NORTH CAROLINA WASTEWATER LAB
ANALYST CLASS 4 EXAM 2026 FULL PRACTICE
TEST WITH SOLUTIONS
◉ What is the problem with over-lubricating a pump bearing?
Answer: It may cause overheating.
◉ What is the surface loading rate of a rectangular tank with a
length of 26 ft and a width of 16 ft. The flow coming in is 1.3 MGD.
Answer: 3,125 gallons per square feet
Solution:
26 x 16 = 416 square feet
1,300,000
---------- = 3,125
416
◉ What is the hydraulic detention time of a rectangular tank with a
length of 26 ft, a width of 22 ft, and a height of 19 ft when the
influent flow is 1.3 MGD? Answer: 1.5 hours
, Solution:
26 x 22 x 19 x 7.48 x 24
-------------------------- = 1.50
1,300,000
◉ How many minutes are in a day? Answer: 1,440
If a math formula answer is normally in hours, but the question is
asking for minutes, multiply by 1440 instead of 24
◉ Write out the entire Ohm's Law formula, including the units, and
the properties they measure. Answer: Amps (Current) = Volts
(Pressure) / Ohm's (Resistance)
◉ Your plant is discharging 1.28 MGD at the outfall. The BOD
concentration in your discharge is 47 mg/L. What is the quantity of
BOD discharged in pounds per day? Answer: 502 lbs/day
Solution:
Multiply flow in MGD x BOD concentration, then multiply it by 8.34
to convert gallons into pounds, since that is the unit they want.
1.28 x 47 x 8.34 = 501.73
ANALYST CLASS 4 EXAM 2026 FULL PRACTICE
TEST WITH SOLUTIONS
◉ What is the problem with over-lubricating a pump bearing?
Answer: It may cause overheating.
◉ What is the surface loading rate of a rectangular tank with a
length of 26 ft and a width of 16 ft. The flow coming in is 1.3 MGD.
Answer: 3,125 gallons per square feet
Solution:
26 x 16 = 416 square feet
1,300,000
---------- = 3,125
416
◉ What is the hydraulic detention time of a rectangular tank with a
length of 26 ft, a width of 22 ft, and a height of 19 ft when the
influent flow is 1.3 MGD? Answer: 1.5 hours
, Solution:
26 x 22 x 19 x 7.48 x 24
-------------------------- = 1.50
1,300,000
◉ How many minutes are in a day? Answer: 1,440
If a math formula answer is normally in hours, but the question is
asking for minutes, multiply by 1440 instead of 24
◉ Write out the entire Ohm's Law formula, including the units, and
the properties they measure. Answer: Amps (Current) = Volts
(Pressure) / Ohm's (Resistance)
◉ Your plant is discharging 1.28 MGD at the outfall. The BOD
concentration in your discharge is 47 mg/L. What is the quantity of
BOD discharged in pounds per day? Answer: 502 lbs/day
Solution:
Multiply flow in MGD x BOD concentration, then multiply it by 8.34
to convert gallons into pounds, since that is the unit they want.
1.28 x 47 x 8.34 = 501.73
