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80 Cards in this Set
- Front
- Back
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Name 2 forms of chlorine used for disinfection |
-Chlorine Gas -Liquid Chlorine/Bleach/Sodium Hypochlorite -Solid Chlorine/Tablets/Calcium Hypochlorite |
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Surge tanks are used mainly for what purpose?
a) To control water hammer b) To keep the system under pressure c) To prevent corrosion d) To store water |
a) To control water hammer b) To keep the system under pressure c) To prevent corrosion d) To store water |
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In a water distribution system, what is a booster pump used for?
a) To boost the elevation of underground tanks b) To increase flow to a water treatment plant c) To increase the pressure in the mains on the discharge side of the main pump d) To pump water during power outages |
a) To boost the elevation of underground tanks b) To increase flow to a water treatment plant c) To increase the pressure in the mains on the discharge side of the main pump d) To pump water during power outages |
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Calculate the volume in gallons of a full cylindrical tank that is 10 feet in diameter and 20 feet tall. |
Area = Diameter squared x 0.785 Volume = Area x Height =(0.785)(10ft)(10ft)(20ft) = 1,570 square ft x 7.48 = 11,743.6 gallons
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What are clear wells used for?
a) For the storage of clear water only b) For the storage of filtered water from a treatment plant c) For the storage of water from wells d) For the storage of water under pressure |
a) For the storage of clear water only b) For the storage of filtered water from a treatment plant c) For the storage of water from wells d) For the storage of water under pressure |
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True or False?
Centrifugal pumps operate with the impeller above the water surface |
True |
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How many pounds of 15% sodium hypochlorite are needed to disinfect a 750,000 gallon storage tank if the desired chlorine dose is 2mg/l? |
lbs = (Vol. x Concentration x 8.34)/ % (0.75 Million Gallons x 2mg/l x 8.34) / 0.15 = 83.4lbs |
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Convert 750,000 gallons to cubic feet |
750,000/7.48 = 100,267.38 cubic feet |
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True or False?
Standpipes can provide large volumes of water at high pressure |
False |
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True or False?
The warmer the water, the faster the chemical corrosion reactions. |
True |
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A pressure gauge on a pipe reads 32 PSI. Convert this reading to feet of head. |
1 psi = 2.31 ft of head 3.2 psi x 2.31 = 73.92 ft of head |
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What is tuberculation?
a) A chemical treatment process b) Corrosion productions that build up inside a metal pipe c) A dermal irritation caused by exposure to chlorine d) Damage to pipe exterior caused by poor backfill material |
a) A chemical treatment process b) Corrosion productions that build up inside a metal pipe c) A dermal irritation caused by exposure to chlorine d) Damage to pipe exterior caused by poor backfill material |
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True or False?
Prestressed concrete pope is rated for pressure (200PSI) applications |
True |
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The size and mass of a thrust block is based on all of the following except
a) Pipe line pressure b) The fitting to be protected c) Pipe line water quality d) Soil type |
a) Pipe line pressure b) The fitting to be protected c) Pipe line water quality d) Soil type |
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Water mains parallel to sanitary sewers must be installed at least...
a) 10 feet horizontally away from sewer and 1 foot lower b) 5 feet horizontally away from sewer and 1 foot lower c) 10 feet horizontally away from sewer and 1 foot higher d) 10 feet horizontally away from sewer and 3 foot lower |
a) 10 feet horizontally away from sewer and 1 foot lower b) 5 feet horizontally away from sewer and 1 foot lower c) 10 feet horizontally away from sewer and 1 foot higher d) 10 feet horizontally away from sewer and 3 foot lower |
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Which of the following is not true. Transmission mains generally
a) Have no service connections b) Are large diameter piping c) Connect the source of supply with the distribution system d) Have service connections to all properties along its route |
a) Have no service connections b) Are large diameter piping c) Connect the source of supply with the distribution system d) Have service connections to all properties along its route |
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True or False
Booster pumps are installed directly on the mains and are designed to increase the available pressure. |
True |
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What is the actual leakage rate in GPD/Mile-Inch from a new section of pipe is the leakage over a 48 hour period was 24 gallons? The pipe section tested was 1.5 miles long and the diameter is 2 feet. |
24gal/48hr = 12gal/day 12GPD/1.5milesx24inches = 12/36 = 0.33GPD/mi-in |
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What is backsiphonage? a) The top layer when backfilling a trench b) The drain flow when emptying an elevated storage tank c) Backflow caused by negative or very low pressure in a water system d) High pressure in the water main |
a) The top layer when backfilling a trench b) The drain flow when emptying an elevated storage tank c) Backflow caused by negative or very low pressure in a water system d) High pressure in the water main |
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Before you dig or excavate, you must call
a) 911 b) 811 c) City hall d) Your supervisor |
a) 911 b) 811 c) City hall d) Your supervisor |
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What conditions cause water hammer? |
Pumps starting or stopping too quickly, or valves opening or shutting too abruptly. |
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Surge tanks are used for what purpose?
a) To keep the system under pressure b) To control water hammer c) To store water d) To prevent corrosion |
a) To keep the system under pressure b) To control water hammer c) To store water d) To prevent corrosion |
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How many pounds of chlorine are needed to disinfect 100,00 gallons of water at a chlorine concentration of 2 mg/l? |
lbs = 8.34 x volume x concentration = 8.34 x 0.1 million gallons x 2mg/l = 1.668 lbs |
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All trenches deeper than ____ feet must be shored. |
All trenches deeper than 5 feet must be shored. |
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Which of the following is not part of a centrigufal pump
a) Impeller b) Shaft c) Compressor d) Volute (Casing) |
a) Impeller b) Shaft c) Compressor d) Volute (Casing) |
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True or False
Higher temperatures accelerate corrosion rates |
True |
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A pressure gauge on a pipe reads 40 PSI. Convert this reading to feet of head. |
1 psi = 2.31 ft of head 40 psi x 2.31 = 92.4 ft of head |
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Name 2 forms of chlorine that are used to disinfect drinking water |
-Chlorine Gas -Liquid Chlorine/Bleach/Sodium Hypochlorite -Solid Chlorine/Tablets/Calcium Hypochlorite |
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What is the actual leakage rate in GPD/mi-inch from a pipe is the leakage over a 36 hour period was 30 gallons? The pipe section tested was 2 miles long and the diameter of the pipe was 3 feet. |
0.278 GPD/mi-in |
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Maintenance performed on a time based schedule is called
a) Preventative maintenance b) Predictive maintenance c) Corrective maintenance d) Supervisory maintenance |
a) Preventative maintenance b) Predictive maintenance c) Corrective maintenance d) Supervisory maintenance |
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True or False
Uncovered distribution reservoirs are generally prohibited |
True |
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How can workers be protected when work is required in a deep trench if shoring is not practical? |
They can slope the sides of the trench so the ground will not cave in around them. |
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Dead-end water mains cause what type of problems? |
Taste and odors develop in the water |
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True or False
Any fixture above the hydraulic grade line will be exposed to negative pressure |
True |
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A 15% sodium hypochlorite solution is used to disinfect a one million gallon storage tank. The desired concentration or chlorine is 2mg/l. How many pounds of sodium hypochlorite solution are required. |
111.2 lbs |
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What kind of valve is installed on the inlet of a centrifugal pump suction pipe to keep the pump and section line full of water?
a) Gate valve b) Foot valve c) Butterfly valve d) Ball valve |
a) Gate valve b) Foot valve c) Butterfly valve d) Ball valve |
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True or False
The inside of a confined elevated storage tank is typically considered a confined space? |
True |
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Water mains need at least ____ inches of cover over the top of the pipe
a) 6 b) 12 c) 30 d) 18 |
a) 6 b) 12 c) 30 d) 18 |
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True or False
Water mains parallel to sanitary sewers should be installed at least 10 feet horizontally away from the sewer and 1 foot higher than any nearby sewer line |
True |
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Taste and odor problems in a storage tank can be caused by which of the following
a) High chlorine residual b) Biological growth c) Long detention times d) Short circuiting e) all of the above |
a) High chlorine residual b) Biological growth c) Long detention times d) Short circuiting e) all of the above |
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What type of valve is used extensively in the distribution system to isolate sections of piping to enable repairs? |
Gate valve |
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Which of the following is not a rotary valve?
a) Ball valve b) Gate valve c) Butterfly valve d) Plug valve |
a) Ball valve b) Gate valve c) Butterfly valve d) Plug valve |
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True or False
Displacement type meters are small diameter meters commonly used for customer services |
True |
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Which of the following is not a high flow velocity type meter
a) Propeller b) Venturi c) Piston d) Turbine |
a) Propeller b) Venturi c) Piston d) Turbine |
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Which of the following backflow preventors afford the most protection for critical purposed?
a) Air gap device b) Double check valve reduced pressure device c) Check valve d) Double check valve device |
a) Air gap device b) Double check valve reduced pressure device c) Check valve d) Double check valve device |
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Trihalomethanes are formed by the reaction of __________ and naturally occurring organic materials in the water
a) Fluoride b) Ammonia c) Chlorine d) Lime |
a) Fluoride b) Ammonia c) Chlorine d) Lime |
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Primary drinking water standards regulate
a) Taste and odor complaints b) Color c) Tubidity d) Toxic compounds |
a) Taste and odor complaints b) Color c) Tubidity d) Toxic compounds |
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What factor has caused more waterborne disease than any other
a) Cross-connections b) Corrosion c) Red water d) Biological aftergrowth |
a) Cross-connections b) Corrosion c) Red water d) Biological aftergrowth |
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True or False
Chlorine is more persistent in the distribution system than chloramines |
False |
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List 3 methods of corrosion control in the distribution system |
- Lining/coating pipes - Cathodic protection - Chemicals that adjust the pH and alkalinity |
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Why should a hydrant valve never be operated in a partially open position? |
If the valve is only partially opened, the drain will not close fully. This could result in flooding that would damage the hydrant if freezing occurred |
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What are 2 advantages of wet tapping a water main as opposed to dry tapping? |
- It is more convenient to the utility because they can do it on their own time rather than scheduling it - The consumers do not lose water supply |
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List 3 components that contribute to the total amount of "unaccounted for water" |
- Theft - Hydrants - Inaccurate meters - Leaks - Unmetered usage |
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How long will it take to fill a storage tank that is 5 feet in diameter and 10 feet high if the flow rater feeding the tank is 3 gallons/min? |
489.32 minutes |
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This system collects, stores, and analyzes distribution and plant data. Operators use it as an interface with the process.
a) SCADA b) CMMS c) GIS d) LIMS |
a) SCADA b) CMMS c) GIS d) LIMS |
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A 400,000 gallon tank is to be disinfected at a chlorine concentration of 50 mg/l. How many pounds of chlorine gas would be required? |
166.8 lbs |
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List 3 of the most important responsibilities of a water utility during a disaster |
- Restore system ASAP - Provide water for drinking, firefighting, etc. - Prevent unnecessary loss of stored water |
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A water meter is tested and a reading of 24 gpm is obtained. The actual flow value for the test was 25 gpm. What was the meter accuracy in percent? |
24gpm/25gpm x 100 = 96% |
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A 6 inche diameter pipe is flushed with water at a velocity of 5ft/sec. What is the flowmeter reading in gallons per minute? |
439.8 gal/min |
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Which of the following is an example of a rotary valve?
a) Gate b) Diaphragm c) Ball d) Globe |
a) Gate b) Diaphragm c) Ball d) Globe |
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What type of valve is used extensively in the distribution system to isolate sections of piping to enable repairs? |
Gate valve |
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What type of valve is used on the supply lines to elevate tanks to control level within the tank?
a) Altitude b) Plug c) Relief d) Butterfly |
a) Altitude b) Plug c) Relief d) Butterfly |
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Which of the following is a small diameter meter used for residences
a) Venturi b) Piston meter c) Turbine d) Mag meter |
a) Venturi b) Piston meter c) Turbine d) Mag meter |
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Under what flow conditions does one use a compound meter? |
If the flow varies from very low flows to high flows. |
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This type of backflow prevention device is installed on services where dangerous materials are present on the premises
a) Check valve b) Reduced pressure backflow device c) Regulating valve d) Relief valve |
a) Check valve b) Reduced pressure backflow device c) Regulating valve d) Relief valve |
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Which of the following is a parameter that falls under the secondary drinking water standards
a) Nitrates b) Trihalomethanes c) Taste and odor d) Lead |
a) Nitrates b) Trihalomethanes c) Taste and odor d) Lead |
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List 2 benefits of using chloramines rather than free chlorine as the disinfectant in the distribution system. |
- Chloramines are more persistant - Chlorine can form trihalomethanes |
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Name 2 factors that would lead to water quality degredation in the distribution system |
- Corrosion - Dead ends |
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List 2 methods to control corrosion in the distribution system |
- Lining/coating pipes - Cathodic protection - Chemicals that adjust pH and alkalinity |
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A water meter is tested using a calibrated 42 inch diameter tank. The tested flow raised the level in the tank by 24 inches in 1 hour and 30 minutes. What was the flow rate in GPM? |
1.598 gal/min |
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Pressure levels in a distribution system should rage between
a) 10 PSI - 50 PSI b) 15 PSI - 60 PSI c) 35 PSI - 100 PSI d) 100 PSI - 160 Psi |
a) 10 PSI - 50 PSI b) 15 PSI - 60 PSI c) 35 PSI - 100 PSI d) 100 PSI - 160 Psi |
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How many gallons of 10% sodium hypochlorite solution will be needed to disinfect a 180,000 gallon storage tank with a chlorine concentration of 50 mg/l? |
90 gallons |
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What is the running annual average maximum contaminant level for trihalomethanes in the distribution system
a) 50 ppb b) 80 ppb c) 10 ppb d) 150 ppb |
a) 50 ppb b) 80 ppb c) 10 ppb d) 150 ppb |
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A 15 inch diameter water main is to be flushed at 5 ft/ sec before disinfection. What should be the reading on the flowmeter in gallons/minute? |
2,753.4 gal/min |
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List 2 reasons why a distribution system may have an abnormally low pressure |
- Leak - Broken water main - Periods of high usage like firefighting |
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How to high temperatures impact water quality in the distribution system? (Name 2 impacts) |
- Increase likelihood for biological growth - Speed up chemical reactions like corrosion which could cause turbidity |
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A trench 30 inches wide, 800 feet long, and 6 feet deep is to be excavated. How many cubic feet of soil will be removed |
12,000 cubic feet |
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The formation and collapse of a gas pocket or bubble on the blade of an impeller or the gate of a valve is called
a) Water hammer b) Titration c) Sequestration d) Cavitation |
a) Water hammer b) Titration c) Sequestration d) Cavitation |
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How often should fire hydrants be inspected and tested |
At least twice a year and after each use |
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List 3 benefits of a water audit |
- Increased knowledge of the system - Increased public relations - Help with legal liabilities |
