Basic Wastewater Operations- Chapter 5 (The Collection System) Exam Questions with Verified Answers (Graded A+) Already Passed

Basic Wastewater Operations- Chapter 5 (The Collection System) Exam Questions with Verified Answers (Graded A+) Already Passed T/F: The purpose of the collection system is to collect and transport waste to the point of treatment. - Answers True T/F: The most important benefit of a collection system is comfort and convenience. - Answers False; Removal of potential health hazards is most important. T/F: Parts of a collection system include wastewater lines, wastewater crossings, inverted siphons, cleanouts, manholes, and lift stations. - Answers True T/F: If gasoline or solvent odors are detected in a manhole, the operator should bolt and gasket the cover. - Answers FALSE T/F: Safety rules for manholes include checking for gases and sufficient oxygen, wearing a lifeline, and having two workers assisting at the surface. - Answers True T/F: Clay and PVC are the most common pipe material. - Answers True T/F: Pipe materials used in collection system construction include polyvinyl chloride, clay, concrete, and iron. - Answers True T/F: Grade (or slope) and flow velocity are important to wastewater pipe installation. - Answers True T/F: For any gravity wastewater, the minimum velocity required to keep solids in suspension is 1 ft/sec. - Answers False; A velocity of 2 ft/sec is required. T/F: Pipe should be laid down so that the bell end is facing downstream or downhill. - Answers False; It should face upstream. Wastewater flowing into a collection system should come from __________. A. Storm drainage B. Homes and businesses C. Industry D. B and C - Answers D. B and C Install wastewater lines no closer to a water line than __________ feet. A. 7 B. 8 C. 9 D. 10 - Answers C. 9 OSHA sets standards for shoring, sloping, or trench boxes for trenches _____________ feet or deeper. A. 6 B. 5 C. 4 D. 3 - Answers B. 5 If the trench is _________ feet or deeper, a means of exit is required. A. 7 B. 6 C. 5 D. 4 - Answers D. 4 If a ladder is used, it must be portable and extend __________ feet above the trench, in addition to being secured. A. 2 B. 3 C. 4 D. 5 - Answers B. 3 A ladder must be within ___________ feet of anyone in the trench. A. 25 B. 24 C. 23 D. 22 - Answers A. 25 Excavation spoil must be at least ________ feet from the edge of the trench. A. 5 B. 4 C. 3 D. 2 - Answers D.2 The primary cause of stoppages is roots or __________. A. Gases B. Sand C. Grease D. Rain - Answers C. Grease Wastewater cleaning can increase pipe capacity, prevent septic conditions, maintain flow velocity, and ____________. A. Increase BOD B. Reduce stoppages C. Kill pathogens D. Reduce flow - Answers B. Reduce stoppages Hydraulic cleaners (jetting units) use __________ under pressure, which is forced through nozzles. A. Air B. Water C. Gas D. Oil - Answers B. Water Maps should be as built, showing corrections made in the field during __________________. A. Planning B. Construction C. Bidding D. Designing - Answers B. Construction When chemicals are used in the system, consider worker and public ____________. A. Safety B. Relations C. Complaints D. Approval - Answers A. Safety When wastewater cannot flow to treatment by __________, a lift station is used. A. Pressure B. Gravity C. Force D. Vacuum - Answers B. Gravity Lift station designs include __________. A. Dry well B. Wet well C. Pneumatic ejector D. All of the above - Answers D. All of the above Dry well stations have the ___________ and pumps in a dry well separated from the adjacent wet well. A. Wastewater