Equipment O & M

Question 1

Which is a principal problem associated with

preliminary treatment screening?

Answer 1

Clogging

Question 2

Particle counters use the principle of light ________.

Answer 2

Blockage

Question 3

How much time does it usually take to slake lime in

the detention-time lime slaker?

Answer 3

20 to 30 minutes

Question 4

At which temperature should the slaking process be

maintained?

Answer 4

160⁰ F or higher

Question 5

Fixed screens or bar screens usually have openings

ranging from _______.

Answer 5

1 to 3 inches

Question 6

Which is the simplest instrument for measuring levels?

Answer 6

Float-type sensor

Question 7

Electricity is the study of the movement that effects

large numbers of _______.

Answer 7

Electrons

Question 8

How often should chlorine supply lines

be replaced?

Answer 8

Every year

Question 9

Which is the most common well

operational problem?

Answer 9

Plugging of the well screen

Question 10

Bar screen assemblies are installed in a waterway at

a _______ angle from the horizontal.

Answer 10

60⁰ to 80⁰

Question 11

Auxiliary equipment for Fluoridation includes?

Answer 11

A flow meter for measuring total flow such that

pacing can be provided.

Question 12

Screen opening in raw water intakes are designed

for flows of ________.

Answer 12

2 ft/sec

Question 13

If chlorine is added before the water enters the microstrainer,

what will occur?

Answer 13

Free chlorine may corrode the mesh.

Question 14

Which chlorine gas feeder can also feed liquids?

Answer 14

Induction mixer

Question 15

The voltage rating on a fuse should be ________ the

voltage of the circuit on which it is applied.

Answer 15

equal to or greater than

Question 16

The streaming current detector is based on what principle?

Answer 16

Electromotive principle

Question 17

Which does the streaming current detector actually

measure for determining the effectiveness of the

coagulant chemical?

Answer 17

Electrical resistance

Question 18

What is the norman rotational speed of a

microstrainer?

Answer 18

5 rpm

Question 19

Which metal has the highest corrosion potential?

Answer 19

Aluminum

Question 20

Which flow measuring device is mechanical?

Answer 20

Loss of head meter

Question 21

Which is the last step in well construction?

Answer 21

Pump test to confirm capacity.

Question 22

Aspiration is the removal of?

Answer 22

Fluid from a container by suction.

Question 23

Which is the best material to use for fittings, lighting, and ventilation systems in a room that houses an ammonia

hydroxide tank?

Answer 23

Stainless Steel

Question 24

Wire size is selected according to which criteria?

Answer 24

Number of amperes to be carried.

Question 25

Field experience has shown that streaming current detectors

require very intensive maintenance at water plants utilizing

treatment chemicals containing?

Answer 25

Iron salts

Question 26

Grease that is water resistant is made with _______.

Answer 26

Calcium

Question 27

Which type of continuous control action when signal is lost?

Answer 27

Floating proportional control

Question 28

Which method for measuring water levels has a distinct

disadvantage where freezing occurs?

Answer 28

Float-type sensor

Question 29

Which is the general test period to confirm design capacity

for a public water supply well that is in an unconfined aquifer?

Answer 29

At least 72 hours

Question 30

Volumetric feeders are less expensive to maintain

than _________.

Answer 30

Gravimetric feeders

Question 31

Which type of continuous control requires meters,

transmitters, and transducers?

Answer 31

Feedback control

Question 32

Which type of continuous control has a controller that

constantly tries to change the output if there is deviation

from the set point?

Answer 32

Proportional plus reset control

Question 33

In fluorid saturator tanks, the chemical should be at

least ________ deep at all times, and if the saturator

treats more than 100 gpm, it should have a chemical

depth of at least ________.

Answer 33

• 6 inches
• 10 inches

Question 34

What metal can be used as an anode because

it is most active?

Answer 34

Mild steel

Question 35

A poor conductor of electricity would

be _______.

Answer 35

deionized water

Question 36

Destruction of pathogenic organisms by chlorine is

directly related to _________.

Answer 36

chlorine concentration

and

contact time.

Question 37

How often should screen equipment be inspected

for corrosion?

Answer 37

Monthly

Question 38

What disinfection treatment requires a monitoring

procedure, other than residual monitoring, to

determine its efficiency?

Answer 38

Ultraviolet

Question 39

A pressure-differential meter is a flow-measuring device

that creates and measures a difference in

pressure ________ to the rate of flow.

Answer 39

proportional

Question 40

What is the most dificult and the most expensive

physical measurement taken in a water plant?

Answer 40

Water flow

Question 41

Most Fluoride dry feeders for large plants should have

a vibrator to prevent __________.

Answer 41

bridging

Question 42

What disinfectant oxidant could have some

THM formation?

Answer 42

Chloramines

Question 43

What is equipment’s worst enemy?

Answer 43

• Dirt and moisture
• Poor maintenance or none at all.

Question 44

What is the major disadvantages of the manual solution

feed method using sodium fluoride?

Answer 44

• It is not as accurate as other methods.
• The dust generated when adde to the day tank.
• Chemical needs to be manually weighed and added to

a mixing tank.

Question 45

Downflow fluoride saturator tanks with a gravel bed should

be cleaned at least ________ depending on how fast

hardness scale builds up.

Answer 45

1 to 3 times per year

Question 46

What type of energy is produced when water moves

through a pipe?

Answer 46

Kinetic energy

Question 47

Most pressure-sensing devices used in water treatment

plants rely on _______.

Answer 47

The metal-distortion principle