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TCEQ CLASS B SURFACE WATER B TEST
MATERIAL Exam Questions and Answers
Latest Versions 2025 Top Rated A+
1. When does Suction Head exist? - correct answer -Suction
head exists when the source of supply is above the centerline
of the pump.
2. What is Net positive Suction Head (NPSH) - correct answer -
NPSH is the pressure under which water enters the eye of the
impeller in a centrifugal pump. Insufficient NPSH is the main
cause of pump cavitation
3. Explain and expand on Chlorine Dioxide (what it reacts with,
oxidizes, etc) - correct answer -Chlorine Dioxide is a gas used
in small quantities to disinfect water. It does not react with
organics to form THMs and HAAs. It oxidizes phenols,
manganese, iron, sulfurous and organic compounds which aids
in the removal of tastes and odors. It is a very effective
bactericide and a superior virocide. It dies not combine with
ammonia. Chlorine Dioxide MRDL is .8 mg/L and monitoring
procedures are the same as for chlorine. The Chlorite MCL is
.q mg/L and must be monitored daily.
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4. What is texas drinking water pH requirements? - correct
answer -The texas drinking water requirements require a pH >
7.0 for the water treatment plant finished water. EPA requires
that pH analysis be preformed within 15 minutes of the sample
being caught.
5. How does pH affect Chlorine activity? - correct answer - When
chlorine is added to water it forms hypochlorous acid (HOCL)
and hydrochloric acid (OCL). The hypochlorous acid is the
effective disinfectant. At a pH of 4.0 there is 100%
hypochlorous acid. At a pH of 11 there is 100% hypochlorite
ion. At a pH of 7, the hypochlorous acid is at about 80% and
the hypochlorite ion makes up about 20% of the chlorine
content. The lower the pH is more effective chlorine is because
you have more hypochlorous acid.
6. What is meant by water stability? - correct answer -Stable
water is defined as water that will neither deposit or dissolve a
calcium carbonate film or scale. Since no water is stable
indefinitely, chemical treatment of water usually is intended to
produce water that is slightly scale forming without being liable
to cause stoppages in small lines and services. Bayliss curve is
the simplest determination of stability. The Langelier saturation
index is also used.
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7. What/how are above ground tanks and piping protected from
corrosion? - correct answer -Corrosion protection for above
ground tanks and piping is prevented by: cathodic protection,
use if protective linings/coatings, eliminating different types of
metals in the distribution system, and treating the water with
chemicals to make it less corrosive
8. How do you tests fir alkalinity? - correct answer -The two
tritiation methods of analysis are a standard acid to titrate a
sample. The end point of the titration is determined by the
following: an indicator that changes color at a certain pH, or
potentiometric titration to end - point pH. Using either of the
methods, a measured amount of sample is titrated with a
standard sulfuric acid to a predetermined pH. Nomograph are a
graphical form of determining alkalinity. If the pH, total
alkalinity, temperature and total dissolved solids are known,
any or all of the alkalinity forms may be estimated.
9. What is Turbidity? - correct answer -Turbidity can be described
as a measure of the relative clarity of water. Turbidity is an
expression of the optical property that causes light to be
scattered and absorbed rather than transmitted in straight lines
through the sample.
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10. What causes Turbidity? - correct answer -Turbidity is caused
by clay, slit, finely divided organic and inorganic material. Other
suspended matter and microscopic organisms can also cause
turbidity. There is one approved method for running turbidity -
the Nephelometric Method (NTU)
11. What is chlorine Demand? - correct answer -The amount of
chlorine used up to completely react with the water and its
suspended or dissolve material
12. What is chlorine residual? - correct answer -When all the
demand of the water is met any additional chlorine produces a
chlorine residual
13. What is chlorine dosage? - correct answer -Demand plus
residual is the chlorine dosage. Chlorine Dosage = Demand +
Residual
14. What determines rate of disinfection? - correct answer -
Chlorine concentration and contact time determines the rate
and degree of disinfection. If concentration increases, the time
can be reduced; if concentration is reduced the time must be
increased.
TCEQ CLASS B SURFACE WATER B TEST
MATERIAL Exam Questions and Answers
Latest Versions 2025 Top Rated A+
1. When does Suction Head exist? - correct answer -Suction
head exists when the source of supply is above the centerline
of the pump.
2. What is Net positive Suction Head (NPSH) - correct answer -
NPSH is the pressure under which water enters the eye of the
impeller in a centrifugal pump. Insufficient NPSH is the main
cause of pump cavitation
3. Explain and expand on Chlorine Dioxide (what it reacts with,
oxidizes, etc) - correct answer -Chlorine Dioxide is a gas used
in small quantities to disinfect water. It does not react with
organics to form THMs and HAAs. It oxidizes phenols,
manganese, iron, sulfurous and organic compounds which aids
in the removal of tastes and odors. It is a very effective
bactericide and a superior virocide. It dies not combine with
ammonia. Chlorine Dioxide MRDL is .8 mg/L and monitoring
procedures are the same as for chlorine. The Chlorite MCL is
.q mg/L and must be monitored daily.
, Page | 2
4. What is texas drinking water pH requirements? - correct
answer -The texas drinking water requirements require a pH >
7.0 for the water treatment plant finished water. EPA requires
that pH analysis be preformed within 15 minutes of the sample
being caught.
5. How does pH affect Chlorine activity? - correct answer - When
chlorine is added to water it forms hypochlorous acid (HOCL)
and hydrochloric acid (OCL). The hypochlorous acid is the
effective disinfectant. At a pH of 4.0 there is 100%
hypochlorous acid. At a pH of 11 there is 100% hypochlorite
ion. At a pH of 7, the hypochlorous acid is at about 80% and
the hypochlorite ion makes up about 20% of the chlorine
content. The lower the pH is more effective chlorine is because
you have more hypochlorous acid.
6. What is meant by water stability? - correct answer -Stable
water is defined as water that will neither deposit or dissolve a
calcium carbonate film or scale. Since no water is stable
indefinitely, chemical treatment of water usually is intended to
produce water that is slightly scale forming without being liable
to cause stoppages in small lines and services. Bayliss curve is
the simplest determination of stability. The Langelier saturation
index is also used.
, Page | 3
7. What/how are above ground tanks and piping protected from
corrosion? - correct answer -Corrosion protection for above
ground tanks and piping is prevented by: cathodic protection,
use if protective linings/coatings, eliminating different types of
metals in the distribution system, and treating the water with
chemicals to make it less corrosive
8. How do you tests fir alkalinity? - correct answer -The two
tritiation methods of analysis are a standard acid to titrate a
sample. The end point of the titration is determined by the
following: an indicator that changes color at a certain pH, or
potentiometric titration to end - point pH. Using either of the
methods, a measured amount of sample is titrated with a
standard sulfuric acid to a predetermined pH. Nomograph are a
graphical form of determining alkalinity. If the pH, total
alkalinity, temperature and total dissolved solids are known,
any or all of the alkalinity forms may be estimated.
9. What is Turbidity? - correct answer -Turbidity can be described
as a measure of the relative clarity of water. Turbidity is an
expression of the optical property that causes light to be
scattered and absorbed rather than transmitted in straight lines
through the sample.
, Page | 4
10. What causes Turbidity? - correct answer -Turbidity is caused
by clay, slit, finely divided organic and inorganic material. Other
suspended matter and microscopic organisms can also cause
turbidity. There is one approved method for running turbidity -
the Nephelometric Method (NTU)
11. What is chlorine Demand? - correct answer -The amount of
chlorine used up to completely react with the water and its
suspended or dissolve material
12. What is chlorine residual? - correct answer -When all the
demand of the water is met any additional chlorine produces a
chlorine residual
13. What is chlorine dosage? - correct answer -Demand plus
residual is the chlorine dosage. Chlorine Dosage = Demand +
Residual
14. What determines rate of disinfection? - correct answer -
Chlorine concentration and contact time determines the rate
and degree of disinfection. If concentration increases, the time
can be reduced; if concentration is reduced the time must be
increased.
