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CWEA COLLECTION SYSTEMS MAINTENANCE
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Q: what elements should be considered to improve worker safety in High speed Temporary Traffic control Zones? Answer: Rerouting traffic around the work site, positioning of law enforcement officers in the temporary traffic control zone, and work zone training Q: What key features would you need to address when developing an S.O.P. for a Lift Station failure? Answer: Traffic Control Plan, By-Pass connections, and Spill containment Q: What tools are used with a power rodder? Answer: Spring Blades Q: Tools used for sewer rodding include: Answer: porcupine, root saw, square bar cork screw Q: What tool would you use to cut VCP pipe? Answer: Chain Pipe Cutter Q: Which conditions should a gas detection device test for? Answer: Hydrogen sulfide, explosive/flammable gases, oxygen Q: What does "LEL" mean on a gas detection meter? Answer: Lower Explosive Limit Q: The oxygen level alarm normally goes off if oxygen levels are below: Answer: 19.5 percent Q: When developing an S.O.P. for scheduled maintenance of electrical equipment, what program should be addressed as a primary safety guideline? Answer:
The L.O.T.O Program Q: What does L.O.T.O. Stand for? Lock out tag out Q: What document would you require to be referenced when developing an S.O.p. for hazardous substace spill clean up? M.S.D.S. Q: 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 Q: 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) Q: How long do you have to report a category 1 SSO? 2 hours Q: 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 Q: Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause: Answer: odors Q: Flatter sewer line grades may cause added sewer maintenance expense and odor nuisance. This is caused by what? Answer: 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 Q: Clear water in entering a collection system is called what? Answer: infiltration Q: Infiltration can occur in a pipe when the pipe is: Answer:
Q: What are some sewer testing methods? Air, water, mandrill, smoke, dye, lamping Q: What are some hydraulic cleaning methods? Answer: Flushing, balling, kites, parachutes, poly pigs (pigging), high velocity cleaning, jetting, skids and tiger tails. Q: what is the formula for the area of a square? Answer: Length x width Q: The main advantage of using CCTV is what? Answer: You can see and record the length and severity of defective pipe Q: A hazard that may damage a TV camera going through a sewer is: Answer: an offset joint Q: What is the formula for the volume of a cube? Answer: Length x Width x Height Q: What is the formula for the area of a circle? 0.785 x Diameter x Diameter Q: What is the formula for the volume of a pipe? 0.785 x Diameter x Diameter x Length Q: A flow of 650 pgm would be how many mgd?
Q: How can the members of a balling crew communicate with each other? Hand Signals Q: Why must you always know where a cleaning tool is in a sewer? so you know where obstructions or difficulties are encountered Q: emergency stoppages in pipelines may be cleared safely by use of: high velocity cleaners
Q: rodents and insects can be controlled by spraying manholes with an approved pesticide Q: Sources of excessive clear water in a collection system are usually caused by: infiltration from a high water table Q: How many types of common shoring are there? 6 Q: What is the "dirt" formula? distance = rate x time Q: What is the total volume (in gallons) of 1,000 feet of 8-inch pipeline? 2,611 gallons Q: What is the most critical task in operation and maintenance of wastewater collection? Answer: Keeping wastewater flowing through pipes Q: Once enrolled in CIWQS, the "Collection System Questionnaire" must be updated at least every: Answer: 12 Months Q: 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? Answer: 162 gallons Q: What would cause a pump to deliver less than its expected rate of discharge? Answer: clogged impeller Q: Why are wear rings installed in a pump? Answer: To concentrate wear on rings instead of volute and impeller Q: What control devices are used to start and stop pumps? Answer: Floats
28 inches Q: After completing a Temporary Traffic Control setup for your work zone it is a good practice to: Observe how effective your TTC setup is working to control traffic and make the necessary changes Q: When a citizen wants information regarding a maintenance operation you should: Give them as much factual information as you can and offer to help them further Q: Before starting a maintenance operation in a basement located in the backyard of a residence you should: Answer: contact the resident and politely ask permission to enter their backyard Q: Maintenance programs are based on: Answer: Preventative and corrective maintenance principles Q: The goal of preventative maintenance is to? Answer: Avoid breakdowns, severe damage, or harmful depreciation Q: What is the definition of a sanitary sewer system? Answer: Any system of pipes, pump stations, sewer lines, or other conveyances, upstream of a wastewater treatment plant head work comprised of more than one mile of pipes and sewer lines, used to collect and convey wastewater to a publicly owned treatment facility Q: What is the definition of "hydraulic capacity"? Answer: The maximum flow a pipe is expected to function at without creating a back up or discharge Q: What is the minimum velocity in a gravity sewer pipe? Answer:
2 ft/s. This speed prevents the settling of solids, which in turn prevents corrosion and odor build- up Q: What are the access points of a gravity sewer system? Answer: Manholes, Lift stations, Building connections, junction chambers, terminal cleanouts Q: What is an Easement? Answer: The legal right that allows placement of sewer in privately owned property Q: What is the springline? Answer: The theoretical center of the pipe Q: What is the top of the pipe called? Answer: The crown Q: What is the lowest point inside of a pipe called? Answer: The invert Q: What are some examples of rigid pipe? Answer: Vitrified clay pipe (VCP), Concrete pipe, other rigid pipe, cast iron. They can support loads without as much back fill/ side support, but cannot distort without cracking or breaking Q: What are some examples of flexible pipe? Answer: Ductile-iron pipe, steel pipe, thermoplastic pipe (PVC, HDPE, ABS), Orangeburg
Answer: 3 days Q: 550 gallons of sewage overflow and do not reach any surface waters. What category of overflow is this? Answer: Category 3 Q: What does FOG stand for? Answer: Fats, oils and greases Q: What are some examples of additives that can prevent FOG build up? Answer: Chemical degreasers, emulsifying degreasers, enzymes and bacteria Q: What are the pros and cons of balling/kites and parachutes? Answer: Pros:dislodges debris, settled inorganics, and small roots from the sewer line, prevents build-up of grease, mitigates H2S odor by removing slime and can be used in large diameter sewers, kites can collapse to prevent flooding Cons: risk of flooding buildings, doesn't work well on steep grades, makes stoppages worse if stoppage is below the sewer ball. Q: what should you do before cleaning sewers? Answer: Notify downstream treatment plants and pump stations. Q: What are poly pigs used for? Answer: to clean sewer force mains. They are propelled by pressurized water flow Q: What are some cons to hydro jetting?
Answer: Efficiency decreases as pipe size decreases, may require multiple passes to fully remove grease and roots Q: What does SDS stand for? Answer: Safety Data Sheet Q: What does GISO stand for? Answer: General Industry Safety Orders. This is in the Cal/OSHA construction safety orders bookWhat does CSO stand for? and establishes minimum occupational safety and health standards Q: What does MUTCD Stand for? Answer: Manual on Uniform Traffic Control Devices Q: What does ANSI Stand for? Answer: American National Standards Institute Q: What does CSO stand for? Answer: Construction Safety Orders Q: Which of the following means you HAVE to do something? you Shall, you Should, you May Answer: Shall Q: What is the OSHA definition of a competent person? Answer: someone who is capable of identifying existing and predictable hazards in the surroundings,or working
When noise could induce hearing loss Q: When is foot protection required? When there is potential for serious injury to the foot from daily job duties Q: When is hand protection required? When there is the potential for injury or exposure to skin contact from chemicals, infectious agents, heat, cold, abrasive or cutting objects Q: What are the four classes of chemical hazards? Flammability, Toxicity, Corrosivity, Reactivity Q: What is the scale for the level of hazard for chemicals 0 - 4, 0 being minimal and 4 being extreme Q: What precautions should be taken for a chemical with a high flammability hazard? Answer: Keep them stored in approved containers, keep emergency extinguishing agents on hand when handling and near them in storage Q: What are some examples of toxic chemicals? Answer: disinfectants, insect repellent, antifreeze, ammonia, mothballs, motor oils, rat poison, windshield wiper fluid, weed killers Q: What factors create a reactivity hazard? Answer: peroxide-forming chemicals, water-reactive chemicals, self-reactive chemicals, incompatibility. Q: What is corrosivity?
Answer: chemicals that can cause tissue damage (permanent bodily harm to the skin, eyes or respiratory tract) Q: What are the routes of exposure for chemicals? Answer: Inhalation, injection, absorption, ingestion Q: What are the characteristics of a permit required confined space? Answer: A possibly Hazardous Atmosphere, the possibility of Engulfment, Internal Configuration that could trap and asphyxiate an entrant, contains any other recognized health hazard Q: What is the difference between 25% oxygen and 100% oxygen? Answer: Neither are suitable for work, but 25% is an increased fire risk and 100% can cause brain damage Q: What are all 7 steps of LOTO procedure? Answer:
- Identify potential hazards
- notify all affected employees
- turn off/disable/isolate controls
- Lock out all energy control switched (sign and date!)
- Test by turning on controls and accounting for personnel before the safety test
- turn control to OFF
- Perform task (when complete, only the person who tagged out may remove the lock and tag) Q: What is the difference between a trench and an excavation? Answer: A trench is an excavation! Trenches specifically are deeper than they are wide, have a bottom width of 15 feet or less and have a higher potential for wall cave in. Excavations are any man- made work-related functions affected by earth removal or disturbance (i.e. cuts, trenches or deprsions) Q: What is the "pipe zone" in the trench? Answer: the portion of the excavation where the pipe is located. Q: What is the "haunch zone" of an excavation?
Q: What are the components of a temporary traffic control? Answer: Traffic space that allows traffic to pass by activity, temporary lanes with a 10' minimum width and a 5' clearance from the excavation, and tapers that are used in the transition area and moves traffic out of its normal path. Q: What is the minimum length of a taper in a temporary traffic control setup? Answer: 50' Q: How high do your traffic cones need to be if the speed limit around your work zone is 35 MPH? Answer: 18". Cone height must be 18" if speed limit is 30 MPH or less and 28" if the speed limit is 45 MPH or more Q: how many flaggers are REQUIRED to perform a basic flagging operation? Answer: one Q: Why are gasoline and volatile solvents objectionable when present in a sewer? Answer: They produce an explosion hazard Q: You should never attempt to install, maintain, repair or replace electrical equipment panels, controls, wiring or circuits unless Answer: You know what you are doing, are qualified and are authorized Q: What are the different areas of traffic zones? Answer: 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! Q: why should hydrogen sulfide be controlled?
Answer: to protect from corrosion and odors Q: Personnel entering a Permit Required Confined Space must have the following training Answer: entry and rescue Q: To find protective gear before application of a product, you should: Answer: look at the MSDS Q: The gas most commonly associated with septic wastewater is Answer: Hydrogen Sulfide Q: 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: Answer: some dangerous gasses are odorless (for example, carbon monoxide) Q: What are the four conditions necessary to create an explosion? Answer: combustible gas, adequate oxygen, heat and proper mixing of gas and oxygen Q: what does the "transition area" mean in traffic control? Answer: It moves traffic out of its normal path
