Page | 1
CWEA ENVIRONMENTAL COMPLIANCE
EXAM 2025/2026 BRAND NEW
QUESTIONS WITH ANSWERS| ACE
YOUR GRADES!
Why are septum vials used for TTO samples? - correct answer -
To prevent sample contact with air
The scouring velocity in a sewer is the speed of wastewater that
will: - correct answer -Prevent the deposition and buildup of
solids.
22. Flatter sewer line grades may cause added sewer
maintenance expense and odor nuisance. The problem is most
likely cased by: - correct answer -A decrease in velocity allowing
organic and inorganic solids to settle out
A cyanide-bearing waste is to be treated by a batch process using
the alkaline chlorination method. The cyanide holding tank
contains 6,000 gallons with a cyanide concentration of 15 mg/L.
Seven pounds of caustic soda and eight pounds of chlorine are
, Page | 2
required to oxidize one pound of cyanide to nitrogen gas. How
many pounds of chlorine are needed? - correct answer -6.0
What types of control devices are used to stop and start pumps? -
correct answer -Floats
What type of pump is used in lift station wet wells? - correct
answer -Submersible
What is the main purpose of gate valves in a lift station? - correct
answer -To isolate the lift station from the wastewater collection
system during maintenance
Which of the following is not a suspended growth biological
treatment system? - correct answer -Trickling filter
Activated sludge is wasted from the reactor to: - correct answer -
control the sludge age.
, Page | 3
A method commonly used to thicken activated sludge prior to
treatment is: - correct answer -dissolved air flotation.
A metal finishing facility generates nickel-plating sludge from the
clarifier of its pretreatment system. The clarifier sludge is 6,000
mg/L and 2 percent of the treatment plant inflow of 50,000 gallons
per day. The sludge is dewatered in a filter press, 5 days per
week, and shipped off site for disposal as hazardous waste once
per week. If the filter press cake is 25 percent solids, how many
pounds of dewatered sludge should be manifested as hazardous
waste each week, assuming a cake density of 8.34 lbs/gallon? -
correct answer -1,000
Which method below is not used to stabilize municipal wastewater
treatment plant sludge? - correct answer -Contact stabilization
What is the first safety planning step prior to making a
pretreatment inspection? - correct answer -Review the facility's
industrial waste permit application and correspondence file
What is a common cause of oxygen deficiency in a sewer
manhole? - correct answer -Bacterial action that replaces oxygen
with other gasses
, Page | 4
How many different areas of traffic zones are there when working
in roadways? - correct answer -Five
What does "transition area" mean in traffic control? - correct
answer -Moves traffic out of its normal path
Permit space emergency personnel must have the following
training - correct answer -Enter and rescue procedures
How does sewer system confined space entry differ from other
permit and non-permit entries? - correct answer -There rarely
exists any way to completely isolate the space
What is always required when working in a confined space? -
correct answer -Continuous air monitoring
Oxygen deficiency occurs when the oxygen level is less than
____ by volume - correct answer -19.5%
CWEA ENVIRONMENTAL COMPLIANCE
EXAM 2025/2026 BRAND NEW
QUESTIONS WITH ANSWERS| ACE
YOUR GRADES!
Why are septum vials used for TTO samples? - correct answer -
To prevent sample contact with air
The scouring velocity in a sewer is the speed of wastewater that
will: - correct answer -Prevent the deposition and buildup of
solids.
22. Flatter sewer line grades may cause added sewer
maintenance expense and odor nuisance. The problem is most
likely cased by: - correct answer -A decrease in velocity allowing
organic and inorganic solids to settle out
A cyanide-bearing waste is to be treated by a batch process using
the alkaline chlorination method. The cyanide holding tank
contains 6,000 gallons with a cyanide concentration of 15 mg/L.
Seven pounds of caustic soda and eight pounds of chlorine are
, Page | 2
required to oxidize one pound of cyanide to nitrogen gas. How
many pounds of chlorine are needed? - correct answer -6.0
What types of control devices are used to stop and start pumps? -
correct answer -Floats
What type of pump is used in lift station wet wells? - correct
answer -Submersible
What is the main purpose of gate valves in a lift station? - correct
answer -To isolate the lift station from the wastewater collection
system during maintenance
Which of the following is not a suspended growth biological
treatment system? - correct answer -Trickling filter
Activated sludge is wasted from the reactor to: - correct answer -
control the sludge age.
, Page | 3
A method commonly used to thicken activated sludge prior to
treatment is: - correct answer -dissolved air flotation.
A metal finishing facility generates nickel-plating sludge from the
clarifier of its pretreatment system. The clarifier sludge is 6,000
mg/L and 2 percent of the treatment plant inflow of 50,000 gallons
per day. The sludge is dewatered in a filter press, 5 days per
week, and shipped off site for disposal as hazardous waste once
per week. If the filter press cake is 25 percent solids, how many
pounds of dewatered sludge should be manifested as hazardous
waste each week, assuming a cake density of 8.34 lbs/gallon? -
correct answer -1,000
Which method below is not used to stabilize municipal wastewater
treatment plant sludge? - correct answer -Contact stabilization
What is the first safety planning step prior to making a
pretreatment inspection? - correct answer -Review the facility's
industrial waste permit application and correspondence file
What is a common cause of oxygen deficiency in a sewer
manhole? - correct answer -Bacterial action that replaces oxygen
with other gasses
, Page | 4
How many different areas of traffic zones are there when working
in roadways? - correct answer -Five
What does "transition area" mean in traffic control? - correct
answer -Moves traffic out of its normal path
Permit space emergency personnel must have the following
training - correct answer -Enter and rescue procedures
How does sewer system confined space entry differ from other
permit and non-permit entries? - correct answer -There rarely
exists any way to completely isolate the space
What is always required when working in a confined space? -
correct answer -Continuous air monitoring
Oxygen deficiency occurs when the oxygen level is less than
____ by volume - correct answer -19.5%
