D2 - WATER DISTRIBUTION OPERATOR EXAM (CALIFORNIA) QUESTIONS WITH CORRECT

D2-WATERDISTRIBUTIONOPERATOREXAM b b b b b




(CALIFORNIA) QUESTIONS WITH CORRECT
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ANSWERS 2025 b b




Threesources ofsupply -RCORRECT ANSWER -
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Surfacewatertreatmentplants,Import/Purchasedwater,andWells.
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TransmissionMain- CORRECTANSWER- b b b b b




ARverylarge main designed to move water from one part of the system to another.
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Shut-OffValve-CORRECTANSWER- b b b b b




A type of valve the water company uses when they need to turn water off to a particular consumer.
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Whereis aShut-Off Valvetypically located? - CORRECT ANSWER - Usually
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found connected to a consumer's meter.
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Why might a water company need to shut water off to a particular consumer? -CORRECT ANSWER - Because of
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a request to connect or disconnect, for repairs, or as a result of non payment.
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Two mostcommon typesof Shut-Off Valves - CORRECT ANSWER -Curbstop&Angle stop.
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Meters -CORRECT ANSWER -Devicesused to read consumer usage.
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Wheredoes awater company's property end - CORRECT ANSWER -At the consumer's meter.
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Most common type ofresidential water meter and why? - CORRECT ANSWER -
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Positive displacement meters,becausetheyaccurately measure allwater thatflows throughthem.
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Threetypes of water systems - CORRECT ANSWER -Arterial loop, Grid, and Tree.
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Minimum acceptable PSI with a system - CORRECT ANSWER -20 PSI b b b b b b b b b b

, Normal acceptable range of PSI within a system - CORRECT ANSWER -35 to 65 PSI
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When must a pressure regulator be installed on a consumer's service line? - CORRECT ANSWER - GREATER
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than 80 PSI.
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What is the highest acceptable PSI within a system, before a pressure regulator needs to be installed? - CORRECT
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ANSWER -80 PSI
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Why are higher pressures generally not desired within a system? - CORRECT ANSWER - It can
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damage plumbing fixtures.
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Dynamic Pressure - CORRECT ANSWER -The pressure within a systemwhen water is moving.
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Six types of pipe found in a water distribution system - CORRECT ANSWER - Ductile
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Iron, Concrete, Steel, Asbestos Cement, Plastic and Gray Cast Iron.
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C-Value - CORRECT ANSWER -The measureofinterior smoothness within a pipe.
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What does a 140+ C-Value mean? - CORRECT ANSWER - Very
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smooth interiorsurface ofa pipe(Plastic,AC, Concrete)
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What does a<100 C-Valuemean? - CORRECT ANSWER -
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Verybadinterior surfaceofa pipe (Tuburculatedold cast iron)
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What is aPnetrometer? - CORRECT ANSWER -A tool for measuring the compressive strength of soil.
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What is aCompetent Person? - CORRECT ANSWER -
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An individual with excavation knowledge and training who is in charge of an excavation job, and who ha s the
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power to start work in the event of a hazard
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When is shoringgenerally required? -CORRECT ANSWER -
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When a trench is 5' or more in depth, or hazardous soil conditions exist.
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