Montana Wastewater Operator Class 1 Practice
Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
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tap water C. Somewhat cooler than tap water D. Very cooler than tap water - ANSWER//A.
Somewhat warmer than tap water Reviewing all aspects of the wastewater treatment
system to determine what would occur during various types of emergency situations is
know as... A. Management effectiveness survey B. Environmental audit C In the activated
sludge process, some of the activated sludge must be wasted to... A. Prevent excessive
solid buildup B. Prevent clogging of the sludge return line C. Prevent overloading of sludge
return pumps D. Increase digester gas production - ANSWER//A. Prevent excessive solid
buildup The best operating strategy for feeding primary sludge to an anaerobic digester is
to feed... A. Several time a day B. Large quantities once or twice a day C. Once a day D.
When the volatile solids drop below 60% - ANSWER//A. Several time a day Why is scum
skimmed from the liquid surface of a primary settling tank? A. To reduce load on the
digester B. To eliminate interference with sludge removal C. To allow aeration of the tank
contents D. To reduce odor and insect nuisance - ANSWER//B. To eliminate interference
with sludge removal Which of the following test would give the fastest indication of toxicity
in an activated sludge process? A. Oxygen Uptake Rate (OUR) B. Settleometer C. MLSS D.
Microscopic Observation - ANSWER//A. Oxygen Uptake Rate (OUR) Filamentous bulking of
activated sludge may be controlled temporarily by... A. Adding sodium chloride to the
aeration tank B. Spraying water on the aeration tank surface C. Carefully chlorinating the
return sludge and mixed liquor D. Aerating the final settling tank - ANSWER//C. Carefully
chlorinating the return sludge and mixed liquor Since reaction rates are lower during the
winter, the operator of an activated sludge plant will usually... A. Increase dissolved oxygen
levels B. Decrease MCRT C. Decrease wasting D. Increase MCRT - ANSWER//D. Increase
MCRT In a healthy activated sludge process which of the following organisms will most
likely be found in the greatest numbers? A. Stalked Ciliates B. Amoebas C. Free swimming
ciliates D. Nymphs - ANSWER//A. Stalked Ciliates Alkalinity is a measure of the ability of
wastewater to... A. Neutralize base B. Neutralize acid C. Dissolve organics D. Maintain
constant temperature - ANSWER//B. Neutralize acid What is one advantage of a COD test
over a BOD test? A. Shorter test time B. More accurate C. Safer D. Less chemicals needed -
ANSWER//A. Shorter test time Fecal coliform results are reported as MPN per... A. 10 mL B.
50 mL C. 100 mL D. 1,000 mL - ANSWER//C. 100 mL A BOD can be removed from the
incubator at 5 days plus of minus... A. 1 hour B. 2 hours C. 3 hours D. 4 hours -
, ANSWER//C. 3 hours When performing an MPN the sample dilution is considered positive
when... A. The Durham tube is found upside down B. The sample turns color from amber to
brown C. No bubbles are found in the Durham tube D. Gas bubbles are found in the
Durham tube - ANSWER//D. Gas bubbles are found in the Durham tube Entrained air
frequently contributes to... A. Reduced wet well capacity B. Less odor around the pump
station C. Lower electrical costs D. Pump cavitation - ANSWER//D. Pump cavitation What
is the purpose of a SCADA system? A. Clean grease lines B. Justify more cleaning crews C.
Control equipment and collect data D. Set collection and data appointments -
ANSWER//C. Control equipment and collect data Which of the following can cause
overheating of mechanical equipment? A. Water hammer B. Under-greasing C. Over-
greasing D. Dried out packing - ANSWER//C. Over-greasing Anaerobic decomposition of
wastewater produces... A. Ammonium chloride B. Hydrogen sulfide C. Carbon monoxide
D. Copper sulfate - ANSWER//B. Hydrogen sulfide Wastewater entering a treatment plant
typically is... A. Somewhat warmer than tap water B. The same temp. as tap water C.
Somewhat cooler than tap water D. Very cooler than tap water - ANSWER//A. Somewhat
warmer than tap water Reviewing all aspects of the wastewater treatment system to
determine what would occur during various types of emergency situations is know as... A.
Management effectiveness survey B. Environmental audit C. Comprehensive performance
evaluation D. Vulnerability assessment - ANSWER//D. Vulnerability assessment How
much education does an operator need? A. Depends largely on the type of treatment
facility and also on local certification and entry-level job requirements B. Depends on
availability and cost of attending local education C. Depends on the faculty and the local
training company D. Depends on the operators ability and time to learn - ANSWER//A.
Depends largely on the type of treatment facility and also on local certification and entry-
level job requirements Which treatment units in a wastewater treatment plant are
designed and operated to remove sludge and scum? A. Disinfection treatment units B. Pre-
aeration treatment units C. Preliminary treatment units D. Primary treatment units -
ANSWER//D. Primary treatment units What are aerobic bacteria? A. Bacteria capable of
spreading disease B. Bacteria that cause algae to bloom C. Bacteria that live and
reproduce only in an environment containing no free or dissolved oxygen D. Bacteria that
live and reproduce only in an environment containing oxygen that is available for their
respiration - ANSWER//D. Bacteria that live and reproduce only in an environment
containing oxygen that is available for their respiration What is pH? A. An expression of the
hardness of a liquid B. An expression of the intensity of the basic or acidic condition of a
liquid C. An expression of the odor intensity emitted from a liquid D. An expression of the
rate of putrefaction of a liquid - ANSWER//B. An expression of the intensity of the basic or
acidic condition of a liquid Historically, Americans have shown a great lack of interest in
the protection of their water resources T/F - ANSWER//True Special care and safety must
Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download
tap water C. Somewhat cooler than tap water D. Very cooler than tap water - ANSWER//A.
Somewhat warmer than tap water Reviewing all aspects of the wastewater treatment
system to determine what would occur during various types of emergency situations is
know as... A. Management effectiveness survey B. Environmental audit C In the activated
sludge process, some of the activated sludge must be wasted to... A. Prevent excessive
solid buildup B. Prevent clogging of the sludge return line C. Prevent overloading of sludge
return pumps D. Increase digester gas production - ANSWER//A. Prevent excessive solid
buildup The best operating strategy for feeding primary sludge to an anaerobic digester is
to feed... A. Several time a day B. Large quantities once or twice a day C. Once a day D.
When the volatile solids drop below 60% - ANSWER//A. Several time a day Why is scum
skimmed from the liquid surface of a primary settling tank? A. To reduce load on the
digester B. To eliminate interference with sludge removal C. To allow aeration of the tank
contents D. To reduce odor and insect nuisance - ANSWER//B. To eliminate interference
with sludge removal Which of the following test would give the fastest indication of toxicity
in an activated sludge process? A. Oxygen Uptake Rate (OUR) B. Settleometer C. MLSS D.
Microscopic Observation - ANSWER//A. Oxygen Uptake Rate (OUR) Filamentous bulking of
activated sludge may be controlled temporarily by... A. Adding sodium chloride to the
aeration tank B. Spraying water on the aeration tank surface C. Carefully chlorinating the
return sludge and mixed liquor D. Aerating the final settling tank - ANSWER//C. Carefully
chlorinating the return sludge and mixed liquor Since reaction rates are lower during the
winter, the operator of an activated sludge plant will usually... A. Increase dissolved oxygen
levels B. Decrease MCRT C. Decrease wasting D. Increase MCRT - ANSWER//D. Increase
MCRT In a healthy activated sludge process which of the following organisms will most
likely be found in the greatest numbers? A. Stalked Ciliates B. Amoebas C. Free swimming
ciliates D. Nymphs - ANSWER//A. Stalked Ciliates Alkalinity is a measure of the ability of
wastewater to... A. Neutralize base B. Neutralize acid C. Dissolve organics D. Maintain
constant temperature - ANSWER//B. Neutralize acid What is one advantage of a COD test
over a BOD test? A. Shorter test time B. More accurate C. Safer D. Less chemicals needed -
ANSWER//A. Shorter test time Fecal coliform results are reported as MPN per... A. 10 mL B.
50 mL C. 100 mL D. 1,000 mL - ANSWER//C. 100 mL A BOD can be removed from the
incubator at 5 days plus of minus... A. 1 hour B. 2 hours C. 3 hours D. 4 hours -
, ANSWER//C. 3 hours When performing an MPN the sample dilution is considered positive
when... A. The Durham tube is found upside down B. The sample turns color from amber to
brown C. No bubbles are found in the Durham tube D. Gas bubbles are found in the
Durham tube - ANSWER//D. Gas bubbles are found in the Durham tube Entrained air
frequently contributes to... A. Reduced wet well capacity B. Less odor around the pump
station C. Lower electrical costs D. Pump cavitation - ANSWER//D. Pump cavitation What
is the purpose of a SCADA system? A. Clean grease lines B. Justify more cleaning crews C.
Control equipment and collect data D. Set collection and data appointments -
ANSWER//C. Control equipment and collect data Which of the following can cause
overheating of mechanical equipment? A. Water hammer B. Under-greasing C. Over-
greasing D. Dried out packing - ANSWER//C. Over-greasing Anaerobic decomposition of
wastewater produces... A. Ammonium chloride B. Hydrogen sulfide C. Carbon monoxide
D. Copper sulfate - ANSWER//B. Hydrogen sulfide Wastewater entering a treatment plant
typically is... A. Somewhat warmer than tap water B. The same temp. as tap water C.
Somewhat cooler than tap water D. Very cooler than tap water - ANSWER//A. Somewhat
warmer than tap water Reviewing all aspects of the wastewater treatment system to
determine what would occur during various types of emergency situations is know as... A.
Management effectiveness survey B. Environmental audit C. Comprehensive performance
evaluation D. Vulnerability assessment - ANSWER//D. Vulnerability assessment How
much education does an operator need? A. Depends largely on the type of treatment
facility and also on local certification and entry-level job requirements B. Depends on
availability and cost of attending local education C. Depends on the faculty and the local
training company D. Depends on the operators ability and time to learn - ANSWER//A.
Depends largely on the type of treatment facility and also on local certification and entry-
level job requirements Which treatment units in a wastewater treatment plant are
designed and operated to remove sludge and scum? A. Disinfection treatment units B. Pre-
aeration treatment units C. Preliminary treatment units D. Primary treatment units -
ANSWER//D. Primary treatment units What are aerobic bacteria? A. Bacteria capable of
spreading disease B. Bacteria that cause algae to bloom C. Bacteria that live and
reproduce only in an environment containing no free or dissolved oxygen D. Bacteria that
live and reproduce only in an environment containing oxygen that is available for their
respiration - ANSWER//D. Bacteria that live and reproduce only in an environment
containing oxygen that is available for their respiration What is pH? A. An expression of the
hardness of a liquid B. An expression of the intensity of the basic or acidic condition of a
liquid C. An expression of the odor intensity emitted from a liquid D. An expression of the
rate of putrefaction of a liquid - ANSWER//B. An expression of the intensity of the basic or
acidic condition of a liquid Historically, Americans have shown a great lack of interest in
the protection of their water resources T/F - ANSWER//True Special care and safety must
