Welcome to the Water Treatment Operator 100 Question Practice Test.
Choose the best possible answer to the question.
1.
An organic particle that is stabilized by attracting a layer of water molecules to its surface is known as a?
2.
What percentage of the air is usually converted to ozone if air is used to generate ozone?
3.
What do long filter runs tend to cause?
4.
Community and non-transient community water systems must test for what if they use ozone for disinfection of oxidation?
5.
It is important not to rinse out the sample bottes used for collecting samples for bacteriological examination because?
6.
The maximum amount of time that between draining, cleaning, and inspection of sedimentation basins with mechanical sludge removal components is?
7.
What chemical oxidant is most effective in reducing the concentration of taste and odor compounds caused by actinomycetes species?
8.
What is the most important reason to reduce turbidity?
9.
Anaerobic conditions in reservoirs can cause what problem?
10.
In the MNO-MUG test the presence of E.coli is indicted by?
11.
What process change be should be done if the level of turbidity in raw water decreased from 7 to 3 NTUs?
12.
Most totalizer meters at treatment plants are commonly
13.
What is the most effective disinfection residual?
14.
The factors that effect coagulation and flocculation with alum are
15.
A method to increase or maintain the DO concentration of a thermally stratified reservoir?
16.
Never install a new gasket when a chlorine cylinder or container is changed.
17.
Community water systems must check the natural radioactivity in their water supply at least?
18.
What conditions will +Eh values of water support?
19.
What chemical is slacked lime?
20.
When should polyphosphates used for sequestration of iron and manganese from a well be injected?
21.
How often should the solids concentration be determined in solid contact basins with fairly constant water quality parameters?
22.
The more hydroxide ions
23.
The release of dissolved gasses in saturated cold water when pressure decreases in filter beds causes?
24.
Every 1.0 mg/L of alum consumes what amount of alkalinity during the formation of floc particles?
25.
What type of filtration is permitted under the Surface Water Treatment Rule?
26.
Which is the most persistent protozoa?
27.
The IDLH (immediately dangerous to life and health) value for chlorine is?
28.
What is the maximum feed rate when adding fluoride to drinking water?
29.
What type of polymers are sometimes formulated with regulated substances?
30.
Floc is produced when there is a chemical reaction between the coagulant and alkalinity. If the alkalinity of raw water is too low the floc formation will be poor. Some form of alkalinity must be added if the amount that is naturally found in the water source is less than?
31.
If the continuous monitoring of the residual disinfectant concentration of the water entering the water system fails, how often will an operator need to collect a grab sample until the problem is fixed?
32.
What is the only MCL that varies with the temperature?
33.
Opening the discharge valve one full turn on a chlorine cylinder will?
34.
The Zeta Protentional measures the number of excess what found on the surface of all particular matter?
35.
The outlet of a forced ventilation system for a chlorinator room she be located?
36.
What causes an increase in taste and odors when natural waters lack DO?
37.
To unclog the head of a chemical feed pump an operator should first?
38.
What makes chlorine use more advantageous over chloramines?
39.
If a water system collects less than 40 samples a month, how many can be coliform positive and the water system still maintain compliance?
40.
Where is the least desirable point in a plug flow sedimentation basin for turbulent flow that resuspends solids would be in the?
41.
What water rights are acquired from diverting a water source and then putting it to beneficial use?
42.
Where does most of the carbon dioxide in groundwater originate from?
43.
Determining the pH is an important water quality test because the results indicate?
44.
What type of charge do the compounds that form when iron or aluminum salts react with water have?
45.
Manganese is rarely found in surface waters above a concentration of?
46.
What is the removal level of cryptosporidium oocysts with conventional sedimentation?
47.
Compared to disinfecting water with free chlorine, what is a disadvantage in switching to ozone?
48.
The hour during the day when the largest volume of water is being pumped is known as peak hourly flow?
49.
Which of the following illnesses is it hardest to kill the organism that causes the illness?
50.
Chlorine is chosen over chloramines because chlorine?
51.
What is used as part of a sedimentation basin to allow a controlled flow of the supernatant to be collected and directed to the filter beds?
52.
What oxidant has a potential of producing ClO3 by products?
53.
When doing coliform analysis use the presence-absence method, a sample should be incubated for?
54.
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?
55.
What does total alkalinity refer to?
56.
What is the cause of temporary hardness?
57.
Which would be an indication that there is an issue with a part of the coagulation-flash mix-flocculation process operation?
58.
What is the optimal pH range for the removal of particulate matter when using Alum as a coagulant?
59.
In pounds, how much ammonia is contained in a 1 ton cylinder that is full?
60.
What is the best process for sequestering manganese?
61.
The maximum safe level of electrical current that will not have any long lasting health effects is?
62.
When abundant in water, what algae genera are most likely to cause taste and odor issues when abundant in water?
63.
The more hydrogen ions
64.
What laboratory device sterilizes laboratory apparatuses and microbial media by using pressurized steam?
65.
What is the MCL for THM's?
66.
A total coliform positive sample must be tested for the presence of?
67.
Which is classified as a secondary contaminant?
68.
If the chlorine demand suddenly increases from 0.4 mg/L to 2.8 mg/L, what could be the reason?
69.
What are the chemical symbols for hypochlorous acid and hypochlorite ions?
70.
What type of chlorine gas feeding equipment would be most appropriate for distribution systems where re-chlorination is required?
71.
The backwash rate must be high enough to?
72.
What type of water violation requires an all clear notification be given to the public?
73.
Which is a chemical used in water treatment as a coagulating chemical?
74.
What forms when you add Alum to turbid water?
75.
Plant growth in a reservoir will usually be found at a depth of?
76.
An increase in filter media head loss could be an indicator of?
77.
What is used for detection of chlorine gas leaks?
78.
What is dental fluorosis?
79.
What factor is used to express the relative volatility of a substance?
80.
An artesian spring occurs when
81.
Trihalomethanes (THM's) are primarily a concern in?
82.
Which natural electrical force keeps colloidal particles apart in water treatment?
83.
What is the most probable solution if crustaceans have clogged the water treatment plant's filters?
84.
A system that fails to collect water samples in their distribution system would fall under which public notification system?
85.
What is the most favorable raw water condition for good flocculation?
86.
When disinfecting a well with free chlorine, what is the required exposure time and what must the concentration be?
87.
What water quality indicator is of greatest concern in a surface water treatment plant?
88.
At what temperature does the maximum density of water occur?
89.
What chemical can be added to the water system to sequester Iron and Manganese?
90.
What test is used to determine the presence of coliform bacteria?
91.
What advantage over Aluminum Sulfate does Ferric Sulfate have?
92.
If a water system collects less than 40 samples a month, how many can be coliform positive and the water system still maintain compliance?
93.
What water quality indicator should be considered in a lake de-stratification program?
94.
Evaporated water in the earth's atmosphere will condense to form
95.
One of the steps taken to determine the threshold odor number is?
96.
If the water temperature decreases this will cause the disinfection action of chlorine to?
97.
Solids contact basins have much shorter detention times than conventional treatment basins.
98.
A constituent dissolved in source water that will precipitate when oxidized is?
99.
Sludge should be removed from a gravity sedimentation basin when reaching a level of?
