Class D Water License – Texas Questions and
Answers| Latest Update
To prevent work area accidents, workers should be trained from the Texas Manual on Uniform
Traffic Control Devices, ________, Austin. Texas Department of Transportation
A system's filtered water must be ____ Nephelometric Turbidity Units (NTU) or less in at least
_____% of the measurements taken each month, and no sample can exceed _____ NTU.
0.3 NTUs
95%
1 NTU
For chemical analysis, surface supplies are sampled ______ a year and groundwater is normally
sampled every ______ years. 1 time
3 years
Water weighs ______ lbs/gal. 8.34 lbs/gal
Texas standard for fluoride in the water is _____ mg/L. The federal limit is _____. 2.0
mg/L
4.0 mg/L
Byproducts of chlorine reacting with dissolved natural organic matter (mostly plant life) are
_____ and _____. Trihalomethanes (THM) and Haloacetic Acids (HAA).
,In water systems using surface water (or groundwater under the direct influence of surface water)
the MCL for total trihalomethanes is _____ mg/L and the MCL for HAA5 (haloacetic acids) is
_____ mg/L. 0.08 mg/L (THMs)
0.06 mg/L (HAAs)
Low _____ can cause water to be corrosive. pH
Within 24 hours of learning of a total coliform positive during a routine sample test, at least
_____ repeat samples must be collected and analyzed. 3 repeat samples
Deep wells are usually _____ wells. artesian wells
Overpumping of groundwater is called _____. mining
Overpumping of groundwater can result in _____. subsidence
The water level in a well when the pump is not running is called the _____ level. static
level
The difference between the pumping level and the static level is called the _____.
drawdown
,_____ is a process that forces water through a membrane. Reverse osmosis
Removing _____ from water also helps reduce pathogens that may cling to the particles.
turbidity
The TCEQ considers a maximum turbidity of _____ NTUs as acceptable going into the filter.
10 NTUs
The state requires pressure filters to operate at _____ gpm per square foot. 2 gpm per
square foot
Chemicals used to disinfect include chloramine, chlorine, chlorine dioxide and _____.
ozone
A gallon of bleach containing 5.25% sodium hypochlorite contains about _____ lbs of chlorine.
0.44 lbs
A 100-lb container of calcium hypochlorite (65%) contains 65 lbs of chlorine and _____ lbs of
lime. 25 lbs of lime
Calcium hypochlorite is not dry chlorine. Dry chlorine is pure chlorine, liquid or gas, containing
less than _____ ppm water. 150 ppm
The most commonly-used valve is the _____ valve. gate valve
, The typical household faucet is a _____ valve. globe valve
An isolation valve is generally not used to _____. throttle water flow
_____ is the force the pump works against. Head
When there is no flow or pumping, the head is _____. When there is flow or pumping, the head
is _____. static
dynamic
_____ occurs inside the pump volute or casing and is caused by insufficient pressure on the
suction side of the pump, which creates a vacuum and causes water vapor bubbles to form.
Cavitation
Area = ____ x ____ length x width
Area of a circle = _____ x _____ x _____ 3.14 x radius x radius
Volume = _____ x _____ x _____ length x width x depth
To find the volume of a vertical cylinder, first get the _____, then multiply by the _____.
area
Answers| Latest Update
To prevent work area accidents, workers should be trained from the Texas Manual on Uniform
Traffic Control Devices, ________, Austin. Texas Department of Transportation
A system's filtered water must be ____ Nephelometric Turbidity Units (NTU) or less in at least
_____% of the measurements taken each month, and no sample can exceed _____ NTU.
0.3 NTUs
95%
1 NTU
For chemical analysis, surface supplies are sampled ______ a year and groundwater is normally
sampled every ______ years. 1 time
3 years
Water weighs ______ lbs/gal. 8.34 lbs/gal
Texas standard for fluoride in the water is _____ mg/L. The federal limit is _____. 2.0
mg/L
4.0 mg/L
Byproducts of chlorine reacting with dissolved natural organic matter (mostly plant life) are
_____ and _____. Trihalomethanes (THM) and Haloacetic Acids (HAA).
,In water systems using surface water (or groundwater under the direct influence of surface water)
the MCL for total trihalomethanes is _____ mg/L and the MCL for HAA5 (haloacetic acids) is
_____ mg/L. 0.08 mg/L (THMs)
0.06 mg/L (HAAs)
Low _____ can cause water to be corrosive. pH
Within 24 hours of learning of a total coliform positive during a routine sample test, at least
_____ repeat samples must be collected and analyzed. 3 repeat samples
Deep wells are usually _____ wells. artesian wells
Overpumping of groundwater is called _____. mining
Overpumping of groundwater can result in _____. subsidence
The water level in a well when the pump is not running is called the _____ level. static
level
The difference between the pumping level and the static level is called the _____.
drawdown
,_____ is a process that forces water through a membrane. Reverse osmosis
Removing _____ from water also helps reduce pathogens that may cling to the particles.
turbidity
The TCEQ considers a maximum turbidity of _____ NTUs as acceptable going into the filter.
10 NTUs
The state requires pressure filters to operate at _____ gpm per square foot. 2 gpm per
square foot
Chemicals used to disinfect include chloramine, chlorine, chlorine dioxide and _____.
ozone
A gallon of bleach containing 5.25% sodium hypochlorite contains about _____ lbs of chlorine.
0.44 lbs
A 100-lb container of calcium hypochlorite (65%) contains 65 lbs of chlorine and _____ lbs of
lime. 25 lbs of lime
Calcium hypochlorite is not dry chlorine. Dry chlorine is pure chlorine, liquid or gas, containing
less than _____ ppm water. 150 ppm
The most commonly-used valve is the _____ valve. gate valve
, The typical household faucet is a _____ valve. globe valve
An isolation valve is generally not used to _____. throttle water flow
_____ is the force the pump works against. Head
When there is no flow or pumping, the head is _____. When there is flow or pumping, the head
is _____. static
dynamic
_____ occurs inside the pump volute or casing and is caused by insufficient pressure on the
suction side of the pump, which creates a vacuum and causes water vapor bubbles to form.
Cavitation
Area = ____ x ____ length x width
Area of a circle = _____ x _____ x _____ 3.14 x radius x radius
Volume = _____ x _____ x _____ length x width x depth
To find the volume of a vertical cylinder, first get the _____, then multiply by the _____.
area
