B TEST MATERIAL - TCEQ CLASS B SURFACEWATEREXAM QUESTIONS AND ANSWERS UPDATED2024/2025ALL ANSWERS CORRECT VERIFIED TOSCOREA+

B TEST MATERIAL - TCEQ CLASS B SURFACEWATEREXAM QUESTIONS AND ANSWERS UPDATED2024/2025ALL ANSWERS CORRECT VERIFIED TOSCOREA+What is the most important factor affecting the useful life of service lines? - CORRECT ANSWERS It is the ability of the material to resist internal and external corrosion When does Suction Head exist? - CORRECT ANSWERS Suction head existswhenthe source of supply is above the centerline of the pump. What is Net positive Suction Head (NPSH) - CORRECT ANSWERS NPSHisthepressure under which water enters the eye of the impeller in a centrifugal pump. Insufficient NPSH is the main cause of pump cavitation Explain and expand on Chlorine Dioxide (what it reacts with, oxidizes, etc) - CORRECT ANSWERS Chlorine Dioxide is a gas used in small quantities todisinfect water. It does not react with organics to form THMs and HAAs. It oxidizesphenols, manganese, iron, sulfurous and organic compounds which aids intheremoval 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 monitoringprocedures are the same as for chlorine. The Chlorite MCL is .q mg/L and must bemonitored daily. What is texas drinking water pH requirements? - CORRECT ANSWERSThetexasdrinking water requirements require a pH 7.0 for the water treatment plant finished ONLYSTUDENTS STORE 2025 ALL THEBESTONLYSTUDENTS STORE 2 DONOTCOPYwater. EPA requires that pH analysis be preformed within 15 minutes of thesamplebeing caught. How does pH affect Chlorine activity? - CORRECT ANSWERS When chlorineisadded to water it forms hypochlorous acid (HOCL) and hydrochloric acid (OCL). Thehypochlorous 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 pHof 7, thehypochlorous 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 becauseyouhave more hypochlorous acid. What is meant by water stability? - CORRECT ANSWERS Stable water is definedas water that will neither deposit or dissolve a calcium carbonate filmor scale. Sinceno water is stable indefinitely, chemical treatment of water usually is intendedtoproduce water that is slightly scale forming without being liable to cause stoppagesin small lines and services. Bayliss curve is the simplest determination of stability. The Langelier saturation index is also used. What/how are above ground tanks and piping protected from corrosion? - CORRECT ANSWERS Corrosion protection for above ground tanks and pipingisprevented by: cathodic protection, use if protective linings/coatings, eliminatingdifferent types of metals in the distribution system, and treating the water withchemicals to make it less corrosive How do you tests fir alkalinity? - CORRECT ANSWERS The two tritiation methodsof analysis are a standard acid to titrate a sample. The end point of the titrationisdetermined 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 ONLYSTUDENTS STORE 2025 ALL THEBESTONLYSTUDENTS STORE 3 DONOTCOPYamount of sample is titrated with a standard sulfuric acid to a predeterminedpH. 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 formsmay be estimated. What is Turbidity? - CORRECT ANSWERS Turbidity can be described as ameasure of the relative clarity of water. Turbidity is an expression of the optical property that causes light to be scattered and absorbed rather than transmittedinstraight lines through the sample. What causes Turbidity? - CORRECT ANSWERS 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 methodfor running turbidity - the Nephelometric Method (NTU) What is chlorine Demand? - CORRECT ANSWERS The amount of chlorineusedup to completely react with the water and its suspended or dissolve material What is chlorine residual? - CORRECT ANSWERS When all the demand of thewater is met any additional chlorine produces a chlorine residual What is chlorine dosage? - CORRECT ANSWERS Demand plus residual is thechlorine dosage. Chlorine Dosage = Demand + Residual What determines rate of disinfection? - CORRECT ANSWERS Chlorine concentration and contact time determines the rate and degree of disinfection. If ONLYSTUDENTS STORE 2025 ALL THEBESTONLYSTUDENTS STORE 4 DONOTCOPYconcentration increases, the time can be reduced; if concentration is reducedthetime must be increased. How does temperature effect chlorine effectiveness? - CORRECT ANSWERSChlorine effectiveness is greater at higher temperatures, up to the point that chlorinevolatizes. At low temperature, chlorine is more stable, but disinfection time increases. Is removing turbidity important for disinfection? - CORRECT ANSWERSTurbiditymust be removed to low levels by sedimentation and filtration to allowchlorinetocontact pathogens. What happens to dissolved solids on contact with chlorine? - CORRECTANSWERSDissolved solids are oxidized on contact further reinforcing the importance of contact time. No residual is formed until reducing agents are destroyed. What are examplesof reducing agents? - CORRECT ANSWERS Manganese, iron, turbidity, organicmatter, ammonia, or nitrates What the 4 stages of the Chlorine Demand Curve chart? - CORRECT ANSWERSStage 1: No residual is formed because inorganic demand destroys the chlorine. (Flat Line) Stage 2: Monochloramines are formed as chlorine combines with organics containing ammonia (rising curve). The chlorine to ammonia weight ratio at thispoint is 5:1. Combined and total residual increases, chloro-organics are formed. ONLYSTUDENTS STORE 2025 ALL THEBESTONLYSTUDENTS STORE 5 DONOTCOPYStage 3: Increasing chlorine dosage (failing curve) to a chlorine/ammonia weight ratio of 7.6:1 destroys chloramines and chloro-organics. Combined decreasesandfree chlorine increases. Stage 4: Enough chlorine is added to reduce all demand. The combined residual remains the same, but free residual increases with dosage. This stage is called"breakpoint" chlorination. The chlorine to ammonia ratio of 10:1 satisfies all demandand disinfects the distribution system. ( second rising curve) What is the difference between free chlorine and combined chlorine (chloramines/chlorine-ammonia) systems? - CORRECT ANSWERS Free chlorineis more powerful than combined chlorine, but combined chlorine lasts longer. - combined chlorine requires a 60-minute detention time while free chlorinerequires10 minutes. -If combined resid