CWEA Collection Systems Maintenance|Complete Questions with 100% Correct Answers

CWEA Collection Systems Maintenance|Complete Questions with 100% Correct Answers Why are gasoline and volatile solvents objectionable when present in a sewer? They produce an explosion hazard You should never attempt to install, maintain, repair or replace electrical equipment panels, controls, wiring or circuits unless You know what you are doing, are qualified and are authorized What are the different areas of traffic zones? Advance Warning Area, Transition Area, Activity Area (buffer space and work space), Termination Area. Could be 4 or 5, justify your answer on the test! why should hydrogen sulfide be controlled? to protect from corrosion and odors Personnel entering a Permit Required Confined Space must have the following training entry and rescue To find protective gear before application of a product, you should: look at the MSDS The gas most commonly associated with septic wastewater is Hydrogen Sulfide The lack of an unpleasant odor in a manhole, lift station or other structures does not always mean that dangerous gases are not present because: some dangerous gasses are odorless (for example, carbon monoxide) What are the four conditions necessary to create an explosion? combustible gas, adequate oxygen, heat and proper mixing of gas and oxygen what does the "transition area" mean in traffic control? It moves traffic out of its normal path what elements should be considered to improve worker safety in High speed Temporary Traffic control Zones? Rerouting traffic around the work site, positioning of law enforcement officers in the temporary traffic control zone, and work zone training What key features would you need to address when developing an S.O.P. for a Lift Station failure? Traffic Control Plan, By-Pass connections, and Spill containment What tools are used with a power rodder? Spring Blades Tools used for sewer rodding include: porcupine, root saw, square bar cork screw What tool would you use to cut VCP pipe? Chain Pipe Cutter Which conditions should a gas detection device test for? Hydrogen sulfide, explosive/flammable gases, oxygen What does "LEL" mean on a gas detection meter? Lower Explosive Limit The oxygen level alarm normally goes off if oxygen levels are below: 19.5 percent When developing an S.O.P. for scheduled maintenance of electrical equipment, what program should be addressed as a primary safety guideline? The L.O.T.O Program What does L.O.T.O. Stand for? Lock out tag out What document would you require to be referenced when developing an S.O.p. for hazardous substace spill clean up? M.S.D.S. in developing an S.O.P. for air monitoring in a Permit Required Confined Space you would include what two factors? Placement of the blower and a weather forecast According to the State Water Resources Control Board Order No. 2006-003-DWQ, each enrollee must develop and implement a system-specific: SSMP (Sewer System Management Plan) How long do you have to report a category 1 SSO? 2 hours To report in the Statewide SSO Data-base California Integrated Water Quality System (CIWQS) regarding the location of a Category 2 SSO, how must you report the location? Using the GPS coordinates Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause: odors Flatter sewer line grades may cause added sewer maintenance expense and odor nuisance. This is caused by what? A decrease in velocity which allows organic and inorganic solids to settle out. This, in turn, allows biological activity to happen which corrodes the pipe and releases hydrogen sulfide (H2S) which smells like rotten eggs Clear water in entering a collection system is called what? infiltration Infiltration can occur in a pipe when the pipe is: cracked, broken, fractures, has roots coming into it etc. The main reason we add sodium hypochlorite to sewers is to control: BOD Roots can enter collection systems through: cracked pipes, broken pipes, fractured pipes The lowest point on the inside of a pipe is called what? the invert The very top of the outside of a pipe is called what? The crown How often must an excavation site and adjacent areas be inspected for hazardous conditions? Daily protective shoring systems options include: proper shoring or benching of the sides of the excavation, supporting the sides of a tench with shoring using a shield in an excavation area. Proper operation and maintenance of wastewater collection is defined as: keeping wastewater flowing through pipes What is minimum design velocity for a sewer? a minimum of two feet per second Vitrified clay pipe is what type of pipe? Rigid What is another name for a manhole? Maintenance hole What are the four parts of a manhole? lid, cone, barrel and base What are some sewer testing methods? Air, water, mandrill, smoke, dye, lamping What are some hydraulic cleaning methods? Flushing, balling, kites, parachutes, poly pigs (pigging), high velocity cleaning, jetting, skids and tiger tails. what is the formula for the area of a square? Length x width The main advantage of using CCTV is what? You can see and record the length and severity of defective pipe A hazard that may damage a TV camera going through a sewer is: an offset joint What is the formula for the volume of a cube? Length x Width x Height What is the formula for the area of a circle? 0.785 x Diameter x Diameter What is the formula for the volume of a pipe? 0.785 x Diameter x Diameter x Length A flow of 650 pgm would be how many mgd? 0.936 How can the members of a balling crew communicate with each other? Hand Signals Why must you always know where a cleaning tool is in a sewer? so you know where obstructions or difficulties are encountered emergency stoppages in pipelines may be cleared safely by use of: high velocity cleaners rodents and insects can be controlled by spraying manholes with an approved pesticide Sources of excessive clear water in a collection system are usually caused by: infiltration from a high water table How many types of common shoring are there? 6 What is the "dirt" formula? distance = rate x time What is the total volume (in gallons) of 1,000 feet of 8-inch pipeline? 2,611 gallons What is the most critical task in operation and maintenance of wastewater collection? Keeping wastewater flowing through pipes Once enrolled in CIWQS, the "Collection System Questionnaire" must be updated at least every: 12 Months You arrive at an SSO and relieve the stoppage 27 minutes after a call was placed to report it. You find that the spill was running at 6 gallons per minute, how much sewage went uncaptured? 162 gallons What would cause a pump to deliver less than its expected rate of discharge? clogged impeller Why are wear rings installed in a pump? To concentrate wear on rings instead of volute and impeller What control devices are used to start and stop pumps? Floats What type of pump is used in lift station wet wells? Submersible Based on new Best Practices of the Common Ground Alliance for marking underground Utilities, the Inquiry Identification Number for an Underground Service Alert (USA) is viable for how many days?