NORTH CAROLINA WASTEWATER LAB
ANALYST CLASS 4 EXAM 2026
CERTIFICATION REVIEW MANUAL
◉ According to the Ohms Law, which electrical unit measures
pressure? Answer: Volts
◉ According to the Ohms Law, which electrical unit measures
resistance? Answer: Ohms
◉ According to the Ohms Law, which electrical unit measures
current? Answer: Amps
◉ How do you convert cubic feet to gallons? Answer: Multiply by
7.48
◉ How do you convert gallons to pounds? Answer: Multiply by 8.34
◉ Calculate the SVI of your aeration basin when your 30-minute
settleable sample is 360 mL/L and your average mixed liquor
suspended solids concentration is 4000 mg/L. Answer: 90
Solution:
,360 x 1,000
------------- = 90
4,000
◉ What is the most widely used dechlorination agent in a
conventional chlorine gas plant? Answer: Sulfur Dioxide
◉ What is the most prominent concern in failing to remove grit from
the wastewater? Answer: Excessive wear and damage on mechanical
equipment
◉ What is the chemical formula for Sulfuric Acid? Answer: H2SO4
◉ What is the ideal velocity in a grit channel, in feet per second?
Answer: 1 fps
◉ Conventional pump packing should be: Answer: Tightened down
to a drip
◉ In a primary clarifier, the expected performance for removing
settleable solids is 90-95% removal. What about the removal of
suspended solids? Answer: 50%
, ◉ When preparing a sample for laboratory analysis that involves
acid and water, how should the sample be poured? Answer: Always
pour the acid into the water
◉ You are tasked with recording a manual flow sample in an open
channel. Where will you position yourself, relative to the weir, to
record the most accurate measure of flow? Answer: Behind the weir,
4 times the maximum head of the weir
◉ Why must a positive displacement pump never be started against
a closed discharge valve? Answer: Excessive pressure may damage
the line, the pump, and the motor
◉ A circular tank is 45 feet in diameter and has a depth of 10 feet.
What is the detention time in hours when the flow is 1.42 MGD?
Answer: 2 hours
Solution:
0.785 x 45 x 45 x 10 x 7.48 x 24
----------------------------------- = 2.038
1,420,000
◉ What is the most common device for measuring flow in an open
channel? Answer: V-notch weir, then ultrasonic flowmeter.
ANALYST CLASS 4 EXAM 2026
CERTIFICATION REVIEW MANUAL
◉ According to the Ohms Law, which electrical unit measures
pressure? Answer: Volts
◉ According to the Ohms Law, which electrical unit measures
resistance? Answer: Ohms
◉ According to the Ohms Law, which electrical unit measures
current? Answer: Amps
◉ How do you convert cubic feet to gallons? Answer: Multiply by
7.48
◉ How do you convert gallons to pounds? Answer: Multiply by 8.34
◉ Calculate the SVI of your aeration basin when your 30-minute
settleable sample is 360 mL/L and your average mixed liquor
suspended solids concentration is 4000 mg/L. Answer: 90
Solution:
,360 x 1,000
------------- = 90
4,000
◉ What is the most widely used dechlorination agent in a
conventional chlorine gas plant? Answer: Sulfur Dioxide
◉ What is the most prominent concern in failing to remove grit from
the wastewater? Answer: Excessive wear and damage on mechanical
equipment
◉ What is the chemical formula for Sulfuric Acid? Answer: H2SO4
◉ What is the ideal velocity in a grit channel, in feet per second?
Answer: 1 fps
◉ Conventional pump packing should be: Answer: Tightened down
to a drip
◉ In a primary clarifier, the expected performance for removing
settleable solids is 90-95% removal. What about the removal of
suspended solids? Answer: 50%
, ◉ When preparing a sample for laboratory analysis that involves
acid and water, how should the sample be poured? Answer: Always
pour the acid into the water
◉ You are tasked with recording a manual flow sample in an open
channel. Where will you position yourself, relative to the weir, to
record the most accurate measure of flow? Answer: Behind the weir,
4 times the maximum head of the weir
◉ Why must a positive displacement pump never be started against
a closed discharge valve? Answer: Excessive pressure may damage
the line, the pump, and the motor
◉ A circular tank is 45 feet in diameter and has a depth of 10 feet.
What is the detention time in hours when the flow is 1.42 MGD?
Answer: 2 hours
Solution:
0.785 x 45 x 45 x 10 x 7.48 x 24
----------------------------------- = 2.038
1,420,000
◉ What is the most common device for measuring flow in an open
channel? Answer: V-notch weir, then ultrasonic flowmeter.
