Water License Part 3 Flashcards
A pump runs for 20 minutes and fills a 40 ft x 20 ft x 10 ft tank with 59,840 gallons of water. Determine the pumping rate in gallons per minute.
2100 gpm
1,383 gpm
1540 gpm
2,992 gpm
2992 gpm
This problem gives you more information than you need. The tank dimensions are irrelevant. The only information you need is the total amount of water pumped and the amount of time it took.
59,840 gallons / 20 minutes = 2,992 gpm
Which motor has a starting current normally less than the full load operating current, has a stator, and the rotor circuit resistance can be controlled while the motor is running?
Squirrel cage
Synchronous
Wound rotor
compound
Wound rotor
Which pump has rotating impellers inside a pump case?
Mixed flow
Centrifugal
Jet
Axial flow
Centrifugal
A five foot deep pipe trench requires exit ladders every twenty-five feet and have
hosts every 10.25 feet
a confined space permit
approved shoring
exit ramps
Approved shoring
What is the motor horsepower (mhp) for a pump with the following parameters?
Motor efficiency: 87%
Total Head (TH): 107 ft
Pump efficiency: 79%
Flow: 2.54 mgd
29 mhp
69 mhp
87 mhp
7 mhp
69 mph
The secondary standard for manganese recommends levels not exceed
0.02 mg/L
0.05 mg/L
0.03 mg/L
0.04 mg/L
0.05 mg/L
A water bearing layer of soil is called
the water table
an aquifer
a well
a capillary
An aquifer
Which of the following is used to measure water depth in a storage facility?
Ventur meter
Hydrometer
Transducer
Magnetic sensor
Transducer
Placing a smaller diameter pipe inside a larger pipe as a method of repair is called
slip lining
stipping
coupling
encasing
Slip lining
What is the recommended chlorine dosage when disinfecting a water main using tablets?
25 mg/L
50 mg/L
4 mg/L
10 mg/L
50 mg/L
The combined natural processes of converting liquid water into gaseous form is called
evaporation
evapotranspiration
condensation
transpiration
Evapotranspiration
A customer’s service is usually measured with what type of meter?
remote reading
positive displacement
nutating disc
miniturbine
Positive displacement
What is the recommended chlorine dosage when disinfecting a water main using the slug method?
500 mg/L
100 mg/L
50 mg/L
300 mg/L
300 mg/L
Large full storage tanks are typically disinfected with a chlorine residual of
15 mg/L
50 mg/L
10 mg/L
25 mg/L
10 mg/L
What is the best valve for limiting a water hammer?
Pinch
Pressure relief
Needle
Pressure reducing
Pressure relief
Calculate the pounds per square inch of pressure at the bottom of a tank if the water level is 44.8 ft deep?
103.5 psi
19.4 psi
34.2 psi
14.0 psi
19.4 psi
Calculate the pressure by dividing the height of the water level by 2.31.
The device used to monitor water flow to a consumer is a
water meter
rotometer
flow regulator
check valve
Water meter
Which type of piping material is the most corrosive resistant?
Concrete
PVC
Stainless steel
Ductile Iron
PVC
Sixty-five parts per billion (65 ppb) is equal to which of the following?
65 mg/L
0.65 mg/L
0.065 mg/L
6.5 ppm
0.065 mg/L
To convert pb to mg/L simply divide by 1,000.
65 ppb / 1,000 = 0.065 mg/L
According to EPA regulations, the owner, or operator, of a public water system that fails to comply with applicable monitoring requirements must give notice to the public within
30 days of the violation by a public service announcement on local radio and television stations.
3 months of the violation, in a daily newspaper in the area served by the system.
1 year of the violation by including a letter with the water bill.
1 week of the violation in a certified letter to each customer.
3 months of the violation, in a daily newspaper in the area served by the system.
The three main components of a centrifugal pump are
bearing, housing, gasket
impeller, case, and shaft
wear rings, lantern rings, and volute
shaft, wear rings, and power connection
impeller, case, and shaft
What type of direct electronic sensor for level measurement is placed above the water level?
Variable resistance level sensor
Diaphragm level sensing system
Probe level system
Ultrasonic level sensing system
Ultrasonic level sensing system
Which device can check water flow in a distribution system?
Pitot meter
Flowmeter
Amperometric meter
Service meter
Flowmeter
What is the primary source of coliforms in a water supply?
Insects that live or die in the water source
Fertilizers
Fecal material from warm-blooded animals
Protozoans and other microorganisms
Fecal material from warm-blooded animals
When sampling for bacteria in a distribution system, which chemical is inside the sterilized bottle?
chlorine tablets
sodium thiosulfate
hydrochloric acid
copper sulfate
Sodium thiosulfate
Sodium Thiosulfate is added to bacteriological sample bottles in order to neutralize the free chlorine present in the water.
When using a power tool to operate a distribution valve, it is best to
Perform last few turns manually
Use the highest speed setting
Loosen the valve manually
Use the lowest speed setting
Perform last few turns manually
Electrical demand in a wiring system is determined by the amount of
Voltage a system draws
Watts consumed
Ohms in the entire system
water pressure in the system
Watts consumed
Surface load refers to
the weightor the pipe on the truck.
the method of loading the pipe for transport
the weight of the back fill on the pipe
the weight of traffic on the pipe
the weight of traffic on the pipe
Peak hour demand is determined by the highest 1-hour period of water usage during one
year
day
month
week
Year
Before collecting a lead and copper sample, how long must the water remain undisturbed in the pipe?
12 hours
24 hours
6 hours
8 hours
6 hours
Which of the following is a measurement of head?
feet
footpounds
absolute pressure
Gauge pressure
Feet
Head is expressed in units of height such as meters or feet.
There are four types of head used to calculate the total head in and out of a pump:
1. Velocity head is due to the bulk motion of a fluid (kinetic energy).
2. Elevation head is due to the fluid’s weight, the gravitational force acting on a column of fluid.
3. Pressure head is due to the static pressure, the internal molecular motion of a fluid that exerts a force on its container.
4. Resistance head (or friction head or Head Loss) is due to the frictional forces acting against a fluid’s motion by the container.
Which curb box eliminates the possibility of misalignment?
Montgomery
Arch
Minneapolis
Chicago
Minneapolis
Which of the following pumps works on the principle of a decrease in the overall specific weight of a confined column of a gas-water mixture?
pistondia
centrifugal
diaphragm
air lift
Air lift
Which temperature sensor uses two wires made of different materials?
Thermoresistor
Thermocouple
Thermistor
Thermoelectrocouple
Thermocouple
Baffling inside a storage facility may be needed to prevent “hot spots” and
long contact times with disinfectants
high temperatures throughout the storage facility
straight through flows
high chlorine residuals throughout the facility
Straight through flows
The term drawdown, is best defined as
The distance from a well that the normal water level is affected by the cone of depression.
The water level in a well after a pump has operated for a period of time
The distance from the ground to the pumping level
A change in water elevation from normal level to pumping level
A change in water elevation from normal level to pumping level
Which of the following is a displacement meter?
Sonic meter
Piston
Venturi
Compound
Piston
When a 150-pound chlorine cylinder fitting has a slight leak around the gasket material, a gauze like material soaked in________should be used below the fittings to confirm the leak.
Oil
ammonia water
chlorine dioxide
sodium thiosulfate
Ammonia water
Fire demand can account for what percent of the total capacity of a storage system?
10%
50%
25%
60%
50%
A fire hydrant is 88 feet below the bottom of a reservoir containing 49 feet of water. What is the static water pressure at the fire hydrant?
42.6 psi
316.5 psi
16.9 psi
59.3 psi
59.3 psi
This is a two step problem.
To determine the total amount of head in feet, add the elevation difference from the hydrant to the bottom of the tank to the height of the water in the tank:
88’ + 49’ = 137’
Now, determine the pressure per square inch (psi) by dividing the total feet of head by 2.31 (2.31 feet of water equals 1 psi):
137 / 2.31 = 59.3 psi