Water distribution practice test D1 /D2 questions and answers already passed

Water distribution practice test D1 /D2 questions and answers already passed The only absolutely reliable method of backflow prevention is the use of Air Gap The bubbles formed in a positive multiple tube fermentation test are Carbon Dioxide The maximum rate of withdrawal of gas from a 150lb chlorine cylinder in 24-hours is 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? Rotate the container to place the leak at the top The most commonly used water disinfectant in the United States is 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 As long as necessary to permit cleaning of service line Sample bottles wich are furnished by a certified laboratory for collection of bacteriological samples 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 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 Altitude valve In an occupied trench requiring personal egress what is the maximum allowable distance between a worker and an exit letter 25 feet A water bearing formation in the soil is referred to as An aquifer The distance between the static water level and the pumping water level is termed the Drawdown To prevent the entry of surface contamination into a well is the purpose of Sanitary seal The presence of coliform bacteria in a distribution system Indicates that pathogenic organisms may be present also The most common valve type in water distribution system is the Gate valve A Venturi is a device used to Measure water flow Backspin is occurring after well shut down this indicates A faulty check valve A ph reading of 6.0 units indicates the water sample is Slightly acidic Chlorine gas Is heavier than air The change in what're demand during the course of a day is called Diurnal variation Catholic protection is a system used for Metallic corrosion inhibition The elevation of the free surface in a water table well wich is not running is called Static water level The maximum momentary load placed on a water supply system is known as Peak demand Most below ground level storage tanks are constructed of Concrete Hey bacteriological sampling bottle should be Filled carefully to leave a small air space When fully open, wich of the following will have the lowest friction loss Gate valve Enclosed, open, and smi closed are terms used for the designation and selection of Impellers The process by wich water changes from the gas to the liquid form is called Condensation Sleeve type and victaulic couplings are the most common forms of Mechanical couplings The most commonly used meter on a small diameter domestic service is the Mutating disc meter If a pump sounds like it's pumping rocks, the most likecly cause is Cavitation "Backflow Device" is termedused to describe a device that Prevents back flow of potentially contaminated source in to drinking water Which is a devices used to measure flow Weir When closing a hydrant, it should be Closed slowly to reduce surges A bacteriological test that measures only the presence or absence of Califorms is Colilert A compound meter is a device which Provides accurate reading over a wide range of flows The rotating element in a centrifugal pump is commonly called the Impeller The packing gland serves many functions in a centrifugal pump. Among these is Keep gritty material from entering the packing box What are the names of positive displacement pumps Reciprocating and rotary What is the practical maximum suction lift for a centrifugal pump in good working condition 15 to 25 feet Residual chlorine refers to The amount of chlorine in the chlorinated water after a selected time The lowest point of the inside of a pipe is known as the Invert If possible why should a main water leak be repaired under pressure To prevent contamination of the water line A connection made in to a main that is full or under pressure is called a Wet tap Shoring is normally required for trenches of that minimum depth 5 feet Standard first aid procedures direct that the first step to control bleeding is to Apply pressure directly to the wound First aid for a first degree burn is to Submerge the burned area in cold water Chlorine leak can be detected by Applying ammonia vapor Red water problems are due primarily to Iron Portable water is defined as Any whater that according to recognized standards is safe for consumption When testing a distribution system for chlorine samples residuals , you shoul Test samples from several points A normally burried valve located on a street water main and leading to water service is known as Corporation Stop A new water main should be flushed disinfected at 50mg/L and held at above 25mg/L for at least 24 hours What percent of all the earths water is readily available as potential drinking water in the form Of lakes, rivers, and ground water? 0.34 What gass kills the sense of smell Hydrogen sulfide Pipe with a "C" factor of 140 is regarded as having an Extremely smooth interior Pumps are primed to Replace air inside the pump with water The drain hole in a dry barrel fire hydrant is designed to remove water from the riser to prevent freezing An aquifer that is located underneath an aquiclude is called A confined aquifer Odors are not as noticeable when the water is Cold the freezing point of water is 32*F. Or 0*C