WASTEWATER CLASS 4 VIRGINIA
EXAM 2025/2026 QUESTIONS AND
ANSWERS 100% PASS
In an electrical circuit, the grounding wire is indicated by which color? - ANS Green
According to the Ohms Law, which electrical unit measures pressure? - ANS Volts
According to the Ohms Law, which electrical unit measures resistance? - ANS Ohms
According to the Ohms Law, which electrical unit measures current? - ANS Amps
How do you convert cubic feet to gallons? - ANS Multiply by 7.48
How do you convert gallons to pounds? - ANS 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. - ANS 90
Solution:
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 360 x 1,000
------------- = 90
4,000
What is the most widely used dechlorination agent in a conventional chlorine gas plant? -
ANS Sulfur Dioxide
What is the most prominent concern in failing to remove grit from the wastewater? -
ANS Excessive wear and damage on mechanical equipment
What is the chemical formula for Sulfuric Acid? - ANS H2SO4
What is the ideal velocity in a grit channel, in feet per second? - ANS 1 fps
Conventional pump packing should be: - ANS 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? - ANS 50%
When preparing a sample for laboratory analysis that involves acid and water, how should the
sample be poured? - ANS 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? -
ANS Behind the weir, 4 times the maximum head of the weir
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
EXAM 2025/2026 QUESTIONS AND
ANSWERS 100% PASS
In an electrical circuit, the grounding wire is indicated by which color? - ANS Green
According to the Ohms Law, which electrical unit measures pressure? - ANS Volts
According to the Ohms Law, which electrical unit measures resistance? - ANS Ohms
According to the Ohms Law, which electrical unit measures current? - ANS Amps
How do you convert cubic feet to gallons? - ANS Multiply by 7.48
How do you convert gallons to pounds? - ANS 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. - ANS 90
Solution:
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 360 x 1,000
------------- = 90
4,000
What is the most widely used dechlorination agent in a conventional chlorine gas plant? -
ANS Sulfur Dioxide
What is the most prominent concern in failing to remove grit from the wastewater? -
ANS Excessive wear and damage on mechanical equipment
What is the chemical formula for Sulfuric Acid? - ANS H2SO4
What is the ideal velocity in a grit channel, in feet per second? - ANS 1 fps
Conventional pump packing should be: - ANS 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? - ANS 50%
When preparing a sample for laboratory analysis that involves acid and water, how should the
sample be poured? - ANS 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? -
ANS Behind the weir, 4 times the maximum head of the weir
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
