Water Treatment Class D( Practice Exam
#3) Questions & Answers
What is the criteria for a community water system? - ANSWERSHas at least 15 service
connections used by all year residents,or regularly serves at least 25 all yesr residents
What is the acceptable limit of copper in drinking water? - ANSWERS1.3 mg/L
Which type of reservoir is rich in nutrients? - ANSWERSeutrophic
What is a mechanical seal? - ANSWERSMetallic flat surfaces used to minimize leakage
around the pump shaft.
What is a confined aquifer? - ANSWERSAn aquifer that is bounded above and below by
confining beds
Which of the following best describes pumping water level in a well? - ANSWERSUpper
surface of the groundwater that is being pumped
What is the name of the deepest layer of a reservoir under thermal stratification ? -
ANSWERShypolimnion
What is the health effect of consuming water with high levels of copper? -
ANSWERSStomach and intestinal distress such as nausea, vomiting, diarrhea and
stomach cramps
Which of the following best describes a turbine pump? - ANSWERSA centrifugal pump
that is mainly used to pump water from wells
What is typically used to clean the sludge on the bottom of a rectangular clarifier? -
ANSWERSChain and flight collectors
How often should preventative maintenance be performed on equipment? -
ANSWERSUse manufacturer's recommendation.
, What is CT? - ANSWERSContact time x chlorine residual concentration
What is absorption? - ANSWERSConstituent is sucked in
What is the purpose of a check valve? - ANSWERSAllows water to flow in one direction,
and prevents reverse flow
What would happen to the pH of water if lime is added? - ANSWERSincreases pH
What is the term used to describe groundwater that flows naturally from the ground? -
ANSWERSSpring
Once thermal stratification occurs in the middle and lower zones of a reservoir, what
type of problem occurs in these layers? - ANSWERSDepletion of total dissolved oxygen
What is the most critical problem that may be encountered when entering a confined
space? - ANSWERSOxygen deficiency and toxic gas
Which of the following is a settleable solid? - ANSWERSSand
Which of the following is not a commonly used coagulant? - ANSWERSsodium
hypochlorite
What is the purpose of a coagulant aid? - ANSWERSAdd density to slow-settling flocs
and add toughness to the flocs.
What is the purpose of coagulant( not coagulant aid)? - ANSWERSNeutralize electrical
charge.
Which of the following is least likely to be removed in the sedimentation process? -
ANSWERSAqueous form of manganese
In the sedimentation process, what would happen if the flowrate were increased? -
ANSWERSlower efficiency
If turbidity is rising rapidly,what should you do? - ANSWERSVerify the effectiveness of
the coagulant chemicals and dosage at the flash mixer
The collection of a bad sample is useful as which of the following? - ANSWERSNo
result
Which of the following is not a mechanism that occurs in a filter media? -
ANSWERSprecipitation
#3) Questions & Answers
What is the criteria for a community water system? - ANSWERSHas at least 15 service
connections used by all year residents,or regularly serves at least 25 all yesr residents
What is the acceptable limit of copper in drinking water? - ANSWERS1.3 mg/L
Which type of reservoir is rich in nutrients? - ANSWERSeutrophic
What is a mechanical seal? - ANSWERSMetallic flat surfaces used to minimize leakage
around the pump shaft.
What is a confined aquifer? - ANSWERSAn aquifer that is bounded above and below by
confining beds
Which of the following best describes pumping water level in a well? - ANSWERSUpper
surface of the groundwater that is being pumped
What is the name of the deepest layer of a reservoir under thermal stratification ? -
ANSWERShypolimnion
What is the health effect of consuming water with high levels of copper? -
ANSWERSStomach and intestinal distress such as nausea, vomiting, diarrhea and
stomach cramps
Which of the following best describes a turbine pump? - ANSWERSA centrifugal pump
that is mainly used to pump water from wells
What is typically used to clean the sludge on the bottom of a rectangular clarifier? -
ANSWERSChain and flight collectors
How often should preventative maintenance be performed on equipment? -
ANSWERSUse manufacturer's recommendation.
, What is CT? - ANSWERSContact time x chlorine residual concentration
What is absorption? - ANSWERSConstituent is sucked in
What is the purpose of a check valve? - ANSWERSAllows water to flow in one direction,
and prevents reverse flow
What would happen to the pH of water if lime is added? - ANSWERSincreases pH
What is the term used to describe groundwater that flows naturally from the ground? -
ANSWERSSpring
Once thermal stratification occurs in the middle and lower zones of a reservoir, what
type of problem occurs in these layers? - ANSWERSDepletion of total dissolved oxygen
What is the most critical problem that may be encountered when entering a confined
space? - ANSWERSOxygen deficiency and toxic gas
Which of the following is a settleable solid? - ANSWERSSand
Which of the following is not a commonly used coagulant? - ANSWERSsodium
hypochlorite
What is the purpose of a coagulant aid? - ANSWERSAdd density to slow-settling flocs
and add toughness to the flocs.
What is the purpose of coagulant( not coagulant aid)? - ANSWERSNeutralize electrical
charge.
Which of the following is least likely to be removed in the sedimentation process? -
ANSWERSAqueous form of manganese
In the sedimentation process, what would happen if the flowrate were increased? -
ANSWERSlower efficiency
If turbidity is rising rapidly,what should you do? - ANSWERSVerify the effectiveness of
the coagulant chemicals and dosage at the flash mixer
The collection of a bad sample is useful as which of the following? - ANSWERSNo
result
Which of the following is not a mechanism that occurs in a filter media? -
ANSWERSprecipitation
