Class C Water Operator License Exam

Class C Water Operator License Exam Ammonia mixed with chlorine gas creates a Ans - white smoke The most difficult part of a water distribution operator's job. Ans - furnish a continuous supply Physical connection between a safe and potentially unsafe water source. Ans - cross connection A distribution system is a Ans - looped system Dead end mains should be flushed Ans - every month Excess nitrate causes a condition called Ans - blue baby syndrome Water hardness is caused by Ans - calcium and magnesium Sewer mains should be __ft away from water mains. Ans - 9 Water with a pH less than 7 is considered to be Ans - acidic Bacti records are kept for ____yrs and chemical records are kept for ___yrs. Ans - 5, 10 Bacti samples have to be returned to the lab within ___hrs of the collection time. Ans - 30 Color in the water supply should be less than _____ units. Ans - 15 Chlorine is ______ times heavier than air. Ans - 2.5 90% of underground pipe failures are related to improper Ans - backfill and bedding The spoil bank should be located at least ___ft away from the ditch. Ans - 2 The following minimum residuals is ______mg/L for free chlorine and ____mg/L for total chlorine. Ans - .2, .5 Public opinion of the water utility is _______ at a standstill. Ans - never A bacti sample should be taken every ____ft of pipe. Ans - 1000 The most common collection point for a bacti sample is the water tap _______. Ans - outside the house A standpipe is considered ground storage unless it exceeds _____ft above the highest ________. Ans - 80, service connection ________ protection is the electrochemical method for preventing ________ of metal tanks. Ans - cathodic, corrosion The _____ is the only cross connection control method approved by _______. Ans - air gap, tceq _______ on a pipeline depend on the _____ or coefficient of pipe roughness. Ans - friction loss, c factor __________ occurs whenever there is a ______ in the velocity or direction of water flow. Ans - water hammer, sudden change The ______ water pressure required by the rules and regulations is ____psi under any and all conditions. Ans - minimum, 20 100, 150, 200 and 250 are approved classes of _____ _____. Ans - working pressure ______ is used to anchor pipe bends. Ans - concrete A general deposit of mineral particles evenly along the inside of the pipe is ________. Ans - tuberculation Shoring should be used if a ditch is ___ft or deeper. Ans - 5 A written sample writing plan is required for _______ monitoring. Ans - coliform Ladders should be placed every ___ft in a ditch. Ans - 25 An oxygen deficient atmosphere is defined as one which contains _____ than ______ % oxygen. Ans - less, 19.5 Characteristics of a Centrifugal Pump: as the head _____ the discharge ________. Ans - increases, decreases The operator should leave a ________ of slack in flexible tubing. Ans - gooseneck The most common type of water meter is the ____ ____ meter. Ans - positive displacement Safe withdrawal weight from a 150lb cylinder is ___lbs and 400lbs from a ____ton cylinder. Ans - 40, 1 The most common valve is the _______. Ans - gate valve The most commonly used fire hydrants used in distribution systems are the _________. Ans - dry barrel Hydrants have a _____ point in case the hydrant is struck by a vehicle. Ans - breakaway Controlling valves regulate pressure flow ____ and flow _______. Ans - rates, direction Electricity is the preferred power source for most distribution systems because of ______, reliability and relatively low _______. Ans - availability, cost 5/8 meters need to be tested at least every _____ to _______ yrs. Ans - 5, 10 When disinfecting a water line, use ____mg/L of chlorine in the main and let stand for ____hrs. Ans - 50, 24 When pressure testing the water main, the test pressure should be ___times as great as the ________ operating pressure. Ans - 1.5, normal Distribution systems are usually laid out in ____ and/or circular designs. Ans - loops Dead ends in a system are usually located on ____ shaped or ____ designs. Ans - tree, grid An operator may refer to Piezometric elevation, static head, or pressure head as ____ height Ans - vertical water column The main purpose of the water storage facility is to provide ____ amount of water to average or equalize the ______ demands plus provide ______ pressures to fight fires. Ans - sufficient, daily, minimum Electrical demand in a wiring system is determined by the amount of ____ consumed. Ans - watts Baffling inside a storage facility may be needed to prevent "hot spots" and ____ flows. Ans - straight through A mass of concrete placed at bends and valve structures to prevent pipeline movement is commonly called a _____. Ans - thrust block What is the main difference between surface water and groundwater contamination? Ans - groundwater takes longer to recover after contamination A cross-connection is a connection between an _____ and an _______ water supply. Ans - approved, unapproved According to the CDC, which mechanism or problem has caused more waterborne disease outbreaks in the US than any other reported factor? Ans - leaking backflows What type of water meter is used when the water flow widely fluctuates? Ans - compound How can mechanical damage to water meters be avoided? Ans - place it behind the curb and in a meter box A piston meter is a _____ meter. Ans - displacement Name one advantage to using centrifugal pumps. Ans - they are easy to repair When residential water meters become worn, they have the tendency to ____ all flows. Ans - under register _____% of the earth's surface is ocean. Ans - 75 Out of all the water on earth, less than _____% of freshwater is immediately available to humans. Ans - 1 The term associated with water that evaporates from living plants is referred to as _____. Ans - evapotranspiration _____% of all the water on earth is saltwater. Ans - 97 Bacti sample bottles are prepared with a chemical called _____ before they are sterilized. Ans - sodium thiosulfate Killing disease causing organisms in the water is the primary purpose of ____ in water mains. Ans - disinfection Liquified chlorine gas will expand ____ times its original volume. Ans - 460 Chlorine gas is ____ times heavier than breathing air. Ans - 2.5 Chlorine gas is considered to be ____% pure. Ans - 100 Bleach is approximately _____% pure. Ans - 5.25