Practice Questions #2 Flashcards
1
Q
What is the criteria for a community water system?
A
Has at least 15 service connections used by all year residence or regularly. Serves at least 25 residence all year long.
2
Q
What is the acceptable limit of copper in drinking water?
A
1.3 mg/L
3
Q
Which type of reservoir is rich in nutrients?
A
Eutrophic
4
Q
What is a mechanical seal?
A
Metallic flat surfaces used to minimize leakage around the pump shaft
5
Q
What is a confined aquifer?
A
An aquifer that is bounded above and below by confining beds
6
Q
Which of the following best describes pumping water level in a well?
A
Upper surface of the ground water that is being pumped
7
Q
What is the name of the deepest layer of a reservoir under thermal stratification?
A
Hypolimnion
8
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
9
Q
Which of the following best describes the turbine pump?
A
A centrifugal pump that is mainly used to pump water from Wells
10
Q
What is typically used to clean the sludge on the bottom of a rectangular clarifier?
A
Chain and flight collectors
11
Q
How often should preventative maintenance before performed on equipment?
A
Use manufactures recommendation
12
Q
What is CT?
A
Contact time x chlorine residual, concentration.
13
Q
What is absorption?
A
Constituent is sucked in
14
Q
What is the purpose of a check valve?
A
Allows water to flow in one direction
15
Q
What would happen to the pH of water if lime is added?
A
Increases pH
16
Q
What is the term used to describe ground water that flows naturally from the ground?
A
Spring
17
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
18
Q
What is the most critical problem that may be encountered when entering a confined space?
A
Oxygen deficiency and toxic gas
19
Q
Which of the following is a settleable solid? Sand, colloidal matter, bacteria, or fine clay.
A
Sand
20
Q
Which of the following is not a commonly used coagulant?
Alum, sodium hypochlorite, ferric sulfate or polymer
A
Sodium hypochlorite
21
Q
What is the purpose of a coagulant aid?
A
Add density to slow settling flocs and add toughness to the flocs
22
Q
What is the purpose of a coagulant (not coagulant aid)?
A
Neutralize electrical charge
23
Q
Which of the following is least likely to be removed in the sedimentation process?
A
Aqueous form of manganese
24
Q
In the sedimentation process, what would happen if the flow rate were increased?
A
Lower efficiency
25
If turbidity is rising rapidly, what should you do?
Verify the effectiveness of the coagulant chemicals and dosage at the flash mixer
26
The collection of a bad sample is as useful as which of the following
No results
27
Which of the following is not a mechanism that occurs in a filter media?
Straining, adsorption, sedimentation on media or precipitation.
Precipitation
28
Which of the following is not a type of filter media used for gravity filtration?
Single media, dual media, diatomaceous earth, or mixed media
Diatomaceous earth
29
What are the three types of media used in a multimedia filtration system?
Sand, anthracite coal and garnet
30
What does the term fluidized mean in filtration?
Filter media is expanded during backwash
31
Which of the following is not an attribute of activated carbon?
Removes unappealing taste, removes odor, removes organic compounds or removes nitrate
Removes nitrate
32
How is the filtration efficiency evaluated?
Turbidity measurement
33
Which of the following is not a way to address backwashing problems in a filter?
Adjust backwash flow rate, adjust surface water flow rate, adjust duration of the backwash cycle or adjust chemical injection rate
Adjust chemical injection rate
34
Which of the following is a requirement of the surface water treatment rule?
At least 99.9% removal of Giardia cysts
35
Which of the following is not a process that will remove pathogens from water? Sedimentation, filtration, disinfection, or screening?
Screening
36
Which of the following will be formed when the free chlorine combines with water?
Hypochlorous acid
37
Which of the following is true about chlorine gas, by itself?
Nonflammable and nonexplosive
38
What is the most common source of water borne disease outbreaks?
Backflow
39
Why would a water utility switch from using sodium hypochlorite to chloramines?
Reduce formation of THM’s
40
What is a CT value?
A measure of the degree of pathogenic inactivation
41
When is a hypochlorinator typically used?
To feed liquid chlorine
42
Which contaminant should never be sampled using a composite sampler?
Bacteria
43
If liquid chlorine is leaking from a cylinder, what should you do?
Turn the container so that the leak is on top
44
Which of the following provides the most convenient and repeatable chlorine residual results?
Amperometric titration
45
Which of the following does not have a primary MCL? Iron, nitrate, lead, or arsenic?
Iron
46
Which of the following is not true about chlorine gas?
2.5 times heavier than air, toxic, corrosive in moist atmospheres, or most people cannot detect chlorine gas at about 2 ppm.
Most people cannot detect chlorine gas at about 2 ppm
47
What is the disadvantage of using ozone to disinfect water?
Cost
48
What is the most common technique used to control taste and odor?
PAC
49
What does an organic compound always contain?
Carbon
50
Which of the following is a type of acid?
Sodium hydroxide, hydrochloric, lime, or caustic soda
Hydrochloric
51
Select the answer that violates the basic rules of laboratory work.
A. Pipette hazardous materials with your mouth.
B. Always wear a lab coat to protect your skin and close.
C. We’re insulated gloves when handling hot objects.
D. Good housekeeping is an effective way to prevent accidents.
Pipette hazardous materials with your mouth
52
Which of the following is true regarding water sampling.
Collecting water samples at a water treatment plant is no different than collecting water samples from a stream or river
53
What has a rotten egg smell?
Hydrogen sulfide
54
Which total coliform bacteria test involves the use of Lauryl tryptose broth?
Multiple tube fermentation method
55
What is alkalinity usually expressed?
Calcium carbonate equivalents
56
What does a pH of 2 represent?
Strong acid
57
What impact does total dissolved solids (TDS) have on water quality?
Adverse taste
58
What is the optimum pH of water for disinfecting bacteria?
7.5
59
What is wire-to-water efficiency?
The combine efficiency of a pump and motor
60
Select the answer that is not a type of positive displacement pump.
Metering, reciprocating, centrifugal, or rotary
Centrifugal
61
Which of the following rotates at a high speed and imparts velocity to the water?
Impeller
62
What is the term used to describe a connection between a drinking water system and an approved water supply?
Cross connection
63
Which is the term used to describe the shallow water of a reservoir with abundant plant growth?
Littoral zone
64
What impact do algae blooms have on the pH of a reservoir?
Increases pH
65
What type of charge would you expect to see on coagulant?
Positive
66
What would cause excessive media to be in the spent backwash water?
Backwashing at high velocity
67
What safety equipment must be worn before entering a confined space?
Harness
68
What are the typical characteristics of the source water, for a direct filtration plant?
Low turbidity levels, less than 2 NTU
69
What is the purpose of the coagulation and flocculation process?
Neutralize the negative charges on the colloids and slowly stir water to create flocs
70
Which of the following would not trigger a filtration system to backwash?
Headloss, time, temperature or turbidity
Temperature
71
What is the definition of disinfection?
Inactivation of most pathogens
72
What is the definition of sterilization?
Inactivation of all pathogens
73
Which of the following is a secondary contaminant?
Nitrate, arsenic, lead, or manganese
Manganese
74
What is the safety hazard of working with polymers?
Slippery floor
75
What is the disadvantage of using chloramines?
Weak disinfectant
76
What is the purpose of a dial indicator?
Measure shaft misalignment
77
What is an attribute of a diatomaceous earth filter?
Mesh screen is pre-coated with powdered media
78
Which of the following is true about the presumptive test?
It takes 48 hours to obtain results for the total coliform test
79
What is a carcinogen?
Causes cancer
80
What is the minimum required disinfection residual concentration leaving a surface water treatment plant?
0.2 mg/L
81
Which of the following is equal to 1 ppm?
1 mg/L
82
What is the disadvantage of using UV to disinfect water?
No disinfectant residual
83
What would most likely occur if a higher quantity of chlorine is added to water?
More THM’s will form
84
What is the most common error in water quality analysis?
Sampling
85
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?
Contamination
86
Which acid is formed when chlorine is mixed with water?
Hypochlorous acid
87
What is an example of a non-community transient water system?
School, rest stop, subdivision, office building
Rest stop
88
What might occur after filter has been backwashed?
Turbidity momentarily increases in the filter effluent
89
What is the lowest reportable concentration for constituents called?
Detection level for reporting
90
Which of the following is part of the multiple tube fermentation analysis?
Presumptive, confirmed, completed
91
What is considered to be a base?
PH in the range of 8 to 14
92
What organisms use organic matter for energy and growth?
Heterotrophic
93
What organism is capable of causing diseases?
Pathogen
94
What is the term used to describe the removal or destruction of all micro organisms?
Sterilization
95
Which process releases water vapor into the atmosphere by living plants?
Transpiration
96
What is the zone of saturation?
The soil located below the top of the ground water table
97
What is an example of combined chlorine?
Monochloramine
98
Which of the following is a chlorine spill kit for a 1 ton container?
Spill kit B
99
What is the purpose of pre-chlorination?
To control taste
100
What should be used to convey chlorine gas out of a 1 ton container
Upper valve
101
What is typically the cause of taste and odor problems in raw surface water?
Algae growth
102
What is the best pH for coagulation?
5-7
103
What are the four zones of clarifier?
Inlet, outlet, settling, sludge
104
What is used to protect the under drain in the filtration system?
Gravel
105
What is not a cause of a short filter run?
A. Low flow.
B. Excessive filtration rate.
C. Excessive mudball formation.
D. Clogging of under drain.
A. Low flow
106
What would not trigger a backwash in a filtration system?
Turbidity, Headloss, time or temperature
Temperature
107
What is a breakthrough?
A crack in the filter bed that allows flocs to pass through
108
Where should sodium hypochlorite be stored?
Away from anything that will corrode
109
What is the Langelier’s saturation index?
An indicator of the corrosivity of water
110
Which of the following is the most resistant to chemical disinfection?
Giardia cyst
111
What DBP would you expect to see in the water that is disinfected with ozonation?
Bromate
112
How long does it take to detect E.Coli using the Colilert method?
24 hours
113
Which chemical is used to remove turbidity?
Alum
114
What is the main purpose of the surface water treatment rule?
Removal of pathogens
115
Which layer of a stratified reservoir will most likely suffer from algae growth?
Epilimnion
116
What are very small particles that do not dissolve?
Colloids
117
What is the typical source of lead and copper in drinking water?
Corrosion of service pipe
118
Which of the following lab equipment is the most accurate measuring device?
Pipet
119
What is the definition of operating ratio?
Ratio of annual operating expenses to operating revenue
120
What are the monthly sampling requirements based on?
Population served
121
What constituent causes hard water?
Manganese, methane, nitrate, magnesium
Magnesium
122
When does chlorine and water reach break point chlorination?
When it stops reacting with organics and inorganics
123
What is the problem with soft water?
Corrosion
124
Which of the following would be considered soft water?
Less than 60 mg/L CaCO3
125
Which of the following is not used to treat hard water?
Carbon dioxide
126
What is another name for caustic soda?
Sodium hydroxide
127
If a significant amount of iron is present in water, what are the adverse impacts?
Taste and staining
128
What is the health impact of drinking water with excess lead?
Development problems in children
129
What is the impact of TDS on water?
Bad taste
130
Which of the following technologies is the most effective way to remove TDS?
Reverse osmosis
131
What is an organic precursor?
Humic acid
132
What is the impact of overdosing potassium permanganate in water?
Pink water
133
Where are samples for lead and copper typically obtained?
Consumers tap
134
Which of the following is the most common way to test for E. coli?
Fluorescence, titration, DPD, or colilert
Colilert
135
Which of the following is the best way to minimize THM’s?
Don’t pre-chlorinate
136
When must the public be notified of a tier 1 violation regarding their water supply?
Within 24 hours after the occurrence of violation
137
What is titration?
A process of adding the chemical reagent in small increments until completion of reaction
138
What is a supernatant?
A relatively Clear water layer between the sludge on the bottom, and the scum on the surface of a basin
139
Which of the following contributes to alkalinity?
Calcium, bicarbonate, sodium, or potassium
Bicarbonate
140
Select the answer that is regulated under the secondary drinking water standards.
Odor, nitrate, arsenic, or lead
Odor
141
Which of the following is a requirement for Viruses under the surface water treatment rule?
99.99% removal and/or inactivation.
142
What is the process that transfers water vapor from living plants into the atmosphere?
Evapotranspiration
143
When must a repeat sample be taken?
Sample tests positive for total coliform
144
Why is fluoride injected into drinking water?
Reduced tooth decay
145
Which of the following is used to test chlorine residual in the field?
DPD
146
What is the largest zone in the sedimentation tank?
Settling zone
147
Which of the following describes the attributes of chlorine dioxide?
It does not form carcinogenic compounds
148
What is a common source of coliform?
Feces
149
What is the hypogeal biological layer formed on the surface of a slow sand filter
Schmutzdecke
150
Which of the following would lead to thermal stratification?
When surface water begins to warm up
151
Which of the following is true about using an inclined plate settler?
Uses a smaller footprint at the plant than a conventional clarifier
152
Which of the following will most likely lead to nitrification?
High concentration of ammonia in water
153
What is the probable cause of reddish brown water?
Iron
154
Which constituent makes water appear black?
Manganese
155
Which of the following is a potentially dangerous condition in a confined space?
Oxygen content drops below 19.5% by volume.
156
Which of the following is not true about to tuberculation?
Increases pipe capacity
157
What is the secondary MCL?
Sets limits for constituents that affect the aesthetic qualities of drinking water
158
Which of the following is a tier 1 violation
Exceeding MCL for nitrate
159
What is used to control the injection of gas chlorine in the water?
Chlorinator
160
Which of the following is a Venturi style injector used for chlorine gas?
Eductor
161
What would happen if a valve is close to quickly?
Waterhammer
162
When must a public notice be issued to the customers?
When there is a serious problem with the drinking water
163
What would cause manganese to precipitate?
Adding sodium hypochlorite
164
What is the purpose of the total Colifirm rule?
Improve public health protection by reducing fecal pathogens to minimal levels
165
What type of pump is used as a chemical metering pump?
Positive displacement pump
166
If you have rights to pull water out of an adjacent river due to the purchase of land, which of the following rights do you have?
Riparian rights
167
Which of the following is a typical characteristic of surface water?
Higher turbidity and organics
168
If groundwater near an ocean has high concentration of chloride’s, which of the following may be true
Seawater intrusion is occurring
169
Which of the following is a thermocline?
Metalimnion
170
What is the purpose of the sanitary seal in a well?
Prevent contamination of groundwater supply
