Download Class C Water Operator License Exam Q&A: Guaranteed Pass 2025-2026 and more Exams Water and Wastewater Engineering in PDF only on Docsity!
Class C Water Operator License Exam|
Answered with a guaranteed pass| 2025- 2026
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 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.
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,. 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 _______.
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. 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
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 A cross-connection is a connection between an _____ and an _______ water supply. approved, unapproved According to the CDC, which mechanism or problem has caused more waterborne disease outbreaks in the US than any other reported factor? leaking backflows What type of water meter is used when the water flow widely fluctuates? compound How can mechanical damage to water meters be avoided? place it behind the curb and in a meter box A piston meter is a _____ meter. displacement Name one advantage to using centrifugal pumps. they are easy to repair
When residential water meters become worn, they have the tendency to ____ all flows. under register _____% of the earth's surface is ocean. 75 Out of all the water on earth, less than _____% of freshwater is immediately available to humans. 1 The term associated with water that evaporates from living plants is referred to as _____. evapotranspiration _____% of all the water on earth is saltwater. 97 Bacti sample bottles are prepared with a chemical called _____ before they are sterilized. sodium thiosulfate Killing disease causing organisms in the water is the primary purpose of ____ in water mains. disinfection Liquified chlorine gas will expand ____ times its original volume.
When turning a centrifugal pump off, "this" must be done to prevent water hammer. close the discharge valve When an operator isolates a motor from an operable system for repair, it is vital that he/she follow a _____/_____ procedure. lockout/tagout Horsepower is defined as _____ft-lbs per minute or 746 watts. 33, The rated flow of a water meter, as stated by the manufacturer, is based upon ______ flow. continuous What is the minimum setback distance for fire hydrants to avoid large vehicle overhang? 2ft What is the primary reason for using dry barrel fire hydrants? to keep it from freezing You must coordinate a plan for shutdown of a water storage facility so that the distribution system will still be able to _____ upon and after the shutdown. meet the customers demands What are the three main components of a centrifugal pump?
impeller, case and shaft Condensation, evaporation, percolation, and precipitation are all components of the _______ cycle. hydrologic The State requires that _____ _____ be kept in storage for disinfection of new water lines. calcium hypochlorite If a major chlorine leak occurs, call the supplier and the _____. tceq Powder activated carbon is commonly used to treat ____ and ____ problems in water. taste, odor The primary goal of coagulation, sedimentation and filtration is to remove ____. turbidity The 2 pathogenic protozoans resistant to chlorination are: __________. giardia and cryptosporidium The process of separating floc from water by gravity is called ____. sedimentation ______ is the last barrier between the public and giardia or cryptosporidium. filtration
To be classified as a pws, the system must have at least __ service connections or serve at least __ individuals at least ___ days out of the year. 15, 25, 60 Concentrations of fluoride greater than (>) _mg.L can cause ____ in teeth over time. 2, mottling Low doses of heavy metals, such as lead and copper, can cause damage to the ______ _____ ______ over time. central nervous system The action level for lead is ____mg.L, and for copper is ____mg/L. 0.015, 1. One by-product of chlorinated water is ____________, a suspected carcinogen when consumed in water over a lifetime. trihalomethane Chlorine is combined with ______ to form chloramines to prevent the formation of .... in surface water. ammonia, thms Supply systems must maintain a minimum water pressure of ___ psi under normal conditions and at least ___psi during emergencies. 35, 20
Service tap components usually consist of a tapping saddle, corporation stop, service line tubing, curb stop and a _____. meter If a repaired main line must be returned to service quickly, dose it with ____mg/L Chlorine, for ___minutes. 500, 30 The 2 primary categories of pumps are: ____ and _____. centrifugal, positive displacement The "Texas Hazard Communications Act" is known as the "____ ___ ____ Act." right to know _____ all shoring from the top down and _____ from the bottom up. install, remove
