WATER OPERATOR D LICENSE TEST
QUESTIONS AND ANSWERS
What do most states require for someone to work as a water treatment plant
operator? - Answer-Operator license
Trihalomethanes - Answer-CANCEROUS - Formed when organic matter reacts with
chlorine. Increased levels indicative of algae bloom.
Dissolved oxygen depletion - Answer-Result of algae blooms, kills fish and
generates public complaints
Reduction - Answer-Occurs in anaerobic conditions, sulfur compounds become
Hydrogen sulfide (H2S) which smells awful. Iron and Manganese begin to dissolve in
water.
Application of Copper Sulfate - Answer-1. Drag bags of it behind a boat
2. Scatter crystals of it using a hopper on a boat
3. Spray or diffuse dissolved chemical through spray bottle or pipe
Cathodic Protection - Answer-Prevents corrosion
What is calcium sulfate also known as? - Answer-Gypsum
Notification of a Tier III violation is done - Answer-Within 12 months (in CCR)
A coliform sample is considered invalid and a new sample must be taken within
24hrs if the HPC count is above? - Answer-500 CFU
Plant growth in reservoirs will usually be found at what depth? - Answer-6 ft
What is the main function of a flocculation basin? - Answer-Allow suspended
particles to aggregate
Granular Activated Carbon (GAC) - Answer-Filter media to remove taste and odor
causing agents
What is the natural attraction between particles that can be used to collect them into
larger groups once destabilization has occurred? - Answer-van der Waal's force
Why is it important to reduce turbidity? - Answer-To remove pathogens
A chlorine evaporator maintains a water bath at what temperature? - Answer-170-
180 degrees F
What will occur if the activation process of silica is not carefully controlled? - Answer-
It could inhibit floc formation
, The porous material just above the water table that holds small quantities of water by
capillary action is called? - Answer-Capillary fringe
Which of the following composes the majority of scale in pipes? - Answer-CaCO3
Which is a chemical used in water treatment as a coagulating chemical? - Answer-
Al2(SO4)3
When must a water system collect annual samples if the water system has been
determined to be reliable by the State and consistently below the MCL level for
organic compounds? - Answer-During the quarter that previously yielded the highest
analytical results
Free Chlorine residual values are based on contact time of at least? - Answer-10
minutes
The process of the buildup of corrosion products is known as? - Answer-
Tuberculation
What is the next test when the membrane filter shows four green colored colonies
after 24 hours? - Answer-Confirm by testing
for E. Coli and fecal coliform bacteria
For maximum charge neutralization, the average zeta potential should be between? -
Answer-0 and +3
Drawback of pneumatic sensors - Answer-Experience 5 to 30 second delays due to
the volume of air in the lines. Max length ~ 1,000 feet.
Fluids in hydraulic systems - Answer-Water, oil, or glycerol.
Intrusion of seawater into groundwater basins results from - Answer-overpumping
fresh water
What is the basic objective of the operation of water treatment plants? - Answer-
Produce safe aesthetically pleasing drinking water at a reasonable cost
Which of the following influence the size of a water treatment plant as well as the
number and types of processes it uses? - Answer-Impurities in raw water and cost
considerations
Which plant operating guidelines are routinely monitored by water treatment plant
operators? - Answer-Flows and water quality indicators
How are initial selection of chemical types and anticipated feed rates for a given
application in a water treatment plant usually determined? - Answer-Pilot plant tests
What is the best source of information about dangerous chemcials? - Answer-SDS
(Safety data sheets)
QUESTIONS AND ANSWERS
What do most states require for someone to work as a water treatment plant
operator? - Answer-Operator license
Trihalomethanes - Answer-CANCEROUS - Formed when organic matter reacts with
chlorine. Increased levels indicative of algae bloom.
Dissolved oxygen depletion - Answer-Result of algae blooms, kills fish and
generates public complaints
Reduction - Answer-Occurs in anaerobic conditions, sulfur compounds become
Hydrogen sulfide (H2S) which smells awful. Iron and Manganese begin to dissolve in
water.
Application of Copper Sulfate - Answer-1. Drag bags of it behind a boat
2. Scatter crystals of it using a hopper on a boat
3. Spray or diffuse dissolved chemical through spray bottle or pipe
Cathodic Protection - Answer-Prevents corrosion
What is calcium sulfate also known as? - Answer-Gypsum
Notification of a Tier III violation is done - Answer-Within 12 months (in CCR)
A coliform sample is considered invalid and a new sample must be taken within
24hrs if the HPC count is above? - Answer-500 CFU
Plant growth in reservoirs will usually be found at what depth? - Answer-6 ft
What is the main function of a flocculation basin? - Answer-Allow suspended
particles to aggregate
Granular Activated Carbon (GAC) - Answer-Filter media to remove taste and odor
causing agents
What is the natural attraction between particles that can be used to collect them into
larger groups once destabilization has occurred? - Answer-van der Waal's force
Why is it important to reduce turbidity? - Answer-To remove pathogens
A chlorine evaporator maintains a water bath at what temperature? - Answer-170-
180 degrees F
What will occur if the activation process of silica is not carefully controlled? - Answer-
It could inhibit floc formation
, The porous material just above the water table that holds small quantities of water by
capillary action is called? - Answer-Capillary fringe
Which of the following composes the majority of scale in pipes? - Answer-CaCO3
Which is a chemical used in water treatment as a coagulating chemical? - Answer-
Al2(SO4)3
When must a water system collect annual samples if the water system has been
determined to be reliable by the State and consistently below the MCL level for
organic compounds? - Answer-During the quarter that previously yielded the highest
analytical results
Free Chlorine residual values are based on contact time of at least? - Answer-10
minutes
The process of the buildup of corrosion products is known as? - Answer-
Tuberculation
What is the next test when the membrane filter shows four green colored colonies
after 24 hours? - Answer-Confirm by testing
for E. Coli and fecal coliform bacteria
For maximum charge neutralization, the average zeta potential should be between? -
Answer-0 and +3
Drawback of pneumatic sensors - Answer-Experience 5 to 30 second delays due to
the volume of air in the lines. Max length ~ 1,000 feet.
Fluids in hydraulic systems - Answer-Water, oil, or glycerol.
Intrusion of seawater into groundwater basins results from - Answer-overpumping
fresh water
What is the basic objective of the operation of water treatment plants? - Answer-
Produce safe aesthetically pleasing drinking water at a reasonable cost
Which of the following influence the size of a water treatment plant as well as the
number and types of processes it uses? - Answer-Impurities in raw water and cost
considerations
Which plant operating guidelines are routinely monitored by water treatment plant
operators? - Answer-Flows and water quality indicators
How are initial selection of chemical types and anticipated feed rates for a given
application in a water treatment plant usually determined? - Answer-Pilot plant tests
What is the best source of information about dangerous chemcials? - Answer-SDS
(Safety data sheets)
