1|Page
Colorado Wastewater Treatment Operator Class B
Verified Exam Questions and Correct Answers with
EXPLANATIONS LATEST UPDATE.pdf
Recommended personal hygiene practices to minimize the
risk of being infected by wastewater pathogens include -
Answer-changing out of your work clothes and showering
before leaving work
When using portable electric tools in damp areas or
around standing water, be sure to plug them into a -
Answer-ground fault circuit interrupter
You are the operator-on-duty. The alarm for the fire
detector in the Belt filter press control room goes off. what
type of fire extinguisher would you take to respond to this
alarm? - Answer-Class C`
In confined space entry, LFL stands for - Answer-Lower
flammability limit
,2|Page
When mixing dry sodium hydroxide and water in an
enclosed vessel or area, be sure that - Answer-the vessel
or area is properly vented
Personnel should not work alone on energized equipment,
for example, a magnetic starter, that operates at or above
- Answer-480 volts. It is considered lethal any amount
about this.
Which of the following hazardous chemicals in a
hydrocarbon? Methane. Phosphoric acid. Sodium
hydroxide. Ferric chloride. - Answer-Methane.
Pulmonary capacity tests are required before operators
can be cleared for using respiratory equipment. These
tests should be performed at a minimum of once every -
Answer-3 years
According to article 250 of the U.S. National Electric Code
(NEC), what color should green wires be? - Answer-
Green.
,3|Page
If your 910 kg (1 ton) chlorine cylander is leaking, what
type of chlorine institute repair kit should be used? -
Answer-Type A is for 70 kg (150 lbs)
Type B is for 1 ton
Type C is for rail cars
If your facility stores _______ or more chlorine, you must
develop a Risk Management Program in compliance with
the U.S. EPA's Chemical Accidental Release Prevention
Regulations. - Answer-1140 kg (2500 lb)
Conventional activated sludge systems typically operate
with a DO range of - Answer-2-5 mg/l
Large debris (sticks, rocks, ect) large floating solids, and
fibrous maters (rags, strings, cloth, etc.) are categorized
as - Answer-Screenings. This material is removed prior to
pumps to prevent damage.
Pumps are often required to bring wastewater into a
treatment plant. What types of pumps are typically used to
lift influent wastewater? - Answer-Centrifugal pumps are
, 4|Page
primarily used to bring in wastewater, positive
displacement pumps are used to transport sludge.
The time it takes for a unit volume of wastewater to pass
entirely through a primary clarifier is called - Answer-
detention time.
After chlorine, what is the most common effluent
wastewater disinfection technique or agent used in the
U.S. today? - Answer-Ultraviolet radiation. Due to fewer
safety concerns
The first step in maintenance staff should take in properly
locking and tagging out a piece of equipment is to -
Answer-alert the operator on duty
When working in an area with two or more floor coverings,
be sure that they are always - Answer-Secured together
When manually lifting any object be sure to - Answer-keep
it close to your body and use leg strength
Oxygen deficiency becomes a concern when the oxygen
level in a confined space is less than - Answer-19.5%
Colorado Wastewater Treatment Operator Class B
Verified Exam Questions and Correct Answers with
EXPLANATIONS LATEST UPDATE.pdf
Recommended personal hygiene practices to minimize the
risk of being infected by wastewater pathogens include -
Answer-changing out of your work clothes and showering
before leaving work
When using portable electric tools in damp areas or
around standing water, be sure to plug them into a -
Answer-ground fault circuit interrupter
You are the operator-on-duty. The alarm for the fire
detector in the Belt filter press control room goes off. what
type of fire extinguisher would you take to respond to this
alarm? - Answer-Class C`
In confined space entry, LFL stands for - Answer-Lower
flammability limit
,2|Page
When mixing dry sodium hydroxide and water in an
enclosed vessel or area, be sure that - Answer-the vessel
or area is properly vented
Personnel should not work alone on energized equipment,
for example, a magnetic starter, that operates at or above
- Answer-480 volts. It is considered lethal any amount
about this.
Which of the following hazardous chemicals in a
hydrocarbon? Methane. Phosphoric acid. Sodium
hydroxide. Ferric chloride. - Answer-Methane.
Pulmonary capacity tests are required before operators
can be cleared for using respiratory equipment. These
tests should be performed at a minimum of once every -
Answer-3 years
According to article 250 of the U.S. National Electric Code
(NEC), what color should green wires be? - Answer-
Green.
,3|Page
If your 910 kg (1 ton) chlorine cylander is leaking, what
type of chlorine institute repair kit should be used? -
Answer-Type A is for 70 kg (150 lbs)
Type B is for 1 ton
Type C is for rail cars
If your facility stores _______ or more chlorine, you must
develop a Risk Management Program in compliance with
the U.S. EPA's Chemical Accidental Release Prevention
Regulations. - Answer-1140 kg (2500 lb)
Conventional activated sludge systems typically operate
with a DO range of - Answer-2-5 mg/l
Large debris (sticks, rocks, ect) large floating solids, and
fibrous maters (rags, strings, cloth, etc.) are categorized
as - Answer-Screenings. This material is removed prior to
pumps to prevent damage.
Pumps are often required to bring wastewater into a
treatment plant. What types of pumps are typically used to
lift influent wastewater? - Answer-Centrifugal pumps are
, 4|Page
primarily used to bring in wastewater, positive
displacement pumps are used to transport sludge.
The time it takes for a unit volume of wastewater to pass
entirely through a primary clarifier is called - Answer-
detention time.
After chlorine, what is the most common effluent
wastewater disinfection technique or agent used in the
U.S. today? - Answer-Ultraviolet radiation. Due to fewer
safety concerns
The first step in maintenance staff should take in properly
locking and tagging out a piece of equipment is to -
Answer-alert the operator on duty
When working in an area with two or more floor coverings,
be sure that they are always - Answer-Secured together
When manually lifting any object be sure to - Answer-keep
it close to your body and use leg strength
Oxygen deficiency becomes a concern when the oxygen
level in a confined space is less than - Answer-19.5%
