Water Distribution Practice Test D1 /D2 Questions and Answers(Graded A+)

The only absolutely reliable method of backflow prevention is the use of - ANSWER-Air Gap The bubbles formed in a positive multiple tube fermentation test are - ANSWER-Carbon Dioxide The maximum rate of withdrawal of gas from a 150lb chlorine cylinder in 24-hours is - ANSWER-40 lbs If you encounter a liquid chlorine leak in a one tone container, what action should you take first, to reduce the severity of the leak? - ANSWER-Rotate the container to place the leak at the top The most commonly used water disinfectant in the United States is - ANSWER-Chlorine When collecting a distribution system sample, the water should be allowed to run for a period of time prior to sample collection. How long - ANSWER-As long as necessary to permit cleaning of service line Sample bottles wich are furnished by a certified laboratory for collection of bacteriological samples - ANSWER-Are ready to use The difference between water pressure upstream and downstream of a pump when it is not in operations is know as the - ANSWER-Total static head A device that automatically shuts off flow in an elevated storage tank when the water level in the tank reache a preset level is termed a - ANSWER-Altitude valve In an occupied trench requiring personal egress what is the maximum allowable distance between a worker and an exit letter - ANSWER-25 feet A water bearing formation in the soil is referred to as - ANSWER-An aquifer The distance between the static water level and the pumping water level is termed the - ANSWER-Drawdown