Waste Water Certification Test Questions
and Answers Graded A
Surface water runoff, storm water, sanitary and industrial. ✔✔A collection system that is called
"combined" may carry this kind of wastewater:
2 ✔✔The flow in a collection system should be a minimum of ____ feet per second (FPS)?
Solids will settle. ✔✔What will happen if the flow is too slow in a collection system?
Odors, Corrosion, Hydrogen Sulfide Gas (all of the above) ✔✔A short detention time in the
collection system will help prevent which of the following problems?
Low areas must be sewered. ✔✔When are lift (pumping) stations installed in a collection
system?
Parentheses, Exponents, Multiplication, Division, Addition, Subtraction ✔✔The order of
operations to solve math problems is: (from first to last)
,27 ✔✔3^3
24 ✔✔(5+7)x4/2=
19 ✔✔7+6X4/2=
4 ✔✔2X+12=20. What is "X" equal to?
3,000,000gal/1,500,000MGD = 2 days = 48 hours ✔✔The volume of a tank is 3,000,000 gallons
(3MG) and the flow rate into the tank is 1,500,000 gallons per day (1.5 MGD). Calculate the
detention time in hours.
(750 GPM)(60 min/hr)(24 hr/day)/1,000,000 = 1.08 MGD ✔✔A pump is rated at 750 gpm.
Calculate the flow rate in million gallons per day (MGD).
1.5MG/1MLSS x 3.785L/1gal = 5.6775MG/1gal x 1lbs/453,592.37MG = 25.04 lbs/day ✔✔A
secondary clarifier discharges 2 MGD and the effluent contains 1.5 mg/l of mixed liquor
suspended solids (MLSS). Calculate the pounds per day of MLSS discharged. (F012, F017,
F022, F035)
,(200 mg/L - 15 mg/L)/(200 mg/L) x 100% = 92.5% ✔✔The influent to a clarifier contains 200
mg/l of total suspended solids (TSS). What is the efficiency in % if there is 15 mg/l of TSS in the
effluent? (F011 , F018)
x= 0.785 x (100)^2 x (20) = 157,000 cf x 7.481/gal = 1,174,517 gal ✔✔A clarifier is 100 ft. in
diameter and 20 ft. deep. How many cu.ft (ft^3) of water does the clarifier hold? How many
gallons of water?
Be subject to categorical standards, >25,000 gpd of process water or 5% or more of POTW
capacity, have a reasonable potential to adversely affect POTW. (all of the above) ✔✔To be
define as a "significant industrial user" the industry must:
Prevent introduction of pollutants that will interfere with and/or pass through with the POTW,
and improve opportunities to recycle and reclaim water and sludges. (Both a and b) ✔✔The
major objectives of National Pretreatment Program include which of the following:
Federal Water Pollution Control Act Amendments of 1972. ✔✔The origin of the National
Pretreatment Program goes back to this act:
, NPDES permit ✔✔The POTW requirement to develop and implement a pretreatment program
for industries is a condition of what?
Once a year ✔✔When are Control Authorities required to inspect significant industrial users?
Identify responsible Control Authority officials, Identify the general time frame for actions,
Potentially escalated actions based on the nature, frequency, magnitude and duration of the
violation. (all of the above) ✔✔What is the purpose of an Enforcement Response Guide (ERG)?
Sludge deposits, floating debris, color, odor, and toxics (all of the above) ✔✔Which of the
following are undesirable conditions or substances in the waters of the state?
Full-body contact recreation ✔✔All surface waters of the state are designated for_____.
Yes, 750 ✔✔My wastewater treatment plant receives brine wastes from water softeners. Could
the salt discharge increase the dissolved solids concentration of the effluent above the state limit
for TDS, which are ______ mg/L?
and Answers Graded A
Surface water runoff, storm water, sanitary and industrial. ✔✔A collection system that is called
"combined" may carry this kind of wastewater:
2 ✔✔The flow in a collection system should be a minimum of ____ feet per second (FPS)?
Solids will settle. ✔✔What will happen if the flow is too slow in a collection system?
Odors, Corrosion, Hydrogen Sulfide Gas (all of the above) ✔✔A short detention time in the
collection system will help prevent which of the following problems?
Low areas must be sewered. ✔✔When are lift (pumping) stations installed in a collection
system?
Parentheses, Exponents, Multiplication, Division, Addition, Subtraction ✔✔The order of
operations to solve math problems is: (from first to last)
,27 ✔✔3^3
24 ✔✔(5+7)x4/2=
19 ✔✔7+6X4/2=
4 ✔✔2X+12=20. What is "X" equal to?
3,000,000gal/1,500,000MGD = 2 days = 48 hours ✔✔The volume of a tank is 3,000,000 gallons
(3MG) and the flow rate into the tank is 1,500,000 gallons per day (1.5 MGD). Calculate the
detention time in hours.
(750 GPM)(60 min/hr)(24 hr/day)/1,000,000 = 1.08 MGD ✔✔A pump is rated at 750 gpm.
Calculate the flow rate in million gallons per day (MGD).
1.5MG/1MLSS x 3.785L/1gal = 5.6775MG/1gal x 1lbs/453,592.37MG = 25.04 lbs/day ✔✔A
secondary clarifier discharges 2 MGD and the effluent contains 1.5 mg/l of mixed liquor
suspended solids (MLSS). Calculate the pounds per day of MLSS discharged. (F012, F017,
F022, F035)
,(200 mg/L - 15 mg/L)/(200 mg/L) x 100% = 92.5% ✔✔The influent to a clarifier contains 200
mg/l of total suspended solids (TSS). What is the efficiency in % if there is 15 mg/l of TSS in the
effluent? (F011 , F018)
x= 0.785 x (100)^2 x (20) = 157,000 cf x 7.481/gal = 1,174,517 gal ✔✔A clarifier is 100 ft. in
diameter and 20 ft. deep. How many cu.ft (ft^3) of water does the clarifier hold? How many
gallons of water?
Be subject to categorical standards, >25,000 gpd of process water or 5% or more of POTW
capacity, have a reasonable potential to adversely affect POTW. (all of the above) ✔✔To be
define as a "significant industrial user" the industry must:
Prevent introduction of pollutants that will interfere with and/or pass through with the POTW,
and improve opportunities to recycle and reclaim water and sludges. (Both a and b) ✔✔The
major objectives of National Pretreatment Program include which of the following:
Federal Water Pollution Control Act Amendments of 1972. ✔✔The origin of the National
Pretreatment Program goes back to this act:
, NPDES permit ✔✔The POTW requirement to develop and implement a pretreatment program
for industries is a condition of what?
Once a year ✔✔When are Control Authorities required to inspect significant industrial users?
Identify responsible Control Authority officials, Identify the general time frame for actions,
Potentially escalated actions based on the nature, frequency, magnitude and duration of the
violation. (all of the above) ✔✔What is the purpose of an Enforcement Response Guide (ERG)?
Sludge deposits, floating debris, color, odor, and toxics (all of the above) ✔✔Which of the
following are undesirable conditions or substances in the waters of the state?
Full-body contact recreation ✔✔All surface waters of the state are designated for_____.
Yes, 750 ✔✔My wastewater treatment plant receives brine wastes from water softeners. Could
the salt discharge increase the dissolved solids concentration of the effluent above the state limit
for TDS, which are ______ mg/L?
