Welcome to the Water Treatment Operator 100 Question Practice Test.
Choose the best possible answer to the question.
1.
An operator must strike a balance between TOC removal and the
2.
In gram staining, part of the coliform verification is?
3.
What is the simplest chlorine gas feeder for controlling chlorine gas flow?
4.
The monitoring program that checks for Benzene (Leaking Underground Storage Tank) is checking for what kind of chemical contaminant?
5.
Powered activated carbon is usually used to control what?
6.
What sludge dewatering process is best for alum sludges when the cakes are very dry, filtrate is clear, and solids capture is very high?
7.
Past the breakpoint chlorination point, what percentage of the total chlorine residual should be free chlorine?
8.
When must a water system collect annual samples if the water system has been determined to be reliable by the State and consistently below the MCL level for organic compounds?
9.
Test results from a multiple tube fermentation test for coliform bacteria are expressed as MPN (most probable number) per 100 milliliters, the number is determined from?
10.
Viruses are sometimes resistant to disinfection.
11.
The actions levels for lead and copper are?
12.
Why is turbidity in drinking water undesirable?
13.
Which is a chemical used in water treatment as a coagulating chemical?
14.
Backwashing rate procedures should be reassessed to determine the cause of granular activated carbon loss if?
15.
Pulsator clarifiers are used to?
16.
Community and non-transient community water systems must test for what if they use ozone for disinfection of oxidation?
17.
What makes chlorine use more advantageous over chloramines?
18.
The Colilert test (ONPG-MUG) shows the presence of total coliforms is shown by?
19.
What was created to have uniform standards in Water Treatment?
20.
A water molecule is made up of ?
21.
What does pinpoint floc, fish eyes, and high turbidity in settled water indicate?
22.
The ion exchange process usually is used to remove what from water?
23.
Alachlor, Lindane, and Toxaphene are examples of?
24.
Ozone contractors must have a system to collect ozone off-gas because?
25.
A 50% solution of caustic soda will begin to crystallize if the temperature drops below?
26.
What process would be most effective for the destruction of heterotrophic bacteria?
27.
What is the total concentration of dissolved solids in the wastewater from the regeneration of ion exchange units?
28.
Where does most of the carbon dioxide in groundwater originate from?
29.
What is the most effective disinfection residual?
30.
What adverse effects does the secondary contaminant manganese have?
31.
When soda ash is added to water for softening purposes what will it do?
32.
Why do operators monitor a filter's operation time, headloss and effluent turbidity level?
33.
Reaching breakpoint chlorination means?
34.
When it is dissolved in water for disinfection purposes, how long does ozone last?
35.
What are the precursors to THMs?
36.
A property that is important to water treatment that is physical as opposed to chemical is?
37.
At what temperature does the maximum density of water occur?
38.
How is chlorine dioxide formed?
39.
What can immediately occur if newly installed manganese greensand was not skimmed of the fines after backwashing and stratification steps were completed?
40.
What is the main purpose for adding coagulant chemicals to raw water?
41.
What does total alkalinity refer to?
42.
The chlorine demand with vary with?
43.
The hour during the day when the largest volume of water is being pumped is known as peak hourly flow?
44.
The most probable cause of a problem with a chlorinator is?
45.
What TON will consumers start to notice?
46.
What is used to prevent water from entering a gas chlorinator?
47.
What are the hair like appendages that Giardia trophozoites use to propel themselves through water are?
48.
What is potassium permanganate most effective in?
50.
Which is classified as a secondary contaminant?
51.
What sludge dewatering process requires a pre-coat of diatomaceous earth and its use has declined due to other newer methods?
52.
In a conventional treatment plant, primary coagulant compounds added to water during the falsh-mix step are?
53.
What will neutralize chlorine?
54.
The fluoride injection point should be located after water has received complete treatment.
55.
When natural zeolites are used for softening and they have become exhausted from use, what chemical are they regenerated with?
56.
When sludge is produced by water drawn from sources with relatively low turbidity it can be?
57.
Protozoa that must be removed from raw water are?
58.
The hydrologic cycles create what two primary sources of water?
59.
Once they become fouled, how are reverse osmosis membranes cleaned?
60.
If adequate surface area and detention time is provided in the sedimentation basin, what would the expected solids removal efficiency level be?
61.
An organic particle that is stabilized by attracting a layer of water molecules to its surface is known as a?
62.
What chemical oxidant would be best for controlling the forming of THMs?
63.
Impurities that do not dissolve in water and settle out eventually are?
64.
Which is the best removal method if a well contains soluble iron?
65.
What is dissolved air flotation good for removing?
66.
What process change be should be done if the level of turbidity in raw water decreased from 7 to 3 NTUs?
67.
What should an operator do to compensate for temperature changes in a conventional water treatment plant with dual media filters that has very cold water in the winter and warm water in the summer?
68.
What test is used to determine the presence of coliform bacteria?
69.
What is put in place in a reservoir to create an even flow rate through the entire volume of a clearwell to provide a consistent amount of detention time and minimize short-circuiting?
70.
What adjustments will the operator of a surface water treatment plant have to make if the raw water is very high in turbidity levels?
71.
What device collects the settled water as it leaves the sedimentation basin?
72.
What type of chlorine gas feeding equipment would be most appropriate for distribution systems where re-chlorination is required?
73.
Post sedimentation process, the turbidity of settled water before it is applied to the filters should be kept below?
74.
What is a major cause of short circuiting in a sedimentation basin?
75.
Which is the strongest disinfectant?
76.
Which natural electrical force keeps colloidal particles apart in water treatment?
77.
What could happen if the sludge in a sedimentation basin becomes too thick?
78.
The proper emergency kit for a 150lb chlorine cylinder is?
79.
What should an authorized entrant do before he/she enters a permitted confined space?
80.
A public water system that can not meet the required removal of TOC can comply if the source water TOC level is what, calculated quarterly as a running annual average.
81.
Where do Enteropathogenic organisms in water supplies originate?
82.
What does the pulsating energy in a pulsator clarifier help to do?
83.
What is a common mistake operators make in regards to flocculation is excessive flocculation time.
84.
What type of charge do the compounds that form when iron or aluminum salts react with water have?
85.
What is true about heterotrophic bacteria?
86.
The backwash rate must be high enough to?
87.
What chemical oxidant would be most effective for controlling biological growth?
88.
What membrane process is used to treat brackish water or seawater?
89.
A change in the water elevation from the normal level to the pumping level is?
90.
For lime-soda ash softening plants, what is the most economical sludge disposal method?
91.
What is the best process for sequestering manganese?
92.
Current regulations require that water treatment wastes be monitored?
93.
Determining the pH is an important water quality test because the results indicate?
94.
A water sample that is acidified must have a final water pH of?
95.
Never apply water to a gaseous chlorine leak because the water will cause more issues.
96.
The size of Giardia in the trophozoite stage is approximately?
98.
How often should the fluoride concentration be measured in treated water?
99.
What type of polar bonds are between the hydrogen atoms and the oxygen atom in water?
100.
The upper surface of the zone of saturation of ground water in an unconfined aquifer is called the?
