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Top Ops Water Grade 3 & 4 > Water Treatment Grades 3 & 4 > Flashcards

Water Treatment Grades 3 & 4 Flashcards

1
Q

Which disinfectant would work best against Cryptosporidium?
a. Ozone
b. Dichloramine
c. Hypochlorite ion
d. Hypochlorous acid

A

a. Ozone

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2
Q

The pH (actual) of a water sample is greater than the pHs (saturation), so the Langelier index
a. indicates that the water is corrosive.
b. is negative.
c. indicates that the water is scale forming.
d. indicates that the water is stable.

A

c. indicates that the water is scale forming.

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3
Q

When water high in calcium bicarbonate is softened by ion exchange
a. all cations are removed.
b. regeneration is usually accomplished by an acid.
c. lime is used at a pH of 9.5.
d. sodium bicarbonate remains in the product water.

A

d. sodium bicarbonate remains in the product water.

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4
Q

Lime softening can effectively disinfect water because
a. particles containing microorganisms are settled out in the process.
b. the pH level is higher than 10.5.
c. the pH level is below 10.5.
d. microorganisms are sensitive to calcium levels.

A

b. the pH level is higher than 10.5.

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5
Q

A noncarbonate hardness compound is
a. CaCO3 (calcium carbonate)
b. MgCO3 (magnesium carbonate)
c. Ca(HCO3)2 (calcium bicarbonate)
d. MgSO4 (magnesium sulfate)

A

d. MgSO4
(magnesium sulfate)

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6
Q

What term refers to the reintroduction of carbon dioxide into water either during or after lime-soda ash softening?
a. Regeneration
b. Recarbonization
c. Replenishment
d. Recycling

A

b. Recarbonization

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7
Q

_____ is the oxidation of unprotected metal surfaces.
a. Corrosion
b. Saturation
c. Softening
d. Chelation

A

a. Corrosion

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8
Q

What is the cause of carbonate hardness?

A

Calcium Bicarbonate

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9
Q

Which two ions are most commonly associated with water hardness?

A

Calcium & Magnesium

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10
Q

For noncarbonate hardness to be removed, what must be added to remove the noncarbonate calcium compounds?

A

Soda Ash

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11
Q

A bypass valve would be used with a
a. gate valve.
b. butterfly valve.
c. needle valve.
d. diaphragm valve.

A

a. gate valve.

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12
Q

Where ground frost is expected, the riser pipes in a meter pit should be at least _____ away from any wall in the meter box to prevent freezing.
a. 1 - 2 inches
b. 2 - 4 inches
c. 4 - 6 inches
d. 6 - 8 inches

A

a. 1 - 2 inches

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13
Q

Which type of pipe joint is available in both, bolted and boltless flexible pipe joint designs?
a. Ball and socket
b. Push-on joint
c. Grooved joint
d. Shouldered joint

A

a. Ball and socket

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14
Q

Which type of pipe joint permits flexible pipe alignment, is inexpensive to manufacture, and is easy to assemble?
a. Mechanical joint
b. Push-on joint
c. Grooved joint
d. Ball and socket joint

A

b. Push-on joint

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15
Q

New polyvinyl chloride pipe has a C-value of about
a. 125.
b. 125 - 128.
c. 135.
d. 150+.

A

d. 150+.

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16
Q

Which type of valve would be particularly useful for throttling the flow of corrosive liquids?
a. Diaphragm valve
b. Butterfly valve
c. Gate valve
d. Pinch valve

A

d. Pinch valve

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17
Q

Water meter pits are usually used in
a. areas where flooding will most likely occur.
b. areas where flooding is very rare.
c. cold climates.
d. hot climates

A

c. cold climates

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18
Q

Fuel oil will permeate which type of pipe?
a. Lead pipe
b. Polyethylene pipe
c. Copper pipe
d. Galvanized pipe

A

b. Polyethylene pipe

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19
Q

How do you calculate the Specific Gravity of a chemical?

A

Chemical lbs/gal divided by 8.34 lbs/gal

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20
Q

In describing pump operation, what type of curve shows the relationship between power and capacity?
a. E - Q curve
b. H - Q curve
c. P - Q curve
d. E - P curve

A

c. P - Q curve

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21
Q

List the type of head pressures used in describing the amount of energy in water.

A
  • Velocity head
  • Pressure head
  • Elevation head
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22
Q

The amount of energy used up by water when moving from one point to another is called what?

A

Head Loss

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23
Q

What’s it called when the reservoir feeding the pump is lower than the pump, the difference in elevation between the pump center line and the free water surface of the reservoir feeding the pump?

A

Static Suction Lift

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24
Q

The amount of work done in a given amount of time.

A

Power

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25
Q

If a water system collects at least 40 sample a month for analysis of total coliforms, what percentage of total coliform positive samples are acceptable for the system to remain in compliance with the maximum contaminant level for total coliforms?
a. No more than 2%
b. No more than 3%
c. No more than 4%
d. No more than 5%

A

d. No more than 5%

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26
Q

Water systems are required to achieve at least _____ removal and/or inactivation of viruses between a point where raw water is not subject to be recontamination by surface water runoff and a point downstream before the first customer.
a. 2-log
b. 2.5-log
c. 3-log
d. 4-log

A

d. 4-log

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27
Q

Where are the sampling points located for required sampling of organics (except trihalomethanes) in a community system?
a. Representative points within the distribution system
b. 75% at locations representative of the population distribution and 25% at the farthest points in the distribution system
c. Entry points to the distribution system
d. Entry points to the distribution system and representative points within the distribution system

A

c. Entry points to the distribution system

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28
Q

Where are the sampling point(s) located for required sampling of natural radionuclides in a community water system?
a. Consumer’s faucet
b. Representative points within the distribution system
c. Each entry point to the distribution system
d. 75% at locations representative of the population distribution and 25% at the farthest points in the distribution system

A

c. Each entry point to the distribution system

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29
Q

Continuous chlorine monitoring is required where the water enters the distribution system under the Surface Water Treatment Rule when the
a. population served is greater than 3,300 people.
b. population is greater than 10,000 people.
c. number of taps is greater than 1,000.
d. number of taps is greater than 2,500.

A

a. population served is greater than 3,300 people.

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30
Q

A community water system must post the Consumer Confidence Report (CCR) on a publicly accessible website if it serves more than
a. 10,000 people.
b. 25,000 people.
c. 50,000 people.
d. 100,000 people.

A

d. 100,000 people.

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31
Q

Public water systems that cannot meet the required removal of total organic compounds (TOCs) can comply if the source-water TOC level is _____, calculated quarterly as a running annual average.
a. less than 1.0 mg/L
b. less than 2.0 mg/L
c. less than 2.5 mg/L
d. less than 5.0 mg/L

A

b. less than 2.0 mg/L

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32
Q

The Surface Water Treatment Rule does NOT specify which of the following treatment technologies?
a. Conventional treatment
b. Membranes
c. Slow sand filtration
d. Chloramine disinfection

A

d. Chloramine disinfection

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33
Q

A regulated contaminant concentration that exceeds the MCL
a. is a Tier 1 violation requiring public notification within 24 hours.
b. is a Tier 2 violation requiring public notification within 30 days.
c. is a Tier 3 violation requiring public notification within 12 months.
d. does not require public notification.

A

b. is a Tier 2 violation requiring public notice within 30 days.

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34
Q

Operators must balance satisfying regulations on the amount of certain chlorinated organic compounds with
a. controlling water hardness.
b. meeting disinfection limits.
c. keeping turbidity below 0.1 ntu.
d. reducing iron levels below the MCL.

A

b. meeting disinfection limits.

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35
Q

A water system using conventional filtration treatment does not have to use enhanced coagulation to achieve the total organic carbon (TOC) percent removal if
a. the total trihalomethanes running annual average is less than or equal to 0.030 mg/L.
b. the sum of haloacetic acids is less than or equal to 0.040 mg/L.
c. the treated water quarterly average TOC is less than 4.0 mg/L.
d. the treated water quarterly running annual average TOC is less than 2.0 mg/L.

A

d. the treated water quarterly running annual average TOC is below 2.0 mg/L.

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36
Q

The Stage 1 DBPR established an MCL of _____ for TTHM (total trihalomethanes).
a. 2.10 mg/L
b. 0.08 mg/L
c. 1.05 mg/L
d. 1.00 mg/L

A

b. 0.08 mg/L

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37
Q

The Safe Drinking Water Act defines a public water system as a supply of piped water for human consumption that has at least _____ service connections, or serves _____ or more persons 60 or more days each year.
a. 15; 25
b. 25; 15
c. 20; 50
d. 10; 25

A

a. 15; 25

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38
Q

Under the enhanced coagulation requirements of the DBPR, treatment plants must remove specific percentages of total organic carbon based on their source water total organic carbon and what other factor?

A

Alkalinity Levels

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39
Q

The Filter Backwash Rule applies to what sizes of systems?

A

All Sizes

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40
Q

Which rule most directly guards against the presence of Escherichia coli in the water system?

A

Total Coliform Rule (TCR)

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41
Q

Which type of sample should always be collected for determining the presence of coliform bacteria?
a. Time composite
b. Grab sample
c. Proportional
d. Composite

A

b. Grab Sample

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42
Q

Water that is to be analyzed for inorganic metals should be acidified with
a. dilute hydrochloric acid.
b. concentrated hydrochloric acid.
c. dilute nitric acid.
d. concentrated nitric acid.

A

d. concentrated nitric acid.

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43
Q

Which chemical is used to remove chlorine from water?
a. Na2S2O3 (sodium thiosulfate)
b. Na2SiO3 (sodium silicate or liquid glass)
c. Na2Sif6 (sodium hexafluorosilicate)
d. NaOCL (sodium hypochlorite)

A

a. Na2S2O3 (sodium thiosulfate)

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44
Q

A typical coliform colony in the membrane filter method has the following characteristics:
a. Blue with a lustrous surface sheen
b. Pink to dark red with a green metallic surface sheen
c. Pink or yellow with a lustrous to metallic surface sheen, depending on species
d. Yellow with a silver metallic lustrous surface sheen

A

b. Pink to dark red with a green metallic surface sheen

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45
Q

Which of the following is the first level of total dissolved solids that is considered unfit for human consumption?
a. 1,000 mg/L
b. 2,500 mg/L
c. 4,000 mg/L
d. 5,000 mg/L

A

c. 4,000 mg/L

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46
Q

Which type of special photometer is used to analyze for heavy metals in water?
a. Electrophotometer
b. Magnetphotometer
c. Spectrophotometer
d. Atomic adsorption spectrophotometer

A

a. Atomic adsorption spectrophotometer

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47
Q

In the multiple-tube fermentation method, which type of culture media is used in the coliform test?
a. Lactose agar
b. Green lactose bile broth
c. Eosin methylene red agar
d. Glucose bile tubes

A

b. Green lactose bile broth

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48
Q

All positive samples in the presence-absence (P-A) test must be confirmed using
a. brilliant green bile tubes.
b. eosin methylene red agar.
c. lauryl tryptose broth.
d. eosin 12-amino acid broth.

A

a. brilliant green bile tubes.

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49
Q

What is pHs?
a. pH oh a solution
b. The Langelier index
c. pH saturation
d. Salt pH

A

c. pH saturation

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50
Q

_____ is the measure of the hydrogen ion concentration present in water.
a. Turbidity
b. pH
c. Gas chromatography
d. Covalence

A

b. pH

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51
Q

What three steps are involved with the multiple-tube fermentation method?

A
  • Presumptive test
  • Confirmed test
  • Completed test
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52
Q

Conductivity (specific conductance) is a measure of the ability of an aqueous solution to do what?

A

Carry an electrical current

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53
Q

What are characteristics of carbon dioxide?

A

A colorless, odorless, noncombustible gas that is found in all waters

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54
Q

In regard to the testing of coagulant effectiveness, which method is the most readily available to most operators and has been commonly used for many years?

A

Jar Test

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55
Q

Which of the following does the saturation point of calcium carbonate primarily depend on?
a. pH
b. Temperature
c. Concentration of calcium
d. Total dissolved solids

A

a. pH

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56
Q

Which of the following will increase pH, hardness, and alkalinity?
a. Sodium hydroxide
b. Zinc orthophosphate
c. Lime
d. Sodium zinc phosphate

A

c. Lime

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57
Q

Which chemical is used for stabilization of potable water is a bacteriological nutrient?
a. Polyphosphate
b. Lime
c. Soda ash
d. Sodium bicarbonate

A

a. Polyphosphate

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58
Q

Wastewater water quality discharge requirements could be extended if which of the following chemicals are used for corrosion control in the water system?
a. Silicate
b. Hexametaphosphate
c. Calcium hydroxide
d. Caustic

A

b. Hexametaphosphate

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59
Q

Lime is commonly used for corrosion control because
a. it can adjust both, alkalinity and pH.
b. it precipitates most particles.
c. it is more effective than caustic.
d. most treatment plants already use it for other purposes.

A

a. it can adjust both, alkalinity and pH.

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60
Q

Buildup of corrosion products (a process known as _____) or uncontrolled scale deposits can seriously reduce pipeline capacity and increase resistance to flow.
a. scaling
b. turbidity
c. tuberculation
d. sludge

A

c. tuberculation

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61
Q

Unslaked lime is also referred to as
a. sodium carbonate.
b. calcium dioxide.
c. quicklime.
d. calcium hydroxide.

A

c. quicklime.

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62
Q

Of the metals, tin, mild steel, zinc, and aluminum, which is most likely to corrode?

A

Zinc

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63
Q

What is the principal source of excessive lead and copper in customers’ water?

A

Corrosion of materials in household plumbing systems

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64
Q

What are three reasons why lime is the most common chemical used for pH and alkalinity adjustment.

A
  • It is relatively easy to feed
  • It is inexpensive compared with other chemicals
  • It is readily available
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65
Q

Which chemical is used to stabilize water after it has been lime-softened?
a. Sulfuric acid
b. Carbon dioxide
c. Sodium hydroxide
d. Zinc orthophosphate

A

b. Carbon dioxide

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66
Q

Usually, raw water can be softened with lime alone when it contains
a. mostly calcium hardness.
b. mostly magnesium hardness.
c. very little carbonate hardness.
d. little to no noncarbonate hardness.

A

d. little to no noncarbonate hardness.

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67
Q

In the lime-soda ash softening process. the soda ash dosage is based
a. only on the amount of carbonate and magnesium hardness to be removed.
b. on the amount of carbonate and carbon dioxide to be removed.
c. primarily on the amount of noncarbonate and magnesium hardness.
d. only on the amount of noncarbonate hardness to be removed.

A

d. only on the amount of noncarbonate hardness to be removed.

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68
Q

Recarbonization after lime-soda ash softening is required to remove calcium carbonate that is in suspension to prevent
a. deposition of the calcium carbonate in the clearwell and the distribution system.
b. scale forming in the distribution piping.
c. customer complaints of turbidity and color.
d. cementation of filter media.

A

d. cementation of filter media.

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69
Q

Which type of hardness usually calls for a two-stage softening process?
a. calcium hardness above 100 mg/L
b. Magnesium hardness
c. Noncarbonate hardness
d. Carbonate hardness

A

c. Noncarbonate hardness

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70
Q

The concentration of solids in the lower level of a sludge blanket in a softening facility’s solids contact basin should be
a. 2 - 7%
b. 5 - 15%
c. 15 - 20%
d. 25 - 30%

A

b. 5 - 15%

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71
Q

It is impossible to produce waters with a hardness less than _____ when using the lime-soda ash process.
a. 9 mg/L
b. 17 mg/L
c. 25 mg/L
d. 50 mg/L

A

c. 25 mg/L

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71
Q

Softened water has a high pH and a high concentration of calcium carbonate. Therefore, stabilization is essential in order to prevent the calcium carbonate from precipitating out
a. in household plumbing.
b. in the clearwell.
c. in the distribution system.
d. on the filters.

A

d. on the filters.

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72
Q

Soda ash is added to water in the lime softening process for what purpose?
a. To disinfect the water and kill the vast majority of protozoans, viruses, bacteria, and other multicellular organisms
b. To raise the pH of the water
c. To decrease the CO2 in the water
d. To remove noncarbonate hardness

A

d. To remove noncarbonate hardness

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73
Q

If soda ash dust, or solution, or lime slurry gets into the eyes, flush the eyes with warm water for at least 15 minutes, and consult a physician
a. immediately.
b. if redness of the eyes occurs.
c. if policy requires.
d. within 24 hours.

A

a. immediately.

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74
Q

Flocculation requires _____ mixing to allow the chemical reactions to be completed and to promote the growth and precipitation of floc.
a. rapid, continuous
b. steady, forceful
c. slow, gentle
d. sporadic

A

c. slow, gentle

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75
Q

What are three specific types of alkalinities?

A
  • Bicarbonate alkalinity
  • Hydroxide alkalinity
  • Carbonate alkalinity
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76
Q

Carryover of sludge solids is often most severe when a considerable portion of the settleable solids is composed of what type of floc particles?

A

Magnesium hydroxide

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76
Q

Natural zeolites used for softening that have become exhausted with use are regenerated by a strong solution of what chemical?
a. NaCl
b. NaOH
c. HCl
d. H2SO4

A

a. NaCl

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77
Q

To prevent scale buildup, magnesium hardness should be reduced to what level through excess-lime treatment?

A

40 mg/L or less

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78
Q

Softening resin exchanges what for the calcium and magnesium that it removes from the water?
a. Sodium
b. Hydroxide
c. Potassium
d. Hydrogen ions (H+)

A

a. Sodium

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78
Q

Ion exchange process can typically be used for direct groundwater treatment as long as turbidity and _____ levels are not excessive.
a. calcium carbonate
b. iron
c. carbon dioxide
d. sodium sulfate

A

b. iron

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79
Q

What are the exchange capacities of natural zeolites?
a. 1 - 2 kilograins/ft3
b. 3 - 5 kilograins/ft3
c. 5 - 8 kilograins/ft3
d. 9 - 12 kilograins/ft3

A

b. 3 - 5 kilograins/ft3

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80
Q

The method of resin renewal is called
a. regeneration.
b. recycling.
c. replenishment.
d. renewal.

A

a. regeneration.

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80
Q

In converting hardness, 1 grain/gal =
a. 14 mg/L
b. 100 mg/L
c. 17.1 mg/L
d. 27.8 mg/L

A

c. 17.1 mg/L

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81
Q

What should the hardness level of water leaving the ion exchange vessel be?

A

Zero

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82
Q

Electrodialysis is used mainly for what process rather than exclusively for softening?

A

Desalination

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83
Q

If an operator knows the exchange capacity of the resin bed, the hardness of water, and the flow rate pf the water through the bed, he or she can predict what?

A

The length of the softening cycle

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84
Q

When should core samples be collected from filters using granular activated carbon?
a. Every 6 months
b. At the time of installation and every 6 months thereafter
c. Every year after installation
d. At the time of installation and every year thereafter

A

b. At the time of installation and every 6 months thereafter

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85
Q

Which bed expansion during backwash must be achieved for filter using granular activated carbon?
a. 29%
b. 25%
c. 30%
d. 50%

A

d. 50%

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86
Q

What is the best approach for feeding powdered activated carbon?
a. Along with prechlorination
b. After filtration
c. After at least 15 minutes following chlorine addition
d. In the chlorine contact chamber

A

b. After filtration

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87
Q

Backwashing rate procedures should be reassessed to determine the cause of granular activated carbon loss if the loss per year exceeds
a. 2 inches
b. 4 inches
c. 6 inches
d. 8 inches

A

a. 2 inches

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88
Q

In regard to safety, wet activated carbon will remove which of the following from the air?
a. Organic gasses and hydrogen sulfide
b. Oxygen
c. Carbon dioxide
d. Carbon monoxide

A

b. Oxygen

89
Q

Which of the following is the most probable cause of tastes and odors persisting or worsening when powdered activated carbon (PAC) is used?
a. PAC is added at the inlet
b. PAC is added during flocculation
c. PAC and chlorine are added too close to each other
d. PAC is added to water with too high of alkalinity

A

c. PAC and chlorine are added too close to each other

90
Q

Because powdered activated carbon is a fine powder,
a. it can dissolved too quickly in solution.
b. dust can be a major problem.
c. it is sold only in small supplies.
d. its cost is prohibitively expensive.

A

b. dust can be a major problem.

91
Q

If the bed is not adequately cleaned, both filtration and adsorption capacity will be lost, and _____ will begin to form.
a. disinfection by-products
b. floc
c. chlorine residuals
d. mudballs

A

d. mudballs

92
Q

The distance between the top of the carbon and the top of the wash-water troughs (or other reference mark) should be measured at least how often to determine the rate of carbon loss?

A

Every three months

93
Q

Because bacteria can thrive in granular activated carbon filters, standard plate count analysis should be performed how often on filtered water and the water after final chlorination?

A

Every day

94
Q

What is the greatest operational challenge with powdered activated carbon (PAC)?

A

Handling it

95
Q

Aeration can cause what problems in filters?
a. Precipitation of odor compounds
b. Increased color
c. Mudball formation
d. Air binding

A

d. Air binding

96
Q

Which of the following is NOT one of the three basic control tests involved with the aeration process?
a. Dissolved oxygen
b. pH
c. Temperature
d. Iron

A

d. Iron

97
Q

As water temperature _____, the operator must adjust the aeration process to maintain the correct level od DO (dissolved oxygen).
a. drops
b. increases
c. stabilizes
d. approaches freezing

A

a. drops

98
Q

The process by which the spaces between the media particles begin to fill up with air bubbles is known as
a. air stripping.
b. oxidation.
c. air binding.
d. oxygen saturation.

A

c. air binding.

99
Q

What are the basic control tests for aeration?

A
  • Dissolved oxygen
  • pH
  • Temperature
99
Q

One of the better procedures for eliminating hydrogen sulfide is to lower the pH to _____ or less before beginning aeration.
a. 8
b. 6
c. 7
d. 4

A

b. 6

100
Q

What removal process is most effective for hydrogen sulfide?

A

Scrubbing at a pH of 6 or less

101
Q

The quantity of water treated by the aeration process should be measures how often?

A

Daily

102
Q

Reverse osmosis membranes will compact waster with
a. higher iron content.
b. higher chlorine contact.
c. higher pressure.
d. higher pH.

A

c. higher pressure.

103
Q

Reverse osmosis reject water cannot be disposed by
a. discharge to wastewater treatment plant.
b. deep well injection.
c. using as drinking water.
d. evaporation ponds.

A

c. using as drinking water.

103
Q

Reverse osmosis membrane cleaning solution feed systems are constructed of
a. stainless steel.
b. copper piping.
c. black iron pipe.
d. Teflon.

A

a. stainless steel.

104
Q

The amount of reject water from a reverse osmosis unit is dependent on the number of stages in which the membranes are configured and the
a. feed pressure.
b. amount of cations.
c. amount of cations and anions.
d. pH of water.

A

a. feed pressure.

105
Q

Over time, the performance of all membranes will change, mainly as a result of compaction and
a. swelling.
b. festering.
c. fouling.
d. disintegrating.

A

c. fouling.

106
Q

The flow of solution adjacent or parallel to the surface of the membrane is referred to as
a. crossflow.
b. direct flow.
c. flux.
d. differential flow.

A

a. crossflow.

107
Q

What is the term for raw water that has undergone pretreatment (acidification or scale inhibitor) prior to entering the membrane arrays?

A

Feedwater

108
Q

What term refers to the process of forcing a liquid through a nonporous membrane, thereby removing particles, dissolved molecules, and ions?

A

Reverse Osmosis

109
Q

The process by which membrane performance gradually changes as a result of compaction is called what?

A

Flux decline

110
Q

Ozone is NOT introduced into the water by
a. air stripping towers.
b. fine-bubble diffusers.
c. spray chambers.
d. injectors.

A

a. air stripping towers.

110
Q

Which oxidant has the potential of producing chlorate (ClO3) by-products?
a. Chlorine dioxide
b. Chlorine
c. Chloramines
d. Calcium hypochlorite

A

a. Chlorine Dioxide

111
Q

Potassium permanganate should be fed
a. after filtration.
b. after chlorination.
c. as pretreatment.
d. together with chlorine.

A

c. as pretreatment.

112
Q

Ozone generators
a. are capable of producing extra electricity.
b. create ozone by exposing oxygen to an electric discharge.
c. can use water as an oxygen source.
d. discharge any excess ozone to the air.

A

b. create ozone by exposing oxygen to an electric discharge.

113
Q

UV disinfection
a. converts nitrate to nitrite.
b. changes bromide to brominated organic compounds.
c. is insensitive to temperature and pH.
d. leaves a lasting residual in treated water.

A

c. is insensitive to temperature and pH.

114
Q

Which method for chlorine dioxide generation is most likely to have substantial amounts of chlorine in solution?
a. Add chlorine to water, then this water to sodium citrate and sodium chlorate.
b. Add chlorine to water, then this water to hydrochloric acid and sodium chlorate.
c. Inject chlorine gas under vacuum into a stream of chlorite solution.
d. Add hydrochloric acid to a chlorite solution.

A

b. Add chlorine to water, then this water to hydrochloric acid and sodium chlorate.

115
Q

When air is used as the feed gas for an ozone generator, it must be
a. warmed first.
b. moisturized first.
c. extremely dry.
d. converted to pure oxygen.

A

c. extremely dry.

115
Q

Because ozone cannot be stored,
a. it simplifies the treatment process for facilities.
b. it must be generated on-site as it is needed.
c. it must be used immediately upon delivery from the manufacturer.
d. it cannot be used in water treatment.

A

b. it must be generated on-site as it is needed.

116
Q

What are some devices available to introduce ozone into water to be treated?

A
  • Conventional fine-bubble diffuser
  • Turbine mixer
  • Injector
  • Packed columns
  • Spray chamber
117
Q

What authority sets the limits for the amount of ozone allowed in the treatment plant and in the area surrounding the plant?

A

Occupational Safety and Health Administration (OSHA)

118
Q

Permanganate dosages of what level are usually sufficient to control most oxidizable taste-and-odor causing compounds in raw water?

A

0.5 - 2.5 mg/L

119
Q

Which national law regulates underground disposal of wastes in deep wells?
a. The Toxic Substances Control Act (TSCA)
b. The Comprehensive Environmental Response, Compensation, and Liability Act (Superfund)
c. The Resource Conservation and Recovery Act (RCRA)
d. The Safe Drinking Water Act (SDWA)

A

d. The Safe Drinking Water Act (SDWA)

120
Q

What is typically the percentage of solid material in alum sludge?
a. 0.1 - 2.0%
b. 2.0 - 5.0%
c. 4.0 - 7.0%
d. 5.0 - 15.0%

A

a. 0.1 - 2.0%

121
Q

Which of the following is the most troublesome operating problem for sedimentation basins?
a. Algae and slime growths
b. Short-circuiting
c. Density currents
d. Sludge collection and removal

A

d. Sludge collection and removal

121
Q

Sludge produced by water drawn from sources with relatively low turbidity
a. is high in silt and organic content.
b. is high in liquid content.
c. can be very gelatinous and difficult to handle.
d. handles like clay.

A

c. can be very gelatinous and difficult to handle.

122
Q

The thicker the sludge,
a. the less expensive its disposal.
b. the less efficient its disposal.
c. the more expensive the disposal.
d. the greater the volume.

A

a. the less expensive its disposal.

122
Q

Which of the following is NOT a type of equipment used in mechanical dewatering?
a. Vacuum filters
b. Belt presses
c. Centrifuges
d. Hydrologic siphon

A

d. Hydrologic siphon

123
Q

In the past, to what locations were treatment residuals typically discharged?

A

To a stream or a lake

124
Q

What type of sludge is the most common residual produced in water plant sedimentation basins?

A

Alum sludge

125
Q

What term refers to the process of removing water from thin sludge, allowing the solid material to remain (thickening) for ultimate disposal?

A

Dewatering

126
Q

The “rule of reasonable sharing” of water is usually called the
a. riparian doctrine.
b. legal use doctrine.
c. priority use doctrine.
d. beneficial use doctrine.

A

a. riparian doctrine.

127
Q

The rule that landowners can “capture” all the water under only their land is called
a. correlative rights.
b. absolute ownership.
c. reasonable use.
d. appropriation-permit system.

A

b. absolute ownership.

128
Q

The rule that a landowner has a right to groundwater as long as it does not harm a neighbor is called
a. correlative rights.
b. absolute ownership.
c. reasonable use.
d. appropriation-permit system.

A

c. reasonable use.

129
Q

Which rule applies when the most important issue is priority, where water rights are based on who has used the water for the longest time?
a. Correlative rights
b. Absolute ownership
c. Reasonable use
d. Appropriation-permit system

A

d. Appropriation-permit system

130
Q

Which of the following would be the most profitable solution to control algae in the source water if the algae were clogging the filters at the water plant?
a. Use activated carbon
b. Decrease oxygen levels
c. Backwash filters more frequently
d. Control nutrients

A

d. Control nutrients

131
Q

a conventional water treatment plant in a rich farming area has to treat water high in nitrates. Which of the following is its best course of action in the long-term?
a. Manage watershed to prevent nitrates from entering the water system
b. Change its treatment to ion exchange
c. Change its treatment to reverse osmosis
d. Add a strong oxidation chemical before coagulation

A

a. Manage watershed to prevent nitrates from entering the water system

132
Q

When a water source is destroyed or damaged due to some sort of disaster that causes total contamination, which of the following would be a short-term goal?
a. Install a dual potable-nonpotable water system
b. Construct a new water source
c. Clean up the source of contamination caused by the disaster
d. Draw water from an adjoining system or systems

A

d. Draw water from an adjoining system or systems

133
Q

The main objective of a customer complaint response program is to
a. gain popularity for a rate increase.
b. address the customer’s concerns.
c. provide company information to the customer.
d. pacify the customer.

A

b. address the customer’s concerns.

134
Q

Typically, the greatest amount of water in residential use can be attributed to the
a. toilet.
b. washing machine.
c. shower.
d. faucet.

A

a. toilet.

134
Q

What are two general categories of catastrophes that can disrupt the operation of a water source?

A
  • Natural
  • Human-caused
135
Q

Water use rates for a community are typically the highest at what time of day?
a. 11 pm to 5 am
b. 6 pm to 10 pm
c. 5 am to 11 am
d. 11 am to 6 pm

A

b. 6 pm to 10 pm

136
Q

What system is based on the principal that the owner of the land owns everything beneath the land, all the way down to the center of the earth?

A

Absolute ownership

137
Q

What are three undesirable consequences of implementing a water conservation program?

A
  • Possible delays in developing additional source capacity
  • Loss of revenue for the utility
  • Difficulty in dealing with drought conditions
138
Q

Which of the following details is NOT recorded for each filter?
a. Rate of flow (in gpm or MGD)
b. Length of run and filter run volume (UFRV)
c. Expected length of filter life
d. Dosage of any filter aid used

A

c. Expected length of filter life

139
Q

How often should an operator record bed expansion measurements, condition and depth of media, and an evaluation of bed surface?
a. Daily
b. Quarterly
c. Hourly
d. Yearly

A

b. Quarterly

140
Q

Which authority suggests that the turbidity performance (and particle count, if available) in each sedimentation basin be recorded periodically (daily, every 4 hours, or hourly)?
a. The Partnership for Safe Water
b. The American Water Works Association
c. The US Environmental Protection Agency
d. The National Institute for Occupational Safety and Health

A

a. The Partnership for Safe Water

141
Q

Which standard covers materials that are in contact with drinking water, such as coatings, construction materials, and components used in processing and distribution of potable water?

A

NSF/ANSI Standard 61

142
Q

How often does the AWWA check that its standards are being met by each water system in the United States?

A

The AWWA does not monitor systems’ adherence to its standards

143
Q

Total dissolved minerals in rainwater are typically
a. low, resulting in very soft water.
b. such that they cause the pH to be above 8.
c. high in calcium.
d. high in nutrients.

A

a. low, resulting in very soft water.

144
Q

A confined aquifer
a. is the intersection of the water table with the surface.
b. cannot be a source of groundwater.
c. is free of pollutants.
d. is a permeable layer between layers of low permeability.

A

d. is a permeable layer between layers of low permeability.

145
Q

The least important issue when considering the selection of the most suitable water treatment process is
a. the water source characteristics.
b. the product water quality.
c. legislative initiative.
d. the capital and operating costs.

A

c. legislative initiative.

146
Q

A treatment plant that incorporates coagulation, sedimentation, filtration, and disinfection is
a. the most common system for treating groundwater.
b. an example of the multi-barrier approach.
c. the least costly treatment plant to operate.
d. mainly used for the removal of iron.

A

b. an example of the multi-barrier approach to treatment.

147
Q

Slow surface runoff
a. can infiltrate the ground and recharge aquifers.
b. causes erosion.
c. dissolves only small amounts of minerals from the soil.
d. mainly used for the removal of iron.

A

a. can infiltrate the ground and recharge aquifers.

148
Q

What is the duration of the general test period to confirm design capacity for a public water supply well that is an unconfined aquifer?
a. At least 24 hours
b. At least 48 hours
c. At least 72 hours
d. At least 96 hours

A

c. At least 72 hours

149
Q

What contaminants commonly found in groundwater most often affect potability?
a. Calcium and magnesium
b. Low amounts of arsenic and radium 228
c. Low concentrations of iron and manganese
d. Chloride and sulfur

A

b. Low amounts of arsenic and radium 228

150
Q

The static water level in a well is
a. the water surface level when the well is being pumped.
b. the water surface level after 24 hours of use.
c. the water surface level when no water is being taken from the aquifer.
d. the water surface level when the pump is off, but other wells nearby are operating.

A

c. the water surface level when no water is being taken from the aquifer.

151
Q

What is the specific capacity of a well with a yield of 100 gpm and a drawdown of 20 ft?
a. 2,000 gal/ft
b. 0.2 gal/ft
c. 10 gal/ft
d. 5 gal/ft

A

d. 5 gal/ft

152
Q

A common method of drilling a water supply well is
a. the cable tool method.
b. the hydraulic jet method.
c. the Texas method.
d. the drive method.

A

a. the cable tool method.

153
Q

Surface water is stored for later use
a. in a river.
b. in an impoundment.
c. in soil.
d. in a water plant.

A

b. in an impoundment.

154
Q

The water supply intake structures used in lakes and reservoirs do NOT include
a. submerged intakes.
b. multiple port intakes.
c. riverbed infiltration galleries.
d. pump intakes.

A

c. riverbed infiltration galleries.

155
Q

Algae control in a lake or reservoir is most effective if
a. alkalinity is above 50 mg/L and pH is 7.
b. alkalinity is below 50 mg/L and pH is 7.
c. alkalinity is above 50 mg/L and pH is 8 - 9.
d. alkalinity is below 50 mg/L and pH is 8 - 9.

A

d. alkalinity is below 50 mg/L and pH is 8 - 9.

156
Q

Stratification in lakes and reservoirs
a. occurs when a warm layer of water overlies a colder layer.
b. separates segments of the water column.
c. occurs when all the water is 4 degrees C from top to bottom.
d. is good because it creates an anerobic zone near the bottom.

A

a. occurs when a warm layer of water overlies a colder layer.

157
Q

Zebra mussels are often controlled by adding
a. chlorine in the treatment plant finished water.
b. chlorine at the plant intake.
c. calcium carbonate in the plant intake.
d. copper sulfate after filtration in the plant.

A

b. chlorine at the plant intake.

158
Q

Screens located on an intake structure to remove sticks, logs, and other large debris are usually called
a. microstrainers.
b. cyclones.
c. pleated filters.
d. trash racks.

A

d. trash racks.

159
Q

Screen equipment is constantly wetted and dried, creating
a. conditions ideal for accelerated corrosion.
b. opportunities for inspection.
c. caking and clogging.
d. a condition where debris can fall off.

A

a. conditions ideal for accelerated corrosion.

160
Q

Systems that have been installed _____ have found that the solids loading of the water entering the treatment plant is reduced.
a. venturi meters
b. plate or tube settlers
c. static mixers
d. chlorination facilities

A

b. plate or tube settlers

161
Q

Microstrainers can improve sand filter operation by removing
a. 50 - 90% of the filter-clogging material.
b. viruses and bacteria.
c. dissolved iron and manganese.
d. Giardia and cryptosporidium.

A

a. 50 - 90% of the filter-clogging material.

162
Q

Source water treatment with _____ is called preoxidation.
a. alum
b. lime
c. ozone
d. electrolysis

A

c. ozone

163
Q

Which of the following is a disadvantage of using static mixers?
a. They do not provide good mixing
b. They are not economical
c. Thet increase head pressure
d. They require too much maintenance

A

c. They increase head pressure

164
Q

Iron salt coagulants are effective _____ than alum.
a. over a wider pH range
b. and less corrosive
c. but, add iron to the water
d. and are less expensive

A

a. over a wider pH range

165
Q

_____ is NOT a classification of polyelectrolytes used as polymer coagulation aids.
a. Cationic
b. Anionic
c. Activated silica
d. Nonionic

A

c. Activated silica

166
Q

Which of the following is a positive displacement pump used to feed liquid chemicals?
a. Peristaltic pump
b. Velocity pump
c. Centrifugal pump
d. Turbine pump

A

a. Peristaltic pump

167
Q

If the activation process of silica is not carefully controlled,
a. the silica could splash due to high heat of reactants.
b. if could inhibit floc formation.
c. it could corrode and destroy the metal and rubber in the flocculators.
d. it could deposit silica on the flocculators and the gears, bringing it eventually to a grinding halt.

A

b. it could inhibit floc formation.

168
Q

If the flocculation time is too long,
a. floc is reduced and flows over the weir.
b. fragile flocs can break up.
c. floc mixing speed should be increased.
d. the flow should be decreased.

A

b. fragile flocs can break up.

169
Q

At which minimum angle must self-cleaning tube settlers be placed?
a. 50 degrees
b. 65 degrees
c. 70 degrees
d. 75 degrees

A

a. 50 degrees

170
Q

At which angle should the parallel inclined plates be installed when using the shallow-depth sedimentation method?
a. 35 degrees
b. 45 degrees
c. 50 degrees
d. 60 degrees

A

b. 45 degrees

171
Q

Why do solids-contact basins have much shorter detention times than conventional treatment basins?
a. Because chemical reactions take place throughout the basin.
b. Because the settling zone water moves upward, while at the same time the mixing zone water moves upward.
c. Because the gentle upward flow of the water throughout the basin is conducive for producing larger settleable floc.
d. Because of the recycled materials from the sludge blanket, the chemical reactions occur more quickly and completely inn the mixing area.

A

d. Because of the recycled materials from the sludge blanket, the chemical reactions occur more quickly and completely in the mixing area.

172
Q

Pulsator clarifiers are used to treat water that is
a. low in temperature, usually less than 50 degrees F (10 degrees C).
b. high in color and low in turbidity.
c. low in color and high in turbidity.
d. high in organic acids.

A

b. high in color and low in turbidity.

173
Q

Typically, the time between backwashing (rinsing) of Trident (or Roberts) contact adsorption clarifiers averages
a. 4 - 8 hours.
b. 16 - 24 hours.
c. 1 - 2 days.
d. 3 - 5 days.

A

a. 4 - 8 hours.

174
Q

Which high-rate process uses microsand?
a. Tube settlers
b. Superpulsators
c. Actiflo process
d. Dissolved-air flotation

A

c. Actiflo process

175
Q

In dissolved-air flotation units, mechanical rubber scrapers travel over the tank surface and push the float over a ramp, called a
a. trap.
b. beach.
c. launder.
d. loading plate.

A

b. beach.

176
Q

Filtration by granular media depends in part on _____, where suspended particles contact and stick onto the surface of the filter media grains.
a. adsorption
b. suspension
c. flotation
d. dissolution

A

a. adsorption

177
Q

Typically, the amount of backwash water used for dual-media filters should never exceed _____ of the amount of treated water.
a. 4%
b. 6%
c. 8%
d. 10%

A

b. 6%

178
Q

Direct filtration is used to treat raw water that has average turbidities
a. below 10 ntu.
b. up to 25 ntu.
c. of 40 - 50 ntu.
d. above 50 ntu.

A

b. up to 25 ntu.

179
Q

Diatomaceous earth filters
a. have a relatively high installation cost.
b. have relatively high operating costs.
c. are used only for water with low turbidity.
d. produce very little backwash sludge.

A

c. are used only for water with low turbidity.

180
Q

An advantage of a variable declining-rate filtration system is that
a. it does not require a loss-of-head indicator.
b. it does not require a rate-of-flow indicator.
c. individual filters keep a constant filtration rate.
d. flow rate changes do not impact the system.

A

b. it does not require a rate-of-flow indicator.

181
Q

Chlorine is advantageous over chloramines in that chlorine
a. is a much stronger oxidant.
b. has a long history of use.
c. is simple to feed.
d. has a persistent residual.

A

a. is a much stronger oxidant.

182
Q

A single chlorine cylinder is delivering 48 lb/d of chlorine to the water process, causing the cylinder to form a little frost. Which of the following would be the best solution to this problem?
a. Install a fan to improve circulation
b. Heat the cylinder immediately below the valve with heat tape
c. Heat the valve only
d. Add another cylinder and feed from both

A

d. Add another cylinder and feed from both

183
Q

Which emergency kit is for chlorine tank cars?
a. Kit A
b. Kit B
c. Kit C
d. Kit D

A

c. Kit C

184
Q

Which chlorine compound will produce the least detectable chlorinous taste and odor?
a. Hypochlorous acid
b. Monochloramine
c. Dichloramine
d. Nitrogen trichloride

A

b. Monochloramine

185
Q

A disadvantage of using chloramines is
a. their vulnerability to nitrification.
b. that they cannot penetrate biofilms in the distribution system.
c. their propensity to form trihalomethanes.
d. that their residual persistence in the distribution system is low.

A

a. their vulnerability to nitrification.

186
Q

A sodium hypochlorite system at room temperature will lose what percentage of its available chlorine content per month?
a. 1 - 2%
b. 2 - 4%
c. 4 - 6%
d. 6 - 8%

A

b. 2 - 4%

187
Q

Where is scale most likely to form in a hypochlorinator?
a. In the push rod
b. In the plunger
c. In the suction and discharge hoses
d. In the spring.

A

c. In the suction and discharge hoses

188
Q

Virgin greensand
a. does not require regeneration.
b. requires regeneration with potassium permanganate (1-hour soak with 60 grams KMnO4 per cubic foot of filter media).
c. requires regeneration with manganese dioxide (2-hour soak with 25% by weight, solution of MnO2).
d. requires regeneration with manganese hydroxide (4-hour soak with 200 grams Mn(OH)2 per cubic foot of filter media).

A

b. requires regeneration with potassium permanganate (1-hour soak with 60 grams KMnO4 per cu/ft media).

189
Q

Bacterial slimes formed due to iron and manganese in the distribution system
a. can increase pipeline flow capacity.
b. increase chlorine demand.
c. lubricate valves so they work easier for a short period.
d. decrease discoloration of household fixtures.

A

b. increase chlorine demand.

190
Q

Granular media filters can be used to remove iron and manganese precipitates without sedimentation if solids are under
a. 5 mg/L
b. 10 mg/L
c. 15 mg/L
d. 20 mg/L

A

a. 5 mg/L

191
Q

Another benefit of using potassium permanganate to oxidize both, iron and manganese is
a. it is a strong disinfectant.
b. pink water indicates that more is needed.
c. odor-causing compounds can be enhanced.
d. no trihalomethanes are formed.

A

d. no trihalomethanes are formed.

192
Q

Manganese greensand filter performance can be improved by adding a filter coal layer on top of the greensand to
a. increase the filter loading rate.
b. decrease the filter run time.
c. reduce solids loading on the greensand bed.
d. increase the operating head.

A

c. reduce solids loading on the greensand bed.

193
Q

At what thickness should the layer of sodium fluoride crystals be maintained in a saturator tank for flows less than 100 gpm?
a. 6-inches
b. 10-inches
c. 1 foot
d. 2 feet

A

a. 6-inches

194
Q

Which type of fluoride chemical should be used in downflow saturators?
a. Tablets of sodium fluorosilicate
b. Granular sodium silicofluoride
c. Crystalline sodium fluoride
d. Powdered sodium fluoride

A

c. Crystalline sodium fluoride

195
Q

Volumetric feeders are
a. usually more difficult to operate than gravimetric feeders.
b. more expensive to purchase than gravimetric feeders.
c. less expensive to maintain than gravimetric feeders.
d. more accurate than gravimetric feeders.

A

c. less expensive to maintain than gravimetric feeders.

196
Q

What safety equipment should be worn when handling fluoride chemicals?
a. No special equipment is required.
b. A respirator approved by NIOSH.
c. Leather or cotton work gloves.
d. An apron.

A

b. A respirator approved by NIOSH.

197
Q

Water used to prepare sodium fluoride solutions should be softened if the hardness exceeds _____ as calcium carbonate.
a. 50 mg/L
b. 75 mg/L
c. 100 mg/L
d. 125 mg/L

A

b. 75 mg/L

198
Q

Magnetic ion exchange resin has been developed to remove
a. total organic carbon.
b. chlorides.
c. iron and magnesium.
d. sulfates and sulfides.

A

a. total organic carbon.

199
Q

Natural zeolites used for softening that have become exhausted with use are regenerated by immersing them in a strong solution of which chemical?
a. NaCl
b. NaOH
c. HCL
d. H2SO4

A

a. NaCl

200
Q

Express a hardness of 100 mg/L as CaCO3 in grains per gallon:
a. 5.85
b. 1,710
c. 140.3
d. 10.0

A

a. 5.85

201
Q

Regeneration of the ion exchange media in the sodium cycle is called
a. rinsing.
b. backwashing.
c. recalcining.
d. brining.

A

d. brining.

202
Q

One common method of removing high levels of fluoride uses
a. aluminum chloralhydrate.
b. alum.
c. activated alumina.
d. activated carbon.

A

c. activated alumina.

203
Q

Water supply regulations require most treatment plants to record data on
a. customer relations.
b. electrical usage.
c. employee hours.
d. volume of water treated.

A

d. volume of water treated.

204
Q

An example of a source of direct current is
a. car battery.
b. household electrical outlet.
c. gasoline powered generator.
d. light fixture.

A

a. car battery.

205
Q

The simplest form of automation is
a. residential loop control.
b. start-stop control.
c. proportional control.
d. flow combined with proportional control.

A

b. start-stop control.

206
Q

When both, flow rate and the chlorine demand vary, what is the best type of control system?
a. Proportional control
b. Residual control
c. Floating proportional control
d. Compound PID loop control

A

d. Compound PID loop control

207
Q

Continuous monitoring is required for _____ to meet EPA regulations.
a. toxic chemicals
b. turbidity
c. bacteria
d. total organic carbon

A

b. turbidity

208
Q

A pump loses its prime because the suction line has an air pocket. What is the best solution?
a. Check the pump’s amperage and be sure its strainer is clean
b. Clean or repair the priming unit
c. Open the suction piping air bleed-off valves
d. Check the external water seal unit

A

c. Open the suction piping air bleed-off valves

209
Q

When the discharge velocity of a pump is blocked, head builds up, typically greater than the pressure generated during pumping. When this occurs, water recirculates within the pump impeller and casing. This flow condition is called
a. run-around.
b. skirting.
c. slip.
d. bypass.

A

c. slip.

210
Q

Vertical turbine pumps
a. are inexpensive to repair.
b. cost less than the same-sized centrifugal pump.
c. are easy to lubricate.
d. cannot pump water containing sand.

A

d. cannot pump water containing sand.

211
Q

The flow restriction between the impeller discharge and suction, necessary for all centrifugal pumps is made by
a. a coupling.
b. wear rings.
c. a shaft sleeve.
d. a packing ring.

A

b. wear rings.

212
Q

Centrifugal pump shaft alignment is important because
a. vibration from misalignment can cause bearing failure.
b. pump efficiency can be reduced.
c. the packing can become pinched, creating high running temperatures.
d. pump stalling can occur.

A

a. vibration from misalignment can cause bearing failure.

213
Q

SCBA used for emergency purposes require inspection by OSHA regulation
a. once a year.
b. quarterly.
c. monthly.
d. before each use.

A

c. monthly.

214
Q

Chlorine cylinders should be stored in a temperature-controlled area because
a. chlorine cannot be withdrawn when the temperature is too cold.
b. chlorine cylinder valves require a constant temperature.
c. fusible plugs can melt at high temperature, releasing chlorine.
d. operators need comfortable working conditions.

A

c. fusible plugs can melt at high temperatures, releasing chlorine.

215
Q

Treatment plant security requires _____ to prevent intruders from entering and causing harm.
a. video cameras
b. physical barriers
c. motion detectors
d. police presence

A

b. physical barriers

216
Q

Each year, approximately what percentage of confined space deaths are would-be rescuers?
a. 25%
b. 50%
c. 67%
d. 75%

A

c. 67%

217
Q

Effectively dealing with treatment disruptions due to employee strikes, natural disasters, and on-site emergencies that require quick support
a. requires careful contingency planning and training.
b. it the state’s responsibility.
c. is the responsibility of the Office of Homeland Security.
d. is the responsibility of the Health Department.

A

a. requires carful contingency planning and training.

Top Ops Water Grade 3 & 4 (1 decks)

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