WATER TREATMENT EXAM QUESTIONS
AND 100% CORRECT ANSWERS
\Q\.The objective of disinfecting water is to kill _____________
___________ _______________-ANSWERS-✔disease causing organisms.
\Q\.There are several methods for disinfecting water. Which of the following are most widely
used in drinking water applications?
a. Ozonation and Iodine
b. Chlorine and bromine
c. Ultraviolet and potassium permanganate
d. Overliming and copper sulfite-ANSWERS-✔b. Chlorine and bromine
\Q\.True or False
Chlorine gas will have an amber color when exposed to air.-ANSWERS-✔False
\Q\.Chlorine gas is ____________times heavier than air.-ANSWERS-✔2.5
\Q\.If you are receiving complaints on chlorine smell in the drinking water what would you
typically do?
,a. Turn the chlorine down to lower the residual
b. Turn the chlorine up to reach break point.
c. Flush hydrants
d. backwash filters-ANSWERS-✔b. Turn the chlorine up to reach break point.
\Q\.True or False
Gas chlorine cylinders should be located directly in front of heaters to prevent cylinders from
freezing up.-ANSWERS-✔False
\Q\.True or False
Chlorine residuals in a distribution system should be taken at the furthest locations from the
well or treatment plant.-ANSWERS-✔True
\Q\.True or False
Chlorine is safe if handled properly-ANSWERS-✔True
\Q\.If you have a minimum free chlorine residual throughout your distribution system, you
have:
a. Proper chloramine residual
b. Overfed chlorine
c. Breakpoint chlorination
d. Monochloramine compound-ANSWERS-✔c. Breakpoint chlorination
,\Q\.When mixing solutions of acid and water together, liquid chlorine or fluoride, you should
always mix the:
a. water to the acid
b. acid to the water
c. never mix together
d. any order-ANSWERS-✔b. acid to the water
\Q\.True or False
The PH of most natural waters is 6.5 – 7.5, chlorine is most effective at a higher PH.-ANSWERS-
✔False
(The lower the PH, the better the disinfection)
\Q\.This species of chlorine is the most germicidal of all chlorine compounds with the possible
exception of chlorine dioxide.
a. Hypochlorite Ion
b. Elemental chlorine
c. Hypochlorous acid
d. Hypochloric acid-ANSWERS-✔c. Hypochlorous acid
\Q\.Which is a common test used to estimate the total bacterial population in water?
a. total coliform analyses
, b. presence–absence test
c. a measurement of zeta potential
d. heterotrophic plate count-ANSWERS-✔d. heterotrophic plate count
\Q\.Suspended particles are caused by _______ in water-ANSWERS-✔turbidity
\Q\.Records of action taken to correct violations must be kept for atleast _____ years.-
ANSWERS-✔Three
\Q\.True or False
Chlorination equipment shall be capable of keeping a free chlorine residual of 2 ppm for at least
30 minutes in finished water at peak flow.-ANSWERS-✔True
\Q\.True or False
Turbidity in drinking water may not exceed 0.5 NTU in 95% of samples each month.-ANSWERS-
✔True
\Q\.A person drinking water containing a particular contaminant above this level over their
lifetime could experience ill effects. This would be an enforceable standard.
a. Treatment Technique Requirements (TTR)
b. Maximum Contaminant Level Goal (MCLG)
c. Maximum Contaminent Level (MCL)
d. None of the above-ANSWERS-✔c. Maximum Contaminent Level (MCL)
\Q\.The Total Coliform Rule (TCR) for all water supplies sets the MCL at:
AND 100% CORRECT ANSWERS
\Q\.The objective of disinfecting water is to kill _____________
___________ _______________-ANSWERS-✔disease causing organisms.
\Q\.There are several methods for disinfecting water. Which of the following are most widely
used in drinking water applications?
a. Ozonation and Iodine
b. Chlorine and bromine
c. Ultraviolet and potassium permanganate
d. Overliming and copper sulfite-ANSWERS-✔b. Chlorine and bromine
\Q\.True or False
Chlorine gas will have an amber color when exposed to air.-ANSWERS-✔False
\Q\.Chlorine gas is ____________times heavier than air.-ANSWERS-✔2.5
\Q\.If you are receiving complaints on chlorine smell in the drinking water what would you
typically do?
,a. Turn the chlorine down to lower the residual
b. Turn the chlorine up to reach break point.
c. Flush hydrants
d. backwash filters-ANSWERS-✔b. Turn the chlorine up to reach break point.
\Q\.True or False
Gas chlorine cylinders should be located directly in front of heaters to prevent cylinders from
freezing up.-ANSWERS-✔False
\Q\.True or False
Chlorine residuals in a distribution system should be taken at the furthest locations from the
well or treatment plant.-ANSWERS-✔True
\Q\.True or False
Chlorine is safe if handled properly-ANSWERS-✔True
\Q\.If you have a minimum free chlorine residual throughout your distribution system, you
have:
a. Proper chloramine residual
b. Overfed chlorine
c. Breakpoint chlorination
d. Monochloramine compound-ANSWERS-✔c. Breakpoint chlorination
,\Q\.When mixing solutions of acid and water together, liquid chlorine or fluoride, you should
always mix the:
a. water to the acid
b. acid to the water
c. never mix together
d. any order-ANSWERS-✔b. acid to the water
\Q\.True or False
The PH of most natural waters is 6.5 – 7.5, chlorine is most effective at a higher PH.-ANSWERS-
✔False
(The lower the PH, the better the disinfection)
\Q\.This species of chlorine is the most germicidal of all chlorine compounds with the possible
exception of chlorine dioxide.
a. Hypochlorite Ion
b. Elemental chlorine
c. Hypochlorous acid
d. Hypochloric acid-ANSWERS-✔c. Hypochlorous acid
\Q\.Which is a common test used to estimate the total bacterial population in water?
a. total coliform analyses
, b. presence–absence test
c. a measurement of zeta potential
d. heterotrophic plate count-ANSWERS-✔d. heterotrophic plate count
\Q\.Suspended particles are caused by _______ in water-ANSWERS-✔turbidity
\Q\.Records of action taken to correct violations must be kept for atleast _____ years.-
ANSWERS-✔Three
\Q\.True or False
Chlorination equipment shall be capable of keeping a free chlorine residual of 2 ppm for at least
30 minutes in finished water at peak flow.-ANSWERS-✔True
\Q\.True or False
Turbidity in drinking water may not exceed 0.5 NTU in 95% of samples each month.-ANSWERS-
✔True
\Q\.A person drinking water containing a particular contaminant above this level over their
lifetime could experience ill effects. This would be an enforceable standard.
a. Treatment Technique Requirements (TTR)
b. Maximum Contaminant Level Goal (MCLG)
c. Maximum Contaminent Level (MCL)
d. None of the above-ANSWERS-✔c. Maximum Contaminent Level (MCL)
\Q\.The Total Coliform Rule (TCR) for all water supplies sets the MCL at:
