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Water License Part 3 > Water License Part 2 > Flashcards

Water License Part 2 Flashcards

1
Q

The primary purpose of disinfecting water mains is to

1.create a chlorine taste and odor
2.sterilize the water main
3.kill disease causing organisms in the water
4.keep the inside of the main clean

A

kill disease causing organisms in the water

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2
Q

What is the most likely cause of decreasing drawdown and a constant static water level?

1.Cone of depression has changed
2.Well screen is worn
3.Aquifer is being pumped at a greater rate than recharge
4.Pump is losing efficiency

A

Pump is losing efficiency

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3
Q

AWWA recommends that 5/8 inch meters be tested every

15 years
3 years
5 years
10 years

A

10 years

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4
Q

To initially disinfect a pipeline, chlorine may be added to the water in a continuous flow, a slug, or

segmented
low dose
tablet
air injection

A

Tablet

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5
Q

What is the term for a framework of wood or metal installed to prevent the collapse of trench walls?

shoring
enforcement
sloping
support

A

Shoring

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6
Q

pH is a measure of

Dissolved solids
Water’s ability to neutralize acid
Conductivity
Hydrogen ions

A

Hydrogen ions

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7
Q

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

1.30 days of the violation by a public service announcement on local radio and television stations.
2.1 year of the violation by including a letter with the water bill.
3.1 week of the violation in a certified letter to each customer.
4.3 months of the violation, in a daily newspaper in the area served by the system.

A

3 months of the violation, in a daily newspaper in the area served by the system.

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8
Q

Which meter is the most accurate over a wide range of flows?

propeller
compound
proportional
turbine

A

Compound

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9
Q

The device used to monitor water flow to a consumer is a

rotometer
flow regulator
check valve
water meter

A

Water meter

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10
Q

Which valve is used to prevent a pipe from collapsing?

Gate valve
Ball valve
Vacuum relief valve
Needle valve

A

Vacuum relief valve

The relief valve is used to control or limit the pressure in a system or vessel which can build up by a process upset, instrument or equipment failure, or fire.

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11
Q

A confined aquifer containing groundwater under positive pressure is called

a flowing aquifer
a nubian aquifer
a geologic aquifer
an artesian aquifer

A

artesian aquifer

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12
Q

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

69 mhp
79 mhp
29 mhp
87 mhp

A

69 mph

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13
Q

What agency establishes drinking water standards in the United States?

FDA
HHS
USGS
EPA

A

EPA

The Environmental Protection Agency (EPA) ensures safe drinking water for the public by setting standards for more than 160,000 public water systems throughout the United States. The EPA oversees states, local governments, and water suppliers to enforce the standards under the Safe Drinking Water Act.

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14
Q

The three main components of a centrifugal pump are

1.impeller, case, and shaft
2.bearing, housing, gasket
3.wear rings, lantern rings, and volute
4.shaft, wear rings, and power connection

A

impeller, case, and shaft

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15
Q

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?

10 minutes
20 minutes
18 minutes
16 minutes

A

18 minutes

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16
Q

At what time of day is the water stored in the distribution system the oldest?

6:00 PM
12:00 AM
6:00 AM
12:00 PM

A

6 AM

Question 16 Explanation: 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.

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17
Q

The hydrologic cycle is composed of all the following terms, except

precipitation
condensation
adsorption
evaporation

A

Adsorption

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18
Q

Which of the following is a measurement of the clarity of water?

pH
Turbidity
Chlorine residual
Hardness

A

Turbidity

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19
Q

What is the main purpose of a water storage facility?

1.To allow storage reserve during wet periods
2.To help maintain adequate pressures throughout the entire system
3.To meet needs for fire protection
4.To provide sufficient amount of water to average or equalize the daily demands plus provide minimum pressures to fight fires

A

To provide sufficient amount of water to average or equalize the daily demands plus provide minimum pressures to fight fires

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20
Q

PVC pipe can use tees, elbows, and other fittings from what other type of pipe?

ductile iron
copper
asbestos cement
concrete

A

Ductile Iron

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21
Q

Common method used to test water for chlorine residual

THM
VOC
DPD
HTH

A

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.

22
Q

Methemoglobinemia, also known as Blue Baby Syndrome, is a serious medical condition caused by high levels of _______________ in drinking water.

Lead
Nitrate
Manganese
Nitrite

A

Nitrate

The MCL for Nitrate is 10 ppm.

Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome.
High levels of Nitrate can be caused by runoff from fertilizer use; leaking septic tanks, sewage; erosion of natural deposits.

23
Q

What is the best valve for limiting a water hammer?

Pinch
Needle
Pressure reducing
Pressure relief

A

Pressure relief

24
Q

The amount of energy, in feet, that a pump supplies to the water is called

pump head
total head
pressure head
velocity head

A

Pump head

25
Q

Which of the following is a measurement of head?

feet
absolute pressure
gauge pressure
foot-pounds

A

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.
26
Q

The amount water that can be raised vertically by a given pressure is called

pressure head
pump head
velocity head
total head

A

Pressure head

27
Q

The primary reason for using dry barrel fire hydrants is to

allow easy maintenance of the hydrant
prevent water hammer
prevent rusting
prevent freezing in cold weather

A

Prevent freezing in cold weather

28
Q

What is the recommended chlorine dosage when disinfecting a water main using tablets?

4 mg/L
10 mg/L
50 mg/L
25 mg/L

A

50 mg/L

29
Q

According to the Center for Disease Control (CDC), what has caused the most waterborne disease outbreaks in the United States?

low chlorination
leaking backflow prevention equipment
corporate pollution
inadequate O&M of filtering systems

A

leaking backflow prevention equipment

30
Q

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

A

0.05 mg/L

31
Q

A waterborne disease that can be transferred to humans if proper disinfection is not provided is

measles
malaria
typhoid
gonorrhea

A

Typhoid

32
Q

Why is excessive water pressure to residential homes objectionable?

1.Decreases the life of water heaters and other appliances using water
2.Causes foaming from faucets
3.Increases particulate matter reaching the customer
4.Causes erosion of the copper plumbing due to the high velocities, giving the water metallic taste

A

Decreases the life of water heaters and other appliances using water

33
Q

What determines the required number of samples to be collected for systems monitoring lead and copper for the first time?

System size
Percentage of customers with old plumbing
Source water
Previous violations

A

Systems size

34
Q

The height which a column of water will rise in a well is called?

Groundwater level
Potentiometric surface
Piezometric surface
Residual drawdown

A

Piezometric surface

35
Q

What is the area of a trench that is 26.7 feet long and 4.1 feet wide?

122 sq ft
7 sq ft
109 sq ft
32 sq ft

A

109 sq ft

Multiply the length times the width

36
Q

As the temperature of the water increases, the disinfecting action of chlorine is

not affected
likely to increase algae growth
less effective
more effective

A

More effective

37
Q

Current meters are also known as

Venturi meters
Orifice meters
Insertion meters
Velocity meters

A

Velocity meters

38
Q

What pump has an efficiency of 90 to 95% at very high pressure, close fitting impellers, and high maintenance costs?

Jet
Centrifugal
Mixed flow
Vertical turbine

A

Vertical turbine

39
Q

What two chemicals cause hardness in water?

lead and copper
iron and manganese
calcium and magnesium
oxygen and hydrogen

A

Calcium and magnesium

40
Q

Large full storage tanks are typically disinfected with a chlorine residual of

10 mg/L
25 mg/L
15 mg/L
50 mg/L

A

10 mg/L

41
Q

How many gallons of paint are required to cover the outside perimeter and the top of a cylindrical tank that is 28-feet high and whose diameter is 14.5-feet? One gallon of paint covers 200 square feet of surface.

9 gallons
10 gallons
7 gallons
8 gallons

A

8 gallons

First calculate the area of the top of the tank using the formula Area = Pi x Radius² (a = π r²)

a = 3.14 (7.25)²

a = 165 sq ft

Next, determine the perimeter of the tank using the formula Circumference = 2 x pi x Radius (C=2πr):

P = 2(3.14) * 7.25

P = 45.53 ft

Next, calculate the area by multiplying the circumference and the height:

28 ft x 45.53 ft = 1,275 sq ft

Now, add the top of the tank area to the perimeter area to get the total surface area:

1,275 sq ft + 165 sq ft = 1,440 sq ft

Finally, divide the total surface area by 200 sq ft, the amount covered by one gallon:

1,440 sq ft / 200 sq ft = 7.2 gallons - You will need 8 gallons to paint the tank.

42
Q

Baffling inside a storage facility may be needed to prevent “hot spots” and

  1. high chlorine residuals throughout the facility
    2.long contact times with disinfectants
    3.straight through flows
    4.high temperatures throughout the storage facility
A

straight through flows

43
Q

Where will you find a nutating disc in a water distribution system?

centrifugal pump
storage tank
fire hydrant
water meter

A

Water meter

44
Q

Concrete thrust blocks are used to keep

joints from opening
valves from sinking
the pipe level
hydrants from being operated

A

Joints from opening

45
Q

One of the major causes of pump and motor shaft coupling wear is

misalignment
a discharge pressure too high
worn seal
worn impeller

A

Misalignment

46
Q

If two rings of packing are used in the stuffing box, how many degrees should the joints be staggered?

180-225 degrees
90-180 degrees
15-45 degrees
45-90 degrees

A

90-180 degrees

47
Q

A type of joint used for ductile iron piping

Rubber gasket joint
Bell and spigot with rubber o-ring
Push-on joint
Expansion joint

A

Push on joint

48
Q

Which class of fire involves sodium or magnesium?

Class B
Class C
Class A
Class D

A

Class D

49
Q

Determine the number of gallons contained in a fully charged 6 inch water main that is 300 feet long.

6,341 gallons
440 gallons
63,415 gallons
1,450 gallons

A

440 gallons

50
Q

The term drawdown, is best defined as

1.The distance from a well that the normal water level is affected by the cone of depression.
2.The water level in a well after a pump has operated for a period of time
3.A change in water elevation from normal level to pumping level
4.The distance from the ground to the pumping level

A

A change in water elevation from normal level to pumping level

Water License Part 3 (4 decks)

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