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water treatment practice exam > Book practice > Flashcards

Book practice Flashcards

1
Q

which of the following is removed at the raw water intake?

A

Fish and debris

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2
Q

which of the following is more likely to be found in groundwater?

A

minerals

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3
Q

what is most commonly used to control algae growth in reservoirs?

A

copper sulfate

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4
Q

what are common filtration rates in gravity filtration

A

2 to 10 GPM/sq.ft.

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5
Q

leakage within a centrifugal pump is intended for what purpose?

A

cool moving parts

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6
Q

which of the following is the definition of a grab sample?

A

a single sample of water collected at a particular time and place which represents the composition of the water only at that time and place

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7
Q

adding sodium hypochlorite to water will have the following effect

A

increase pH

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8
Q

what is the purpose of the groundwater rule

A

to protect the groundwater from disease-causing microorganisms

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9
Q

what is true about the total coliform rule?

A

establishes an MCL based on the presence and absence of total coliforms or E.coli

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10
Q

what will happen to the water quality if chlorine is injected at the same location as power activated carbon (PAC)

A

chlorine will react with carbon and neutralize the effects of both

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11
Q

which of the following will react with chlorine to form trihalomethane

A

natural organic matter

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12
Q

what type of pump has a piston within the casing?

A

reciprocating

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13
Q

What must be located near a hazardous chemical storage room?

A

SDS

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14
Q

What term describes the depression of a water table?

A

Cone of depression

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15
Q

What is the radius of influence?

A

The radial distance from the center of a well bore to the point where there is no lowering of the water table

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16
Q

What is the best way to monitor filter performance ?

A

Turbidity

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17
Q

What causes the water to look cloudy?

A

Suspended material

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18
Q

Which chemical is sprayed near a chlorine gas leak to produce white smoke?

A

Ammonia

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19
Q

Which water sample parameters must be taken in the field?

A

pH and temperature

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20
Q

If the total coliform tests positive, then what must be done next?

A

Test for fecal coliform

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21
Q

What is performed to evaluate susceptibility to potential threats and identify corrective actions that can reduce or mitigate the risk for a water system?

A

Vulnerability assessment

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22
Q

What is the definition of holding time for water samples?

A

The length of time a water sample is retained between taking the sample and laboratory analysis

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23
Q

From a bacteriological standpoint, what is important for a well?

A

Protect it from contaminated runoff

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24
Q

Which is true of chlorine gas?

A

It is 2.5 times heavier than air

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25
Q

What happens after breakpoint chlorination is achieved?

A

Chlorine dose and residual increases at the same rate

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26
Q

If chlorine residual is not detected after 3 mg/l of dosage is applied, then what might be occurring in the water?

A

Demand has not been met

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27
Q

Which of the following is an indicator organisms for pathogens?

A

Coliform

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28
Q

what would happen if there is an increase in turbidity, organics, and manganese in the water?

A

increase in chlorine demand

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29
Q

which of the following would increase alkalinity in the water?

A

CaC03

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30
Q

If you dropped the lid of a sample bottle prior to sampling, what should you do?

A

Use a new container

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31
Q

What is the purpose of the lantern ring in a centrifugal pump?

A

provide lubrication and cooling

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32
Q

What is the definition of well draw down?

A

distance between static and pumping water level

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33
Q

what should be done with a water sample that cannot be analyzed in a timley manner?

A

refrigerate it

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34
Q

which of the following source water would most likely contain cryptosporidium and giardia

A

stream

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35
Q

what is the purpose of chlorine residual

A

provides a safeguard to kill additional microorganism encountered after treatment

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36
Q

which of the following is equivalent to 3 log removal

A

99.9%

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37
Q

how is turbidity measured

A

nephelometric

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38
Q

which chemical is used to dechlorinate water?

A

sodium thiosulfate

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39
Q

what must you wear prior to being exposed to chlorine gas?

A

Self-contained breathing apparatus

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40
Q

what is the minimum chlorine concentration required prior to introducing the effluent from a surface water filtration plant to the distribution system

A

0.2ppm

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41
Q

which of the following best describes a water table?

A

upper water surface of an aquifer

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42
Q

the total coliform rule applies to which of the following water systems?

A

all public water systems

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43
Q

what is the purpose of a shaft sleeve in a pump

A

protects shaft from wear at stuffing box

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44
Q

why isnt chlorine injected immediately prior to filtarion

A

increases THMs

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45
Q

which of the following is a disinfection by-product

A

trihalomethane

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46
Q

which of the following is used to describe a well that is under pressure

A

artesian well

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47
Q

what would cause high concentration of nitrate in groundwater

A

over-fertilization of land

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48
Q

what is the purpose of the lead and copper rule

A

protect the public health by minimizing lead and copper in drinking water primarily by reducing water corrosivity

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49
Q

which of the following is not affected by chlorine dose?

A

hardness

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50
Q

how long should you run the water before you grab a water sample

A

2 to 3 minutes

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51
Q

which of the following is a typical form of calcium hypochlorite?

A

65% solid tablet

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52
Q

frosting around the outlet connection of a chlorine gas cylinder indicates which of the following

A

reduce flow of chlorine gas

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53
Q

which of the following describes trickling of water from the ground surface towards the aquifer

A

percolation

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54
Q

what is a likely discharge of industrial waste found in surface water

A

organic solvents

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55
Q

why shouldn’t you have zero pressure in a water main

A

back siphonage may contaminate the water main

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56
Q

what should be inside a sample bottle when obtaining a sample for a coliform test

A

sodium thiosulfate

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57
Q

if the MCL for a constituent is violated, who is responsible for notifying the customers about this?

A

water purveyor

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58
Q

what is the typical concentration of sodium hypochlorite

A

12.5%

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59
Q

if 2.5mg/l of chlorine is dosed, and there is 0.5mg/l of residual, what is the reason for the residual

A

the residual is present as a safeguard for unanticipated chlorine demand in the distribution system

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60
Q

which of the following must always be done before repairing a pump

A

lock out equipment

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61
Q

which of the following is least likely to affect the effectiveness of chlorine

A

sodium

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62
Q

which of the following is considered safe to drink

A

no pathogens

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63
Q

which reading must be taken in the field when obtaining a sample

A

chlorine residual

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64
Q

which of the following devices will give you the hydrogen ion concentraion

A

pH meter

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65
Q

which of the following is the correct laboratory procedure?

A

add acid to water

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66
Q

when dealing with a high pressure pipeline, which must you do?

A

open and close a valve slowly

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67
Q

which of the following water source is more likely to have iron and manganese

A

groundwater

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68
Q

which will affect chlorine demand the most

A

turbidity and organics

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69
Q

which will make chlorine more effective in water?

A

moderate increase in temperature

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70
Q

what are colloidal particles ?

A

very small particles that do not dissolve and remain dispersed in a liquid for a long time due to their small size and electrical charge

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71
Q

what is alkalinity

A

the capacity of water to neutralize acid

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72
Q

what does MCL stand for

A

maximum contaminant level

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73
Q

what is in the zone of saturation

A

aquifer

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74
Q

what is a hydrologic cycle

A

continuous movement of water throughout the planet

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75
Q

what typically occurs at the beginning of breakpoint chlorination curve

A

chlorine destroyed by reducing compounds

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76
Q

what is the drawback of pre-chlorination

A

formation of THMs

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77
Q

how long should the tap remain turned off before grabbing a sample for a lead and copper test

A

6 hours

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78
Q

the secondary MCL is set for what purpose?

A

aesthetic

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79
Q

which of the following will lead to an illness

A

nitrate

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80
Q

what is the most likely cause of decreasing chlorine residual in the water main?

A

Bacteria and organics may be present

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81
Q

what is the aquifer typically composed of?

A

sand and gravel

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82
Q

what is used to lower pH in water

A

CO2

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83
Q

what is the maximum allowable chlorine residual concentration in the distribution main

A

4mg/l

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84
Q

why is trihalomethane considered to be harmful

A

it is a carcinogen

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85
Q

which of the following describes turbidity

A

cloudiness or haziness of a fluid caused by suspended solids

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86
Q

what is a pathogen

A

disease causing microorganism

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87
Q

what is the impact of algae to water quality

A

taste and odor problems

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88
Q

what is the concentration of chlorine gas

A

100%

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89
Q

which of the following is not used to mix coagulants

A

horizontal paddle wheel

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90
Q

what is considered to be a quick remedy to address a sudden increase in filtered water turbidity

A

feed a filter-aid chemical to filter the filter influent

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91
Q

what is the likely cause of a pinging noise in a pump

A

cavitation

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92
Q

which of the following controls the efficiency of removing suspended solids in the sedimentation process

A

flowrate

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93
Q

what is a sanitary survey

A

an analysis to determine all potential water quality impacts to a proposed well

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94
Q

which of the following categories does bacteria belong to

A

colloidal

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95
Q

under the surface water treatment rule, what must the reduction of viruses be through filtration and disinfection?

A

99.99%

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96
Q

which of the following is not considered free residual chlorine?

A

monochloramine

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97
Q

why is coliform used as an indicator organism

A

it reduces the complexity and cost of analysis

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98
Q

what is an example of a non-community, non-transient water system?

A

school

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99
Q

what is the purpose of a packing in a pump?

A

control the leakage of water along the pump shaft and prevent air from entering along the shaft when the pump is in a suction lift condition

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100
Q

what does the addition of carbon dioxide do to the pH of water?

A

lowers it

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101
Q

what is an unconfined aquifer

A

one in which groundwater possesses a free surface open to atmospher

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102
Q

what is static water level in a well

A

water level when pump is not runnning

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103
Q

which of the following will least likely impact the formation of flocs during the coagulation and focculation process

A

hardness

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104
Q

what is formed when free chlorine reacts with ammonia

A

chloramine

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105
Q

which contaminant causes blue baby syndrome

A

nitrate

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106
Q

what is free chlorine

A

the concentration of residual chlorine in water which is present as dissolved gas, hypochlorous acid, and hypochlorite ion

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107
Q

what is a thermocline

A

a thin but distinct layer in a reservoir in which temperature changes more rapidly with depth that it does in the layers above or below

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108
Q

what agency protects the health and safety of industrial employees

A

OSHA

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109
Q

what is the first priority in water treatment?

A

production of safe drinking water

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110
Q

what is the health effect of consuming water with high levels of lead

A

cardiovascular effects, increased blood pressure and incidence of hypertension

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111
Q

what is an imaginary surface to which groundwater rises under hydrostatic pressure in wells or springs?

A

piezometric surace

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112
Q

what is used to evaluate new coagulants or polymers being considered for use at the plant

A

Jar test

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113
Q

what are the 4 zones of a clarifier

A

inlet,outlet,settling,sludge

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114
Q

which type of filtration process is approved by the surface water treatment rule?

A

conventional water treament

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115
Q

which of the following impacts the color of source water

A

organics,such as soil and leaves

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116
Q

coliform is most likely to be found in which of the following water supply

A

lake

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117
Q

what is the amount of water that can be withdrawn from an aquifer without significant environmental impact

A

safe yield

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118
Q

pH will increase if the following chemical is added to water

A

ammonia

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119
Q

which of the following is an unstable form of disinfection

A

ozonation

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120
Q

how many stages are in a breakpoint chlorination curve

A

4

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121
Q

chlorine demand is best describes which of the following

A

chlorine dose - residual

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122
Q

what is an example of natural organic matter

A

fallen leaves

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123
Q

what is a typical characteristic of a colloidal particle in raw water?

A

negative charge on the surface

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124
Q

what is short circuiting in a claifer

A

shorter settling time in basin

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125
Q

what would cause a filter to begin backwashing

A

headloss

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126
Q

what is the purpose of surface washing in a filtration unit

A

break-up mudballs

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127
Q

where would you most likely see high levels of nitrate in the groundwater supply?

A

near agricultural land

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128
Q

what is adsorption

A

constituents sticking to the surface of a subtance

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129
Q

in which part of the water treatment plant are 99% of the suspended solids removed

A

sedimentation and filtration

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130
Q

which of the following will most likely lead to the lowest concentration of THMs in treated water

A

chloramines

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131
Q

which of the following is not true about the total colifrom rule

A

smaller systems that collect fewer that 40 samples cannot have coliform positive results in more than 2 samples per month

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132
Q

which of the following is true about fusible plugs on a chlorine container?

A

never remove it

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133
Q

what is the most common water quality complaint from customers?

A

taste and odor problems

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134
Q

what information should be identified on the sampling container?

A

sampling location, date and time

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135
Q

what is the standard requirement for conventional and direct filtration

A

filtered water must be less than or equal to 0.3 NTU in 95% of monthly measurements

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136
Q

what is the main drawback of using sodium hypochlorite to disinfect water

A

formation of THMs

137
Q

what is one of the causes of hardness in water?

A

calcium

138
Q

which chemical is used to raise the pH in water

A

soda ash

139
Q

what is the purpose of flocculation

A

slowly stir water to bring smaller flocs together to form larger ones

140
Q

which of the following range of pH is considered to be acidic?

A

0-6

141
Q

what is the term used to describe the upper layer of a stratified reservoir?

A

epilimnion

142
Q

what is another name for the multiple tube fermentation test

A

MPN

143
Q

what impact does precipitated manganese have on water?

A

blackish water

144
Q

which of the following is not part of the surface water treatment rule

A

all water systems are allowed to use disinfection only for surface water sources that meet criteria for water quality and watershed protection

145
Q

what is a typical characteristic of chlorine gas

A

greenish yellow color

146
Q

which of the following is not true about the total coliform rule

A

monthly sampling requirements are not based on population served

147
Q

what can be done to minimize the formation of THM

A

eliminate or reduce chlorination before the filters

148
Q

what is the source of fecal coliform bacteria

A

feces

149
Q

what is the drawback of using UV for disinfection

A

high energy cost

150
Q

what are the two types of aquifers

A

confined and unconfined

151
Q

what is a common problem associated with hardness in water

A

scaling

152
Q

what is the problem with very soft water

A

corrosion

153
Q

why is it harmful to backwash at a high velocity

A

flushes some media into spent backwash water

154
Q

what occurs on the right side of the breakpoint chlorination curve

A

free available residual chlorine begin to form

155
Q

how does PAC remove contaminants from the water

A

adsorption

156
Q

which entity is responsible for enforcing the drinking water standards

A

state

157
Q

how is the rate of head loss affected by a more uniform filter media

A

slower

158
Q

which of the following is true about soluble iron and manganese

A

colorless

159
Q

what is the reason for adding coagulants at the flash mixer

A

neutralize negative charge of colloids

160
Q

why would a water purveyor switch from chlorine gas to sodium hypochlorite

A

safety

161
Q

which pathogen is smallest in size

A

virus

162
Q

which of the following is not an example of a suspended solid

A

soluble calcium

163
Q

which of the following is not a type of coliform test

A

DPD

164
Q

what is the definition of a public water system

A

publicly or privately owned water system that has at least 15 service connections, or regularly serves an average of at least 25 people daily at least 60 days per year

165
Q

when is brilliant green bile used to test for coliform

A

multiple tube fermentation method

166
Q

which of the following is the correct order of treatment for a conventional water treatment plant

A

intake, coagulation, flocculation, sedimentation, filtration, disinfection

167
Q

what might happen if insufficient amount of coagulants were injected into the flash mixer

A

some colloids may repel each other

168
Q

which of the following is a grab sample

A

sample taken on a one time biases without consideration of flow or time

169
Q

what happens over the course of a filter run time

A

headloss increases

170
Q

when is direct filtration used instead of conventional water treatment

A

when source water is low in turbidity, color, and odor

171
Q

what is the criteria for a community water system?

A

has at least 15 service connections used by all-year residents, or regularly serves at least 25 all-year residents

172
Q

what is the acceptable limit of copper in drinking water

A

1.3 mg/l

173
Q

which type of reservoir is rich in nutrients

A

eutrophic

174
Q

what is a mechanical seal

A

metallic flat surfaces used to minimize leakage around the pump shaft

175
Q

what is a confined aquifer

A

an aquifer that is bounded above and below by confining beds

176
Q

which of the following best describes pumping water level in a well?

A

upper surface of the groundwater that is being pumped

177
Q

what is the name of the deepest layer of a reservoir under thermal stratifation

A

hypolimnion

178
Q

what is the health effect of consuming water with high levels of copper

A

stomach and intestinal distress such as nausea, vomiting, diarrhea and stomach cramps

179
Q

which of the following best describes a turbine pump

A

a centrifugal pump that is mainly used to pump water from wells

180
Q

what is typically used to clean the sludge n the bottom of a rectangular clarifer

A

chain and flight collectors

181
Q

how often should preventative maintenance be performed on equipment

A

use manufacturer’s recommendation

182
Q

what is CT?

A

contact time x chlorine residual concentration

183
Q

what is absorption

A

constituent is sucked in

184
Q

what is the purpose of a check valve

A

allows water to flow in on direction, and prevents reverse flow

185
Q

what would happen to the pH of water if lime is added?

A

increase pH

186
Q

what is the term used to describe groundwater that flows naturally from the ground?

A

spring

187
Q

once thermal stratification occurs in the middle and lower zones of a reservoir, what type of problem occurs in these layers?

A

depletion of total dissolved oxygen

188
Q

what is the most critical problem that may be encountered when entering a confined space

A

oxygen deficiency and toxic gas

189
Q

which of the following is a settleable solid

A

sand

190
Q

which of the following is not a commonly used coagulant

A

sodium hypochlorite

191
Q

what is the purpose of a coagulant aid

A

add density to slow settling flocs

192
Q

which of the following is least likely to be removed in sedimentation process?

A

aqueous form of manganese

193
Q

in the sedimentation process what would happen if the flowrate were increased

A

lower efficiency

194
Q

if turbidity is rising rapidly, what should you do

A

verify the effectiveness of the coagulant chemicals and dosage at the flash mixer

195
Q

the collection of a bad sample is useful as which of the following

A

no result

196
Q

which of the following is not a mechanism that occurs in a filter media

A

precipation

197
Q

which of the following is not a type of filter media used for gravity filtration

A

diatomaceous earth

198
Q

what are the three types of media used in a multi-media filtration system

A

sand, anthracite coal, and slurry

199
Q

what does the term “fluidized” mean in filtration?

A

filter media is expanded during backwash

200
Q

which of the following is not an attribute of activated carbon

A

removed nitrate

201
Q

how is the filtration efficiency evaluated

A

turbidity measurement

202
Q

which of the following is not a way to address backwashing problems in a filter

A

adjust chemical injection rate

203
Q

which of the following is a requirement of the surface water treatment rule

A

at least 99.9 % removal of giardia cysts

204
Q

which of the following is not a process that will remove pathogens from water?

A

screening

205
Q

which of the following will be formed when free chlorine combines with water

A

hypochlorous acid

206
Q

which of the following is true about chlorine gas, by itself

A

nonflammable and nonexplosive

207
Q

what is the most common source of waterborne disease outbreaks

A

backblow

208
Q

why would a water utility switch from using sodium hypochlorite to chloramines

A

reduce formation of THMs

209
Q

what is a CT value

A

a measure of the degree of pathogenic inactivation

210
Q

when is a hypochlorinator typically used

A

to feed liquid chlorine

211
Q

which contaminant should never be sampled using a composite sample

A

bacteria

212
Q

if liquid chlorine is leaking from a cylinder, what should you do

A

turn the container so that the leak is on top

213
Q

which of the following provides the most convenient and repeatable chlorine residual results

A

amperometric titration

214
Q

which of the following does not have a primary MCL

A

iron

215
Q

which of the following is not true about chlorine gas?

A

most people cannot detect chlorine gas at about 2ppm

216
Q

what is the disadvantage of using ozone to disinfect water

A

cost

217
Q

what is the most common technique used to control taste and odor?

A

PAC

218
Q

what does an organic compound always contain

A

carbon

219
Q

which of the following is a type of acid?

A

hydrochloric

220
Q

select the answer that violates the basic rules of laboratory work

A

pipet hazardous materials with your mouth

221
Q

which of the following is true regarding water sampling

A

collecting water samples at a water treatment plant is no different than collecting samples from a stream or river

222
Q

what has a rotten egg smell

A

hydrogen sulfide

223
Q

which total coliform bacteria test involved the use of lauryl tryptose broth

A

multiple tube fermentation method

224
Q

how is alkalinity usually expressed

A

calcium carbonate equivalents

225
Q

what does a pH of 2 represent?

A

strong acid

226
Q

what impact does Total dissolved solids (TDS) have on water quality?

A

adverse taste

227
Q

what is the optimum pHof water for disinfecting bacteria?

A

7.5

228
Q

what is wire to wire efficiency

A

the combine efficiency of a pump and motor

229
Q

select the answer that is not a type of positive displacement pump

A

centrifugal

230
Q

which of the following rotates at high speed and imparts velocity to the water?

A

impelelr

231
Q

what is the term used to describe a connection between a drinking water system and an unapproved water supply

A

cross connection

232
Q

which is the term used to describe the shallow water of a reservoir with abundant plant growth

A

littoral zone

233
Q

what impact does algal blooms have on the pH of a reservoir

A

increases pH

234
Q

what type of charge would you expect to see on a coagulant

A

positive

235
Q

what would cause excessive media to be in the spent backwash water

A

backwashing at high velocity

236
Q

what safety equipment must be worn before entering a confined space

A

harness

237
Q

what are the typical characteristics of the source water for a direct filtration plant

A

low turbidity level, less than 2 NTU

238
Q

what is the purpose of the coagulation and focculation process

A

neutralize the negative charges on the colloids, and slowly stir water to create flocs

239
Q

which of the following would not trigger a filtration system to backwash

A

temperature

240
Q

what is the definition of disinfection

A

inactivation of most pathogens

241
Q

which of the following is a secondary contaminant

A

manganese

242
Q

what is the safety hazard of working with polymers

A

slippery floor

243
Q

what is the disadvantage of using chloramines

A

weak disinfectant

244
Q

what is the purpose of a dial indicator

A

measure shaft misalignment

245
Q

what is an attribute of a diatomaceous earth filter

A

mesh screen is pre-coated with powdered media

246
Q

which of the following is true about the presumptive test

A

it takes 48 hours to obtain results for the total coliform test

247
Q

what is a cercinogen

A

causes cancer

248
Q

what is the minimum required disinfection residual concentration leaving a surface water treatment plant

A

0.2 mg/l

249
Q

which of the following is equal to 1ppm

A

1 mg/l

250
Q

what is the disadvantage of using UV to disinfect water?

A

no disinfectant residual

251
Q

what would most likely occur if a higher quantity of chlorine is added to water

A

more THMs will form

252
Q

what is the most common error in water quality analysis

A

sampling

253
Q

what is the term used to describe the introduction into water of microorganisms, chemicals, and toxic substances in a concentration that makes the water unfit for its next intended use?

A

contamination

254
Q

which acid is formed when chlorine is mixed with water

A

hypochlorous acid

255
Q

what is an example of a non-community, transiet water system

A

rest stop

256
Q

what might occur after a filter has been backwashed?

A

turbidity momentarily increases in the filter effluent

257
Q

what is the lowest reportable concentration for constituents called

A

detection level for reporting

258
Q

which of the following is part of the multiple tube fermentation analysis

A

presumptive, confirmed, completed

259
Q

what is 4 log removal

A

99.99%

260
Q

what is considered to be a base

A

pH in the range of 8 to 14

261
Q

what organisms use organic matter for energy and growth

A

heterotrophic

262
Q

what organism is capable of causing diseases

A

pathogen

263
Q

what is the term used to describe the removal or destruction of all microorganisms

A

sterilization

264
Q

which process releases water vapor into the atmosphere by living plants

A

transpiration

265
Q

what is the zone of saturation

A

the soil located below the top of the groundwater table

266
Q

what is an example of combined chlorine

A

monochloramine

267
Q

which of the following is a chlorine spill kit for a one-ton container

A

spill kit B

268
Q

what is the purpose of pre-chlorination

A

to control taste

269
Q

what should be used to convey chlorine gas out of a one-ton container

A

upper valve

270
Q

what is typically the cause of tase and odor problems in raw surface water?

A

algae growth

271
Q

what is the best pH for coagulation

A

5-7

272
Q

what are the 4 zones of clarifer

A

inlet, outlet, settling, sludge

273
Q

what is used to protect the underdrain in a filtration system

A

gravel

274
Q

what is not a cause of a short filter run

A

low flow

275
Q

what would not trigger a backwash in a filtration system

A

temperature

276
Q

what is a breakthrough

A

a crack in the filter bed that allows flocs to pass thruogh

277
Q

where should sodium hypochlorite be stored

A

away from anything that will corrode

278
Q

what is the langeliers saturation index

A

an indicator of the corrosivity of water

279
Q

which of the following is the most resistant to chemical disinfection

A

giardia cysts

280
Q

what DBP would you expect to see in the water that is disinfected with ozonation

A

bromate

281
Q

how long does it take to detect E.Coli using the colilert method

A

24 hours

282
Q

which chemical is used to remove turbidity

A

alum

283
Q

what is the main purpose of the surface water treatment rule

A

removal of pathogens

284
Q

which layer of a stratified reservoir will most likely suffer from algae growth

A

eplilmnion

285
Q

what are very small particles that do not dissolve

A

colloids

286
Q

what is the typical source of lead and copper in drinking water

A

corrosion of service piper

287
Q

which of the following lab equipment is the most accurate measuring device

A

pipet

288
Q

what is the definition of operation ratio

A

ratio of annual operating expenses to operating revenue

289
Q

what are the monthly sampling requirements based on

A

population served

290
Q

which constituent causes hard water?

A

magnesium

291
Q

when does chlorine and water reach breakpoint chlorination

A

when it stops reacting with organics and inorganics

292
Q

what is the problem with soft water

A

corrosion

293
Q

which of the following would be considered soft water

A

less than 60 mg/l CaCo3

294
Q

which of the following is not used to treat hard water

A

carbon dioxide

295
Q

what is another name for caustic soda

A

sodium hydroxide

296
Q

if a significant amount of iron is present in water, what are the adverse impacts

A

taste and staining

297
Q

what is the health impact of drinking water with excess lead

A

development problems in children

298
Q

what is the impact of TDS on water

A

bad taste

299
Q

which of the following technologies is the most effective way to remove TDS

A

reverse osmosis

300
Q

what is an organic precursor

A

humic acid

301
Q

what is the impact of overdosing potassium permanganate in water

A

pink water

302
Q

where are samples for lead and copper typically obtained

A

consumers tap

303
Q

which of the following is the most common way to test for e.coli

A

Colilert

304
Q

which of the following is the best way to minimize THMs

A

dont prechlorinate

305
Q

when must the public be notified of a tier 1 violation regarding their water supply

A

within 24 hours after occurrence of violation

306
Q

what is titration

A

a process of adding the chemical reagent in small increments until completion of reaction

307
Q

what is supernatant

A

the relatively clear water layer between the sludge on the bottom and the scum on the surface of a basin

308
Q

which of the following contributes to alkalinity

A

bicarbonate

309
Q

select the answer that is regulated under the secondary drinking water standards

A

odor

310
Q

which of the following is a requirement for viruses under the surface water treatment rule?

A

99.99% removal and or inactivation

311
Q

what is the process that transfers water vapor from living plants into atmosphere

A

evapotranspiration

312
Q

when must a repeat sample be taken

A

sample tests positive for total colifrom

313
Q

why is fluoride injected into drinking water

A

reduce tooth decay

314
Q

which of the following is used to test chlorine residual in the field

A

DPD

315
Q

what is the largest zone in a sedimentation tank

A

settling zone

316
Q

which of the following describes the attributes of chlorine dioxide

A

it does not form carcinogenic compounds

317
Q

what is a common source of coliform

A

feces

318
Q

what is the hypogeal biological layer formed on the surface of a slow sand filter

A

schmutzdecke

319
Q

which of the following would lead to thermal stratification

A

when surface water begin to warm

320
Q

which of the following is true about using an inclined plate settler

A

uses a smaller footprint at the plant than a conventional clarifer

321
Q

which of the following will most likely lead to nitrification

A

high concentration of ammonia in water

322
Q

what is the probable cause of reddish brown water

A

iron

323
Q

which constituent makes water appear black

A

manganese

324
Q

which of the following is a potentially dangerous condition in a confined space

A

oxygen content drops below 19.5% by volume

325
Q

which of the following is not true about tuberculation

A

increases pipe capacity

326
Q

what is the secondary MCL

A

sets limits for constituents that affect the aesthetic qualities of drinking water

327
Q

which of the following is a tier 1 violation

A

exceeding MCL for nitrate

328
Q

what is used to control the injection of gas chlorine into water

A

chlorinator

329
Q

which of the following is a venturi style injector used for chlorine gas

A

eductor

330
Q

what would happen if a valve is closed to quickly

A

water hammer

331
Q

when must a public notice be issued to the coustomers

A

when there is a serious problem with the drinking water

332
Q

what would cause manganese to precipitate

A

adding sodium hypochlorite

333
Q

what is the purpose of the total coliform rule

A

improve public health protection by reducing fecal pathogens to minimal levels

334
Q

what typo of pump is used as a chemical metering pump

A

positive displacement pump

335
Q

if you have rights to pull water out of an adjacent river due to the purchase of a land, which of the following rights do you have

A

riparian

336
Q

which of the following is a typical characteristic of surface water

A

higher turbidity and organics

337
Q

if groundwater near an ocean has high concentration of chlorides, which of the following may be true

A

seawater intrusion is occuring

338
Q

which of the following is a thermocline

A

metalimnion

339
Q

what is the purpose of the sanitary seal in a well

A

prevent contamination of groundwater supply

water treatment practice exam (1 decks)

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