# Water Distro 1 set 2

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1. The difference between water pressures upstream and downstream of a pump when it is not in operation is known as the
2. The sum of the total static head plus friction in the suction and discharge lines
of a pump is that pump’s
3. Pumps are primed to
Replace air inside the pump with water
4. Backspin is occurring after well shutdown; this
indicates
A faulty check valve
5. Enclosed,open, and semi-closed are terms used for the designation and selection of
Impellers
6. A pump’s packing gland serves many purposes, including which of the following?
• Keeps gritty material from
• entering the packing box
7. If a pump sounds like it is pumping rocks, the
most likely cause is
Cavitation
8. Which of the following is a positive
displacement pump?
a.         Air lift pump

b.         Centrifugal pump

c.         Piston pump

d.         Turbine pump

e.         All of the above
Piston pump
9. The practical maximum suction lift for a
centrifugal pump in good condition
20-feet to 25-feet
10. A type of pump that can cause discharge line
rupture from over-pressurizing is
Positive displacement
11. A common horizontal linkage between a centrifugal pump and its motor is the
Coupling
12. The main water-containing body of a centrifugal pump is commonly called the
Volute
13. The total dynamic head of a pump is 255 feet.
This is equivalent to
110 psi = 255/2.31
14. A pump is located at elevation 250 feet, and it is moving water from elevation
275 feet on its suction side to elevation 400 feet on its discharge side.  What is the total static head?
125 feet
15. The rotating element in a centrifugal pump is commonly called the
Impeller
16. A pump is located at elevation 250 feet, and it is moving water from elevation
275 feet on its suction side to elevation 400 feet on its discharge side.  What is the static pressure on the suction
side of this pump?
25 feet
17. A pump is located at elevation 250 feet, and it is moving water from elevation 275 feet on its suction side to elevation 400
feet on its discharge side.  The friction
in this system is equivalent to 20 feet of head.  What is the total dynamic head for this pump?
145 feet
18. A field chlorine residual measurement shows no reading after one minute during the free test, but 2.1 mg/L after three minutes during the total test.  This indicates that
There is no free chlorine residual, but there are 2.1 mg/L of chloramines
19. Chlorine residual is measured in the field using
the
DPD colorimetric method
20. The fusible plug that is in all chlorine
containers
Should never be removed or tampered with
21. Working within an atmosphere with a severe
chlorine gas leak requires the use of
• Self-contained breathing
• apparatus (SCBA)
22. The device that generates the vacuum conditions for chlorine gas application is called an
Eductor
23. Chlorine gas

a.   Is heavier than air

b.   Is lighter than air

c.   Will turn to liquid at normal room
temperatures

d.   Is dark blue in color

e.   Is non-toxic in low concentrations
Is heavier than air
24. The substance used to detect the presence of
small chlorine gas leaks is
Ammonia
25. The device used to regulate and control the rate of feed of chlorine gas is called a
Chlorinator
26. The amount of gas that can be withdrawn from a one-ton chlorine container is
400 pounds per day
27. Chlorine in the
gas form is

a.   100% chlorine

b.   Highly toxic

c.   Yellow-green in color

d.   An effective drinking water disinfectant

e.   All of the above
All of the above
28. Hypochlorous acid in water is also known as
Free chlorine
29. The purpose of fusible plugs on chlorine
containers is to
• Relieve excess
• internal pressure and thus avoid explosions
30. A “B” repair kit is used to address equipment
failures on
One-ton chlorine containers
31. When chlorine gas is to be withdrawn from a
one-ton container, you must use the
Upper valve
32. How many pounds per day of chlorine gas are needed
to treat a flow of 8.5 MGD at a dosage of 2.75 mg/L?
• lb/day        =          mg/L x  8.34  x  MGD
•
•                  =          2.75  x  8.34 X 8.5

=          195 lb/day
33. A chlorinator is feeding 240 pounds per day at a treatment plant operating at 24 MGD.
What is the current chlorine dosage rate in milligrams per liter?
• mg/L         =          lb/day  ÷ (8.34  x  MGD)
•
•                 =    240       ÷ (8.34  x  24)
•                 =    1.2 mg/L
34. A treatment plant’s desired chlorine dosage rate is 3.5 mg/L, and its current
flow rate is 8000 gallons per minute.
What should the pounds per day setting be on the plant’s chlorinator?
• lb/day        =          mg/L x  8.34  x (MGD)
•                 =    3.5 x  8.34  x (8000 gal/min x                  1440 min/day ÷ 1,000,000 gal/Mgal)
• =          336 lb/day
35. Which of the following is the least potent
disinfectant?
a.   Hypochlorous acid

b.   Hypochlorite ion

c.   Chloramines

d.   Ozone

e. All of the above are equally potent
c.   Chloramines
36. The concentration of available chlorine in chlorine gas from 1-ton containers is
100%
37. Which of the following will produce the highest
concentration of THMs?
a.   Free chlorine

b.   Chlorine dioxide

c.   Chloramines

d.   Ozone

e.   All of the above are equal in THM production
a.         Free chlorine
38. Chlorine isapplied at a dosage rate of 2.5 mg/L. After a reaction time of over 4 hours in the clearwells, the chlorine
residual is 1.5 mg/L.  What is the
chlorine demand?
a.   1.0 mg/L
39. Free chlorine residual in water exists in
two forms.  These are
• Hypochlorous acid and
• hypochlorite ion
40. What percentage of routine distribution system
samples must exhibit a detectable disinfectant residual?
d.   95 %
41. When sodium hypochlorite is dissolved in water, which of the following is formed?
Sodium hydroxide (lye, or caustic soda)
42. Which of the following is formed when any type of chlorination chemical is added to water?
Hypochlorous acid
43. Which of the following is the most potent disinfectant?

a.   Free chlorine

b.   Chlorine dioxide

c.   Chloramines

d.   Ozone

e.   All of the above are equally potent
Ozone
44. The sum of a disinfectant’s demand and its
residual is equal to the
Applied dosage
45. Which of the following is best at removing odors from water?
a.   Free chlorine

b.   Chlorine dioxide

c.   Chloramines

d.   Ozone

e.   All of the above will equally form bromate
d.   Ozone
46. The sum of a disinfectant’s demand and its residual is equal to the
Applied dosage
47. Which of the
following is being used as an alternative drinking water disinfectant?

a.   Sodium hypochlorite

b.   Ultraviolet light

c.   Ethanol

d.   Protons

b.         Ultraviolet light
48. .     Which of the following is the most
associated with the DBP bromate?

a.   Free chlorine

b.   Chlorine dioxide

c.   Chloramines

d.   Ozone

e.    All of the above will equally form            bromate
d.   Ozone
49. The chemical normally withdrawn from a bulk chlorine storage tank car or rail car is
Chlorine liquid
50. Which of the
following is the most associated with the DBP chlorite?
Chlorine dioxide
51. Which of the
following is also known as “combined chlorine”?

a.   Chlorine dioxide

b.   Trichloromethane

c.   Carbon tetrachloride

d.   Chlorobutane

e.   Chloramines
Chloramines
52. Which of the following is commonly used as a
secondary disinfectant?
Chloramines
53. Which of the following will normally produce a residual effect for less than two hours?
a.   Chlorine dioxide

b.   Calcium hypochlorite

c.   Sodium hypochlorite

d.   Chlorine gas

e.   Chloramines
Chlorine dioxide
54. In an occupied trench where exits (i.e.,
ladders) are required, what is the maximum allowed travel distance between an
occupant and the nearest exit?
55. Standard first aid procedures direct that the
first step to control bleeding is to
Apply pressure directly to the wound
56. When excavating materials that will not stand in a vertical position, the most suitable form of shoring is
Solid sheeting
57. A potable water supply discharges into an
irrigation water storage tank.  The
potable supply line should be terminated
Above the tank overflow by at least two pipe diameters
58. Which of the following gases is toxic at the
lowest concentration?
Hydrogen sulfide
59. Entry into an atmosphere with high
concentrations of chlorine gas requires
A self-contained breathing apparatus
60. What information must be on a warning tag attached to a locked-out switch?
Signature of the person who locked out the switch and who will remove it
61. An abnormal flow condition caused by a
difference in water pressures is known as
Backflow
62. A bacteriological sampling bottle should be
Filled carefully to leave a small air space
63. A cross-connection means
A connection between potable water and “unapproved” water supplies
64. A backflow prevention device that can be used in any cross-connection situation is a
Reduced pressure zone device
65. A confined space that contains a material that
has the potential to engulf an entrant is
A permit space
66. Egress is normally required for trenches of what minimum depth?
4-feet
67. Bacteriological sample bottles which are
furnished by a certified laboratory
68. How long must a sample tap be flushed prior to sample collection?
As long as necessary to permit clearing of the service line
69. What condition must exist for an area to be
considered a confined space?
a.         Limited or restricted means of entry             or exit

b.         Is large enough for a person to enter
and perform work

c.         Is not designated for continuous
occupancy

d.         All of the above

e.         None of the above
d.         All of the above
70. The backflow prevention device used in home lawn sprinkler systems is a
Atmospheric vacuum breaker
71. A completely fail-safe means of backflow
prevention is
Air gap
72. Which of the following is the most likely to be
a fuel involved in a Class B fire?
a.         Wood

b.         Magnesium

c.         Electrical equipment

d.         Gasoline

e.         Paper and/or fabrics
 Author: Hazard ID: 268948 Card Set: Water Distro 1 set 2 Updated: 2014-04-02 16:53:26 Tags: Water Distribution Folders: Description: Water Distribution 2nd set Show Answers: