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
What type of meter is used when the water flow has large fluctuations?
Nutating-disc meters
Compound meters
Venturi meters
Proporional meters
Compound meters
Concrete thrust blocks are used to keep
joints from opening
valves from sinking
the pipe level
hydrants from being operated
Joints from opening
Which hydrant is under pressure and has no drain mechanism?
Breakaway
Flush
Cold climate
Wet barrel
Wet barrel
The chlorine residual in water may be determined by using which reagent
ethylendiaminetetraacetic acid (EDTA)
diethyl-p-phenylendiamine (DPD)
polychlorinated bephenyls (PCB)
sodium thiosulfate (Na2S203)
diethyl-p-phenylendiamine (DPD)
What type of temperature sensor uses a semi-conductive material?
Thermistor
Thermoresistor
Thermocouple
Thermoelectrocouple
Thermistor
The unit of measurement for a material’s resistance to the flow of electric current is
Amperes
Ohms
Volts
Watts
Ohms
A type of joint used for ductile iron piping
Rubber gasket joint
Expansion joint
Push-on joint
Bell and spigot with rubber o-ring
Push on joint
When taking a storage facility out of service you must
1.increase the water pressure to the system
2.have it back in service within 72 hours
3.coordinate and plan the shutdown so that the distribution system will be able to meet customer’s demands
4.use a backup storage system
coordinate and plan the shutdown so that the distribution system will be able to meet customer’s demands
The primary purpose of disinfecting water mains is to
kill disease causing organisms in the water
sterilize the water main
keep the inside of the main clean
create a chlorine taste and odor
kill disease causing organisms in the water
Red water is coming from a water main on Elm Street, but the water from all surrounding mains is clear. Lab tests show the water is not corrosive. Which of the following is the most likely cause?
bacteria
THM/HAA
water temperature
scale build up
Bacteria
Which of the following valve is used in maintaining prime to a pump?
butterfly
suction
foot
vacuum header
Foot
The C-Factor relates to
a water service shutoff valve
the smoothness of the interior of a pipe
the elevation of energy head of water
the elevation of the invert of a pipeline
the smoothness of the interior of a pipe
The lower the C-factor the rougher the pipe. A low C-Factor causes increased friction loss.
A higher C-Factor represents a smoother pipe and lower friction loss.
Measures the total flow through a water line by multiplying the flow through the meter by a specific factor.
Current
Magnetic
Proportional
Insertion
Proportional
Common method used to test water for chlorine residual
DPD
VOC
HTH
THM
DPD
The most common colorimetric method used today is called the DPD Colorimetric Method.
In this method, N,N-diethyl-p-phenyldiamine (DPD) is the reagent added to the sample.
Chlorine oxidizes this DPD to form a magenta colored compound known as Wurster Dye.
What is the pressure head at a service connection with a static pressure of 58 psi?
94psi
25 psi
134 psi
58 psi
134 psi
The term for the height to which water will rise in a well tapped into an artesian aquifer
piezometric surface
head pressure
watertable
hycroic gradient
Piezometric surface
What is a cross-connection?
a piping tee connecting crossing water lines
a connection between two water systems
a connection between a ground water supply and surface water supply
any connection between an approved and unapproved water supply
any connection between an approved and unapproved water supply
A mass of concrete placed at bends and valve structures to prevent pipeline movement is called a
curb stop
megalug
corp stop
thrust block
Thrust block
What pump has an efficiency of 90 to 95% at very high pressure, close fitting impellers, and high maintenance costs?
Jet
Vertical turbine
Centrifugal
Mixed flow
Vertical turbine
What level sensor should not be used where the water could freeze?
Direct electronic sensor
Bubbler tube
Float mechanism
Diaphragm element
Float mechanism
Which type of pump works on the basis of inertia or mass moving in a circular motion?
gear
diaphragm
air lift
centrifugal
Centrifugal
Horsepower is defined as
550 ft-Ibs per minute or 647 watts
33,000 ft-Ibs per minute or 746 watts
550 ft-Ibs per minute or 746 watts
33,000 ft-Ibs per second or 746 watts
33,000 ft-lbs per minute or 746 watts
Which meter has no moving parts?
propeller
venturi
rotometer
proportional
Venturi
What is the diameter of a tank with a circumference of 422 ft?
211
67.2
134.4
1,325.1
134.4
To calculate the diameter, divide the circumference by 3.14 (pi)
422 / 3.14 = 134.4
A waterborne disease that can be transferred to humans if proper disinfection is not provided is
measles
malaria
gonorrhea
typhoid
Typhoid
What is needed to overcome the resistance to flow in the pipe?
increased flow
discharge head
velocity head
horsepower
Horsepower
Wet-barrel hydrants
have main butterfly valve
have standard compression main valves
have no main valves, but separate nozzle valves
have slide gate main valves
have no main valves, but separate nozzle valves
What is the purpose of a bypass valve on a larger gate valve?
To reduce pressure across both sides in order to ease opening and closing
Allow easy location of the main valve
Increase flow through the main line
Y Connect a new main to an exsing main
To reduce pressure across both sides in order to ease opening and closing
As the temperature of the water increases, the disinfecting action of chlorine is
more effective
less effective
not affected
likely to increase algae growth
More effective
The Safe Drinking Water Act (SDWA) defines a public water system that supplies water for human consumption as one that has
1.10 service connections or serves 20 or more people for 60 or more days per year
2.15 service connections or serves 20 or more people for 90 or more days per year
3.10 service connections or serves 25 or more people for 30 or more days per year
4.15 service connections or serves 25 or more people for 60 or more days per vear
15 service connections or serves 25 or more people for 60 or more days per vear
Definition of a Public Water System (PWS) can be found in Section 1401(4) of the SDWA
A connection from the municipal water supply directly to the packing gland of a centrifugal wastewater pump
is undesirable because too much water is required.
is a hazard to the safety of the potable water supply.
is necessary to dilute the wastewater.
reduces the power consumption of the motor driving the pump.
is a hazard to the safety of the potable water supply.
What is the gauge pressure exerted at the bottom of a water tank that is 45 feet high and has a 35 foot diameter, when the tank is 75% full?
19.4 psig
104 psig
14.6 psig
77.8 psig
14.6 psig
In this problem it’s critical to determine what information is needed. The diameter of the tank does not affect the pressure. You only need to know the height of the tank and the water level.
In this case, the tank is only 75% full. To calculate the height of the water multiply the tank height by 0.75:
45 ft * 0.75 = 33.75 ft
Now, divide the water level by 2.31, the psi for each foot of water:
33.75 ft / 2.31 psi/ft = 14.6 psig
Determine how many gallons of paint are needed to cover the outside, and top, of a cylindrical tank with a top area of 452 f2 and a pressure gauge at the bottom of the tank reads 15 psi when the tank is full. One gallon of paint covers 250 ft?.
15
16
14
17
16
When residential water meters become worn, they have the tendency to
under measure all flows
under measure small flows
over measure all flows
cause pressure drops at high flows
under measure all flows
The most common location for a service connection leak is
Gate valve
Pressure reducer
Home plumbing
Curb stop
Curb stop
When the impeller in a centrifugal pump becomes worn, the amount of energy used will be the amount used by a new pump.
less than
the same as
more than
more efficient than
More than
At what time of day is the water stored in the distribution system the oldest?
6:00 AM
6:00PM
12:00 PM
12:00AM
6:00 AM
Storage tanks are typically filled and emptied quickly during the day. As water usage declines during the evening hours tanks are filled and drained at a much slower rate. The age of the water in the system affects the water quality. As the water ages, the level of residual disinfectant decreases. At the same time, the level of disinfection byproducts (DBPs), such as trihalomethanes and haloacetic acids, may increase. Frequent water turnover in the system helps to ensure higher levels of residual disinfectant and lower levels of DBPs.
Why is it essential to ventilate a valve vault before entry?
Remove excess moisture
Eliminate foul odors
Remove hazardous gases
Equalize temperature and pressure
Remove hazardous gases
A 6 inch water line needs to be flushed. If the length of pipe to be flushed is 425 feet, how long will it take to flush the line at 35 gpm?
16 minutes
10 minutes
20 minutes
18 minutes
18 minutes
The hydrologic cycle is composed of all the following terms, except
condensation
adsorption
precipitation
evaporation
Adsorption
What is the most likely cause of decreasing drawdown and a constant static water level?
Well screen is worn
Aquifer is being pumped at a greater rate than recharge
Cone of depression has changed
Pump is losing efficiency
Pump is losing efficiency
What is a plat?
A map
Storage area for pipes, valves, etc
A contaminant
A section of the water main.
A map
A plat is a scaled map showing the divisions of a piece of land. Plats typically show the distance and bearing between property section corners, sometimes including topographic or vegetation information. City or town or village plats show subdivisions into blocks with streets and alleys. More detailed plats often split blocks into individual lots, usually for the purpose of selling the described lots; this has become known as subdivision. After a plat is filed, legal descriptions can refer to block and lot-numbers rather than portions of sections.
Which of the following is typically associated with trihalomethanes?
High levels of iron and manganese
Water containing organics that has been chlorinated
High levels of dissolved oxygen in raw water source
Groundwater with high levels of inorganics
Water containing organics that has been chlorinated
Disinfection by-products (DBPs), such as trihalomethanes and haloacetic acid, result from reactions between organic and inorganic matter in water with chemical treatment agents during the water disinfection process. DBPs increase with longer exposure to residual disinfectants.
Air relief valves are installed for the purpose of
Releasing energy created by water hammer
Reducing pressure during hydrant maintenance without disrupting service to customers
Releasing air that has accumulated in high points of the water line.
stopping now when the tank is full
Releasing air that has accumulated in high points of the water line.
Where are the specifications for maximum contaminant levels in drinking water specified?
Standard Methods for the Examination of Water and Wastewater
National Primary Drinking Water Regulations
American Water Works Association
safe Drinking Water Act
National Primary Drinking Water
The term associated with water that evaporates from living plants is referred to as
precipitation
condensation
evapotranspiration
transpiration
Evapotranspiration
What is the maximum theoretical suction lift of a centrifugal pump at sea level?
72 ft
16 ft
34 ft
48 ft
34 ft
To initially disinfect a pipeline, chlorine may be added to the water in a continuous flow, a slug, or
tablet
low dose
segmented
air injection
Tablet
What percent is 1,288 of 3,294?
12.8
39.1
33.5
2.6
39.1
of the following service line materials is not flexible?
galvanized-iron
copper
plastic
lead
Galvanized Iron
pH is a measure of
Dissolved solids
Conductivity
Water’s ability to neutralize acid
Hydrogen ions
Hydrogen ions
The optimal maximum water velocity through a pipe under normal operating conditions is
7 fps
3 fps
9 fps
5 fps
5 fps
The maximum recommended head loss for positive displacement meters less than 2 inches is
11 psi
15 psi
13 psi
9 psi
15 psi
Dead ends in a system are usually located on
Oval designs
Tree shaped and Grid designs
Loops or circular designs
Transmission mains
Tree shaped and grid designs
Which of the following is a measure of the smoothness of a pipe?
S value
T Coefficient
Hazen-Williams formula
C factor
C factor
Minimum pressure a distribution system should maintain, even under fire flow conditions
35 psi
20 psi
5 psi
10 psi
20 psi
Which of the following causes taste and odor problems and is often described as smelling like rotten eggs?
Chlorine
Benzene
Fluoride
Hydrogen sulfide
Hydrogen sulfide
The primary reason for using dry barrel fire hydrants is to
prevent freezing in cold weather
prevent water hammer
allow easy maintenance of the hydrant
prevent rusting
Prevent freezing in cold weather
A curb box which fits loosely over the curb stop and meter?
Montgomery
Minneapolis
Arch
Chicago
Arch
What is the optimal level of protection for the exterior of a coated steel pipe?
polyethylene tape
cathodic protection
bituminous materials
plastic coating
Cathodic protection
Cathodic Protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects protected metal to a more easily corroded sacrificial metal, which acts as the anode. The sacrificial metal corrodes instead of the protected metal.
