Wastewater Collection - Level 1 Training Exam Fully Solved.

A flow of 60 gph (227 L/h) is equal to a) 1 mgd (3.785 x 10cubic m3/d) b) 1 mg/L (1mg/L) c) 10 gpm (0.63 L/s) d) 1 gpm (0.063 L/s) - Answer d) 1 gpm (0.063 L/s) The slope of a sewer is measured by a) The difference from the crown to the invert. b) The difference in invert elevations over a length of pipe. c) Using the diameter of the pipe. d) Only entering the manhole. - Answer b) The difference in invert elevations over a length of pipe. An air gap can be used to a. Clean sewer blockages cause by grease b. Let air into manholes c. Prevent back-flow of wastewater into a drinking water supply d. Test for oxygen deficiency in manholes - Answer c. Prevent back-flow of wastewater into a drinking water supply A cross-connection is a a. Cast iron pipe connected to a concrete pipe. b. Steel pipe connected to an asbestos pipe