LEVEL II WASTEWATER TREATMENT
PRACTICE TEST EXAMINATION TEST 2026
QUESTIONS WITH SOLUTIONS
◉ Normal BOD removal rate Answer: The normal BOD removal rate
for an activated sludge plant is 95-100%.
◉ Daily pollution budget Answer: The daily pollution budget for a
receiving stream is known as TMDL.
◉ Grit chamber velocity Answer: The velocity of a grit chamber should
be about 1.5 fps.
◉ Drying sludge method Answer: A way to dry sludge using percolation
and evaporation is a drying bed.
◉ Bar screen vs. rack Answer: A rack has wider spaces than bar screens.
◉ Oxidation pond depth Answer: The depth of an oxidation pond should
never be less than 3 feet to prevent weed growth.
◉ Oxidation pond levy slope Answer: The inside of an oxidation pond
levy should be sloped 3:1.
, ◉ Effect of lime on wastewater Answer: Lime raises the pH.
◉ Advantage of COD test Answer: A COD test is run much quicker
than a BOD test.
◉ Supernatant return Answer: Supernatant is returned to the final
clarifier.
◉ Biosolids disposal methods Answer: Biosolids can be disposed of by
hauling to a landfill, made into fertilizer, or incinerated.
◉ Aeration basin problem indicator Answer: Chocolate brown color and
musty smell in the aeration basin indicates that D.O. is too low.
◉ Microscopic bug indicating health Answer: Protozoa can indicate
whether the aeration basin is healthy or not.
◉ Shock load definition Answer: A shock load on a wastewater plant
can be defined as excessive BOD entering the plant.
◉ Gas produced by algae Answer: Algae produces oxygen.
◉ Aerobic definition Answer: Aerobic means needs oxygen to thrive.
PRACTICE TEST EXAMINATION TEST 2026
QUESTIONS WITH SOLUTIONS
◉ Normal BOD removal rate Answer: The normal BOD removal rate
for an activated sludge plant is 95-100%.
◉ Daily pollution budget Answer: The daily pollution budget for a
receiving stream is known as TMDL.
◉ Grit chamber velocity Answer: The velocity of a grit chamber should
be about 1.5 fps.
◉ Drying sludge method Answer: A way to dry sludge using percolation
and evaporation is a drying bed.
◉ Bar screen vs. rack Answer: A rack has wider spaces than bar screens.
◉ Oxidation pond depth Answer: The depth of an oxidation pond should
never be less than 3 feet to prevent weed growth.
◉ Oxidation pond levy slope Answer: The inside of an oxidation pond
levy should be sloped 3:1.
, ◉ Effect of lime on wastewater Answer: Lime raises the pH.
◉ Advantage of COD test Answer: A COD test is run much quicker
than a BOD test.
◉ Supernatant return Answer: Supernatant is returned to the final
clarifier.
◉ Biosolids disposal methods Answer: Biosolids can be disposed of by
hauling to a landfill, made into fertilizer, or incinerated.
◉ Aeration basin problem indicator Answer: Chocolate brown color and
musty smell in the aeration basin indicates that D.O. is too low.
◉ Microscopic bug indicating health Answer: Protozoa can indicate
whether the aeration basin is healthy or not.
◉ Shock load definition Answer: A shock load on a wastewater plant
can be defined as excessive BOD entering the plant.
◉ Gas produced by algae Answer: Algae produces oxygen.
◉ Aerobic definition Answer: Aerobic means needs oxygen to thrive.
