TEXAS CLASS D WATER LICENSE TEST
2026/2027 BANK EXAM QUESTIONS
ACCURATE ACTUAL EXAM / FREQUENTLY
TESTED QUESTIONS WITH DETAILED
ANSWERS | GUARANTEED PASS | GRADED
A | LATEST UPDATE
In the event of low distribution pressure (below _____ psi),
water outages, repeated unacceptable microbiological
samples, or failure to maintain adequate chlorine residuals,
special precautions must be instituted by the water
system. - ....ANSWER...20 psi
In Texas, all public water systems are required to have
________ facilities.
a. ozonation
b. chlorination
c. softening
d. trihalomethane - ....ANSWER...b. chlorination
,Chlorination is the most important process in the
production of ________ water. - ....ANSWER...potable
Besides disinfection, chlorine is used for taste and odor
control and ________.
a. oxidation of iron and manganese
b. oxidation of hydrogen sulfide
c. disinfection of repairs
d. all listed - ....ANSWER...d. all listed
Sodium hypochlorite is liquid ________. -
....ANSWER...bleach
Bleach used in public water systems must be ________
approved. - ....ANSWER...NSF
Calcium hypochlorite is made by reacting chlorine with
________. - ....ANSWER...lime
Calcium hypochlorite will cause explosions or fires if it
contacts ________ material. - ....ANSWER...organic
,At room temperature, chlorine gas is greenish-yellow, has
a pungent odor, is ________ times heavier than air. -
....ANSWER...2.5
The maximum sustained gas withdrawal rate from 150-lb.
cylinders (vacuum transmission) is ________ lb(s)./day per
degree F. - ....ANSWER...1 lbs/day
Disinfection capacity for drinking water must be
________% greater than the highest expected dosage. -
....ANSWER...50%
Small water systems often use ________ to disinfect their
water supply. - ....ANSWER...hypochlorinators
Hypochlorinators consist of a mixing tank, water,
________ hypochlorite, or ________ hypochlorite and a
chemical pump. - ....ANSWER...sodium hypochlorite
calcium hypochlorite
, Gas chlorinators use a rotameter to meter chlorine in
________ or grams/hr. - ....ANSWER...lbs/day
Dosage is the amount of chemical applied, demand is the
amount of chemical used up, ________ is the amount of
chemical remaining after reacting with demand. -
....ANSWER...residual
Minimum chlorine residuals of ________ (free) and
________ (combined) are required in the far reaches of the
distribution system. - ....ANSWER...0.2 (free)
0.5 (combined/total)
The DPD and chlorine reaction turns the water a
________ color. - ....ANSWER...pink to red
Chlorine and water make two acids: hydrochloric (HCl)
and ________ (HOCl).
a. hypochlorous
b. hypochloric
c. hyperclorous
d. hydrachloric - ....ANSWER...a. hypochlorous
2026/2027 BANK EXAM QUESTIONS
ACCURATE ACTUAL EXAM / FREQUENTLY
TESTED QUESTIONS WITH DETAILED
ANSWERS | GUARANTEED PASS | GRADED
A | LATEST UPDATE
In the event of low distribution pressure (below _____ psi),
water outages, repeated unacceptable microbiological
samples, or failure to maintain adequate chlorine residuals,
special precautions must be instituted by the water
system. - ....ANSWER...20 psi
In Texas, all public water systems are required to have
________ facilities.
a. ozonation
b. chlorination
c. softening
d. trihalomethane - ....ANSWER...b. chlorination
,Chlorination is the most important process in the
production of ________ water. - ....ANSWER...potable
Besides disinfection, chlorine is used for taste and odor
control and ________.
a. oxidation of iron and manganese
b. oxidation of hydrogen sulfide
c. disinfection of repairs
d. all listed - ....ANSWER...d. all listed
Sodium hypochlorite is liquid ________. -
....ANSWER...bleach
Bleach used in public water systems must be ________
approved. - ....ANSWER...NSF
Calcium hypochlorite is made by reacting chlorine with
________. - ....ANSWER...lime
Calcium hypochlorite will cause explosions or fires if it
contacts ________ material. - ....ANSWER...organic
,At room temperature, chlorine gas is greenish-yellow, has
a pungent odor, is ________ times heavier than air. -
....ANSWER...2.5
The maximum sustained gas withdrawal rate from 150-lb.
cylinders (vacuum transmission) is ________ lb(s)./day per
degree F. - ....ANSWER...1 lbs/day
Disinfection capacity for drinking water must be
________% greater than the highest expected dosage. -
....ANSWER...50%
Small water systems often use ________ to disinfect their
water supply. - ....ANSWER...hypochlorinators
Hypochlorinators consist of a mixing tank, water,
________ hypochlorite, or ________ hypochlorite and a
chemical pump. - ....ANSWER...sodium hypochlorite
calcium hypochlorite
, Gas chlorinators use a rotameter to meter chlorine in
________ or grams/hr. - ....ANSWER...lbs/day
Dosage is the amount of chemical applied, demand is the
amount of chemical used up, ________ is the amount of
chemical remaining after reacting with demand. -
....ANSWER...residual
Minimum chlorine residuals of ________ (free) and
________ (combined) are required in the far reaches of the
distribution system. - ....ANSWER...0.2 (free)
0.5 (combined/total)
The DPD and chlorine reaction turns the water a
________ color. - ....ANSWER...pink to red
Chlorine and water make two acids: hydrochloric (HCl)
and ________ (HOCl).
a. hypochlorous
b. hypochloric
c. hyperclorous
d. hydrachloric - ....ANSWER...a. hypochlorous
