Class C Water Operator License Exam Questions and Answers | Latest Updated 2024/2025 | 100% Correct | Graded A+

Ammonia mixed with chlorine gas creates a white smoke The most difficult part of a water distribution operator's job. furnish a continuous supply Physical connection between a safe and potentially unsafe water source. cross connection A distribution system is a looped system Dead end mains should be flushed every month Excess nitrate causes a condition called blue baby syndrome Water hardness is caused by calcium and magnesium Sewer mains should be __ft away from water mains. 9 Class C Water Operator License Exam Questions and Answers | Latest Updated 2024/2025 | 100% Correct | Graded A+ Water with a pH less than 7 is considered to be acidic Bacti records are kept for ____yrs and chemical records are kept for ___yrs. 5, 10 Bacti samples have to be returned to the lab within ___hrs of the collection time. 30 Color in the water supply should be less than _____ units. 15 Chlorine is ______ times heavier than air. 2.5 90% of underground pipe failures are related to improper backfill and bedding The spoil bank should be located at least ___ft away from the ditch. 2 The following minimum residuals is ______mg/L for free chlorine and ____mg/L for total chlorine. .2, .5 Public opinion of the water utility is _______ at a standstill. never A bacti sample should be taken every ____ft of pipe. 1000 The most common collection point for a bacti sample is the water tap _______. outside the house A standpipe is considered ground storage unless it exceeds _____ft above the highest ________. 80, service connection ________ protection is the electrochemical method for preventing ________ of metal tanks. cathodic, corrosion The _____ is the only cross connection control method approved by _______. air gap, tceq _______ on a pipeline depend on the _____ or coefficient of pipe roughness. friction loss, c factor __________ occurs whenever there is a ______ in the velocity or direction of water flow. water hammer, sudden change The ______ water pressure required by the rules and regulations is ____psi under any and all conditions. minimum, 20 100, 150, 200 and 250 are approved classes of _____ _____. working pressure ______ is used to anchor pipe bends. concrete A general deposit of mineral particles evenly along the inside of the pipe is ________. tuberculation Shoring should be used if a ditch is ___ft or deeper. 5 A written sample writing plan is required for _______ monitoring. coliform Ladders should be placed every ___ft in a ditch. 25 An oxygen deficient atmosphere is defined as one which contains _____ than ______ % oxygen. less, 19.5 Characteristics of a Centrifugal Pump: as the head _____ the discharge ________. increases, decreases The operator should leave a ________ of slack in flexible tubing. gooseneck The most common type of water meter is the ____ ____ meter. positive displacement Safe withdrawal weight from a 150lb cylinder is ___lbs and 400lbs from a ____ton cylinder. 40, 1 The most common valve is the _______. gate valve The most commonly used fire hydrants used in distribution systems are the _________. dry barrel Hydrants have a _____ point in case the hydrant is struck by a vehicle. breakaway Controlling valves regulate pressure flow ____ and flow _______. rates, direction Electricity is the preferred power source for most distribution systems because of ______, reliability and relatively low _______. availability, cost 5/8 meters need to be tested at least every _____ to _______ yrs. 5, 10 When disinfecting a water line, use ____mg/L of chlorine in the main and let stand for ____hrs. 50, 24 When pressure testing the water main, the test pressure should be ___times as great as the ________ operating pressure. 1.5, normal Distribution systems are usually laid out in ____ and/or circular designs. loops Dead ends in a system are usually located on ____ shaped or ____ designs. tree, grid An operator may refer to Piezometric elevation, static head, or pressure head as ____ height 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. sufficient, daily, minimum Electrical demand in a wiring system is determined by the amount of ____ consumed. watts Baffling inside a storage facility may be needed to prevent "hot spots" and ____ flows. straight through A mass of concrete placed at bends and valve structures to prevent pipeline movement is commonly called a _____. thrust block What is the main difference between surface water and groundwater contamination? groundwater takes longer to recover after contamination