Water Distribution FINAL EXAM PREP 2025/2026 ACCURATE QUESTIONS AND CORRECT DETAILED ANSWERS WITH RATIONALES || 100% GUARANTEED PASS LATEST VERSION

Water Distribution FINAL EXAM PREP 2025/2026 ACCURATE QUESTIONS AND CORRECT DETAILED ANSWERS WITH RATIONALES || 100% GUARANTEED PASS LATEST VERSION 1. Who is responsible for setting drinking water standards and ensuring their enforcement? - ANSWER U.S. EPA 2. What year was the Safe Water Drinking Act amended? - ANSWER 1986 3. A new well must be disinfected at the well, pump and screen with a ____mg/l solution. - ANSWER 50 4. Before disinfecting mains you must first ______ them. - ANSWER Flush 5. When flushing mains you must flush with a minimum velocity of at least ____ft/sec. - ANSWER 2.5 6. The maximum rate of chlorine removal from a 150lb cylinder is ___lbs per day or freezing will occur. - ANSWER 40 7. The 1991 Uniform Fire Code states that the exhaust fan for chlorine must be taken from - ANSWER A point within 12 inches from the floor 8. Death can occur after a few deep breaths at what exposure rate? - ANSWER 1000ppm 9. A __________ has limited means for entry or exit, is not designed for continuous occupancy and is large enough that an employee can enter to perform work. - ANSWER Confined space 10. Before entering a confined space you must first ________. - ANSWER Test atmosphere 11. How far above the excavation must a ladder extend? - ANSWER 3 ft 12. How often must excavations be inspected? - ANSWER Daily 13. What are clear wells? - ANSWER Storage facilities for treated water at water treatment plants 14. What is the most common means of disinfecting drinking water used today to protect the public's health? - ANSWER Chlorination 15. Why do surface waters require treatment? - ANSWER To remove, kill, or inactivate disease causing organisms 16. What do turbidity units measure? - ANSWER The cloudiness of water 17. The U.S. National Primary Drinking Water Regulations is regulated at which level - ANSWER Federal 18. What is the absolute minimum pressure a water main should be taken down to before a boil water advisory is issued? - ANSWER 20 psi 19. What are the separations of water and sewer lines when being laid in the ground? - ANSWER 10' horizontal and 1' vertical 20. What is the most common form of cross connection? - ANSWER A garden hose 21. Continuous pressure is considered to be: - ANSWER Constant water system pressure of 20 psi 22. A phrase used in determining whether the substance in a non-potable system is toxic or non-toxic: - ANSWER Degree of hazard 23. The most common consumer complaint is: - ANSWER Red water 24. A chemical with a pH of 12.0 is considered: - ANSWER Basic A noisy or vibrating valve may be an indication of what? - ANSWER Cavitation 25. The selective destruction or inactivation of pathogenic organisms is - ANSWER Disinfection 26. Pathogenic organisms can be removed from water, killed, or inactivated by - ANSWER Filtration 27. The most commonly used distribution system disinfection is - ANSWER Free chlorine 28. A greenish- yellow gas with a penetrating and distinctive odor, two and a half times heavier than air is - ANSWER Chlorine 29. A brief session to discuss aspects of a job and safety - ANSWER Tailgate safety meeting 30. The most common means of disinfecting drinking water used today to protect the public's health? - ANSWER Chlorination 31. What is the responsibility of water distribution system operators? - ANSWER Ensure safe and pleasant drinking water is delivered to everyone's tap 32. A valve that automatically shuts off the flow into an elevated tank when the water level in the tank reaches a predetermined level. - ANSWER Altitude valve 33. A pump consisting of an impeller fixed on a rotating shaft, that is enclosed in a casing, and having an inlet and a discharge connection would be called - ANSWER Centrifugal pump 34. Which is not a type of water ? - ANSWER Apparent 35. Which layer of a lake is considered nutrient poor? - ANSWER Hypolimnion (Bottom Layer) 36. Copper Sulfate (Blue Stone) is used in lake management to ? - ANSWER Control Algae Bloom 37. The Surface Water Treatment Rule requires that - ANSWER 3-log removal 99.9% for virus,4-log removal 99.99% for virus 38. TDS (Total Dissolved Solids) levels of 1000mg/L is considered ? - ANSWER Unfit for human consumption 39. An "Appropriate Right" is defined as what type of " water use" right? - ANSWER Beneficial Use Right 40. What are the acceptable and practical forms of public notification for most water systems for acute violations? - ANSWER Mail, Newspaper, Radio broadcast 41. A "Transmission Main" is a water main that - ANSWER Is normally large in size , has very little service connections 42. What well measurement must be known to calculate the specific capacity for a well ? - ANSWER Draw down and discharge capacity 43. A map containing the size, location, and ties of water mains; valves; hydrants; tanks; and reservoirs is called a ? - ANSWER Comprehensive map 44. Under the " Safe Drinking Water " act , Lead Free means ? - ANSWER Provided the use of lead in the system meets certain percentage levels 45. When employees are working in trenches requiring a means of escape (such as a ladder or steps) exits must be located no further than ? - ANSWER 25' apart 46. A water audit consists of the following techniques ? - ANSWER Using standard accounting principles to determine the cost of water loss Conducting field test with work crews to gather information on leaks Using listening devices and flow measurements Testing meters for accuracy 47. A device used to check flows in a distribution system is called a - ANSWER Pressure gauge 48. Generally, a hydrant log should be kept whenever a hydrant is taken out of service . At a minimum the log should include - ANSWER Date and time when it was placed out of service, Name of party contacted, Date and time when returned to service 49. The type of hydrant that has a wet-top, where-by, the threaded end of the main rod and opening nut are not sealed from water when the main valve is open is the - ANSWER Dry-Barrel hydrant 50. Standard "pumper-connection" fire hydrants should not be installed on water mains smaller than...... - ANSWER 6 inches in diameter 51. The type of corrosion caused by the use of dissimilar metals in a water system is ......... - ANSWER Galvanic Series 52. In the distribution systems FLOWS should not exceed.... - ANSWER 3.5 feet per second 53. The " Nutating Disc" meter is classified as a ....... - ANSWER Positive- displacement meter 54. A direct water connection to a boiler containing a highly corrosive scale prevention compound must be protected by a (an)..... - ANSWER Reduced Pressure Principal 55. A cross-connection is defined as a connection between - ANSWER A potable and non-potable water system 56. An "Air Gap" technique is used to ......... - ANSWER Prevent back-flow of non-potable water into the drinking water supply 57. An approved device to prevent back-flow and back-siphonage is a ....... - ANSWER check-valve 58. A tank containing industrial solvent is under constant pressure . An employee accidentally opens a valve that is connected to the potable water system . Pressure in the tank forces the solvent into the potable water system . This is called........ - ANSWER Back pressure 59. What is the one major difference between a "Double check" DC and a "Reduced Pressure" RP device ? - ANSWER An RP is used for toxic substances and a DC is used for Non-toxic substances 60. A cross connection prevention program is - ANSWER the responsibility of the water utility 61. SPADNS is a reagent used in the analysis of - ANSWER Fluoride 62. What is an example of an "Acute Violation" - ANSWER Occurrence of fecal coli-form/E.Coli Violation of the MCL for Nitrate 63. What is the primary role of a State that has accepted primacy which means accepting guidelines at a state level to a local level - ANSWER Implementing the requirements of the state drinking water program 64. Which is not a class of public water systems covered by the "Safe Water Drinking Act"? - ANSWER Transient ,community water systems 65. How many service connections or persons must a water system have for at least 60 days or more annually to qualify as a public water system under the SDWA? - ANSWER 15 connections or 25 persons 66. If a water system fails to conduct the required water quality analysis , i.e. bac-t's , what action will the state generally direct the system to take ? - ANSWER Provide public notification 67. There are several factors that affect the accuracy of a meter. Even something as simple as location can have an effect due to - ANSWER Turbulence 68. The type of hydrant that has valves located at each individual outlet is called - ANSWER wet-barrel 69. A compound meter consists of both a large turbine meter and a small bypass meter. The bypass meter will usually be of the Positive Displacement Type - ANSWER 70. After a water main has been depressurized for repairs the operator should? - ANSWER Flush the line , collect special bac-t samples,and return to service 71. CAL-OSHA considers an open trench of ___ or deeper a possible hazardous atmosphere condition - ANSWER 4 feet 72. CAL-OSHA requires tool-box, tail-gate meetings to be conducted a minimum of ______ days for field workers - ANSWER 10 days 73. The minimum height for delineation type poles for traffic control is..... - ANSWER 36 inches 74. The pH scales range from - ANSWER 0 to 14 75. Which of the following are considered physical characteristics of water - ANSWER Color, odor,taste,temperature and turbidity 76. A __________is a instrument for measuring and comparing the turbidity of liquids by passing light through them and determining how much light is reflected by the particles in the liquid - ANSWER Turbidi-meter 77. A well that provides drinking water to a school in a rural area with less than 15 service connections is classified as a? - ANSWER Non-transient non community water system 78. Which of the following is a AWWA C-651 water main disinfection method for disinfecting the interior walls of water mains - ANSWER 50 ppm/24 hrs 79. Sewer lines should be separated from potable water mains by at least ___ vertical and ____ parallel - ANSWER 1 foot/ 10 feet 80. Which of the following is not used as a line valve in water system? - ANSWER Rising stem gate 81. Which device changes alternating current to direct current by allowing the electric current to flow in one direction but blocking flow in the opposite direction? a.) Regulator b.) Converter c.) Inverter d.) Rectifier - ANSWER d.) Rectifier 82. To ease the installation of impeller wear rings, they can be: a.) Lubricated with a light oil b.) Greased with lithium c.) Heated d.) Cooled - ANSWER c.) Heated 83. A positive fecal coliform test must be reported to the primary agency within: a.) 8 hours b.) 12 hours c.) 24 hours d.) 48 hours - ANSWER c.) 24 hours 84. Which is the approximate angle of repose for average soils when using the sloping method for the prevention of cave-ins? (Note: horizontal to vertical distance, respectively) a.) 0.5:1.0 b.) 1.0:1.0 c.) 1.5:1.0 d.) 2.0:1.0 - ANSWER b.) 1.0:1.0 85. A system that fails to collect water samples in their distribution system would fall under which public notification requirement? a.) Tier I b.) Tier II c.) Tier III d.) Tier IV - ANSWER a.) Tier I 86. Iron can cause "red water" and thus customer complaints when its concentration is above its secondary maximum contaminant level of: a.) 0.01 mg/L b.) 0.05 mg/L c.) 0.10 mg/L d.) 0.30 mg/L - ANSWER d.) 0.30 mg/L 87. Which of the following is a type of joint for ductile iron piping? a.) Welded joint b.) Restrained joint c.) Expansion joint d.) Rubber gasket joint - ANSWER b.) Restrained joint 88. Which of the following is a type of joint for ductile iron piping? a.) Welded joint b.) Bell and spigot joint c.) Expansion joint d.) Flanged joint - ANSWER d.) Flanged joint 89. Minor head losses are caused by: a.) Slime growths and corrosion or scaling b.) Corrosion and tuberculation c.) The type of material and "C" factor