Water Distribution Exam Sample Text Questions and Answers (Graded A), Exams of Water Resources Planning and Management

Download Water Distribution Exam Sample Text Questions and Answers (Graded A) and more Exams Water Resources Planning and Management in PDF only on Docsity! Water Distribution Exam Sample Text Questions and Answers (Graded A) What is the federal law that protects public water supplies from harmful contaminants? - ANSWER-SDWA Safe Drinking Water Act MCL stands for - ANSWER-Maximum Contaminant Level True or False? Primary regulations are mandatory - ANSWER-TRUE Secondary regulations are about what 3 things? - ANSWER-Taste Odor Color of water True or False? Secondary regulations are mandatory - ANSWER-FALSE What is the minimum pressure that must be maintained at all times in a distribution system? - ANSWER-20 PSI The limit for velocity in a system is? - ANSWER-5 ft/sec The spoil pile should be located how far back from the trench wall? - ANSWER-2 feet (min) True or False? A vent in a chlorine room should be located near the ceiling. - ANSWER-FALSE An area is considered unsafe when the oxygen level drops to below a) 19.5% b) 20.2% c) 10.5% d) 19.25% - ANSWER-a) 19.5% The most common valve used in a distribution system is a) butterfly b) gate c) ball d) check - ANSWER-b) gate A chain of custody is required for a sample a) from collection to disposal b) from collection to the lab c) from the lab to disposal d) all of the above - ANSWER-b) from the collection to the lab 1 (one) cubic foot of water is _____ lbs a) 7.48 b) 8.34 c) 27 d) 62.38 - ANSWER-d) 62.38 How should a CL2 (chlorine) storage room be vented? a) mechanically at the floor b) mechanically at the ceiling c) in the middle of the wall d) no ventilation is required - ANSWER-a) mechanically at the floor If a chlorine leak develops in a room where you are working, you should a) quickly leave the room b) crawl on the floor and quickly leave the room c) close your mouth, hold your head as high as possible and quickly leave the room d) call 911, then leave the room - ANSWER-c) close your mouth, hold your head as high as possible and quickly leave the room a beard could prevent proper use of what safety equipment? a) goggles b) fire extinguisher c) SCBA d) Safety Vest - ANSWER-SCBA (self contained breathing apparatus) Prior to entering a storage tank you should a) Throw a match in the tank to check for explosive gas b) mechanically blow air into the tank c) Do nothing, just go ahead and enter the tank a) amps b) volts c) watts d) ohms - ANSWER-a) amps Lead in a distribution system is a) always dangerous to children and pregnant women b) of no concern in water distribution c) only dangerous at a pH of 8.0 - ANSWER-a) always dangerous to children and pregnant women What type of flow meters is most common for residential water taps? a) positive displacement meters b) multiple meters c) venturi meters d) none of the above - ANSWER-a) positive displacement meters A pipe that is described as light weight, easy to install, and corrosion resistant is a) concrete b) asbestos cement c) ductile iron - ANSWER-b) asbestos cement A sample is taken from a single location in the distribution system and comes back clear. This would indicate that a) the distribution system is functioning as desired b) no more samples are required for 7 days c) the tap that was sampled was clear at the exact time and date that the sample was pulled from the tap - ANSWER-c) the tap that was sampled was clear at the exact time and date that the sample was pulled from the tap A customer on a looped system is complaining of stale water. What would you check for? a) coliform b) a closed valve on the distribution system c) is their meter working properly? - ANSWER-b) a closed valve on the distribution system What type of pipe should be installed on a chlorinator? a) PVC b) ductile iron c) copper - ANSWER-a) PVC How can an operator check for leaks in a chlorine line? a) sniff the line b) check with an ammonia soaked rag c) do nothing - ANSWER-b) check with an ammonia soaked rag ??? What disinfecting a line with chlorine tablets, the tablets should be a) along the bottom of the pipe b) along the top of the pipe c) anywhere in the pipe is ok - ANSWER-b) along the top of the pipe You have exceeded the maximum contaminate level (MCL) for coliform. What action needs to be taken? a) notify the public b) do nothing c) none of the above - ANSWER-a) notify the public The minimum vertical distance between water and sewer lines should be? a) 18 inches b) 3 inches c) 3 feet d) there is no limit - ANSWER-a) 18 inches A corporation stop is used to cut off water at the customer service line. This valve is located where? a) on the water main b) on the water meter c) none of the above - ANSWER-a) on the water main When a wet tap is made on a water main, the water is... a) turned off b) drained from the pipe c) still under pressure from the main - ANSWER-c) still under pressure from the main Water distribution system gate valves should be exercised at least once a a) week b) every 5 years c) year - ANSWER-c) year An area is considered unsafe when the oxygen content drops below a) 22% b) 10% c) 19.5% - ANSWER-c) 19.5% Exits must be provided within 25 feet of all workers in a trench with a minimum depth of a) 5 feet b) 10 feet c) 8 feet - ANSWER-a) 5 feet Before returning a new or repaired water main to service, the line should be flushed at 2.5 feet per second, then tested for a) friction loss b) compaction c) bacterial contamination - ANSWER-c) bacterial contamination Chlorine residuals in the distribution system should be no less than a) 1.6 mg/L b) 0.2 mg/L c) 0.5 mg/L - ANSWER-b) 0.2 mg/L The most common type of valve in the distribution system is a) globe b) stem c) foot d) gate - ANSWER-d) gate The two types of hydrants are a) high and low volume b) red and white c) dry barrel and wet barrel d) in line and end of line - ANSWER-c) dry barrel and wet barrel The main purpose for thrust blocks in a distribution system at bends and valves are a) to fill the ditch line b) to prevent the movement of pipe