Welcome to the Water Treatment Operator 100 Question Practice Test.
Choose the best possible answer to the question.
1.
What does the operator use to adjust the amount of liquid or gas delivered to water?
2.
The pH scale ranges from?
3.
Past the breakpoint chlorination point, what percentage of the total chlorine residual should be free chlorine?
4.
The most accurate chlorine residual measurement would be taken with?
5.
What is a physical separation between a water supply outlet and the flood-level rim of a receiving vessel that must be at least twice the diameter of the water supply outlet and the flood-level rim of the receiving vessel. This separation must be at leasttwice the diameter of the water supply outlet and never less than one inch?
6.
When natural zeolites are used for softening and they have become exhausted from use, what chemical are they regenerated with?
7.
Sludge should be removed from a gravity sedimentation basin when reaching a level of?
8.
One ton chlorine containers are equipped with two valves, one for liquid and one for gas.
9.
Which of the following composes the majority of scale in pipes?
10.
What determines whether or not colloidal sized particles in suspension repel each other, stay in suspension, or agglomerate and eventually settle?
11.
What is the best process for sequestering manganese?
12.
When the temperature of raw surface water drops significantly the flocculator paddle speed should be?
13.
What tests are performed most frequently in drinking water systems?
14.
What is the sample size for lead and copper analysis?
15.
If a water system collects less than 40 samples a month, how many can be coliform positive and the water system still maintain compliance?
16.
What is the filtration flow rate through a manganese greensand pressure filter at 10 degrees Celsius?
17.
What is the most favorable raw water condition for good flocculation?
18.
Who can declare the vulnerability of a water source?
19.
Which is classified as a secondary contaminant?
20.
What process change be should be done if the level of turbidity in raw water decreased from 7 to 3 NTUs?
21.
At its endpoint, what color does the oxidant potassium permanganate turn?
22.
What part of the human body is the most vulnerable to allowing microorganisms to enter it?
23.
Filter alum and polymer compounds are primarily
24.
Most regulated contaminants in drinking water?
25.
When soda ash is added to water for softening purposes what will it do?
26.
Anionic polymers are used as filter aids to agglomerate small floc particles left in the sedimentation basin effluent and make them tougher to avoid?
27.
Reaching breakpoint chlorination means?
28.
What occurs in raw water as the level of ammonia decreases?
29.
If a water system collects at least 40 samples per month for total coliform analysis, no more than 20% of samples can come back positive.
30.
Records of sanitary surveys must be kept for?
31.
Which natural electrical force keeps colloidal particles apart in water treatment?
32.
The most favorable condition in raw water for good flocculation with alum is?
33.
According to the AWWA, at 0.1 NTUs filtration can remove what percent of giardia cyts?
34.
What is the removal level of cryptosporidium oocysts with conventional sedimentation?
35.
Why is water softening a part of the water treatment process?
36.
How much carbon is approximately lost during the reactivation process for granular activated carbon?
37.
What is potassium permanganate most effective in?
38.
The injection of fluoride should be as far away as possible from any chemical containing?
39.
Most totalizer meters at treatment plants are commonly
40.
Which of the following illnesses is it hardest to kill the organism that causes the illness?
41.
Why is turbidity in drinking water undesirable?
42.
What type of polymers are sometimes formulated with regulated substances?
43.
In order to prevent air binding in a rapid sand filter, head loss should never exceed?
44.
Why are polyphosphates used in drinking water?
45.
What is the specific gravity standard for gases?
46.
What type of self-contained breathing apparatus should be used at water plants?
47.
During daylight hours, algae growth in a reservoir will do what?
48.
What is the MCL for HAA5s?
49.
What effect will caustic soda (NaOH)have on water?
50.
What is a common mistake operators make in regards to flocculation is excessive flocculation time.
51.
What chemicals are used to substitute chlorine as pre-oxidants to minimize the formation of disinfection byproducts in a water plant?
52.
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?
53.
What does it mean when a filter is ripening?
54.
The marble test is used to determine if water is saturated with calcium carbonate and has what other general use?
55.
What is the natural attraction between particles that can be used to collect them into larger groups once destabilization has occurred?
56.
The disinfection treatment process is?
57.
When should polyphosphates used for sequestration of iron and manganese from a well be injected?
58.
What is the cause of temporary hardness?
59.
What can be done to prevent discharge cavitation from occurring?
60.
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?
61.
What is the total concentration of dissolved solids in the wastewater from the regeneration of ion exchange units?
62.
A constituent dissolved in source water that will precipitate when oxidized is?
63.
What is the optimal pH range for the removal of particulate matter when using Alum as a coagulant?
64.
According to the AWWA, the time period a filter should be used and then replaced is?
65.
Every 1.0 mg/L of alum consumes what amount of alkalinity during the formation of floc particles?
66.
What chemical can be created by certain bacterial organisms and accelerate the corrosion process?
67.
What will ion exchange remove?
68.
Which process helps remove contaminants in water by causing them to cling to the surface of certain filter grains?
69.
The maximum sustained flow possible from a well mostly depends on?
70.
The chlorine demand with vary with?
71.
What happens when there is high algae growth in a reservoir?
72.
Vegetation control in and around reservoirs is practiced to control the release of chemical compounds that
73.
Where are the two points on a gravity filter used to measure head loss located?
74.
If there is a notification of a HazMat spill of an unknown chemical into a stream that provides water to a water treatment plant, what would be the best action taken?
75.
A water molecule is made up of ?
76.
The IDLH (immediately dangerous to life and health) value for chlorine is?
77.
The size of Giardia in the trophozoite stage is approximately?
78.
Viruses are sometimes resistant to disinfection.
79.
Coliform bacteria are always?
80.
A total coliform positive sample must be tested for the presence of?
81.
What is recarbonation?
82.
If a water system collects less than 40 samples a month, how many can be coliform positive and the water system still maintain compliance?
83.
What changes does an operator need to make when there are issues with floc formation?
84.
If a body of water has high salinity and is warm, it will generally be high in dissolved oxygen.
85.
The process by which water becomes a gas and rises is called?
86.
What chemical may encourage growth of algae and microorganisms?
87.
The release of dissolved gasses in saturated cold water when pressure decreases in filter beds causes?
88.
What adverse effects does the secondary contaminant manganese have?
89.
What is a major cause of short circuiting in a sedimentation basin?
90.
A system that fails to collect water samples in their distribution system would fall under which public notification system?
91.
For surface water systems without filtration, the Surface Water Treatment Rule requires public water systems to
92.
When using chloramines
93.
What is dissolved air flotation good for removing?
94.
What angle should the parallel inclined plates be installed when using the shallow depth sedimentation method?
95.
Assuming all other variables remain the same, a decrease in the pH when using free chlorine would?
96.
What does pinpoint floc, fish eyes, and high turbidity in settled water indicate?
97.
Water treatment chemicals are added based on?
98.
What percentage of the earth's surface is covered in water?
99.
Trihalomethanes (THM's) are primarily a concern in?
100.
What chemical oxidant would be best for controlling the forming of THMs?
