WASTEWATER CLASS 4 EXAM VIRGINIA
WITH COMPLETE SOLUTIONS GRADED A+
QUESTIONS AND ANSWERS
In an electrical circuit, the grounding wire is indicated by which color? ANSWER -
Green
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
WITH COMPLETE SOLUTIONS GRADED A+
QUESTIONS AND ANSWERS
In an electrical circuit, the grounding wire is indicated by which color? ANSWER -
Green
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
