CLASS D WATER OPERATOR EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
Sand pumping can be reduced by______ the gpm pump rate. - Answer-lowering
Sand pumping can be reduced by correcting problems such as loss of ________. -
Answer-gravel pack
What is the maximum contaminant level for THM's (Trihalomethanes)? - Answer-.08
mg/L
What is the maximum contaminant level for HAA's (Haloacetic Acids)? - Answer-.06
mg/L
What is the action level for lead? - Answer-.015 mg/L
What is the action level for copper? - Answer-1.3 mg/L
The Surface Water Treatment Rule (SWTR) is to determine possible direct influence
of surface water on a well. This is not required as long as the well is more than
_____ feet deep and more than ______ feet away from surface water sources,
constructed properly, screened or perforated below a confining bed, and has had no
quality shifts or coliform issues. - Answer-50
200
No boat ramps, marinas, docks, or fishing piers can be within _____ feet of a surface
water treatment plant intake. - Answer-1,000
All activities shall be restricted within _____ feet of a surface water treatment plant
intake. - Answer-200
What is the most effective treatment for bacteria or algae in a surface water
treatment plant? - Answer-Activated carbon adsorption
What are three common coagulating chemicals? - Answer-alum, ferrous sulfate, and
ferric chloride
In a surface water treatment plant, a ____ test assists the operator in determining
which chemical and how much to apply. - Answer-jar
Using jar tests to determine chemical dosages, the operator should ensure that no
concentrations of turbidity greater than ____ NTU, preferably as low as ____ NTU,
shall go to the filter for the filtration process. - Answer-10
5
, After the floc forms, the water flows into a sedimentation basin. A detention time of at
least ____ hours is required to allow the floc to settle. - Answer-6
T/F
Pathogens such as Giardia and Cryptosporidium are resistant to chlorine, but
filtration works. - Answer-True
_______ is the final step in removing suspended matter and chlorine resistant
microorganisms. - Answer-Filtration
A sand filter has _____ to ____ inches of porous material such as sand or anthracite
coal, called filter media. - Answer-24" to 30"
A common filter is the rapid sand filter, which filters ____ gpm/ft2 of filter media. -
Answer-2
As the solids increase, there will be a loss of head pressure through the filter due to
increased friction. When this head loss is about ____ to _____ feet, the filter must be
backwashed. - Answer-6-10 feet
While the backwashing is taking place, the filter bed should expand ____ % to _____
% to ensure good scouring action. - Answer-30 to 50 %
Disinfection capacity for drinking water must be at least ______% greater than the
highest expected dosage. - Answer-50
What is the purpose of a clear well? - Answer-The clear well provides detention time
for disinfection and extra storage.
T/F
Most microorganisms are not pathogens. - Answer-True
When collecting a bacteriological sample, why does the container need sodium
thiosulfate in it? - Answer-to neutralize the chlorine residual
Bacteriological samples must be recieved by the lab within _____ hours or they are
rejected. Cool the samples on ice prior to and during transport. Keep samples off
dashboards. Heat stimulates biological growth! - Answer-30
DOSAGE = _________ + __________ - Answer-DEMAND + RESIDUAL
TCEQ rules and regulations require a free chlorine residual of _____ mg/L or a total
(chloramine) residual of ______ mg/L. - Answer-0.2
0.5
What is the maximum gas withdrawal rate (vacuum transmission) for a 150 lb
cylinder? - Answer-1 lb/day/*F
Is surface water or groundwater more likely to contain natural organic matter? -
Answer-surface water
QUESTIONS WITH COMPLETE
SOLUTIONS
Sand pumping can be reduced by______ the gpm pump rate. - Answer-lowering
Sand pumping can be reduced by correcting problems such as loss of ________. -
Answer-gravel pack
What is the maximum contaminant level for THM's (Trihalomethanes)? - Answer-.08
mg/L
What is the maximum contaminant level for HAA's (Haloacetic Acids)? - Answer-.06
mg/L
What is the action level for lead? - Answer-.015 mg/L
What is the action level for copper? - Answer-1.3 mg/L
The Surface Water Treatment Rule (SWTR) is to determine possible direct influence
of surface water on a well. This is not required as long as the well is more than
_____ feet deep and more than ______ feet away from surface water sources,
constructed properly, screened or perforated below a confining bed, and has had no
quality shifts or coliform issues. - Answer-50
200
No boat ramps, marinas, docks, or fishing piers can be within _____ feet of a surface
water treatment plant intake. - Answer-1,000
All activities shall be restricted within _____ feet of a surface water treatment plant
intake. - Answer-200
What is the most effective treatment for bacteria or algae in a surface water
treatment plant? - Answer-Activated carbon adsorption
What are three common coagulating chemicals? - Answer-alum, ferrous sulfate, and
ferric chloride
In a surface water treatment plant, a ____ test assists the operator in determining
which chemical and how much to apply. - Answer-jar
Using jar tests to determine chemical dosages, the operator should ensure that no
concentrations of turbidity greater than ____ NTU, preferably as low as ____ NTU,
shall go to the filter for the filtration process. - Answer-10
5
, After the floc forms, the water flows into a sedimentation basin. A detention time of at
least ____ hours is required to allow the floc to settle. - Answer-6
T/F
Pathogens such as Giardia and Cryptosporidium are resistant to chlorine, but
filtration works. - Answer-True
_______ is the final step in removing suspended matter and chlorine resistant
microorganisms. - Answer-Filtration
A sand filter has _____ to ____ inches of porous material such as sand or anthracite
coal, called filter media. - Answer-24" to 30"
A common filter is the rapid sand filter, which filters ____ gpm/ft2 of filter media. -
Answer-2
As the solids increase, there will be a loss of head pressure through the filter due to
increased friction. When this head loss is about ____ to _____ feet, the filter must be
backwashed. - Answer-6-10 feet
While the backwashing is taking place, the filter bed should expand ____ % to _____
% to ensure good scouring action. - Answer-30 to 50 %
Disinfection capacity for drinking water must be at least ______% greater than the
highest expected dosage. - Answer-50
What is the purpose of a clear well? - Answer-The clear well provides detention time
for disinfection and extra storage.
T/F
Most microorganisms are not pathogens. - Answer-True
When collecting a bacteriological sample, why does the container need sodium
thiosulfate in it? - Answer-to neutralize the chlorine residual
Bacteriological samples must be recieved by the lab within _____ hours or they are
rejected. Cool the samples on ice prior to and during transport. Keep samples off
dashboards. Heat stimulates biological growth! - Answer-30
DOSAGE = _________ + __________ - Answer-DEMAND + RESIDUAL
TCEQ rules and regulations require a free chlorine residual of _____ mg/L or a total
(chloramine) residual of ______ mg/L. - Answer-0.2
0.5
What is the maximum gas withdrawal rate (vacuum transmission) for a 150 lb
cylinder? - Answer-1 lb/day/*F
Is surface water or groundwater more likely to contain natural organic matter? -
Answer-surface water
