CLASS D WATER OPERATOR EXAM QUESTIONS AND100%CORRECT ANSWERS .

CLASS D WATER OPERATOR EXAM QUESTIONS AND100%CORRECT ANSWERS . ______ is the final step in removing suspended matter and chlorine resistant microorganisms. - Answer-Filtration .____________ is buildup of oxidized iron, calcium carbonate, or other chemicals in mains. High pressure water, pigs or swabs, and chemicals are methods of removing scale. - Answer-Tuberculation ._____________ is the process where ice and snow evaporate into the atmosphere without first melting into a liquid form. - Answer-Sublimation .1 psi = ________ ft of water column - Answer-2.31 .A common filter is the rapid sand filter, which filters ____ gpm/ft2 of filter media. - Answer-2 .A cross connection is a physical connection between a public water system and: - another supply of _________ quality - any source that may contain _________ -any water treated to a __________ degree - Answer-unknown or questionable contamination lesser .A safety program must start with support from the _________, then extend to all employees. - Answer-top official .A sand filter has _____ to ____ inches of porous material such as sand or anthracite coal, called filter media. - Answer-24" to 30" .A scale called the ________ measures odor. - Answer-Threshold Odor Number (TON) .A standpipe is considered ground storage unless it exceeds _____ft above the highest service connection. - Answer-80 .A system's filtered water must be _______ Nephelometric Turbidity Units (NTU) or less in at least 95% of the measurements taken each month, and no sample can exceed _____ NTU. - Answer-0.3 1 .A tank resting on the ground that is greater in height than diameter is called a _________. - Answer-standpipe .A water system with ground storage is allowed pressure tank capacity of ______ gallons per connection. - Answer-20 gallons per connection .A water system without ground storage must have pressure tank capacity of _____ gallons per connection. - Answer-50 gallons per connection .According to OSHA, soil that has previously been disturbed is classified as soil type _________. - Answer-C .According to OSHA, three criteria classify a _____________. 1) large enough and so configured that an employee may enter and do work; 2) has limited or restricted means of entry or exit; 3) is not designed for continuous occupancy. - Answer-confined space .After the floc forms, the water flows into a sedimentation basin. A detention time of at least ____ hours is required to allow the floc to settle. - Answer-6 .All activities shall be restricted within _____ feet of a surface water treatment plant intake. - Answer-200 .All community and non-transient, non-community water systems must not exceed a maximum free chlorine or chloramine residual of ______ mg/L based on the running annual average of all distribution samples. - Answer-4 mg/L .All ground storage tanks must have an access opening at least _______ inch diameter. - Answer-30" .An exterior and interior inspection of all tanks must be conducted how often? How long must the documented inspection results be kept? - Answer-Yearly inspection required, keep results 5 years .As the solids increase, there will be a loss of head pressure through the filter due to increased friction. When this head loss is about ____ to _____ feet, the filter must be backwashed. - Answer-6-10 feet .At what level will fluoride cause mottling of teeth, a condition known as fluorosis? - Answer-4.0 mg/L .Bacteriological samples must be recieved by the lab within _____ hours or they are rejected. Cool the samples on ice prior to and during transport. Keep samples off dashboards. Heat stimulates biological growth! - Answer-30 .Can dissolved solids be removed by filtration? - Answer-No .Chemical characteristics of water generally cannot be detected by sight, smell, or taste and must be determined by __________. - Answer-laboratory analysis .Chemical laboratory analysis must be sampled _______ per year for surface water and normally _______ for groundwater. - Answer-once/year for surface water once every three years for groundwater .Color above ______ units is objectionable in a public water supply. - Answer-15 units .Combining chlorine with _______ greatly reduces THM and HAA formation. - Answer-ammonia .Detect chlorine leaks by holding an open bottle of _______ % ammonium hydroxide under the suspected point. - Answer-10% .Disinfection capacity for drinking water must be at least ______% greater than the highest expected dosage. - Answer-50 .Do not place a new main into service until a bacteriological sample is analyzed and shows negative results. One sample is required for each _______ feet of completed main. - Answer-1000 feet .Does high or low pH make water more corrosive? - Answer-low pH .Does high or low temperature make water more corrosive? - Answer-high temperature .DOSAGE = _________ + __________ - Answer-DEMAND + RESIDUAL .Each foot of water column produces ______ psi. - Answer-0.433