CLASS "C" WATER EXAM QUESTIONS
WITH COMPLETE SOLUTIONS
Stand pipe - Answer-A storage vessel that is the same diameter from the ground to
the top and is more than 20 feet but less than 85 feet is called a-
35 psi - Answer-Potable water must be stored at an elevation at least 80.85 feet
above the highest known connection to provide the minimum operating pressure of-
Hydro pneumatic tank - Answer-A water tank that uses compressed air over water to
provide pressure is called a-
8.0% - Answer-According to the lead and copper rule, pipe and fittings may not
contain more than ___ lead or solder and flux may not contain more than 0.2% lead.
Red - Answer-When testing for chlorine residual DPD is used as an indicator, when
DPD is added to water containing chlorine what color does the sample turn?
Gate valve - Answer-The most common valve(s) used for isolating a water leak is the
___ valve.
Water hammer - Answer-In the distribution system when a valve or hydrant is
opened or closed too fast it could result in a-
Centrifugal - Answer-The most commonly used pump in the distribution system is-
250 - Answer-A Texas Class D Certified Operator can operate a public water system
up to ___ connections.
3 years - Answer-All state of Texas Operator License's after issue are good for ___
years.
Collect another sample at the site that tested positive plus one within five
connections upstream and one within five connections downstream and re-submit -
Answer-After analyzing monthly bacteriological samples the operator is notified that
one testing point tested positive. The operator should-
5 feet - Answer-Any excavation greater than ___ feet in depth requires the use of
OSHA approved shoring equipment or sloping of walls to prevent cave-ins.
Call for assistance and wait
Put on a self contained breathing apparatus and attach lifeline
Once assistance arrives-enter the room and shut off the valve on the cylinder and
wait for exhaust fan to evacuate chlorine from room - Answer-If an operator
discovers a chlorine leak on a 150 lb. cylinder inside a room he/she should
immediately-
, 9 feet - Answer-Waterlines should be installed no closer than___ feet to any sewer
lines or other possible contaminate lines.
65-75% - Answer-Calcium Hypochlorite (HTH) is used as a disinfectant in small
systems, what percentage chlorine is this material typically?
Immediately notify TCEQ Regional Office and they will notify law enforcement and
investigate to determine if there is a danger or threat to public health and safety
Pull the electrical disconnect on the pumps and close valves isolating the tank until it
can be analyzed - Answer-A certified operator is doing his/her routine daily check of
wells, pumps, and storage facilities discovers a cut lock on the entry gate, there is
also a cut lock on the roof hatch to the storage tank and suspicious looking
containers lying on the ground that does not belong. What should the operator do?
3.14 - Answer-When calculating area, one will use the standard for pi, what is the
standard accepted numerical value for pi?
Once every month - Answer-Flushing dead-end mains- current state regulations
require that all public water systems flush dead-end mains to assure chlorine
residual and water quality. What is the minimum flushing requirement?
Must conform to the National Sanitation Foundation (NSF) Standard 60 - Answer-In
small systems liquid bleach is an approved method of disinfection, provided the
product used meets basic industry standards. What is the current standard bleach
must meet in order to be approved for disinfection in a public water system?
Breakpoint chlorination - Answer-The process of adding enough chlorine to a water
supply to complete all reactions with reducing compounds, ammonia, and organic
materials so that some free chlorine is left is called-
Aquifers - Answer-Water bearing formations beneath the earth's surface that are
used as a source of water for public water supplies are-
Determine water levels in the well - Answer-The purpose of an air line on a well is-
Reduce the amount of sand pumped - Answer-The mesh size is an important feature
of a well screen because property sized openings should-
pH, alkalinity, temperature, and chemical dosage - Answer-When treating surface
water, the process of coagulation will be most affected by the-
When the loss of head gauge indicated between 6 and 10 ft. - Answer-A rapid sand
filter should be backwashed when-
0.2 mg/L free chlorine residual
0.5 mg/L chloramine residual for a surface water supply
0.8 mg/L chloramine residual when using chloramine treatment
0.5 mg/L free chlorine residual for a groundwater supply - Answer-Which of the
following is an acceptable disinfection residual at the far reaches of the distribution
system-
WITH COMPLETE SOLUTIONS
Stand pipe - Answer-A storage vessel that is the same diameter from the ground to
the top and is more than 20 feet but less than 85 feet is called a-
35 psi - Answer-Potable water must be stored at an elevation at least 80.85 feet
above the highest known connection to provide the minimum operating pressure of-
Hydro pneumatic tank - Answer-A water tank that uses compressed air over water to
provide pressure is called a-
8.0% - Answer-According to the lead and copper rule, pipe and fittings may not
contain more than ___ lead or solder and flux may not contain more than 0.2% lead.
Red - Answer-When testing for chlorine residual DPD is used as an indicator, when
DPD is added to water containing chlorine what color does the sample turn?
Gate valve - Answer-The most common valve(s) used for isolating a water leak is the
___ valve.
Water hammer - Answer-In the distribution system when a valve or hydrant is
opened or closed too fast it could result in a-
Centrifugal - Answer-The most commonly used pump in the distribution system is-
250 - Answer-A Texas Class D Certified Operator can operate a public water system
up to ___ connections.
3 years - Answer-All state of Texas Operator License's after issue are good for ___
years.
Collect another sample at the site that tested positive plus one within five
connections upstream and one within five connections downstream and re-submit -
Answer-After analyzing monthly bacteriological samples the operator is notified that
one testing point tested positive. The operator should-
5 feet - Answer-Any excavation greater than ___ feet in depth requires the use of
OSHA approved shoring equipment or sloping of walls to prevent cave-ins.
Call for assistance and wait
Put on a self contained breathing apparatus and attach lifeline
Once assistance arrives-enter the room and shut off the valve on the cylinder and
wait for exhaust fan to evacuate chlorine from room - Answer-If an operator
discovers a chlorine leak on a 150 lb. cylinder inside a room he/she should
immediately-
, 9 feet - Answer-Waterlines should be installed no closer than___ feet to any sewer
lines or other possible contaminate lines.
65-75% - Answer-Calcium Hypochlorite (HTH) is used as a disinfectant in small
systems, what percentage chlorine is this material typically?
Immediately notify TCEQ Regional Office and they will notify law enforcement and
investigate to determine if there is a danger or threat to public health and safety
Pull the electrical disconnect on the pumps and close valves isolating the tank until it
can be analyzed - Answer-A certified operator is doing his/her routine daily check of
wells, pumps, and storage facilities discovers a cut lock on the entry gate, there is
also a cut lock on the roof hatch to the storage tank and suspicious looking
containers lying on the ground that does not belong. What should the operator do?
3.14 - Answer-When calculating area, one will use the standard for pi, what is the
standard accepted numerical value for pi?
Once every month - Answer-Flushing dead-end mains- current state regulations
require that all public water systems flush dead-end mains to assure chlorine
residual and water quality. What is the minimum flushing requirement?
Must conform to the National Sanitation Foundation (NSF) Standard 60 - Answer-In
small systems liquid bleach is an approved method of disinfection, provided the
product used meets basic industry standards. What is the current standard bleach
must meet in order to be approved for disinfection in a public water system?
Breakpoint chlorination - Answer-The process of adding enough chlorine to a water
supply to complete all reactions with reducing compounds, ammonia, and organic
materials so that some free chlorine is left is called-
Aquifers - Answer-Water bearing formations beneath the earth's surface that are
used as a source of water for public water supplies are-
Determine water levels in the well - Answer-The purpose of an air line on a well is-
Reduce the amount of sand pumped - Answer-The mesh size is an important feature
of a well screen because property sized openings should-
pH, alkalinity, temperature, and chemical dosage - Answer-When treating surface
water, the process of coagulation will be most affected by the-
When the loss of head gauge indicated between 6 and 10 ft. - Answer-A rapid sand
filter should be backwashed when-
0.2 mg/L free chlorine residual
0.5 mg/L chloramine residual for a surface water supply
0.8 mg/L chloramine residual when using chloramine treatment
0.5 mg/L free chlorine residual for a groundwater supply - Answer-Which of the
following is an acceptable disinfection residual at the far reaches of the distribution
system-
