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89 Cards in this Set
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- Back
Acid rain |
Precipitation that has been rendered (made) acidic by airborne pollutants |
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Algae (3) |
Microscopic plants containing chlorophyll that live floating or suspended in water. They also may be attached to structures rocks or other submerged surfaces.
Excess algal growths can impart tastes and odours to potable water. Algae produce oxygen during sunlight hours and use oxygen during the night hours.
Their biological activities appreciably affect the pH, alkalinity, and dissolved oxygen of the water |
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Algal bloom |
Sudden, massive growths of microscopic and macroscopic plant life, such as green or blue-green algae, which develop in lakes, reservoirs, and lagoons under the proper conditions |
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Anaerobic |
A condition in which atmospheric or dissolved oxygen (DO) is not present in the aquatic (water) environment |
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Aquifer |
A natural, underground layer of porous, water-bearing materials (sand, gravel) usually capable of yielding a large amount or supply of water |
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Back pressure |
A pressure that can cause water to backflow into the water supply when a user's water system is at a higher pressure than the public water system |
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Backflow |
A reverse flow condition, created by a difference in water pressures, that causes water to flow back into the distribution pipes of a potable water supply from any source or sources other than an intended source. Also see backsiphonage |
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Backsiphonage |
A form of backflow caused by a negative or below atmospheric pressure within a water system. Also see backflow |
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Capillary action |
The movement of water through very small spaces dye to molecular forces |
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Capillary fringe |
The porous material just above the water table that may hold water by capillarity (a property of surface tension that draws water upward) in the smaller void spaces |
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Carcinogen |
Any substance that tends to produce cancer in an organism |
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Chloramines |
Compounds formed by the reaction if hypochlorous acid (or aqueous chlorine) with ammonia |
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Cross-connection |
A connection between a drinking (potable) water system and an unapproved water supply or between a storm drain system and a sanitary collection system. Less frequently, a connection between two sections of a collection system to handle anticipated overloads of one system |
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Direct runoff |
Water that flows over the ground surface directly into streams, rivers, or lakes. Also called storm runoff. |
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Electrochemical reaction |
Chemical changes produced by electricity (electrolysis) or the production of electricity by chemical changes (galvanic action). In corrosion, a chemical reaction us accompanied by the flow of electrons through a metallic path. The electron flow may come from an external force and cause the reaction, such as electrolysis caused by a direct current (DC) electric railway, or the electron flow may be caused by chemical reaction, as in the galvanic action of a flashlight dry cell |
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Entrain |
To trap bubbles in water either mechanically through turbulence or chemically through a reaction; or to trap one substance or material by another substance or material |
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Head |
The vertical distance, height, or energy of water above a reference point. A head of water may be measured in either height (feet or meters) or pressure (pounds per square inch or kilograms per square centimeter). Also see discharge head, dynamic head, static head, suction head, suction lift, and velocity head. |
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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 |
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Interface |
The common boundary layer between two substances, such as water and solid (metal); or between two fluids, such as water and a gas (air); or between a liquid (water) and another liquid (oil) |
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Macroscopic organisms |
Organisms big enough to be seen by the eye without the aid of a microscope |
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Overturn |
The almost spontaneous mixing of all layers of water in a reservoir or lake when the water temperature becomes similar from top to bottom. This may occur in the fall/winter whether surface waters cool to the same temperature as the bottom waters and in the spring when the surface waters warm after the ice melts. Also called turnover. |
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Palatable |
Water at a desirable temperature that is free from objectionable tastes, odours, colors, and turbidity. Pleasing to the senses. |
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Potable water |
Water that does not contain objectionable, pollution, contamination, minerals, or infective agents and is considered satisfactory for drinking |
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Raw water |
Water in it's natural state, before any treatment, especially as it enters the first treatment process of a water treatment plant |
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Soft water |
Water having a low concentration of calcium and magnesium ions. According to US Geological Survey guidelines, soft water is water having a hardness of 60 milligrams per liter or less |
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Stratification |
The formation of separate layers (of temperature, plant life, or animal life) in a lake or reservoir. Characteristics within each layer are similar; for instance, all water in the same layer has the same temperature. Also see thermal stratification. |
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Subsidence |
The dropping or lowering of the ground surface as a result of removing excess water (overdraft or overpumping) from and aquifer. After excess water has been removed, the soil will settle, becoming compacted, and the ground surface will drop, which can cause the settling or underground utilities |
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This (trihalomethanes) |
Derivatives of methane, CH4, in which three halogen atoms (chlorine or bromine) are substituted for three of the hydrogen atoms. Often formed during chlorination by reactions with natural organic materials in the water. The resulting compounds (THMs) are suspected of causing cancer. |
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Topography |
The arrangement of hills and valleys in a geographic area |
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Transpiration |
The process by which water vapour is released to the atmosphere by living plants. This process is similar to people sweating. Also called evapotranspiration |
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Turbidity |
The cloudy appearance of water caused by the presence of suspended and colloidal matter. In the waterworks field, a turbidity measurement is used to indicate the clarity of water. Technically, turbidity is an optical property of the water based on the amount of light reflected by suspended particles. Turbidity cannot be directly equated to suspended solids because white particles reflect more light than dark-coloured particles and many small particles will reflect more light than an equivalent large particle. |
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Tubercle |
A crust of corrosion products (rust) that builds up over a pit caused by the loss of metal due to corrosion |
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Vortex |
A revolving mass of water that forms a whirlpool. This whirlpool is caused by water flowing out of a small opening un the bottom of a basin or reservoir. A funnel-shaped opening is created downward from the water surface. |
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Water cycle |
The process of evaporation of water into the air and its return to earth by precipitation (rain or snow). This process also includes transpiration from plants, groundwater movement, and runoff into rivers, streams, and the ocean. Also see hydrologic cycle. |
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Water table |
The upper surface of the zone of saturation of groundwater in an unconfined aquifer |
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Why has it become necessary to conserve and properly budget our water sources? |
Because water is a limited resource and it's sustainability is essential to the planet's survival |
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How are water shortages and energy consumption linked together? |
As groundwater levels fall, more energy is required to pump water from deeper levels of the basin. |
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Why do many sources of water need treatment? |
To remove contaminants and provide potable water to the end consumer |
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Name three ways groundwater may become contaminated? |
Seawater contamination Seepage from septic tank leeching systems Agricultural drainage systems Improper disposal of hazardous wastes in sanitary landfills and dumps Surface runoff into poorly constructed wells |
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List the 2 major sources of water supplies. |
Groundwater Surface water |
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What is the water (hydrologic) cycle? |
Is the natural movement of water through means of runoff, evaporation, transpiration, condensation and precipitation. |
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What are the general water quality characteristics of surface water supplies? |
Low calcium and magnesium content (soft water) Turbidity Suspended solids Some colour Microbial contamination |
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What items should be considered before selecting a location and constructing a water supply intake located in a river or stream? (7) |
Upstream pollution River bottom scouring Changing channels Design of intake to withstand floods Heavy silting Ice Adverse runoff
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How can provisions be made to allow recreation on water supply lakes and reservoirs without endangering water quality? |
Requires proper construction and location of: Boat launching ramps Boat harbours Picnic and camping areas Fishing Open beach areas away from intake area Wastewater collection, treatment and disposal facilities |
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What are the general water quality characteristics of ground water supplies? |
High concentration of dissolved solids Dissolved gases Hard water No suspended solids No microbial contamination (usually) |
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What causes the flow of groundwater within an aquifer? |
Difference in head (energy) between two locations (for example, a higher area of recharge and a lower area of recharge) |
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How can the sustained yield of an aquifer be exceeded? |
By pumping at a rate that exceeds the rate of replacement. |
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List some of the possible uses of reclaimed wastewater? |
Greenbelt (parks) areas Golf course irrigation Industrial reuse Groundwater recharge (possible exception) Landscape impoundments Wetlands/marsh enhancement
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How much treatment should reclaimed water receive before use? |
Should be appropriate for the intended use. The greater the potential risk to the public, the more extensive the treatment needs to be according to the regulatory agency. |
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Why have water quality standards been prepared and used by the waterworks industry? |
To provide quality control and ensure the acceptability of the product. |
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Drinking water quality standards can generally be categorized as being related either to _______ or _______. |
Health or Aesthetics |
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MCL stands for what three words? |
Maximum Contaminant Levels |
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Water quality is the general term used to describe which characteristics of a water supply (3)? |
Composite chemical physical biological |
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A domestic water supply is considered to be of good quality when it meets what guidelines or criteria (4)? |
Free of disease-causing organisms and toxic chemicals Attractive in taste and appearance Chemical composition produces no corrosive or scale-forming effects on water distribution system Satisfies requirements of domestic and industrial consumers |
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What are the consequences of delivering poor quality water to the consumer(2)? |
Not acceptable to consumer because of it's appearance or taste Illness or death |
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What are trihalomethanes (THMs)? |
Derivatives of methane CH4 in which three halogen atoms (chlorine or bromine) are substituted for three of the hydrogen atoms. Often formed during chlorination by reactions with natural organic materials in the water. The resulting compounds (THMs) are suspected of causing cancer. |
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What physical qualities of water are important to the consumers (6)? |
Colour Turbidity Taste Odour Temperature Macroscopic organisms |
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Where might contamination of water occur (4)? |
At source of supply Water treatment plant Distribution system storage facilities Water mains |
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How can water quality be degraded in the distribution system (9)? |
Cross-connections Corrosion Biological growth and activity High temperatures Unusual flows Time in system Dead ends Age of facilities Operational procedures |
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Why are natural source waters never completely pure (9)? |
During precipitation and their passage over or through the ground, they can acquire a wide variety of dissolved or suspended impurities |
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How can surface waters become contaminated or degraded? |
Decaying vegetationMinerals in soilsWaste discharges and spillsRefuse disposalRecreationConstructionAnimal activitiesAlgae growth and weedsRadioactive fallout |
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How can groundwater become contaminated or degraded (8)? |
Poorly constructed wells Surface water moving above the groundwater table Contaminants at or near the ground surface Leaching from wastewater operations or disposals Spills Humic materials Flood waters Passage through mineralized formations |
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What problems can be created by improper chlorination in water treatment plants (3)? |
Pathogenic organisms entering the distribution system
Formation of trihalomethanes Tastes and odours |
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What is the most frequently reported cause of water-borne disease outbreaks in the United states? |
Backflow of unacceptable substances through cross-connections to distribution systems |
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How can corrosion cause health problems? |
Heart disease caused by elevated levels of lead, cadmium, copper, zinc, asbestos and certain organic compounds found in water being served from distribution systems as a result of corrosive action. |
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Slime growths can cause what problems in distribution systems? |
Tastes and odours Accelerated corrosion Reduced flow |
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Which form of chlorine is most effective against biofilms? |
Chloramines |
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What impacts does water temperature have on distribution system water quality? |
High temperatures tend to speed the rate of chemical reactions and increase biological growth rates. Biological decomposition may be intensified by summer temperatures, and chlorine demand may be considerably greater so residuals will not carry as far in the distribution system in summer |
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What problems can be caused by low flows? |
Changes in water velocity and flow reversals can result in sediments being stirred up and carried along until they reach the consumer Low circulation and stagnant water can result in the growth of organisms, formation of sediment and corrosion products, depletion of oxygen, and increased tastes and odours Turbulence can entrain air into the supply causing milky water |
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How is water affected by length of time it remains in a distribution system? |
The longer water remains in the system, the more time is available for chemical and biological changes to take place |
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What problems can develop as transmission and storage facilities become older (3)? |
More maintenance Gradual deterioration in protection against corrosion can lead to water quality issues Ruptures in pipes become more frequent |
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What problems can develop at the interface where distribution pipe and water meet? |
Reduced flows permit greater chemical and biological activity at the interface where the pipe and water meet. |
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Why may chlorination treatment not be effective at the dead end of a water main? |
Because of increased chlorine demand by organics, biological forms, and corrosion products |
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What is the major quality concern regarding coal tar-lined pipe or plastic pipe? |
The possibility of leaching of material from the pipe or the lining by the water. |
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How can water be protected from contaminants that enter the system during construction of new mains and repair of old mains? |
To ensure the safety of the delivered water, proper protective, cleaning, and disinfection practices must be followed. When lines are being repaired, keep the hole dewatered to prevent possible contamination of the water line. After repair, flush the line downstream. After flushing, disinfect the line before being returned to service. |
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What is the purpose of air valves (or some form of air bleed valve)? |
They are important to relieve entrapped air and to help prevent milky water and surge problems when lines are being filled. |
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What problem might result from hydrant testing and flushing programs? |
Dirty water complaints |
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How can open reservoirs become contaminated? |
Vandalism Windblown and atmospheric contaminants Animals including birds and rodents Illegal bathing Fishing |
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Why can a poorly constructed reservoir roof be worse than no roof at all in terms of contamination? |
Bird droppings, dust and other materials that accumulate and roof gets washed into the reservoir. |
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What are some of the problems associated with below-ground reservoirs? |
Subject to contamination by leaching through cracks in side walls Nearby septic systems or wastewater facilities are of special concern Susceptible to flooding by surface stormwater and windblown contamination Easier to vandalize |
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Why should the water level in storage facilities not be allowed to get too low? |
A vortex will be formed in the water being discharged. Air may be entrained or materials that have settled ro the bottom of the reservoir may be stirred up and get into the mains and the customers' service lines. |
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Why is there a need for water system operators? |
Needed to operate, maintain, repair, and manage water distribution systems, as well as interact with the public they serve. Responsible to deliver safe and pleasant drinking water from their systems. Responsible for the health and well-being of the community served by the water system |
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What influences the knowledge and skills operators are required to have for their jobs? |
The size and type of water distribution system |
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Who hires water system operators (4)? |
City Water agency or district Private utility company Large industries that operate their own water system facilities |
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Why should water system operators discuss proposed facilities with engineers? |
Your jobs is to discuss with the engineer how these new facilities could be operated, maintained, and repaired. Make suggestions on how these jobs could be done more easily Be sure there is adequate room for maintenance and repair equipment, even insuring adverse weather conditions |
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Why are adequate and reliable records very important? |
Without adequate, reliable records of important phases of operation and maintenance, the effectiveness of your operation has not been documented (recorded). Also, accurate records are required by regulatory agencies for compliance with the drinking water regulations of the Safe Drinking Water Act |
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To whom might you have to explain the purpose and operation of your facilities? |
Civic organizations School classes Representatives of news media City council members or directors |
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Why is the appearance of pump stations and elevated tanks and the grounds around them important? |
If facilities are run down and unkempt, you will be unable to convince the public that you are going a good job. |
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Why is safety important? |
Work in traffic and excavating for the installation or repair of pipes can be extremely hazardous. Explosive conditions can develop when painting the inside of an elevated tank if adequate ventilation is not provided Most accidents result from carelessness or negligence. |