Act : acronym: CWA Congressional legislation passed in 1972 creating the Environmental Protection Agency, requiring a nationwide system for controlling pollutant discharges and providing for construction and regulation of publicly owned treatment works.

8 Clearwell : Storage basin at the downstream end of the treatment works where disinfectant contacts water.

Closed Loop Recirculation : The return of all or part of the effluent from a treatment process to the influent of a lagoon system.

Coagulants : Chemicals that cause very fine particles to clump together into larger particles. This makes it easier to separate the solids from the water by settling, skimming, draining or filtering.

Coagulation : The clumping together of very fine particles into larger particles caused by the use of chemicals (coagulants). The chemicals neutralize the electrical charges of the fine particles and cause destabilization of the particles. This clumping together makes it easier to separate the solids from the water by settling, skimming, draining, or filtering.

Code of Federal Regulations : A publication of the United States government which contains all of the proposed and finalized federal regulations, including safety and environmental regulations.

Coliform Bacteria : A group of bacteria commonly found in the intestines of warm-blooded animals (including humans), but may also be found in soil and water. The presence of coliform bacteria is an indication that the water is polluted and may contain pathogenic organisms.

Colloid : Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.

Combined Available Chlorine : The portion of the residual chlorine that has combined with ammonia, other nitrogen compounds, or organic matter.

Combined Chlorine Residual : The result of chlorine reacting with other materials such as organics and ammonia.

Combined Filter Effluent : acronym: CFE Water coming from more than one filter, usually two filters.

Combined Sewer : When storm drains and sanitary sewers are connected together.

Combined Sewer Overflow : acronym: CSO Situations that occur when the capacity of the combined storm water and sanitary sewer system is exceeded and untreated wastewater overflows into receiving waters.

Comminutor : A mechanical device placed at the headworks of some wastewater systems used to shred and chop large pieces of waste so the waste will not plug pipes or damage equipment. 9

Community Water System : acronym: CWS A public water system which serves at least 15 service connections used by year-round residents or regularly serve at least 25 year-round residents.

Composite Sample : A collection of individual samples obtained at regular intervals during a 24-hour period. Each individual sample is combined with the others in proportion to the rate of flow when the sample is collected. The resulting mixture, or composite, forms a representative sample and is analyzed to determine the average conditions during the sampling period.

Compound : A substance composed of two or more elements whose composition is constant. For example, table salt (NaCl) is a compound.

Comprehensive Performance Evaluation : acronym: CPE A thorough review and analysis of a treatment plant's performance-based capabilities and associated administrative, operation and maintenance practices. It is conducted to identify factors that may be adversely impacting a plant's capability to achieve compliance and emphasizes approaches that can be implemented without significant capital improvements. The comprehensive performance evaluation must consist of at least the following components: Assessment of plant performance; evaluation of major unit processes; identification and prioritization of performance limiting factors; assessment of the applicability of comprehensive technical assistance; and preparation of a CPE report.

Conductivity : A measure of the ability of water to carry an electric current. Conductivity is increased as the total dissolved solids in water increase.

Cone of Depression : The depression, roughly conical in shape, produced in the water table by the pumping of water from a well.

Confined Aquifer : An aquifer in which ground water is confined under pressure which is significantly greater than atmospheric pressure.

Consolidated Deposit : A geologic material whose particles are stratified (layered), cemented or firmly packed together (hard rock).

Constant Displacement Pump : A type of piston, diaphragm, gear or screw pump that delivers a constant volume with each stroke. It is often used as a chemical solution feeder.

Consumer Confidence Report : acronym: CCR An annual report to consumers of each community public water supply system on the source of their water and the levels of contaminants found in the drinking water.

Contact Time : The time it takes water to move from where disinfectant is added to where residual is measured. 10

Containment : Prevention measures to restrict the backflow of pollutants or contaminants from consumer facilities into the public water system.

Contaminant : Anything found in water (including microorganisms, minerals, chemicals, radionuclides, etc.) which may be harmful to human health.

Contamination : The introduction into water of microorganisms, chemicals, toxic substances, wastes, or wastewater in a concentration that makes the water unfit for its next intended use.

Continuing Education Credit : acronym: CECs Credits earned by certified operators through attendance at or participation in approved training events. Continuing education credits, or CECs are required for maintaining certified operator status.

Continuing Education Unit : acronym: CEUs Units earned by certified operators through attendance at or participation in approved training events. Continuing education units are required for maintaining certified operator status. Referred to as TUs in Colorado.

Controlled Discharge : Discharge from a wastewater lagoon to a receiving stream, only when necessary, by opening and closing effluent discharge valves.

Corporation Stop : A water service shutoff valve located at a street water main. This valve cannot be operated from the ground surface because it is buried and there is no valve box.

Corrosion : The gradual decomposition or destruction of a material by chemical action, often due to an electrochemical reaction.

Corrosivity : An indication of the corrosiveness of water. The corrosiveness of water is described by the water's pH, alkalinity, hardness, temperature, total dissolved solids, and the dissolved oxygen concentration.

Crest : The bottom edge of a weir plate.

Cross-Connection : Any actual or potential connection between a drinking (potable) water system and an unapproved water supply or other source of contamination.

Crustacean : A class of aquatic animals that consume large quantities of bacteria and algae.

11 Cryptosporidiosis : An infectious condition of humans and domestic animals, characterized by fever, diarrhea, and stomach cramps. It is spread by a protozoan of the genus Cryptosporidium.

Cryptosporidium : An oocyst-forming protozoan found in water that causes gastrointestinal illness in humans. The primary sources are human and animal feces.

Dechlorination : The deliberate removal of chlorine from water. The partial or complete reduction of residual chlorine by any chemical or physical process. A commonly used chemical dechlorinating agent is sodium thiosulfate.

Delineated : The identification and mapping of an area around a pumping well.

Delineation : Identification and mapping of the area around a pumping well.

Denitrification : An anaerobic process that occurs when nitrite and nitrate ions are reduced to nitrogen gas and bubbles are formed. These bubbles attach to sludge flocs, causing sludge to rise and float to the surface.

Detention Time : The theoretical time that one drop of water is retained in a lagoon, assuming there is no mixing or short-circuiting. Detention time is the total volume of the lagoon divided by the flow rate, usually expressed in days of time.

Device : A self-contained backflow-prevention mechanism that lacks shut-off valves and test cocks.

Diatomaceous Earth Filtration : acronym: DE Filtration A filtration method resulting in substantial particulate removal, that uses a process in which: 1) a "precoat" cake of diatomaceous earth filter media is deposited on a support membrane (septum), and 2) while the water is filtered by passing through the cake on the septum, additional filter media, known as "body feed," is continuously added to the feed water to maintain the permeability of the filter cake.

Diffuser : A submerged mechanical device with porous holes used to introduce air as bubbles into water or wastewater.

Direct Runoff : Water that flows over the ground surface or through the ground directly into streams, rivers, and lakes.

Discharge : 1) A rate of flow at a given instant in terms of volume per unit of time. 2) Ground water is said to discharge when it emerges from the ground. 3) Treated wastewater is said to discharge when it is released to a stream from a wastewater treatment facility.

12 Discharge Monitoring Report : The form on which NPDES permit parameters must be reported monthly to the state primacy agency or EPA (EPA Form No. 3320-1).

Discharge Point : The location where treated wastewater is released into a stream or river.

Disinfectant : A chemical (commonly chlorine, chloramine, or ozone) or physical process (e.g., ultraviolet light) that kills microorganisms such as bacteria, viruses, and protozoa.

Disinfection : The process designed to kill most microorganisms in water, including essentially all pathogenic (disease-causing) bacteria and viruses.

Disinfection by-Product : acronym: DBP A compound formed by the reaction of a disinfectant such as chlorine with organic material in the water supply.

Dissolved Organics : Organic materials that cannot be filtered out of water or wastewater, but remain in suspension.

Dissolved Oxygen : acronym: DO 1) The amount of oxygen water contains in solution. 2) A measure of water quality indicating free oxygen dissolved in water.

Dissolved Solids : The salts and other residues left after the evaporation of laboratory-filtered water. Dissolved solids cannot be filtered out. Some colloidal solids may not be totally dissolved, but if they pass through the standard membrane filter, they are considered dissolved solids. (see suspended solids)

Diurnal Fluctuation : The biological and chemical variations that occur within a lagoon system during the daytime.

Domestic Wastewater : Wastewater in which the largest contributing source is from homes/residences. Domestic wastewater is a more formal name for sewage.

Double Check Valve : acronym: DC The double check assembly is basically two check valves in a single apparatus with isolation valves at each end and four test cocks. It can be used to protect against both back-pressure and back-siphonage. The functioning of both valves can be tested inline unlike two independent check valves. Because each valve is spring loaded to close, it can push against small debris and still seal effectively. It is protective even when one valve malfunctions and is one of the many devices used to prevent cross-connections.

DPD Method : acronym: DPD

13 A method of measuring the chlorine residual in water. The residual may be determined by either titrating or comparing a developed color with color standards. DPD stands for N, N-diethyl-p- phenylene-diamine.

Drainfield : In a septic system, the network of pipes or tiles through which wastewater is dispersed into the soil.

Drawdown : 1) This refers a drop in the water table or level of water in the ground when water is being pumped from a well. 2)The amount of water used from a tank or reservoir, which is measured as the drop in the water level of a tank or reservoir.

Effluent : Water or other liquid - raw (untreated), partially or completely treated - flowing from a reservoir, basin, treatment process, or treatment plant.

Element : A substance which cannot be separated into its constituent parts and still retain its chemical identity. For example, sodium (Na) is an element.

Environmental Protection Agency : acronym: EPA The U.S. agency responsible for efforts to control air, land, and water pollution, radiation, and pesticide hazards, and to promote ecological research, pollution prevention, and proper solid waste disposal.

Escherichia Coli : acronym: E. Coli Species of bacterium that inhabits the stomach and intestines of warm-blooded animals.

Eutrophic : Reservoirs and lakes which are rich in nutrients and very productive in terms of aquatic plant life.

Eutrophication : The nutrient enrichment of waters which result in many changes within the receiving waters including increased algae growth, deterioration of fisheries, deterioration of water quality, and other changes that are found to be undesirable and interfere with water uses by plants, animals, and man.

Evaporation : The process by which water or other liquid becomes a gas (water vapor or ammonia vapor).

Evapotranspiration : The process by which water vapor passes into the atmosphere from living plants (also called transpiration). Can also be the total water removed from an area by transpiration (plants) and by evaporation from soil, snow and water surfaces.

Exemption : A state-granted relief for a public water supply system which allows the system to not meet a specific MCL, treatment technique requirement, or both, if certain conditions exist. The conditions include consideration of why the requirement cannot be met and that there are not any unreasonable risks to public health as a result of the exemption. 14

Exfiltration : The gradual flow of wastewater out of a pipe into the soil and ground water.

Facultative : A combination of both aerobic and anaerobic conditions. Facultative cells have both aerobic and anaerobic zones. Facultative bacteria are able to exist in both aerobic and anaerobic conditions. A facultative pond is commonly used to treat wastewater flows in small communities - it has an upper aerobic zone, a lower anaerobic zone, and algae provide most of the oxygen for the bacteria in the aerobic zone.

Fecal Coliform : Bacteria found in the intestinal tracts of warm blooded animals. The presence of high numbers of fecal coliform bacteria in a water body can indicate the recent release of untreated sewage and/or the presence of animal feces. These organisms may also indicate the presence of pathogens that are harmful to humans.

Fermentation : A process of decomposition of organic materials, including solids, by bacteria and other biological actions under anaerobic conditions.

Filter Media : Permeable material that separates solids from liquids passing through it. The material is either sand, anthracite coal, some other granular material or a combination of these.

Filter Self-Assessment : An evaluation performed on a filter by the water treatment system itself. This is required of water systems by the IESWTR and the LT1ESWTR for any individual filter that has a measured turidity level greater than 1.0 NTUs in two consecutive measurements taken 15 minutes apart in each of 3 consecutive months.

Filtration : A process for removing particulate matter from water by passage through porous media.

Floc : Clumps of bacteria and particulate impurities that have come together and formed a cluster.

Flocculation : The gathering together of fine particles in water by gentle mixing after the addition of coagulant chemicals to form larger particles.

Flow : 1) To be in constant movement that is typically in a single direction. 2) In water this term usually relates to a volume per unit of time, gallon per minute, cubic feet per second, million gallons per day (MGD), etc.

Flow Meter : A mechanical device which measures the amount of water passing through a given pipe. Flow is typically recorded as gallons per minute or cubic feet per second. Total flow and rate of flow are commonly recorded by flow meters.

15 Flume : A flow measuring device with an open channel flow section usually including a converging section, throat and diverging section. The flume creates a known hydraulic condition where the area of the water stream can be measured to determine flow.

Fluoridation : The addition of a chemical to increase the concentration of fluoride in drinking water to a predetermined optimum limit to reduce the incidence of tooth decay in consumers.

Fluoride : acronym: F A trace mineral that occurs naturally in soil and water. It has been found to prevent tooth decay.

Foot Valve : A special type of check valve located at the bottom end of the suction pipe on a pump. The valve opens to allow water to flow when the pump operates and closes when the pump shuts off to prevent water from flowing out of the suction pipe.

Force Main : A pipe in the wastewater collection system in which wastewater moves under pressure from a pump’s discharge end to a point of gravity flow.

Free Available Chlorine Residual : The portion of the total available chlorine residual remaining in water after chlorination. This does not include chlorine that has combined with ammonia, nitrogen or other compounds.

Free Chlorine Residual : The application of chlorine to water to produce a free available chlorine residual equal to at least 80 percent of the total residual chlorine (sum of free and combined available chlorine residual).

Freeboard : The vertical distance from the surface of the water in a lagoon cell to the top of the dike or confining wall.

Friction Head : The head loss in piping, valves and fittings of a water or wastewater system due to friction.

Gaining Stream : The section of a stream, river or other surface water body which receives ground water discharging from an aquifer. (Same as Receiving Stream)

Galvanic Corrosion : Corrosion caused by the electrochemical reactions created when two dissimilar metals are in contact with each other.

Geographic Information System : acronym: GIS A computer program that combines mapping with detailed information about the physical locations of structures such as pipes, valves, and manholes within geographic areas. The system is used to help operators and maintenance personnel locate utility system features or structures and to assist with the scheduling and performance of maintenance activities.

16 Giardia Lamblia : A cyst-forming protozoan found in water that causes gastrointestinal illness in humans. The primary sources are human and animal feces.

Giardiasis : A contagious (infectious) form of diarrhea caused by the protozoan parasite Giardia lamblia that is most commonly transmitted through direct contact with infected feces or by eating food or drinking water that is contaminated by feces.

Grab Sample : A single sample of water or wastewater collected at a particular time and place that represents the composition of the water only at that time and place.

Grams Per Gallon : acronym: gpg A measure of concentration by weight of a substance per unit volume. A concentration of one gram per gallon means one gram of a substance is dissolved in each gallon of water.

Granular Activated Carbon : acronym: GAC Granules of adsorptive carbon obtained by heating carbon (such as wood). These granules have a high capacity to selectively remove certain trace and soluble materials from water.

Green Algae : The common form of algae in an aerobic lagoon environment and in natural aquatic systems. Green algae are essential for lagoon treatment processes.

Green Sand : Natural mineral, handled as a sand, having good adsorption properties for dissolved iron and manganese.

Greensand : A natural mineral, handled as a sand, having good adsorption properties for dissolved iron and manganese.

Grit : Solids in raw sewage such as sand and other heavier settleable solids.

Ground Water : Water that occupies voids, cracks, or other spaces between particles of clay, silt, sand, gravel or rock within a saturated formation.

Ground Water Rule : Establishes multiple barriers meant to protect against bacteria and viruses in drinking water from ground water supplied public water systems. It aims to identify systems that are contaminated or at-risk, and require disinfection of contaminated systems.

Ground Water under the Direct Influence of Surface Water : acronym: GWUDISW Any water beneath the surface of the ground with: 1) significant occurrence of insects or other macroorganisms; 2) significant and relatively rapid shifts in water characteristics which closely correlate to climatological or surface water conditions. Direct influence must be determined for individual sources in accordance with criteria established by the State.

17 Grout : Cement or other suitable material used to fill the annular space between the well casing and the borehole.

Hard Water : Water containing dissolved salts that interfere with some industrial processes, prevent soap from sudsing and cause scale buildup in fixtures.

Hardness : Characteristic of water caused mainly by the salts of calcium and magnesium. Excessive hardness in water is undesirable because it causes the formation of soap curds, increased use of soap, deposition of scale in boilers, damage in some industrial processes, and sometimes causes objectionable tastes in drinking water.

Headloss : In a filter, the difference in head, measured in feet of water, between the water on the filter and the effluent control weir. Ranges from 1-2 feet in a clean filter to 8-10 feet immediately before backwashing.

Heavy Metals : Metallic elements with high molecular weights that are generally toxic to plants and animals in low concentrations. Examples include mercury, chromium, cadmium and lead.

Heterotrophic Bacteria : Bacteria that use organic matter for the production of energy and cellular mass.

Human-Machine Interface : acronym: HMI A connection between the operator and the computer or SCADA system, usually by video display screen, keyboard or mouse.

Hydraulic Gradient : In general, the direction of ground water flow due to changes in the depth of the water table; the slope of the water surface in an open channel, the slope of the water surface of the ground water table, or the slope of the water pressure for pipes under pressure.

Hydraulic Head : An expression of the energy of water; a function of pressure, elevation and velocity.

Hydraulic Loading : The flow of water per unit of surface area of a wastewater lagoon, such as acre-feet per day per acre or inches per day.

Hydraulics : 1) The study of liquids, particularly water, under all conditions of rest and motion. (2) The branch of physics having to do with the mechanical properties of water and other liquids in motion.

Hydrogen Sulfide : acronym: H2S A gas produced under anaerobic conditions that has a rotten egg odor. Hydrogen sulfide gas is very poisonous to the respiratory system, explosive, flammable, colorless and heavier than air. It is particularly dangerous because it dulls the sense of smell so that you do not notice it after you have been around it for a while. 18

Hydrologic Cycle : A process that describes the constant movement of water above, on, and below the earth's surface. Precipitation, evaporation, condensation, infiltration, and runoff comprise the cycle. Within the cycle, water changes forms in response to the Earth's climatic conditions.

Hydropneumatic : A water system, usually small, in which a water pump is automatically controlled (started and stopped) by the air pressure in a compressed-air tank.

Impermeable : Not easily penetrated. The property of a material or soil that does not allow, or allows only with great difficulty, the movement or passage of water.

Indicator Bacteria : Bacteria analyzed for in water (such as coliform bacteria) which serve as a surrogate indicator for the potential presence of pathogens in the same water.

Individual Filter Effluent : acronym: IFE Water coming from a single, individual filter.

Induced Infiltration : The gradual flow or movement of water into and through the pores of rock or soil due to the effects of other sources such as a nearby stream, lake or river.

Industrial Wastewater : Wastewater generated by industrial plants or manufacturing processes. Examples include paper and fiber mills, steel mills, meat packing plants, petroleum refineries, etc.

Infiltration : The gradual flow or movement of water into and through the pores of rock or soil and cracks of pipes.

Inflow : Water discharged into the wastewater conveyance system from sources other than regular connections, including yard drains, foundation drains and around manhole covers.

Influent : Water, wastewater, or other liquid flowing into a reservoir, basin, or treatment plant.

Information Collection Request : acronym: ICR A description of information to be gathered in connection with rules, proposed rules, surveys, and guidance documents that contain information-gathering requirements. The ICR describes what information is needed, why it is needed, how it will be collected, and how much collecting it will cost. The ICR is submitted by the EPA to the Office of Management and Budget (OMB) for approval.

Inorganic : Chemical substances that come from mineral origin instead of living matter that are not primarily composed of carbon. Examples are sand, salts, iron, and sulfur.

19 Inorganic Compound : A substance of mineral origin not having carbon in its molecular structure.

Intake : A physical structure within a body of water used to draw water directly from the water source to treatment plant or some other structure.

Inter-Aquifer Leakage : The movement of groundwater (and associated contaminants) from one aquifer to another.

Intermediate Zone : The subsurface area between the unsaturated zone of soil moisture and the capillary fringe. Water is held in the interstices by surface tension or adhesive forces.

Interstices : Openings or spaces in a rock or soil.

Ion Exchange : A process by which an ion exchange medium can exchange an ion of one kind for an ion of another kind. For example, a resin can exchange one hardness causing ion for an ion that does not cause hardness, temporarily hold the new ion, and then release it when a regenerating solution passes over the resin.

Iron : acronym: FE 1) An inorganic chemical which causes reddish-brown stains on laundry and fixtures if present above about 0.3 mg/L. 2) A form of metal used in the making of piping for water and wastewater systems.

Iron Bacteria : A specialized group of bacteria capable of using iron for metabolic processes and which commonly cause red-water, slime or encrustation in well water systems.

Isolation : Backflow prevention within a customer's facility, with the purpose of protecting that customer's water system.

Jar Test : A laboratory procedure that simulates a water treatment plant's coagulation/flocculation units with differing chemical doses and also energy of rapid mix, energy of slow mix, and settling time.

Jet Pump : A device that pumps fluid by converting the energy of a high-pressure fluid into that of a high- velocity fluid.

Lagoon : Human-made bodies of water confined within natural boundaries or a lined pond that collects and detains wastewater for a period of time sufficient to allow the microorganisms and chemistry to stabilize the wastewater, and for gravity to settle out the solids. (see stabilization pond)

Laminar Flow : Water flow in which the stream lines remain distinct and the flow direction at every point remains unchanged with time. 20

Leachate : A Liquid that has percolated through a soil and that carry substances in solution or suspension.

Lift Pump : A pump used to lift or raise a liquid then force the liquid up.

Lift Station : Used in a gravity flow system to pump wastewater up in the collection system so that it can flow downward again to the next lift station or to the wastewater treatment plant.

Liter : acronym: L A metric measurement of volume equal to 1000 cubic centimeters.

Load : The amount and strength of a wastewater flowing to a lagoon.

Losing Stream : A reach of a river or stream or other surface water body from which water infiltrates into the ground water aquifer.

Macropores : Large holes or cracks in a geologic formation that can supply a pathway for contamination.

Manganese : acronym: Mn An inorganic chemical which causes brownish-black staining on laundry and fixtures if present in water at concentrations above about 0.05 mg/L.

Material Safety Data Sheets : acronym: MSDS Informational documents provided by chemical suppliers which detail hazards of the chemical, handling requirements, spill remediation, and other safety issues pertinent to the specific product.

Maximum Contaminant Level : acronym: MCL The maximum permissible level of a contaminant in a public water supply system.

Maximum Contaminant Level Goal : acronym: MCLG The maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. Maximum contaminant level goals are non-enforceable health goals.

Methane : acronym: CH4 A combustible gas produced during anaerobic fermentation of organic matter, such as by anaerobic digestion of wastewater solids.

Methemoglobinemia : Also referred to as "blue baby syndrome" is an ailment caused by high levels of nitrate or nitrite in water. When ingested, these compounds interfere with the ability of blood to carry oxygen 21 and result in a blue color of afflicted individuals. It can be fatal for the unborn, infants and young children.

Microbes : Tiny living organisms that can be seen only with the aid of a microscope. Some microorganisms can cause acute health problems when consumed in drinking water. More formally known as microorganisms.

Micrograms Per Liter : acronym: µg/L A measure of concentration by weight of a substance per unit volume. A concentration of one microgram per liter means one microgram of a substance is dissolved in each liter of water. For practical purposes, this unit is equal to parts per billion since one liter of water is equal in weight to one billion micrograms.

Microorganism : Microscopic living organism.

Microscopic Particulate Analysis : acronym: MPA A specialized analysis of particles in water which are trapped on a cartridge filter. The particles (algae, insects, and other debris) are assessed to determine relative populations and types of organisms present. It is useful for GWUDISW determinations and for assessing the performance of water filtration plants.

Milligram : acronym: mg A metric measurement of one thousandth of a gram; 1,000 mg (milligrams) = 1 g (gram).

Milligrams Per Liter : acronym: mg/L A measure of the concentration of a dissolved substance. A concentration of one milligram per liter means one milligram of a substance is dissolved in each liter of water. For practical purposes, this unit is equal to parts per million (ppm) since one liter of water is equal in weight to one million milligrams.

Milliliter : acronym: mL A metric measurement of one thousandth of a liter, 1,000 mL (milliliters) = 1 L (liter).

Million Gallons Per Day : acronym: mgd or MGD A measure of the volume of a liquid produced or used in one day expressed as million gallons per day.

Minimum Design Standards : Minimum criteria for construction and design established to ensure provision of a sufficient quantity of water from the source through a reliable treatment and distribution system.

Mixed Oxidant : Oxidants produced in a liquid stream using salt, water and electricity. The mixed oxidants are collected in a tank and injected into the water at rates appropriate for the treatment objectives.

22 Mixing : A mechanical method to keep the contents of the wastewater lagoon from stratifying and to distribute the oxygen throughout the upper portion of the cell.

Mixing Zone : The area within a stream in which the effluent discharged from a wastewater lagoon becomes completely mixed with the stream water.

Multiple Barrier Concept : A concept for public health protection which involves several steps or barriers to prevent the passage of contaminants to a potable water supply. The independent steps include source protection, treatment, disinfection and assurance of distribution system integrity.

Municipal : Referring to an incorporated city or town as opposed to other units of local government.

National Pollutant Discharge Elimination System : acronym: NPDES Establishes national levels of treatment and conditions for discharges to receiving waters as defined by the Clean Water Act.

National Primary Drinking Water Regulation : acronym: NPDWR The SWDA requires the EPA to establish drinking water regulations for contaminants in drinking water that may have an adverse effect on human health. These regulations are known as the NPDWR and include the setting of maximum contaminant levels or treatment techniques for nearly 100 contaminants. Monitoring and testing procedures are also specified.

Navigable Water : Waters in which boats and/or ships can maneuver.

Nephelometric Turbidity Unit : acronym: NTU A measure of the cloudiness of water. NTUs are an empirical quantity which is based on the amount of light that is scattered by particles of a polymer reference standard called formazine which produces particles that scatter light in a reproducible manner. NTUs are measured by using an instrument called a nephelometer. A nephelometer passes light through a sample and the amount of light deflected is then measured. (also referred to as tu)

Nitrate : - acronym: NO3 Nitrates are inorganic chemical contaminants of water systems which pose an immediate threat to infants under six months of age because they may lead to a condition known as methemoglobinemia. Nitrate reverts to nitrite in the human body, which causes the condition.

Nitrification : An aerobic process in which bacteria change ammonia and organic nitrogen into the nitrite and nitrate forms of nitrogen.

Nitrifying Bacteria : Bacteria that perform the nitrification process of changing ammonia and organic nitrogen into the nitrite and nitrate forms of nitrogen.

23 Nitrite : acronym: NO2 Nitrite is an inorganic which does not typically occur in natural water at high levels. If it does, that is usually an indication of wastewater contamination or a lack of oxidizing conditions. When nitrate is reduced to nitrite in the saliva and GI tract of babies or young animals ethoglobinemia occurs. The nitrite oxidizes hemoglobin to methemoglobin, which cannot carry oxygen in the blood, causing anoxia and possibly death.

Nitrogenous BOD : The oxygen used by nitrifying bacteria to convert ammonia and organic nitrogen into nitrite and nitrate; a portion of measured BOD. This oxygen demand is more pronounced in treated wastewater effluents.

Non-Community Water System : acronym: NCWS A public water system that is not a community water system. There are two types of NCWSs: transient (TNCWS) and non-transient (NTNCWS).

Non-Transient Non-Community Water System : acronym: NTNCWS Public water supply system which regularly serves at least 25 of the same non-resident persons per day for more than six months per year.

Nonpoint Source : Pollution of water from numerous widespread locations that are hard to identify or pinpoint, as in agricultural chemicals through leaching or runoff.

Nutrients : Substances required by living plants and organisms. Forms of nitrogen and phosphorus are nutrients that can cause problems in receiving waters.

Operation and Maintenance : acronym: O and M An important and continued event for public water and wastewater systems, often referred to as O & M.

Organic : Substances containing carbon that come from plant or animal sources or synthetic chemicals based on tetrahedrally-bonded carbon atoms.

Organic Acids : Week acids formed from organic compounds, such as acetic acid and citric acid. In anaerobic processes these acids form first and then are converted to methane gas.

Organic Loading : Organic material in wastewater that flows to the lagoon system. It is usually expressed as pounds of BOD per acre per day.

Organic Loading Rate : The amount of organic material in wastewater that flows to the lagoon system. It is usually expressed as pounds of BOD per acre per day.

24 Original Interstices : Openings or spaces in rock or soil created by geologic processes governing the geologic formation. They are found in sedimentary and igneous rocks.

Overloading : The condition where the hydraulic flow or organic concentration added per unit area exceeds the design parameters of a wastewater lagoon, resulting in the incomplete treatment of waste.

Oxidation : Oxidation is the addition of oxygen, removal of hydrogen, or the removal of electrons from an element or compound. In the environment, organic matter is oxidized to more stable substances.

Oxidation Pond : A term often used interchangeably with lagoon. Sometimes oxidation ponds are used after other wastewater treatment processes.

Ozone : A gaseous form of oxygen with three oxygen atoms per molecule, formed by electrical discharge in oxygen. It acts as a strong oxidizing agent and is used in water purification. Although considered a pollutant in the lower atmosphere where it is present in very small quantities, it forms a protective ozone layer in the upper atmosphere.

Parallel Mode : The operation of at least two cells of a multi-cell lagoon in a “side by side” direction equally dividing the flow between the two cells.

Parshall Flume : A flow-measuring device consisting of a specially configured channel section with a restrictive area called the throat. The depth of the water is measured at a stilling well just upstream from the narrow part of the throat. Then a chart is used to obtain flow rate.

Parts Per Million : acronym: ppm A measure of the concentration of a dissolved substance. A concentration of one part per million means one part of a substance is dissolved in a million parts of water. For practical purposes, this unit is equal tomilligrams per liter since one liter of water is equal in weight to one million milligrams.

Pathogenic : An organism which is capable of causing disease.

Pathogens : Microorganisms that can cause disease in other organisms or in humans, animals, and plants. They may be bacteria, viruses, or parasites. Pathogens are found in sewage, in runoff from animal farms, in rural areas populated with domestic and/or wild animals, and in water used for swimming. Fish and shellfish contaminated by pathogens, or the contaminated water itself, can cause serious illnesses.

Percolation : 1) The slow passage of water through a filter medium. 2) The gradual penetration of soil and rocks by water.

25 Perforated Interval : The vertical length of a well casing that is perforated with holes, measured from ground surface (e.g. 85-105 feet).

Perforation Type : The apertures in the well casing within the water-bearing formation can be drilled holes, slots cut into the casing, or a special screen in place of the casing material.

Permeability : Generally used to refer to the ability of rock or soil to transmit water.

Permeable : Said of rock or soils that have the ability to transmit water. pH : The numerical measure of hydrogen ion activity with a scale of 0 to 14. Neutral is pH 7; values below 7 are acidic, and values above 7 are alkaline.

Photosynthesis : A complex process in all green plants that contain chlorophyll. The process uses sunlight as energy to convert carbon dioxide and water into carbohydrates. As a by-product oxygen is released.

Piezometric Surface : The surface defined by the elevation above sea level to which water rises in a well that is open to the atmosphere. This is the same as a potentiometric surface.

Pipe Grade : The slope at which pipe is lying in the ground.

Pipette : A measuring instrument consisting of a graduated glass tube used to measure or transfer precise volumes of a liquid by drawing the liquid up into the tube.

Pitless Adapter : An adapter which attaches to the well casing and allows a submersible pump to discharge from below ground level. This eliminates the need for well pits or houses over the wellhead.

Plume : A concentrated mass of contaminants that can flow along the same path as ground water. The size and speed of a plume depends on the amount and type of contaminant, its solubility and density, and the velocity of the surrounding water.

Point of Application : The point at which a chemical is applied to water, after thorough mixing of the chemical into the water stream.

Point Sources : Well-defined sources of water pollution, as in a leaking underground storage tank or a discharge pipe from a sewage treatment plant.

Point-of-Use : acronym: POU

26 The treatment of water at the point it is used. A common example would be water treatment at the kitchen sink for drinking and cooking uses. Reverse osmosis, distillation and ozone are examples of POU treatment methods.

Point-of-Use Reverse Osmosis : acronym: POU-RO Describes a reverse osmosis water treatment device located where the water will be used. For example under a sink where water is treated for drinking.

Polishing Pond : A final lagoon cell after other treatment cells that completes the treatment or “polishes” the effluent. (See tertiary pond)

Pollutant : A substance that causes pollution.

Pollution : Change in the physical, chemical or biological properties of water and other substances that can adversely affect the health, survival or activities of humans and other living organisms.

Polymer : A chemical formed by the union of many monomers (a molecule of low molecular weight). Polymers are used with other chemical coagulants to aid in binding small suspended particles to larger chemical flocs for their removal from water.

Polyphosphate : A chemical compound, in the form of a salt or ester of polyphosphoric acid, used in water treatment to sequester (or tie up) other compounds or ions so they cannot be involved in chemical reactions.

Population Equivalent : The average BOD contribution from each person to a domestic wastewater. The accepted population equivalent is 0.2 pounds of BOD per person per day.

Population Loading : The number of persons served per acre of surface area of a wastewater lagoon.

Porosity : The ratio (usually expressed as a percentage) of the volume of openings in soils or rocks to the total volume of the soil or rock.

Positive (constant) Displacement Pump : A type of piston, diaphragm, gear or screw pump that delivers a constant volume with each stroke. They are often used as chemical solution feeders.

Positive Displacement Pump : Pumps that delivers a precise volume of liquid for each stroke of the piston or turn of the shaft.

Potable Water : Water that is safe for drinking and cooking.

Potassium Permanganate : acronym: KMnO4

27 An oxidant used to control taste and odors in raw water. Also helps to remove hydrogen sulfide, iron, and manganese, as well as, control trihalomethanes.

Potentiometric Surface : The surface defined by the elevation above sea level to which water rises in a well that is open to the atmosphere. This is the same as a piezometric surface.

Pounds Per Square Inch : acronym: psi A unit for measuring pressure. One psi equals the pressure resulting from a force of one pound force acting over an area of one square inch.

Poweder Activated Carbon : acronym: PAC Activated carbon in a fine powder form used primarily for removing organic compounds that cause taste and odor problems. It is usually added to water as a slurry.

Precipitate : 1) An insoluble, finely divided substance which is a product of a chemical reaction within a liquid. 2) The separation from solution of an insoluble substance.

Precipitation : 1) The process by which atmospheric moisture falls onto a land or water surface as rain, snow, hail, or other forms of moisture. 2) The chemical transformation of a substance in solution into an insoluble form (precipitate).

Precursors : Natural organic compounds found in all surface and ground waters. These compounds may react with halogens (such as chlorine) to form trihalomethanes (THMs); they must be present in order for THMs to form.

Pressure Head : The vertical distance in feet equal to the pressure in psi at a specific point. The pressure head is equal to the pressure in psi times 2.31 ft per psi.

Pressure Vacuum Breaker Assembly : acronym: PVB An assembly consisting of a loaded air inlet valve, an internally loaded check valve, two properly located test cocks, and two isolation valves.

Pressure Zones : Hydraulically defined areas of a distribution system which pull from a given storage reservoir or water source.

Pretreatment : Most often required of industries which discharge and treat their waste through publicly owned treatment works. The waste may be too toxic to be handled by the publicly owned treatment works.

Primacy : Primary enforcement authority granted to states for implementation and enforcement of federal regulations.

28 Primary Standard : An enforceable drinking water standard.

Programmable Control Module : acronym: PCM Used to monitor, control and report information from devices such as human-machine interfaces in treatment plants back to a main computer.

Protozoa : 1) A varied group of single-celled higher organisms (not bacteria). Many protozoans that are human pathogens can be transmitted through drinking water. Examples are Giardia and Cryptosporidium. 2) A form of microscopic animal that consumes individual bacteria and algae. Protozoa are divided into groups based on their method of movement through water such as amoeba, ciliated or free swimming, flagellated or stalked.

Protozoan : 1) A varied group of single-celled higher organisms (not bacteria). Many protozoans that are human pathogens can be transmitted through drinking water. Examples are Giardia and Cryptosporidium. 2) A form of microscopic animal that consumes individual bacteria and algae. Protozoa are divided into groups based on their method of movement through water such as amoeba, ciliated or free swimming, flagellated or stalked.

Public Notification : An advisory that EPA requires a water system to distribute to affected consumers when the system has violated MCLs or other regulations. The notice advises consumers what precautions, if any, they should take to protect their health.

Public Water Supply System : acronym: PWSS Defined by EPA as a system with 15 or more service connections or a system that serves 25 people a day for at least 60 days a year.

Pump Curves : Graphic plots of data which indicate the expected performance of a specific pump at specified head and flow conditions.

Pumping Water Level : acronym: PWL 1. The depth below ground surface of the water level in a well when the well is being pumped at a steady rate. 2. dynamic level - The vertical distance in feet from the centerline of the pump discharge to the level of the free pool while water is being drawn from the pool.

Radioactivity : The emission of alpha or beta particles, or gamma rays from a natural or man-made element. Radioactivity is a public health concern due to the cancer-causing potential of these particles and rays.

Radionuclide : Any man-made or natural element which emits radiation in the form of alpha or beta particles, or as gamma rays.

Ranney Collector : This water collector is constructed as a dug well from 12 to 16 feet (3.5 to 5 m) in diameter that has been sunk as a caisson near the bank of a river or lake. Screens are driven radially and 29 approximately horizontally from this well into the sand and the gravel deposits underlying the river.

Rate Structure : The technique or framework used to determine rates paid by customers who use water and wastewater systems.

Raw Water : 1) Water in its natural state, prior to any treatment. 2) Usually the water entering the first treatment process of a water treatment plant.

Reagent : A pure chemical substance that is used to make new products or is used in chemical tests to measure, detect, or examine other substances.

Receiving Stream : 1) The section of a stream, river or other surface water body which receives ground water discharging from an aquifer (same as gaining stream), or 2)receives treated wastewater from a wastewater treatment facility.

Recharge : 1) The process by which rain water (precipitation) seeps into the ground water system. 2) Replenishment of water in an aquifer.

Reclamation : The use of wastewater effluent for beneficial purposes, such as irrigating golf courses.

Regulatory Agency : The organization responsible for enforcing the Safe Drinking Water Act standards for drinking water or for enforcing the Clean Water Act standards for wastewater in a particular geographic area and with the authority to impose fines and other punitive measures.

Remote Terminal Unit : acronym: RTU An electronic data collection device designed for location at a remote site that communicates data to a host system by using telemetry (such as radio or dial-up telephone).

Repeat Samples : Bacteriological quality samples collected after receiving results that routine samples were unsatisfactory. These are also often referred to as "Check Samples".

Replacement Sample : Bacteriological quality samples collected to replace a routine sample which was too old (beyond the 30-hour sample-to-analysis time limit) or had interference from heterotrophic plate count bacteria.

Residual : The quantity left over at the end of a process. For example, residual chlorine is the amount of free and/or available chlorine remaining after a given contact time under specified conditions.

Reverse Osmosis : acronym: RO A water treatment method used to remove dissolved inorganic chemicals and suspended particulate matter from a water supply. Water, under pressure, is forced through a semi- 30 permeable membrane that removes molecules larger than the pores of the membrane. Large molecules are flushed into waste waters. Smaller molecules are removed by an activated carbon filter.

Riprap : Rocks and other rock-like material used along the shores of wastewater lagoon dikes to prevent erosion.

Rotifer : A form of microscopic animal that feeds on algae and bacteria. Rotifers require aerobic conditions.

Routine Coliform Monitoring : Periodic, usually monthly, bacteriological quality monitoring required of all public water supply systems.

Safe Drinking Water Act : acronym: SDWA An Act passed by Congress in 1974. The Act establishes a cooperative program among local, state and federal agencies to insure safe drinking water for consumers.

Sample Site Plan : Bacteriological sample collection location plans required of all community public water supply systems which identify the locations used for routine monitoring and any necessary repeat monitoring.

Sample Tap : A tap upstream of any customer connection, typically in the pump house, for the purpose of collecting periodic samples of water for chemical and microbiological analysis. If the water is treated there should be sample taps to collect both raw and treated water.

Sanitary Sewer : A wastewater collection system that carries only domestic wastewater.

Sanitary Survey : An on-site review of the water sources, facilities, equipment, operation, and maintenance of a public water system for the purpose of evaluating the adequacy of the facility for producing and distributing safe drinking water.

Saturated Zone : The area below the water table where all open spaces are filled with water.

Saturation : Oxygen saturation is the concentration of free dissolved oxygen in water that is in equilibrium with atmospheric oxygen. It varies with both temperature and atmospheric pressure. Saturation is measured in mg/L.

Secondary Interstices : Openings or spaces in rock or soil that developed after the rock was formed. Examples include joints, fractures and solution openings.

Secondary Maximum Contaminant Level : acronym: SMCL

31 Non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. However, states may choose to adopt them as enforceable standards.

Secondary Treatment : A biologic treatment and sedimentation process that follows primary treatment. Typically the process converts dissolved and/or suspended solids into a form easily separated from the water portion of the wastewater.

Sedimentation : A water treatment process in which solid particles settle out of the water being treated in a large clarifier or sedimentation basin.

Seepage Pit : A seepage pit is similar to a cesspool in construction consisting of a large pit lined with concrete rings, or porous masonry block to support the walls of the pit, and a surrounding bed of gravel. The difference is, only effluent that has come from a septic tank enters a seepage pit. A cesspool has no septic tank prior to it.

Semi-Consolidated : A term used to describe geologic formations which are partially cemented such as some limestone and sandstones.

Semi-Consolidated Deposits : Geologic materials that are partially cemented such as limestones and sandstones; usually occurring at a depth below the ground surface.

Septic : A condition that exists when there is no dissolved oxygen (see anaerobic) in the wastewater. Anaerobic bacteria and other microorganisms continue to use parts of the waste for food, but produce foul odors and black colored water that is slightly acidic. Waste stored in septic tanks is an example.

Sequestering Agent : A chemical agent used to prevent precipitation of some metals (such as iron and manganese) from water.

Series Mode : The operation of a multi-cell lagoon in which wastewater flows from one cell to another cell to another cell. The first cell is called the primary cell. Subsequent cells are called secondary cells and the final cell is called the polishing or tertiary cell.

Settleable Solids : Suspended solids with enough mass and density to be pulled out of suspension by gravity under quiescent conditions.

Sewage : The used water and water-carried solids from homes and businesses that flow to a wastewater treatment plant. The preferred term is wastewater.

Short-Circuiting : A condition within a lagoon system in which untreated wastewater travels the shortest path between the influent and effluent points. 32

Significant Industrial User : A non-domestic wastewater generator that discharges more than 25,000 gallons per day of industrial waste, or is subject to specific categorical pretreatment standards under the Part 403 regulations of the Clean Water Act.

Slow Sand Filtration : A process involving passage of raw water through a bed of sand at low velocity (generally less than 0.4 m/h) resulting in substantial particulate removal by physical and biological mechanisms.

Sludge : 1) The settleable solids separated from wastewater during treatment. 2) The settled particles which fallout of water in the sedimentation basin during the water treatment process.

Sludge Blanket : A layer of sludge found on the bottom of a wastewater lagoon.

Sludge Judge : A clear cylindrical device for collecting a water/sludge core from a lagoon. When removed from the pond, the device contains a sample cross-section of the pond core, showing the depth of the sludge solids.

Sodium : acronym: Na An inorganic chemical element (Na) commonly found in table salt and some natural waters. High sodium concentrations in water may be of concern to persons on sodium restricted diets.

Sodium Hypochlorite : acronym: NaOCl One of several forms of chlorine which is commonly used for chlorination of public water supply and wastewater treatment systems. Sodium hypochlorite is available in about a 6.5 percent chlorine solution.

Source Water : Water in its natural state, prior to any treatment for drinking.

Source Water Protection : acronym: SWP Programs for protection of watersheds and well head protection zones intended to identify, control, and thereby reduce the potential for contamination or degradation of sources of drinking water.

Special Samples : Bacteriological quality samples collected for reasons other than compliance monitoring. Examples would be samples collected to check the quality of water in a repaired main or new storage tank before the water therein is returned to service.

Specific Capacity : A measure of the productivity of a well, expressed as the reliable yield divided by the drawdown (gpm/foot).

Specific Gravity : acronym: S.G. 33 The weight of a particular volume of any substance compared to the weight of an equal volume of water at a reference temperature (usually 4 degrees Celsius).

Spectrophotometer : An instrument used to measure the amount of light reflected from a water sample when illuminated by a controlled light source. This measurement of reflected light can then be used to calculate the amount of a given substance in the water sample.

Stabilization Pond : A treatment system with two or more cells or individual ponds that receive raw untreated wastes. In these ponds the wastes undergo stabilization, where biodegradable materials are converted into more stable materials.

Static Head : Includes the suction lift and the discharge static head, which is the difference in elevation between the pump reference line and the discharge to the treatment system or gravity flow line.

Static Water Level : acronym: SWL The elevation or level of the water table in a well when the pump is not operating, or the elevation to which water would rise in a tube connected to an artesian aquifer, basin, or conduit under pressure.

Sterilization : The removal or destruction of all microorganisms.

Stratification : The formation of separate layers in a lake, reservoir, or wastewater lagoon. Each layer has uniform temperature, plant, or animal life.

Submerged Intake : A physical structure anchored to the bottom within a body of water used to draw water directly from near the bottom of the water source.

Submersible Pump : A vertical turbine pump with the motor placed below the impellers. The motor is designed to be submersed in water.

Subsidence : The dropping or lowering of the ground surface as a result of removing excess water (overdraft or pumping) from an aquifer. After excess water has been removed, the soil will settle and become compacted and the ground surface will drop and cause the settling of underground utilities.

Suction Line : 1) The line through which water enters a pump. 2) That on the "suction side" of the pump.

Sulfide : Also referred to as hydrogen sulfide gas (H2S). It is a colorless gas with the distinct smell of rotten eggs.

Supernatant : Liquid removed from settled sludge. Supernatant commonly refers to the liquid between the sludge on the bottom and the water surface of a basin or container. 34

Supervisory Control and Data Acquisition : Acronym: SCADA A common process control application that collects data from sensors located throughout the treatment and/or collection or distribution system and then sends the data to a central computer for management and control.

Surface Impoundment : Relatively shallow ponds or lagoons used by industries and municipalities to store, treat, and dispose of liquid wastes.

Surface Intake : A physical structure within a body of water used to divert water from the water source into a manmade channel.

Surface Water : Water above the surface of the ground including, however not limited to, lakes, rivers, streams, wetlands, wastewater, flood water, and ponds.

Surface Water Treatment Rule : acronym: SWTR A federal regulation specifically targeting removal of particulates and control of pathogenic organisms (such as Giardia Lamblia) encountered in surface water supplies and ground water under the direct influence of surface water.

Suspended Solids : 1:Solid material so finely divided or light in weight that it does not settle, but can be filtered in a laboratory test and weighed. Also referred to as Total Suspended Solids or TSS. 2:Solids that either float on the surface or are suspended in water or other liquids, and which are largely removable by laboratory filtering.

Suspended Water : Underground water held in a zone of aeration by molecular attraction exerted on water by rock and earth materials and by attraction exerted by water particles on one another. Sometimes referred to as vadose water.

Synthetic Organic Compound : Man-made substance whose molecules contain one or more (often many more) carbon atoms.

Ten-State Standards : Publications known as the Ten-State Standards. One is "The Recommended Standards for Water Works" and the other is "The Recommended Standards for Wastewater Facilitites" published by the Great Lakes-Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers, is a commonly used guide for good engineering practices.

Tertiary Pond : The final pond used in a series of treatment ponds to treat wastewater by removing nutrients prior to discharge back to the receiving stream. (see polishing pond)

Tertiary Treatment : Follows primary and secondary treatment processes to treat the wastewater by removing waste materials, such as nutrients, insufficiently removed in prior treatment processes. This process is usually employed when the water is going to be reused or cannot otherwise meet discharge permit requirements. 35

Test Pump Rate : The flow from a new well during test pumping, measured in gallons per minute.

Thrust Block : A concrete wedge placed between a fitting and the trench wall, used to transfer the force from the fitting to the trench wall. This prevents the fitting from being pushed away from the pipe.

Time of Travel : The time required for a contaminant to move in the saturated zone from a specific location to another, typically to a well.

Titrant : A solution of known concentration which is added (titrated) to another solution to determine the concentration of a chemical species in the second solution. The chemical concentration is calculated by determining how much titrant was used and performing the proper calculation.

Titrator : The instrument used when adding a titrant to another solution to determine the concentration of a chemical species in the second solution. The chemical concentration is calculated by determining how much titrant was used and performing the proper calculation.

Total Coliform Bacteria : A group of indicator bacteria used to detect the possible contamination of water by pathogenic organisms.

Total Dynamic Head : acronym: TDH Is equal to the sum of the static head, friction head and pressure head put upon a pump.

Total Residual Chlorine : The amount of available chlorine remaining after a given contact time. The sum of the available residual chlorine and the free available residual chlorine combined.

Total Suspended Solids : acronym: TSS A test used to measure the amount of filterable solids in wastewater.

Totalized Flow : The flow that passes through a meter over a known period of time.

Toxic : A substance that is poisonous to an organism.

Transient Non-Community Water System : acronym: TNCWS Non-community water systems that do not serve 25 of the same nonresident persons per day for more than six months per year.

Transmission Line : A pipeline that transports raw water from its source to a water treatment plant, or treated water from the plant to the distribution system.

36 Transmissivity : The capacity of an aquifer to transmit water. It is dependent on the water-transmitting characteristics of the saturated formation (hydraulic conductivity) and the saturated thickness.

Trihalomethanes : A group of chemical compounds which are known or suspected cancer-causing agents. They are typically formed as byproducts of the disinfection process.

True Color : Color remaining in water after particles have been filtered from the water sample. True color is composed of color-causing dissolved constituents.

Tuberculation : The development or formation of small mounds of corrosion products (rust) on the inside of iron pipe. These mounds (tubercules) increase the roughness of the inside of the pipe thus increasing resistance to water flow.

Turbidimeter : An instrument for measuring and comparing the turbidity of liquids by passing light through them and determining how much light is reflected by the particles in the liquid. The normal measuring range is 0 to 100 and is expressed as Nephelometric Turbidity Units (NTUs).

Turbidity : acronym: TU The cloudy appearance of water caused by the presence of suspended and colloidal matter.

Turbidity Unit : acronym: TU A measure of the cloudiness of water. TUs are an empirical quantity which is based on the amount of light that is scattered by particles of a polymer reference standard called formazine which produces particles that scatter light in a reproducible manner. TUs are measured by using an instrument called a nephelometer. A nephelometer passes light through a sample and the amount of light deflected is then measured. (also referred to as NTU)

Typhoid : An acute infectious disease caused by the typhoid bacillus Salmonella typhi. The bacillus is transmitted by milk, water, or solid food contaminated by feces of typhoid victims or of carriers, that is, healthy persons who harbor typhoid bacilli without presenting symptoms.

Typhoid Fever : Acute infectious disease caused by the typhoid bacillus Salmonella typhi. The bacillus is transmitted by milk, water, or solid food contaminated by feces of typhoid victims or of carriers, that is, healthy persons who harbor typhoid bacilli without presenting symptoms.

Ultraviolet : Radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays.

Ultraviolet Light : acronym: UV Radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays. The sun is an important source of ultraviolet light. This radiation can be used for disinfection of drinking water but has no residual effect.

37 Unaccounted-for Water : The difference between the amount of water pumped into the distribution system and the total amount of water recorded as passing through customer meters.

Unconfined Aquifer : An aquifer containing water that is not under pressure; the water level in the well is the same as the water table outside the well.

Unconsolidated Deposit : Deposits composed of loose rock or mineral particles of varying sizes. Examples include clay, silt, sand and gravel.

Undercurrent : Lower than standard line current.

Unsaturated Zone : The area between the land surface and water table in which the pore spaces are only partially filled with water. Also called "zone of aeration".

Variable Displacement Pump : Pumps for which as head increases, the flow from the pump decreases. Examples include centrifugal, jet, and air lift pumps.

Variance : A state-granted relief for a public water supply system which allows the system to not meet a specific MCL if certain conditions exist. The conditions include installation of best available technology which fails to treat the water to the level required by the MCL and that there not be any unreasonable risk to public health as a result of the variance.

Vectors : Organisms by which disease can be transmitted from one organism to another.

Velocity : The direction and speed of motion.

Violation : A failure to meet any state or federal drinking water or wastewater regulation.

Virus : A microorganism, smaller than bacteria, which can not grow or reproduce apart from a living cell. Viruses are common to many human infections and some rare diseases, from the common cold (rhinovirus) to AIDS (human immunodeficiency virus).

Volatile Organic Compound : acronym: VOC An organic compound which readily vaporizes at a relatively low temperature.

Wastewater : Water that is used to carry human-made waste products from homes, schools, commercial establishments and industrial businesses.

38 Water Hammer : The sound like someone hammering on a pipe that occurs when a valve is opened or closed very rapidly. It is caused by the rise and fall of water pressure caused by the rapid change in valve position.

Water Rights : The rights acquired under law, to use the water accruing in surface water or ground water, for a specific purpose in a given manner and usually within the limits of a given time period.

Water Table : 1) The level of ground water. 2) the upper surface of the zone of saturation.

Waterborne : Transmitted in water or transported by water.

Waterborne Disease : Disease that arises from infected water and is transmitted when the water is used for drinking or cooking (for example, cholera or typhoid).

Watershed : The land area that drains into a stream or river. An area that contributes runoff to a specific delivery point.

Weir : A wall or plate placed in an open channel and used to measure the flow of water. The depth of the flow over the weir can be used to calculate the flow rate or a chart or conversion table may be used. A weir can also be defined as a wall or obstruction used to control flow to assure uniform flow rate and avoid short-circuiting.

Well Cap : A device installed on the terminal end of a well casing which prevents entry of insects, rodents and precipitation to the well.

Well Log Report : The report submitted by the driller to the pertinent state agency, concerning a well just completed. Contains a descriptive geological profile, notes on water occurrence in the borehole, and a description or diagram of the well casing and screen.

Well Seal : A type of well cap intended for use indoors. The seal has a rubber gasket which fits inside the well casing and is held in place by metal plates.

Well Slab : The concrete pad surrounding a wellhead designed to prevent surface water from flowing down the outside of the well casing.

Well Vent : A down turned, screened opening to the well casing which allows entry of air during drawdown and release of air during water table recovery. It serves the important role of preventing contaminants from being sucked into the well during creation of a vacuum during drawdown, and prevents uncontrolled release of air when the water table recovers and air is forced out of the casing.

39 Well Yield : The quantity of water pumped from a well per unit of time, usually in gallons per minute (gpm).

Well-Mixed : A sample that is acquired in an area of high turbulence so that the volume sampled is representative of the whole flow.

Wellhead : 1) The area immediately surrounding the top of a well or the top of a well casing. 2) The physical structure, facility, or device at the land surface from or through which ground water flows or is pumped from subsurface, water-bearing formations.

Wellhead Protection Area : The surface and subsurface area surrounding a water well or well field supplying a public water system through which contaminants are reasonably likely to move and reach the water well or well field.

Wellhead Protection Program : acronym: WHPP A pollution prevention and management program established in 1986 by the SDWA to protect underground based sources of drinking water. The law specified that certain program activities, such as delineation, contaminant source inventory, and source management, be incorporated into State Wellhead Protection Programs, which are approved by EPA prior to implementation.

Wilson's Disease : An inherited disorder which causes the body to absorb and retain excessive amounts of copper. Excess copper can deposit in the liver, kidneys, brain and eyes. Liver failure and damage to the central nervous system are the most common and dangerous effects of this disorder.

Yield : The quantity of water (expressed as a rate of flow - GPM, GPH, GPD, or total quantity per year) that can be collected for a given use from surface or ground water sources. The yield may vary with the use proposed, with the plan of development, and also with economic considerations.

Zone of Contribution : The area of the aquifer that recharges the well.

Zone of Influence : The land area above the cone of depression of a well which contributes ground water to the production well.

Zone of Soil Moisture : The zone extending from the surface soil to the intermediate zone where little movement occurs except when rain or snow sends a new wave of moisture into this unsaturated zone.

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