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TCEQ SURFACE WATER B
LICENSE TEST WITH QU ESTIONS
& ANSWERS
Question 1: What is the most important factor affecting
the useful life of service lines?
CORRECT ANSWER: It is the ability of the material to
resist internal and external corrosion
Question 2: When does Suction Head exist?
CORRECT ANSWER: Suction head exists when the
source of supply is above the centerline of the pump.
Question 3: 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
Question 4: Explain and expand on Chlorine Dioxide
(what it reacts with, oxidizes, etc)
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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.
Question 5: 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.
Question 6: 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
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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.
Question 7: 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.
Question 8: 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
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different types of metals in the distribution system, and treating the water with chemicals to make it less corrosive
Question 9: 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.
Question 10: 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.