TCEQ Class D Water License EXAM NEWEST 2026
(GRADED A+ 100% DETAILED VERIFIED ANSWERS)
Who is authorized to remove a lock and tag placed on a piece of equipment to isolate it for
maintenance? - ANSWER✅ Only the person who placed the lock and tag
Although each step of the water treatment process is important, which process is often
referred to as the most important? - ANSWER✅ Disinfection
What is/are the required locations for vent(s) in a chlorine gas cylinder storage room? -
ANSWER✅ At least one high-level and one floor level vent
A surface water treatment plant is flowing at 3.1 MGD. How many gallons per minute (gpm) is
this? - ANSWER✅ 2,153
Which chemical below is a solid form of chlorine that is often used by small water systems
as their primary disinfectant? - ANSWER✅ Calcium Hypochlorite
If an operator knows the pumping water level and the static water level in a well, he/she will
be able to calculate the: - ANSWER✅ Drawdown
Coagulation by the addition of positively charged ions can also be described as: -
ANSWER✅ Charge neutralization
,Rule of capture - ANSWER✅ Permits owner of a well to pump as much water as desired,
even if water is drained from beneath the land of others
when treating surface water, the process of coagulation will be affected by - ANSWER✅ all
of the above
a public water system is responsible for providing - ANSWER✅ all of the above
a common type of oxidant that is used at most surface water treatment plants to kill
bacteria and to prevent trihalomethane formation is - ANSWER✅ combined chlorine
Which of the following is a required step in collecting a routine distribution sample of
microbiological analysis - ANSWER✅ use a sterilized bottles containing sodium thiosulfate
The purpose of an airline on a well is - ANSWER✅
which minerals cause water hardness - ANSWER✅ calcium and magnesium
Before a new main is placed into service, it must be properly disinfected with a minimum
chlorine dosage of:
a) 50 mg/L
b) 30 mg/L
c) 40 mg/L
,d) 75 mg/L
e) 25 mg/L - ANSWER✅ 25 mg/L
A disease which may be spread by inadequately disinfected water is - ANSWER✅ Hepatitis
A
A physical connection between a potable water supply and non-potable water source is -
ANSWER✅ cross connection
underground geological water bearing formations that are used for public water supplies
are called - ANSWER✅ aquifers
Gravity filters will remove which of the following from surface water supplies:
a) turbidity
b) taste and odors
c) nitrates
d) hardness
e) chlorides - ANSWER✅ turbidity
Activated carbon is used at a surface water treatment plant primarily for - ANSWER✅
taste and odor control
Which of the following is part of a hyperchlorination system - ANSWER✅
, A common chemical used for disinfecting a small public water supply is - ANSWER✅
Your ground storage tank is 15 feet high and 30 feet in diameter. About how much water can
it hold?
a) 31,700 gallons
b) 79,270 gallons
c) 50, 490 gallons
d) 25,150 gallons
e) 10,600 gallons - ANSWER✅ 79270
If you added 3.5 mg/L of chlorine to your storage tank and 30 minutes later measured the
residual at 1.2 mg/L, what was the chlorine demand in the tank?
a) 4.2
b) 2.9
c) 0.3
d) 2.3
e) 4.7 - ANSWER✅ 2.3
which of the following chemicals is commonly used as a coagulant in surface water
treatment - ANSWER✅ aluminum sulfate
The drawdown of a well is determined by:
(GRADED A+ 100% DETAILED VERIFIED ANSWERS)
Who is authorized to remove a lock and tag placed on a piece of equipment to isolate it for
maintenance? - ANSWER✅ Only the person who placed the lock and tag
Although each step of the water treatment process is important, which process is often
referred to as the most important? - ANSWER✅ Disinfection
What is/are the required locations for vent(s) in a chlorine gas cylinder storage room? -
ANSWER✅ At least one high-level and one floor level vent
A surface water treatment plant is flowing at 3.1 MGD. How many gallons per minute (gpm) is
this? - ANSWER✅ 2,153
Which chemical below is a solid form of chlorine that is often used by small water systems
as their primary disinfectant? - ANSWER✅ Calcium Hypochlorite
If an operator knows the pumping water level and the static water level in a well, he/she will
be able to calculate the: - ANSWER✅ Drawdown
Coagulation by the addition of positively charged ions can also be described as: -
ANSWER✅ Charge neutralization
,Rule of capture - ANSWER✅ Permits owner of a well to pump as much water as desired,
even if water is drained from beneath the land of others
when treating surface water, the process of coagulation will be affected by - ANSWER✅ all
of the above
a public water system is responsible for providing - ANSWER✅ all of the above
a common type of oxidant that is used at most surface water treatment plants to kill
bacteria and to prevent trihalomethane formation is - ANSWER✅ combined chlorine
Which of the following is a required step in collecting a routine distribution sample of
microbiological analysis - ANSWER✅ use a sterilized bottles containing sodium thiosulfate
The purpose of an airline on a well is - ANSWER✅
which minerals cause water hardness - ANSWER✅ calcium and magnesium
Before a new main is placed into service, it must be properly disinfected with a minimum
chlorine dosage of:
a) 50 mg/L
b) 30 mg/L
c) 40 mg/L
,d) 75 mg/L
e) 25 mg/L - ANSWER✅ 25 mg/L
A disease which may be spread by inadequately disinfected water is - ANSWER✅ Hepatitis
A
A physical connection between a potable water supply and non-potable water source is -
ANSWER✅ cross connection
underground geological water bearing formations that are used for public water supplies
are called - ANSWER✅ aquifers
Gravity filters will remove which of the following from surface water supplies:
a) turbidity
b) taste and odors
c) nitrates
d) hardness
e) chlorides - ANSWER✅ turbidity
Activated carbon is used at a surface water treatment plant primarily for - ANSWER✅
taste and odor control
Which of the following is part of a hyperchlorination system - ANSWER✅
, A common chemical used for disinfecting a small public water supply is - ANSWER✅
Your ground storage tank is 15 feet high and 30 feet in diameter. About how much water can
it hold?
a) 31,700 gallons
b) 79,270 gallons
c) 50, 490 gallons
d) 25,150 gallons
e) 10,600 gallons - ANSWER✅ 79270
If you added 3.5 mg/L of chlorine to your storage tank and 30 minutes later measured the
residual at 1.2 mg/L, what was the chlorine demand in the tank?
a) 4.2
b) 2.9
c) 0.3
d) 2.3
e) 4.7 - ANSWER✅ 2.3
which of the following chemicals is commonly used as a coagulant in surface water
treatment - ANSWER✅ aluminum sulfate
The drawdown of a well is determined by:
