Class C Water Operator License Exam 100% VERIFIED ANSWERS 2024/2025 CORRECT STUDY SET, Exams of Health sciences

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Class C Water Operator License Exam 100% VERIFIED ANSWERS 2024/2025 CORRECT STUDY SET 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. 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 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 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. 460 Chlorine gas is ____ times heavier than breathing air. 2.5 Chlorine gas is considered to be ____% pure. 100 Bleach is approximately _____% pure. 5.25 HTH dry powder chlorine is set at ____% purity. 65 A commonly used method to test for chlorine residual in water is called the ____ method. dpd When chlorine gas is added to water, the pH goes down due to the two _____ that form. Ground water supply systems serving more than ___ connections must have a total ground storage capacity of ___ gal/connection and elevated storage capacity of ___ gal/connection or pressure tank capacity of __ gal/connection. 50, 200, 100, 20 The State recommends a TON (Threshold Odor Number) of less than ____. 3 In Texas ___% of water is used for commercial, industrial or agricultural purposes. 75 In Texas ag water demands accounts for about ___% of the total water used. 57 The federal regulator of drinking water is the ___. epa The primary state regulator of water utilities is the ____. tceq 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, 1.3 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