BASIC WASTEWATER OPERATOR
PRACTICE EXAM CLASS 3
Stalked-ciliates---ans-✔✔What-is-the-predominant-organism-in-a-healthy-Activated-
Sludge-Treatment-Plant?
Representative-and-Sub-samples-time-spaced-over-15-minutes-apart---ans-✔✔A-
composite-sample-must-be?
300ml---ans-✔✔What-is-the-standard-volume-for-a-BOD-sample-bottle?
Plug-valve---ans-✔✔If-you-have-a-lime-slurry-feed-line,-what-is-the-best-valve-to-use?
Old-Sludge---ans-✔✔If-you-notice-a-predominance-of-rotifers-in-your-activated-sludge-
sample-while-looking-at-it-under-a-microscope,-what-does-this-indicate?
Settling-in-the-clarifiers---ans-✔✔If-your-activated-sludge-plant-begins-to-nitrify,-what-
conditions-would-you-expect-to-decrease?
360mg/l---ans-✔✔Calculate-the-BOD-given-the-information:
Initial-DO:-8.3
Final-DO:-5.9
Milliliters-of-sample-used:-2
By-measuring-the-pump-output---ans-✔✔How-do-you-calibrate-a-chemical-feed-pump?
H2SO4---ans-✔✔What-is-the-chemical-formula-for-sulfuric-acid?
extended-aeration---ans-✔✔What-is-the-most-common-type-of-Activated-Sludge-package-
plants?
Increase-wasting---ans-✔✔What-is-the-most-appropriate-method-of-reducing-the-F:M-
Ratio?
Unequal-air-distribution-caused-by-a-blown-diffuser---ans-✔✔An-operator-notices-a-
portion-of-the-aeration-tank-with-large-bubbles-rising-up.-What-is-the-most-likely-problem?
, The-pressure-on-the-suction-side-of-the-pump---ans-✔✔What-is-suction-lift?
22.5-mg/l---ans-✔✔The-primary-effluent-to-a-RBC-system-is-350-mg/l-BOD.-The-primary-
unit-removes-83%,-the-secondary-unit-removes-50%,-and-the-final-unit-removes-25%.-
What-is-the-BOD-leaving-the-final-unit-of-the-RBC-train?
Decrease-the-lag-time-for-pump-operation-by-moving-the-floats-closer-together---ans-
✔✔The-influent-to-the-treatment-plant-is-septic.-It-is-determined-that-it-is-coming-from-a-lift-
station-upstream-from-the-plant.-What-should-the-operator-do?
To-protect-chemicals-that-are-sensitive-to-light---ans-✔✔What-is-the-purpose-of-amber-
storage-bottles?
24-days---ans-✔✔Calculate-SRT
GIVEN:-Mixed-liquor-suspended-solids-(MLSS)-=-2400mg/l
Aeration-basin-volume-=-35,000-gallons-=-0.0350-million-gallons-(MG)
Waste-activated-sludge-(WAS)-concentration-=-3500mg/l
Waste-activated-sludge-(WAS)-flowrate-=-0.001MGD
Horizontal-&-Horizontal---ans-✔✔How-should-a-1-ton-chlorine-cylinder-be-moved?
0.68---ans-✔✔Calculate-F:M-ratio
GIVEN:-Influent-BOD5-=-290mg/l
Influent-Flow-=-5.0MGD
Aeration-basin-MLSS-=-2650-mg/l
Aeration-basin-volume-=-0.8MG
Clogged-impeller---ans-✔✔What-would-most-likely-cause-a-submersible-pump-to-have-an-
AMP-reading-that-is-above-the-optimum-level?
Stator---ans-✔✔Which-of-the-following-are-non-moving-parts-of-a-running-motor?
225---ans-✔✔Calculate-SVI
GIVEN:-30-minute-settling-test-=-1800ml-in-a-2000ml-container
MLSS:-4000mg/L
magnetic---ans-✔✔What-type-of-flow-meters-are-used-during-normal-operations-of-the-
sludge-removal?
Waste-more-sludge---ans-✔✔What-should-be-done-when-the-bio-reactor-in-an-SBR-plant-
is-organically-overloaded?
To-keep-valves-from-being-submerged---ans-✔✔Why-are-approved-backflow-devices-
installed-above-ground-level?
PRACTICE EXAM CLASS 3
Stalked-ciliates---ans-✔✔What-is-the-predominant-organism-in-a-healthy-Activated-
Sludge-Treatment-Plant?
Representative-and-Sub-samples-time-spaced-over-15-minutes-apart---ans-✔✔A-
composite-sample-must-be?
300ml---ans-✔✔What-is-the-standard-volume-for-a-BOD-sample-bottle?
Plug-valve---ans-✔✔If-you-have-a-lime-slurry-feed-line,-what-is-the-best-valve-to-use?
Old-Sludge---ans-✔✔If-you-notice-a-predominance-of-rotifers-in-your-activated-sludge-
sample-while-looking-at-it-under-a-microscope,-what-does-this-indicate?
Settling-in-the-clarifiers---ans-✔✔If-your-activated-sludge-plant-begins-to-nitrify,-what-
conditions-would-you-expect-to-decrease?
360mg/l---ans-✔✔Calculate-the-BOD-given-the-information:
Initial-DO:-8.3
Final-DO:-5.9
Milliliters-of-sample-used:-2
By-measuring-the-pump-output---ans-✔✔How-do-you-calibrate-a-chemical-feed-pump?
H2SO4---ans-✔✔What-is-the-chemical-formula-for-sulfuric-acid?
extended-aeration---ans-✔✔What-is-the-most-common-type-of-Activated-Sludge-package-
plants?
Increase-wasting---ans-✔✔What-is-the-most-appropriate-method-of-reducing-the-F:M-
Ratio?
Unequal-air-distribution-caused-by-a-blown-diffuser---ans-✔✔An-operator-notices-a-
portion-of-the-aeration-tank-with-large-bubbles-rising-up.-What-is-the-most-likely-problem?
, The-pressure-on-the-suction-side-of-the-pump---ans-✔✔What-is-suction-lift?
22.5-mg/l---ans-✔✔The-primary-effluent-to-a-RBC-system-is-350-mg/l-BOD.-The-primary-
unit-removes-83%,-the-secondary-unit-removes-50%,-and-the-final-unit-removes-25%.-
What-is-the-BOD-leaving-the-final-unit-of-the-RBC-train?
Decrease-the-lag-time-for-pump-operation-by-moving-the-floats-closer-together---ans-
✔✔The-influent-to-the-treatment-plant-is-septic.-It-is-determined-that-it-is-coming-from-a-lift-
station-upstream-from-the-plant.-What-should-the-operator-do?
To-protect-chemicals-that-are-sensitive-to-light---ans-✔✔What-is-the-purpose-of-amber-
storage-bottles?
24-days---ans-✔✔Calculate-SRT
GIVEN:-Mixed-liquor-suspended-solids-(MLSS)-=-2400mg/l
Aeration-basin-volume-=-35,000-gallons-=-0.0350-million-gallons-(MG)
Waste-activated-sludge-(WAS)-concentration-=-3500mg/l
Waste-activated-sludge-(WAS)-flowrate-=-0.001MGD
Horizontal-&-Horizontal---ans-✔✔How-should-a-1-ton-chlorine-cylinder-be-moved?
0.68---ans-✔✔Calculate-F:M-ratio
GIVEN:-Influent-BOD5-=-290mg/l
Influent-Flow-=-5.0MGD
Aeration-basin-MLSS-=-2650-mg/l
Aeration-basin-volume-=-0.8MG
Clogged-impeller---ans-✔✔What-would-most-likely-cause-a-submersible-pump-to-have-an-
AMP-reading-that-is-above-the-optimum-level?
Stator---ans-✔✔Which-of-the-following-are-non-moving-parts-of-a-running-motor?
225---ans-✔✔Calculate-SVI
GIVEN:-30-minute-settling-test-=-1800ml-in-a-2000ml-container
MLSS:-4000mg/L
magnetic---ans-✔✔What-type-of-flow-meters-are-used-during-normal-operations-of-the-
sludge-removal?
Waste-more-sludge---ans-✔✔What-should-be-done-when-the-bio-reactor-in-an-SBR-plant-
is-organically-overloaded?
To-keep-valves-from-being-submerged---ans-✔✔Why-are-approved-backflow-devices-
installed-above-ground-level?
