Abc Water Operator Additional Practice Questions

Front 1

What is the principal scale-forming substance in water?

Back 1

Calcium carbonate

Front 2

What oxidant should be fed as early as possible in the treatment process to allow for complete reaction before it enters the distribution system?

Back 2

Potassium permanganate

Front 3

The flexible copper tubing that connects the 150 lbs chlorine cylinder to ta manifold should be rated at _______.

Back 3

500 psi

Front 4

The buildup of corrosion products is a process known as _____.

Back 4

tuberculation

Front 5

_______ should be fed before chlorine.

Back 5

Potassium permanganate

Front 6

Low values for what water characteristic may require the addition of lime, caustic soda, or sodium bicarbonate?

Back 6

Alkalinity

Front 7

What chemical could cause pink water problems?

Back 7

Potassium permanganate

Front 8

The most frequent in situ well treatment is the application of a(n) __________.

Back 8

oxidant to reduce iron bacteria.

Front 9

What chemical is slaked lime?

Back 9

Ca(OH)2

Front 10

Calcium sulfate (CaSO4) is also know as _______.

Back 10

gypsum.

Front 11

Which color does the oxidant potassium permanganate turn at its end point?

Back 11

Yellow

Front 12

The simplest chlorine gas feeder for controlling chlorine gas flow is ________.

Back 12

sonic flow.

Front 13

What is usually used to disinfect the gravel packing of a groundwater well?

Back 13

Powder of calcium hypochlorite tablet

Front 14

What is true regarding chlorine one-ton containers.

Back 14

One-ton containers are equipped with two valves, one for liquid and one for gas

Front 15

Teeth are likely to become pitted when the fluoride concentration in drinking water goes above ___ mg/L.

Back 15

4 mg/L

Front 16

How many pounds of ammonia are contained in a full 1-ton cylinder?

Back 16

800

Front 17

High pH favors the formation of what?

Back 17

total trihalomethanes.

Front 18

How often is it recommended to check the fluoride feed system?

Back 18

Every Hour

Front 19

Low pH favors the formation of what?

Back 19

haloacetic acids

Front 20

Dental fluorosis is __________.

Back 20

mottling of the teeth.

Front 21

One volume of liquid chlorine will expand to approximately how many volumes of gas?

Back 21

460

Front 22

In general, how long does ozone last when it is dissolved in water for disinfection purposes?

Back 22

A few seconds to a few minutes.

Front 23

Is Sodium fluoride odorless.

Back 23

Yes

Front 24

What does the saturation point of calcium carbonate primarily depend upon?

Back 24

pH

Front 25

Which will increase pH, hardness, and alkalinity?

Back 25

Lime

Front 26

How often should the fluoride concentration of treated water be measured?

Back 26

Everyday

Front 27

What is the pH of a saturated solution of sodium fluoride?

Back 27

7.0

Front 28

Which is the most effective wavelength when using ultraviolet light for disinfection?

Back 28

2650 angstroms

Front 29

What type of chlorine gas feeder is the most commonly used?

Back 29

Vacuum

Front 30

What substance is a depolarizer?

Back 30

Nitrates

Front 31

What composes the majority of scale in pipe?

Back 31

CaCO3

Front 32

The specific gravity standard for gases is __________.

Back 32

air

Front 33

What chemical oxidant is the most effective in reducing the concentration of taste-and-odor compounds caused by actinomycetes species?

Back 33

Peroxone

Front 34

What oxidant is a bluish toxic gas with a pungent odor?

Back 34

Ozone

Front 35

Past the breakpoint chlorination point, what percentage of the total chlorine residual should be free chlorine?

Back 35

85 to 90%

Front 36

Sodium hypochlorite has a pH range of ________.

Back 36

9.0 to 11.0 pH units

Front 37

Where should the fluoride injection point be located?

Back 37

After water has received complete treatment.

Front 38

The corrosion process can be accelerated by certain bacterial organisms because they produce which chemical?

Back 38

CO2

Front 39

What chemical would be best to use for corrosion inhibition if the water is very low in alkalinity and calcium concentration?

Back 39

Polyphosphates

Front 40

If the temperature drops below _______ a 50% solution of caustic soda will begin to crystallize.

Back 40

54 degrees F

Front 41

When chlorine has destroyed all reducing compounds, any chlorine remaining will react with __________

Back 41

ammonia and form chloramines.

Front 42

Low values for what water characteristic usually cause poor coagulation, flocculation, and settling characteristics?

Back 42

Water Temperature

Front 43

Polyphosphates would most likely give the best results at _________.

Back 43

low pH values.

Front 44

What is the most effective disinfectant for inactivating bacteria?

Back 44

Hypochlorous Acid

Front 45

What chemical oxidant is the weakest?

Back 45

Chloramines

Front 46

What is the density of liquid chlorine?

Back 46

1.50

Front 47

What device(s) uniformly disperse(s) the chlorine solution into the main flow of water?

Back 47

Diffusers

Front 48

The pressure is a chlorine cylinder depends on the ____________.

Back 48

temperature of the chlorine liquid.

Front 49

Sodium bicarbonate needs to be stored in a cool, dry place because it decomposes rapidly as the temperature nears _______.

Back 49

100 degrees F

Front 50

In the breakpoint chlorination curve, in which zone do inorganic chlorine demand-causing compounds consume free chlorine?

Back 50

Zone 1

Front 51

What is the optimal pH level for sulfate-forming reactions with chlorine?

Back 51

6

Front 52

Liquid chorine is what color?

Back 52

Amber

Front 53

When chlorine gas is under a vacuum reliquefaction will not occur until the temperature drops below ____.

Back 53

-30 degrees F

Front 54

What method can be used to control scale and corrosion?

Back 54

pH and alkalinity adjustment with lime.

Front 55

What is the chemical formula for hydrated lime?

Back 55

Ca(OH)2

Front 56

Once iron bacteria become established in a well, shock chlorination will be required. The shock treatment is required _________.

Back 56

at increasingly shorter intervals.

Front 57

What should accompany shock treatment to maximize its effectiveness for a well that has been fouled by iron bacteria?

Back 57

Air surging, valved surge blocks, or jetting