CWEA Collection Systems Maintenance (140 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, ...

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? 28 days A person who completes a training program in accordance with the requirements of Title 8, Calif. Code of Regulations, Minimum Guidelines of the Common Ground Alliance is considered a ______________ person Qualified Person You receive a dispatch at 4:30 pm informing you that raw sewage spewing out of a manhole onto the ground and into an adjacent small stream. The caller said the sewer has been overflowing since 2pm. You arrive at 5:15 and find that the spill is overflowing at 166 gallons per minute. You clear the problem after 22 minutes, how many reportable unrecoverable gallons of raw sewage had reached the creek? 36,022 gallons (don't be intimidated by how long these word problems are! Just find the important information and take it one step at a time.) "High priority subsurface installations ae high pressure natural gas pipelines with normal operating pressures greater than 415 kPa gauge, petroleum pipelines, conductors or cables that are potentially hazardous to employees, or the public, if damaged." This paragraph indicates that before the start date of an excavation, what should occur? An agreed upon site visit Temporary traffic control lanes created as part of a Temporary Traffic control Zone setup on a street with a 35 MPH maximum speed limit shall be a minimum width of ______ 10 ft For a nighttime Short Term Stationary Traffic Control Zone setup on low speed/ low volume street, the minimum height of the traffic cones used shall be ________ 28 inches 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 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 Before starting a maintenance operation in a basement located in the backyard of a residence you should: contact the resident and politely ask permission to enter their backyard Maintenance programs are based on: Preventative and corrective maintenance principles The goal of preventative maintenance is to? Avoid breakdowns, severe damage, or harmful depreciation What is the definition of a sanitary sewer system? 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 What is the definition of "hydraulic capacity"? The maximum flow a pipe is expected to function at without creating a back up or discharge What is the minimum velocity in a gravity sewer pipe? 2 ft/s. This speed prevents the settling of solids, which in turn prevents corrosion and odor build-up What are the access points of a gravity sewer system? Manholes, Lift stations, Building connections, junction chambers, terminal cleanouts What is an Easement? The legal right that allows placement of sewer in privately owned property What is the springline? The theoretical center of the pipe What is the top of the pipe called? The crown What is the lowest point inside of a pipe called? The invert What are some examples of rigid pipe? 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 What are some examples of flexible pipe? Ductile-iron pipe, steel pipe, thermoplastic pipe (PVC, HDPE, ABS), Orangeburg What is the name of the testing that confirms your pipe was not bent under pressure from being buried? Mandrel Inspection, also know as "pigging" What is an Operating Range? It is the range in which the pump in a pump station is on What are some examples of level control devices (devices that turn a pump at a pump station on and off)? Bubbler Level Gauge, Mercury/Mechanical Float Switches, Ultra Sonic Sensor What are some common types of valves? Plug, Gate, Butterfly, Ball, Check What is infiltration? water ENTERING a sewer through pipe joints, cracks or voids what is ex-filtration? leakage OUT of pipes through joints, cracks or voids What is a confined space? A space with limited or restricted meas for entry or exit that is NOT designed for continuous employee occupancy. What is the upper oxygen concentration that would indicate a hazardous atmosphere? 23.5% How long do you have to report a category 2 or 3 SSO? 3 days 550 gallons of sewage overflow and do not reach any surface waters. What category of overflow is this? Category 3 What does FOG stand for? Fats, oils and greases What are some examples of additives that can prevent FOG build up? Chemical degreasers, emulsifying degreasers, enzymes and bacteria What are the pros and cons of balling/kites and parachutes? 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. what should you do before cleaning sewers? Notify downstream treatment plants and pump stations. What are poly pigs used for? to clean sewer force mains. They are propelled by pressurized water flow What are some cons to hydro jetting? Efficiency decreases as pipe size decreases, may require multiple passes to fully remove grease and roots What does SDS stand for? Safety Data Sheet What does GISO stand for? 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 What does MUTCD Stand for? Manual on Uniform Traffic Control Devices What does ANSI Stand for? American National Standards Institute What does CSO stand for? Construction Safety Orders Which of the following means you HAVE to do something? you Shall, you Should, you May Shall What is the OSHA definition of a competent person? someone who is capable of identifying existing and predictable hazards in the surroundings,or working conditions which are unsanitary, hazardous, or dangerous to employees AND who has the authorization to take prompt corrective measure to eliminate them what are some characteristics of a competent person? Trained and knowledgeable, can identify soil class, understands the importance of PPE and the SDS, knows how to identify problems What is a qualified person? designated by the employer by reason of training, experience, instruction, previous demonstration of the ability to safely perform all assigned duties, properly licensed with federal, state and local laws and regulations What does SWP stand for? Safe Work Procedures What does PPE stand for? Personal Protective Equipment What does PPE do? Personal Protective Equipment is used to create a protective barrier between a worker and hazards in the workplace. It is critical in everyday operation and protects from burns, chemical and biological exposure, bruises, fractures, abrasions, cuts, punctures, and amputations. What is required when there is a potential injury to the head from falling objects? Head Protection When is hearing protection required? When noise could induce hearing loss When is foot protection required? When there is potential for serious injury to the foot from daily job duties 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 What are the four classes of chemical hazards? Flammability, Toxicity, Corrosivity, Reactivity What is the scale for the level of hazard for chemicals 0-4, 0 being minimal and 4 being extreme What precautions should be taken for a chemical with a high flammability hazard? Keep them stored in approved containers, keep emergency extinguishing agents on hand when handling and near them in storage What are some examples of toxic chemicals? disinfectants, insect repellent, antifreeze, ammonia, mothballs, motor oils, rat poison, windshield wiper fluid, weed killers What factors create a reactivity hazard? peroxide-forming chemicals, water-reactive chemicals, self-reactive chemicals, incompatibility. What is corrosivity? chemicals that can cause tissue damage (permanent bodily harm to the skin, eyes or respiratory tract) What are the routes of exposure for chemicals? Inhalation, injection, absorption, ingestion What are the characteristics of a permit required confined space? A possibly Hazardous Atmosphere, the possibility of Engulfment, Internal Configuration that could trap and asphyxiate an entrant, contains any other recognized health hazard What is the difference between 25% oxygen and 100% oxygen? Neither are suitable for work, but 25% is an increased fire risk and 100% can cause brain damage What are all 7 steps of LOTO procedure? 1. Identify potential hazards 2. notify all affected employees 3. turn off/disable/isolate controls 4. Lock out all energy control switched (sign and date!) 5. Test by turning on controls and accounting for personnel before the safety test 6. turn control to OFF 7. Perform task (when complete, only the person who tagged out may remove the lock and tag) What is the difference between a trench and an excavation? 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) What is the "pipe zone" in the trench? the portion of the excavation where the pipe is located. What is the "haunch zone" of an excavation? Either side of the arched section in the bottom half of the pipe What type of equipment should be used to excavate a broken sewer pipe? Backhoe Name and describe the three soil types Type A: cohesive soils like clay Type B: Cohesive soil that have been disturbed or angular gravel Type C: Granular Soils like sand. These are the least stable What three steps can prevent harm to you whole in a trench? 1. Find the competent person 2. Work in protected areas 3. Check your escape What are some factors that can make soil unstable? Excessively wet, Loose, Excessive roots What are the maximum allowable slopes or all the soil types? Type A: 3/4:1 Type B: 1:1 Type C: 1.5:1 What are some advantages of hydraulic shoring systems? They are light enough to be installed by one worker: from top down They are gauge-regulated to ensure even distribution of pressure along the trench line They can have their trench faces "preloaded" to use the soils natural cohesion to prevent movement They can be adapted easily to various trench depths and widths What are the components of a temporary traffic control? 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. What is the minimum length of a taper in a temporary traffic control setup? 50' How high do your traffic cones need to be if the speed limit around your work zone is 35 MPH? 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 how many flaggers are REQUIRED to perform a basic flagging operation? one