CDPH Water Distribution Exam Questions and Answers, Latest Update 2024/2025 Graded A+

What term is used when a water utility divides its total operating expenses into the total revenue? a.) Debt ratio b.) Operating ratio c.) Credit ratio d.) Coverage ratio b.) Operating ratio Under the requirements of the Safe Drinking Water Act, it is the duty of the water purveyor to deliver potable water of proper quality only as far as the: a.) Entry point of the distribution system b.) Customer's curb box and service connection c.) Consumer's tap inside the home d.) Furthest water main blow-off or sampling point c.) Consumer's tap inside the home CDPH Water Distribution Grade 2 Questions and Answers Latest Update 2024/2025 Graded A+ According to the USEPA drinking water regulations, the owner or operator of a public water system which fails to comply with applicable monitoring requirements must give public notice within: a.) 45 days of the violation by posting a notice at the town hall b.) 1 year of the violation by including a letter with the water bill c.) 3 months of the violation in a daily newspaper in the area served by the system d.) 1 week of the violation in a letter hand delivered to customers c.) 3 months of the violation in a daily newspaper in the area served by the system A mixture of air and gas is considered hazardous when the mixture exceeds what percentage of the lower explosive limit (LEL)? a.) 0% b.) 3% c.) 7% d.) 10% d.) 10% Which of the following duties should not be performed by a small system operator? a.) Disinfect water mains b.) Observe pump motors to detect unusual noises, vibrations, or excessive heat c.) Repair and overhaul chlorinators d.) Wire pump, compressors and electrical components of the water system d.) Wire pump, compressors and electrical components of the water system Which form of hypochlorite is the most dangerous to handle? a.) Sodium b.) Fluoride c.) Calcium d.) Chlorine c.) Calcium What type of fire extinguisher should be used for fires with live electricity present? a.) Class A b.) Class B c.) Class C d.) Class D c.) Class C To ensure that the water supplied by a public water system meets federal and state requirements, the water system operator must regularly collect samples and: a.) Test the water at the nearest water testing laboratory b.) Determine a sampling schedule based on the lab's recommendations c.) Send all analysis results to the State periodically d.) Count the number of active wells in the system c.) Send all analysis results to the State periodically How many coliform samples are required per month for a water system serving a population between 25 and 100? a.) 1 b.) 2 c.) 3 d.) 4 a.) 1 What test method best determines chemical feed/dosage rates? a.) Jar b.) Turbidity c.) Hammer d.) Hardness a.) Jar After a new water mains is installed and pressure tested it should be: a.) Flushed with clean water for 24 hours and put into service b.) Filled with a solution of 25ppm to 50ppm free chlorine for at least 24 hours prior to flushing c.) Filled with clean water and allowed to sit for 5 days at full pressure before turning the water into the system d.) Photographed so that mapping can be avoided until the system is complete b.) Filled with a solution of 25ppm to 50ppm free chlorine for at least 24 hours prior to flushing What chlorine concentration should be produced when disinfecting a well or well pump? a.) 25 mg/L b.) 50 mg/L c.) 75 mg/L d.) 100 mg/L b.) 50 mg/L When disinfecting a new or repaired main, what is the minimum chlorine residual at the extreme end of the main after standing for 24 hours? a.) 15 mg/L b.) 20 mg/L c.) 25 mg/L d.) 30 mg/L c.) 25 mg/L Chlorine will destroy bacteria most rapidly at what pH? a.) 7.5 b.) 8.5 c.) 9.5 d.) 10.5 a.) 7.5 Which of the following pH ranges would deposit a thin film of calcium carbonate on the inside surface of a pipe? a.) 2.0-3.0 b.) 4.0-5.0 c.) 6.0-7.0 d.) 8.0-9.0 d.) 8.0-9.0 Where should sodium hypochlorite (liquid bleach) be stored? a.) Away from flammable objects, as it is a fire hazard b.) Away from equipment that is susceptible to corrosion c.) In closed containers at room temperature for no longer than 6 months d.) Near the chemical feed pump day tank, to lessen operator handling risks b.) Away from equipment that is susceptible to corrosion The space between the inner or protective casing and the outer casing or drill hole should be filled with cement grout to a minimum of how many feet? a.) 10 feet b.) 15 feet c.) 20 feet d.) 35 feet a.) 10 feet Clearwells are used for: a.) Treated water b.) Pumps and supplies c.) High pH water d.) Untreated well water a.) Treated water The four components of a fire hydrant are: a.) The inlet pipe connection from water supply, main valve, barrel, and the arm b.) The inlet pipe connection from water supply, main valve, barrel, and the head c.) The outlet pipe connectionto water supply, main valve, barrel, and the head d.) the inlet pipe connection from water supply, the trigger, barrel, and the head b.) The inlet pipe connection from water supply, main valve, barrel, and the head Electrical demand in a wiring system is determined by the amount of: a.) Ohms in the entire system b.) Voltage a system draws c.) Watts consumed d.) Water pressure in the system c.) Watts consumed