1
Wastewater Collector Class D License Exam
Questions and Answers Already Passed Latest
Updated 2024/2025 | Graded A+
书山有路勤为书山有路勤为径，学海无涯苦作舟书
How山书山有路勤为径，学海无涯苦作舟有路勤为径，
many PPB equals one PPM? - (answer)One thousand parts per billion
学海无涯苦作舟径，学海无涯苦作舟
equals one part per million
If the bubbler system air supply line at the wet well is clogged, what will this
cause the pump to do? - (answer)Pressure build up in the supply line would
signal more water column then there really was, causing the pump to run
longer than necessary, possibly not kick off and run continually
If the bubbler system air supply line at the wet well has a hole in it above the
water level, what will this cause the pump to do? - (answer)It would cause a
low pressure reading showing a lower water level then there really is, or
possible not even kicking on the pump
What is the best way to keep within the operating budget? - (answer)keep list
of purchases and expenses to date during fiscal year
comparisons should be made with budget allocations to avoid excess purchases
review purchases monthly and compare to budget
, 2
If a diaphragm pump has 2 check valves open, what will the pump do? -
(answer)It would not pump properly because 1 check valve should be shut
while书山有路勤为书山有路勤为径，学海无涯苦作舟书
the other is open
山书山有路勤为径，学海无涯苦作舟有路勤为径，
学海无涯苦作舟径，学海无涯苦作舟
A suction lift pump on the inlet side normally reads 2in of mercury on the psi
vacuum gauge but not reads 3in of mercury. What is the problem with the
pump? - (answer)A higher vacuum than normal may indicate a partially
plugged or restricted suction line.
A lower vacuum may indicate a higher wet well level or a worn pump impeller
or wearing rings.
One mg per L equals how many pounds per 1 MG? - (answer)8.34
What is the proper way to put packing in a pump? - (answer)cut the packing
rope about 45 degree angle, place around shaft, be sure to offset/stagger the
next joint from the previous
How many drips of water should you have coming out of a packing seal? -
(answer)no drip on a mechanical seal
How many drips of water should you have coming out of a packing seal? 2 -
(answer)what the operation and maintenance manual recommends
, 3
A one horsepower motor that runs on 110 volts using 10 amps has what
书山有路勤为书山有路勤为径，学海无涯苦作舟书
efficiency? - (answer)most motors run from 80-95% efficiency
山书山有路勤为径，学海无涯苦作舟有路勤为径，
学海无涯苦作舟径，学海无涯苦作舟
A motor that has 440 volt supply is usually what phase of power? - (answer)3
phase
NPDES - (answer)National Pollutant Discharge Elimination System
the regulatory agency document issued by either a federal or state agency
which is designed to control all discharges of pollutants from point sources into
US waterways - (answer)NPDES permit
What is the name of our operating permit? - (answer)NPDES
What is the best way to promote safety in the workplace? - (answer)the
supervisor needs to be safe and promote safety in such a manner to get the
employees involved
What is normally used to raise the pH in sludge? - (answer)lime
, 4
What is the common device used to measure the effluent of a lagoon? -
(answer)v notch weir
书山有路勤为书山有路勤为径，学海无涯苦作舟书
山书山有路勤为径，学海无涯苦作舟有路勤为径，
学海无涯苦作舟径，学海无涯苦作舟
What concentration of H2S is unsafe to humans? - (answer)death in a few
minutes at 0.2%. Paralyzes respiratory center
What is the minimum O2 concentration that is safe for workers to enter a
manhole? - (answer)If O2 is less than 19.5%, do not enter space without
respiratory protection. Normal air contains 20.93% of O2.
Normal air contains ______% of O2 - (answer)19.5%
What knob is turned to control the usage of chlorine applied? -
(answer)rotameter
Can you store BOD at 4C for 48 hours? - (answer)yes
What is the minimum velocity of the water flow for a grit chamber and the
maximum flow? - (answer)1.0 feet per second minimum
1.5 feet per second optimum
2.0 feet per second maximum
Wastewater Collector Class D License Exam
Questions and Answers Already Passed Latest
Updated 2024/2025 | Graded A+
书山有路勤为书山有路勤为径，学海无涯苦作舟书
How山书山有路勤为径，学海无涯苦作舟有路勤为径，
many PPB equals one PPM? - (answer)One thousand parts per billion
学海无涯苦作舟径，学海无涯苦作舟
equals one part per million
If the bubbler system air supply line at the wet well is clogged, what will this
cause the pump to do? - (answer)Pressure build up in the supply line would
signal more water column then there really was, causing the pump to run
longer than necessary, possibly not kick off and run continually
If the bubbler system air supply line at the wet well has a hole in it above the
water level, what will this cause the pump to do? - (answer)It would cause a
low pressure reading showing a lower water level then there really is, or
possible not even kicking on the pump
What is the best way to keep within the operating budget? - (answer)keep list
of purchases and expenses to date during fiscal year
comparisons should be made with budget allocations to avoid excess purchases
review purchases monthly and compare to budget
, 2
If a diaphragm pump has 2 check valves open, what will the pump do? -
(answer)It would not pump properly because 1 check valve should be shut
while书山有路勤为书山有路勤为径，学海无涯苦作舟书
the other is open
山书山有路勤为径，学海无涯苦作舟有路勤为径，
学海无涯苦作舟径，学海无涯苦作舟
A suction lift pump on the inlet side normally reads 2in of mercury on the psi
vacuum gauge but not reads 3in of mercury. What is the problem with the
pump? - (answer)A higher vacuum than normal may indicate a partially
plugged or restricted suction line.
A lower vacuum may indicate a higher wet well level or a worn pump impeller
or wearing rings.
One mg per L equals how many pounds per 1 MG? - (answer)8.34
What is the proper way to put packing in a pump? - (answer)cut the packing
rope about 45 degree angle, place around shaft, be sure to offset/stagger the
next joint from the previous
How many drips of water should you have coming out of a packing seal? -
(answer)no drip on a mechanical seal
How many drips of water should you have coming out of a packing seal? 2 -
(answer)what the operation and maintenance manual recommends
, 3
A one horsepower motor that runs on 110 volts using 10 amps has what
书山有路勤为书山有路勤为径，学海无涯苦作舟书
efficiency? - (answer)most motors run from 80-95% efficiency
山书山有路勤为径，学海无涯苦作舟有路勤为径，
学海无涯苦作舟径，学海无涯苦作舟
A motor that has 440 volt supply is usually what phase of power? - (answer)3
phase
NPDES - (answer)National Pollutant Discharge Elimination System
the regulatory agency document issued by either a federal or state agency
which is designed to control all discharges of pollutants from point sources into
US waterways - (answer)NPDES permit
What is the name of our operating permit? - (answer)NPDES
What is the best way to promote safety in the workplace? - (answer)the
supervisor needs to be safe and promote safety in such a manner to get the
employees involved
What is normally used to raise the pH in sludge? - (answer)lime
, 4
What is the common device used to measure the effluent of a lagoon? -
(answer)v notch weir
书山有路勤为书山有路勤为径，学海无涯苦作舟书
山书山有路勤为径，学海无涯苦作舟有路勤为径，
学海无涯苦作舟径，学海无涯苦作舟
What concentration of H2S is unsafe to humans? - (answer)death in a few
minutes at 0.2%. Paralyzes respiratory center
What is the minimum O2 concentration that is safe for workers to enter a
manhole? - (answer)If O2 is less than 19.5%, do not enter space without
respiratory protection. Normal air contains 20.93% of O2.
Normal air contains ______% of O2 - (answer)19.5%
What knob is turned to control the usage of chlorine applied? -
(answer)rotameter
Can you store BOD at 4C for 48 hours? - (answer)yes
What is the minimum velocity of the water flow for a grit chamber and the
maximum flow? - (answer)1.0 feet per second minimum
1.5 feet per second optimum
2.0 feet per second maximum
