WASTEWATER D LICENSE 2024/2025 EXAM QUESTIONS
WITH 100% CORRECTLY SOLVED ANSWERS
1) How many PPB equals one PPM? -- Answer ✔✔ One thousand parts per billion
_ _ _ _ _ _ _ _ _ _ _ _ _ _
equals one part per million _ _ _ _
2) 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 _ _ _ _ _ _
3) 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
_ _ _ _
4) 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
_ _ _ _ _ _
5) 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 the other is
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
open
6) 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. _
7) One mg per L equals how many pounds per 1 MG? -- Answer ✔✔ 8.34
_ _ _ _ _ _ _ _ _ _ _ _ _ _
8) 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
_ _ _
9) How many drips of water should you have coming out of a packing seal? -- Answer
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
✔✔ no drip on a mechanical seal
_ _ _ _ _ _
10) How many drips of water should you have coming out of a packing seal? 2 -- Answer
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
✔✔ what the operation and maintenance manual recommends
_ _ _ _ _ _ _
11) A one horsepower motor that runs on 110 volts using 10 amps has what efficiency? --
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_Answer ✔✔ most motors run from 80-95% efficiency
_ _ _ _ _ _ _
12) A motor that has 440 volt supply is usually what phase of power? -- Answer ✔✔ 3
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
phase
13) NPDES -- Answer ✔✔ National Pollutant Discharge Elimination System
_ _ _ _ _ _ _ _
14) 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
_ _ _ _
15) What is the name of our operating permit? -- Answer ✔✔ NPDES
_ _ _ _ _ _ _ _ _ _ _
16) 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 _
17) What is normally used to raise the pH in sludge? -- Answer ✔✔ lime
_ _ _ _ _ _ _ _ _ _ _ _ _
, 18) What is the common device used to measure the effluent of a lagoon? -- Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
v notch weir
_ _
19) What concentration of H2S is unsafe to humans? -- Answer ✔✔ death in a few
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
minutes at 0.2%. Paralyzes respiratory center
_ _ _ _ _
20) 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. _ _ _ _ _ _
21) Normal air contains ______% of O2 -- Answer ✔✔ 19.5%
_ _ _ _ _ _ _ _ _
22) What knob is turned to control the usage of chlorine applied? -- Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _ _ _
rotameter
23) Can you store BOD at 4C for 48 hours? -- Answer ✔✔ yes
_ _ _ _ _ _ _ _ _ _ _ _
24) 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
_ _ _ _
25) How many mg/L equals one grain per gallon? -- Answer ✔✔ 17.1 mg/L
_ _ _ _ _ _ _ _ _ _ _ _
26) Dissolved oxygen increases when the temperature __________ -- Answer ✔✔
_ _ _ _ _ _ _ _ _ _
decreases
27) You can tell if a clarifier scraper arm is working by what means? -- Answer ✔✔ the
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
simplest is to visual check to see if the scum scraper arm is moving properly
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
check into foam _ _
28) If the sludge is thick or thin, then what does this tell you about the sludge scraper? --
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Answer ✔✔ possible answer is the flights are damaged or the speed of the
_ _ _ _ _ _ _ _ _ _ _ _ _ _
WITH 100% CORRECTLY SOLVED ANSWERS
1) How many PPB equals one PPM? -- Answer ✔✔ One thousand parts per billion
_ _ _ _ _ _ _ _ _ _ _ _ _ _
equals one part per million _ _ _ _
2) 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 _ _ _ _ _ _
3) 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
_ _ _ _
4) 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
_ _ _ _ _ _
5) 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 the other is
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
open
6) 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. _
7) One mg per L equals how many pounds per 1 MG? -- Answer ✔✔ 8.34
_ _ _ _ _ _ _ _ _ _ _ _ _ _
8) 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
_ _ _
9) How many drips of water should you have coming out of a packing seal? -- Answer
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
✔✔ no drip on a mechanical seal
_ _ _ _ _ _
10) How many drips of water should you have coming out of a packing seal? 2 -- Answer
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
✔✔ what the operation and maintenance manual recommends
_ _ _ _ _ _ _
11) A one horsepower motor that runs on 110 volts using 10 amps has what efficiency? --
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
_Answer ✔✔ most motors run from 80-95% efficiency
_ _ _ _ _ _ _
12) A motor that has 440 volt supply is usually what phase of power? -- Answer ✔✔ 3
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
phase
13) NPDES -- Answer ✔✔ National Pollutant Discharge Elimination System
_ _ _ _ _ _ _ _
14) 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
_ _ _ _
15) What is the name of our operating permit? -- Answer ✔✔ NPDES
_ _ _ _ _ _ _ _ _ _ _
16) 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 _
17) What is normally used to raise the pH in sludge? -- Answer ✔✔ lime
_ _ _ _ _ _ _ _ _ _ _ _ _
, 18) What is the common device used to measure the effluent of a lagoon? -- Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
v notch weir
_ _
19) What concentration of H2S is unsafe to humans? -- Answer ✔✔ death in a few
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
minutes at 0.2%. Paralyzes respiratory center
_ _ _ _ _
20) 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. _ _ _ _ _ _
21) Normal air contains ______% of O2 -- Answer ✔✔ 19.5%
_ _ _ _ _ _ _ _ _
22) What knob is turned to control the usage of chlorine applied? -- Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _ _ _
rotameter
23) Can you store BOD at 4C for 48 hours? -- Answer ✔✔ yes
_ _ _ _ _ _ _ _ _ _ _ _
24) 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
_ _ _ _
25) How many mg/L equals one grain per gallon? -- Answer ✔✔ 17.1 mg/L
_ _ _ _ _ _ _ _ _ _ _ _
26) Dissolved oxygen increases when the temperature __________ -- Answer ✔✔
_ _ _ _ _ _ _ _ _ _
decreases
27) You can tell if a clarifier scraper arm is working by what means? -- Answer ✔✔ the
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
simplest is to visual check to see if the scum scraper arm is moving properly
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
check into foam _ _
28) If the sludge is thick or thin, then what does this tell you about the sludge scraper? --
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Answer ✔✔ possible answer is the flights are damaged or the speed of the
_ _ _ _ _ _ _ _ _ _ _ _ _ _
