In responding to a backflow incident the water purveyor should (A) Call the mayor (B) Implement the emergency response plan (C) Install a vacuum breaker (D) Develop a good excuse - answer-Implement the emergency response plan A mixture of air and gas is considered hazardous when the mixture exceeds what percentage of gthe lower explosive limit (A) 0% (B) 3% (C) 7% (D) 10% - answer-10% To exert a pressure of 1.0 psi at base of a water column the column would have to be (A) 4.34 high (B) 14.7 high (C) 27.75 high (D) 33.89 high - answer-27.75 high A DC must be tested (A) Upon installation (B) Every 6 month (C) Annually on a health hazard (D) none of the above - answer-Upon installation An absolute perssure of 25 psiaa (at sea level) is equal to approximately (A) 5 psi (B) 10 psi (C) 20 psi (D) 25 psi - answer-10 psi Dueing a field test the air inlet on PVB must open at (A) Above 2.0 psid (B) Below 1.0 psid (C) Above 1.0 psid (D) Below 2.0 psid - answer-Above 1.0 psid A differential pressuer gauge is used to field test (A) PVB's (B) Dual Checks (C) AVB's (D) All the above - answer-PVB's Backflow in a water supply can be caused by (A) Backpressure only (B) A Barometric Loop (C) Backsiphonage only (D) Backpressure and Backsiphonage - answer-Backpressure and Backsiphonage A BPAT tester is required to report test information on the proper forms to the (A) Administrative authority (B) Manufacturer's Rep (C) EPA (D) None of the above - answer-Administrative authority The relief valve opens when closing #2 shut off valve on a RP What is the most probable cause (A) #1 Shut off valve is open (B) #2 Shut off valve is open (C) #1 check is fouled open (D) Shut off is leaking - answer-#1 check is fouled open