wastewater C1 exam ch 5b-14
What additional equipment is needed when working with scooters?
A 1,000-2,000-gallon tank truck; debris traps, control lines, and storage reel; roller cable guides; safety equipment; Upper and lower manhole jacks.
What equipment is necessary for air testing when searching for a specific leak?
A distance marker system; an air compressor and an air pressure control console; two plugs with inflation boots---one with at least one through-plug air attachment; two winches to pull the plugs and hoses through the pipe.
What is total dynamic head?
A measurement of the amount of energy that a pump must develop to move a liquid.
What takes place during a bypass pump operation?
A plug placed in the upstream manhole causes flow to surcharge in the manhole.
What is an important step when starting a repair?
After about 12 inches of dirt have been removed, use a rod or probe to locate possible water or gas lines in the area being excavated.
what information should be included in a collection system inventory?
Age of system, condition of system, size of the system, type of the system
Cavitation problems are caused by which actions or conditions?
Air leaks on the suction side of the pump; excessive tip speed of the impeller; high friction losses in suction pipes; restrictions in the suction line;
Larger, more complex programmable logic controller (PLC) systems are designed to control which systems or functions in the pump station?
Alarm systems; graphic displays of pump station components; Remote process control systems; Variable frequency drives;
Which safety precautions should be taken before and during a scooter operation?
Allow time for setting up and removing larger scooters when preparing work schedules; Always examine the equipment cables before starting and when finishing cleaning each section to avoid having a cable break when the scooter is in the middle of a sewer; Determine if a buildup of water in the working manhole and in the sewer being cleaned will flood a residence or business; Examine the manhole structure to be sure the sewer scooter can be installed.
A motor service factor greater than 1.0 allows for which item?
Allows an added margin of safety to account for higher voltage or frequency variations.
What are some of the steps in cutting pavement?
An assistant opens the upstream and downstream manholes to observe and record the amount of flow and the depth to the top of the pipe; Crew members connect and safety pin the air hose to prevent it from whipping around if it uncouples from the pavement breaker; Crew members measure the distance from manhole to manhole and other important distances to verify the accuracy of the job sketch; Crew members verify the repair locations by measuring the distance from the designated manhole; the repair crew marks off the area of the pavement to be cut with a chalk line
What is a relay?
An electrical device in which an input signal, usually of low power, is used to operate a switch at controls another circuit, often of higher power.
What is "ground"?
An expression representing an electrical connection to earth or a large conductor that is at the earth's potential or neutral voltage
Why should an electric motor service factor above 1.0 never be relied upon to accommodate continuous loads?
Because such use will quickly degrade the insulation system.
Why should a pump never be allowed to run dry?
Because the water is a lubricant between rings and impeller.
Before air testing pipes, why should the sewer line be thoroughly cleaned to remove any sand, silt, or other debris?
Because these materials may prevent the inflatable plugs from passing through the line and making a good seal against the pipe wall.
Why are dynamic heads greater than static heads?
Because they include the static heads plus the friction losses in the suction and discharge pipes.
If a check valve is supplied on a pump discharge pipe, this valve can become a problem when which condition occur?
Stringy material gets caught on the flapper and it stays in the open position.
Why are the electrical control panels, motors, ventilation equipment, necessary station controllers, and auxiliary equipment housed on the upper floor of the dry well?
To provide protection to station equipment in case of a broken valve or fitting or a leak.
Air release and vacuum relief valves are installed on force mains for which main purpose?
To release accumulated entrained air and gases.
Under what conditions is flexible shafting particularly suited?
To transmit power into areas where moisture, dust, corrosive, or explosive conditions, or flooding would adversely affect the driving machinery.
When does peak demand in a multiple-pump station usually occur?
When all pumps are operating at peak flow conditions.
Under what conditions would it be necessary to construct sewer lines in a tunnel?
When lines are to deep for trench excavations or the surface conditions do not allow an open construction.
If a sewer line does not pass the water exfiltration test, how is the search for specific leaks usually conducted?
With air pressure
Which maintenance tasks must be performed on a sectional rodder?
check the stacking of the rod on the reel; inspect the drive chains to the sprockets; inspect the rod hose guides; inspect the tension of the drive head chain; tighten the rod couplings as necessary.
The material in a sewer is removed by what types of clearing actions caused by a mechanical cleaning device or machine?
cutting action; pulling action; pushing action; scraping action;
Which lift station operation and maintencance costs must be recorded?
electrical power costs, fuel costs, such as gasoline, diesel, and natural or bottled gas, operational and maintenance costs on the basis of labor, vehicles, equipment, and supplies; scheduled preventive maintenance and repair costs on the basis of labor, parts, and shop expenses; Unscheduled repair costs, including responding to the station telemetry alarms and power failures.
Why do mechanical seals need water?
For lubrication and to dissipate heat generated at the faces of the seal.
Excessive pump impeller clearances can cause which problem?
Frequent plugging and loss of pump capacity.
Upon returning to the maintenance yard, what should be discussed with your supervisor?
Future or potential problems
Which items are limitations of electrode controllers used to sense or detect water levels?
Grease or slime can cover an electrode, thus preventing good conductivity and causing intermittent or unreliable operation; Rags and debris can wrap around electrodes and altar desired start and stop water levels and sequences of pumps;
High water velocities used by hydraulic sewer cleaning methods can effectively remove which items from sewers?
Grease; roots; sand.
Equipment for mechanical compaction of backfill material consists of which devices?
Hand-held air tampers; Gasoline-driven impactors; Plate vibrators; vehicle-mounted impactors; vibrating rollers
What causes offset joints and sagged pipes?
Heavy traffic loading above the pipe; pipes settling over time creating holes for roots, debris, and groundwater to enter the collection system; poor bedding and bedding and backfill installation practices during construction; seismic activity and dramatic changes in ground water elevations
Which factors are common causes of odor problems in collection systems?
High temperatures; long transmission lines; low-velocity flows; poorly maintained collection system
What are some of the topics covered in the OSHA Technical Manual (OSHA Instruction TED 01-00-015)?
Shoring types; soil mechanics; special health and safety considerations
The release of hydrogen sulfide can cause which problems?
Corrosive conditions; obnoxious odors; toxic atmospheres;
When inspecting the wet well in a newly constructed lift station, which questions should the operator consider?
Are there enough openings in a sanitary wet well for washing sump walls and floor?; Can the wet well be ventilated easily?; What kinds of conditions will be encountered when you attempt to clean the sump or remove grit?; What type and size of ladder will you need for access?;
Why should motor frames and all electric tools and equipment enclosures be connected to ground?
As a safety precaution that protects you and the motors, tools, and equipment
What safety equipment is important for operating power bucket machines?
Atmospheric monitoring equipment; Barricades and traffic signs; flags and cones; Safety harness, lifeline, and tripod; Self-contained breathing apparatus( SCBA)
In order to select the proper pump or pumps for a lift station, the design engineer must carefully estimate flows under which important operating conditions?
Average daily dry weather flow; peak wet weather flow; seasonal dry weather flow;
Which provisions must be made to ensure the continuous operation of the lift station during power failures and equipment failures in the lift station?
Backups for station equipment; Multiple pumps; portable lifts; standby portable generators;
Which items are basic rules of operation that should be observed when running rodding machines?
Be sure that forward pressure is adjusted to low levels to avoid bending or breaking the rod; do not allow any bends or S-curves to remain in the guide hose; do not jam the rod into and obstruction; do not rotate the rod in on position for an extended period; When torque builds up, retract the tool from the material to relieve the torque and then return to the material.
When handling or storing oils and greases, which precautions should be followed?
Be sure to keep any spills wiped up; Make sure that all the lids are tight on their containers; make sure the storage area does not create a fire hazard; Post "NO SMOKING" sings outside the building;
To inspect a pump shaft, which major areas should be examined in accordance with the manufacturer's recommendations?
Bearing fits; coupling end; impeller end; stuffing box area;
Why are air tests better than water tests for sewers in steep terrain?
Because of excessive water pressure created at the lower end of the sewer line.
Which factors can cause pump misalignment?
Bolts can loosen; foundations can settle unevenly;
A megger or megohmmeter is used for checking the insulation resistance on which items?
Branch circuit wiring; bus bar systems; feeders; generators; motors;
What are the causes of stoppages in sewers?
Broken pipe; debris; grease; joint failure; roots
Misalignment is one of the most frequent causes of vibration problems in lift station motors and pumps and it frequently causes which additional problems?
Broken shafts; damage to motor windings; destruction of the rotor element in the motor; premature failure of bearings; premature failure of mechanical seals and packing;
Ensuring consistent procedures for performing lift station maintenance work is accomplished by which means?
By an evaluation of the completed work by supervisors; by providing the operators with necessary tools; by providing operators with proper training; by providing the operators with written instructions;
How is wastewater lifting accomplished in lift stations?
By centrifugal pumps; by diaphragm pumps;
In regions with high humidity, how can condensation in lift stations be kept under control?
By dehumidifiers
How is proper alignment of pumps and motors accomplished?
By the use of wedges and shims under the pump or motor.
Which steps are part of a final inspection of a wastewater collection system construction project?
Check that surface restoration and cleanup are completed; Compile a detailed list of items of work still to be completed; Conduct a final visual inspection of sewer lines for indications of grade misalignment; conduct a walk-through inspection to verify that all the construction tools and debris have been removed; correct all defects
Which steps are port of the basic method for joining pipe with resilient joints?
Check the alignment and grade of pipe; guide the spigot end of the pipe into the bell; inspect the joint for proper gasket seating; lubricate the gasket and seat it on the pipe.
Which daily tasks should be included on a typical pump maintenance schedule?
Check the motor temperature; check the packing and seals for leaks; check the piping connections for leaks or corrosion; check the pump and motor bearings; check the pump for noise when running;
Which maintenance tasks should be performed daily when operating a high-velocity cleaner?
Check the stacking of the rod on the reel; inspect the drive chains to the sprockets; inspect the rod hose guides; inspect the tension of the drive head chain; tighten the rod couplings as necessary
Lift station electrical equipment protective devices may consist of which devices?
Circuit breakers; fuses; grounds; motor and circuit overload devices;
High-velocity cleaners are most effective at which tasks?
Cleaning lines of silt, sand, sludge, and other light debris; clearing roots; opening stoppages; removing light grease and detergents; washing manholes and wet wells;
What is the assigned task of collection system preventive maintenance crews?
Cleaning sewers to prevent stoppages and odor complaints.
What site preparation needs to be completed before excavation work can begin?
Clearing grass and brush; installing sediment control devices and storm sewer inlets; removing obstacles, pavement, and existing structures; staging equipment, tools, and materials at the job site
When backfilling a trench, which of the following is correct?
Compact the bedding material until it completely covers the pipe by 6-12 inches.
Which types of sewer pipe should be protected from movement or breakage until the trench is backfilled after it has been laid to a true grade and alignment?
Concrete pipe; Rigid types of pipe; small-diameter pipe; small-diameter pipe; vitrified clay pipe (VCP)
What are the advantages of mechanical seals?
Continual adjusting, cleaning, or repacking are not required; they last from three to four years without having to touch them, resulting in labor savings; Usually, there is no damage to the shaft sleeve when they need replacing;
Which serious problems are caused by hydrogen sulfide in collection systems?
Corrosion and possible collapse of sewers, structures, and equipment; flammable and explosive atmosphere under certain circumstances; loss of capacity in the sewer;
What problems do drop lines in manholes correct?
Corrosion; difficult working conditions; odors; splashing
Which common lift station conditions can affect the performance and the life of electrical equipment?
Corrosive atmospheres; heat and cold; humidity; vibration; water and dust;
Which items are sources of sewer line damages and stoppages?
Damage by the public or other utility agencies; improper taps; roots
What are the reasons why a pump will fail to function?
Debris jamming a check valve; debris plugging an impeller; malfunction in the electrical system; malfunction in the mechanical system;
A well-prepared sewer construction inspector should have the ability to perform which tasks?
Determine if construction materials conform to specifications; Establish and maintain cooperative working relations with those contacted in the course of work; keep accurate records, gather data, and prepare accurate reports; read and interpret plans, specifications, ordinances, and regulations applicable to wastewater collection system construction.
Which factors determine piston pump capacity?
Diameter of the piston or plunger; Length of the stroke; Number of fluid cylinders; number of strokes per minute;
Which items of work should be inspected during a pipe laying operation?
Each sewer pipe in place must be closely inspected for any visible defects such as a cracked bell or an unseated gasket; Sewer pipe bedding placed to prescribed depth and grade; Sewer pipe laid to grade with joints made in accordance with manufactures instructions; The interior of the pipe should be free of bedding materials, dirt, boards, or other debris that could create problems in the wastewater collection system.
Power rodders can be used for which purposes?
Emergency clearing of stoppages; routine preventive maintenance; scheduled clearing of grease deposits; scheduled clearing of roots; threading cable for bucket machines.
Which precautions must be taken to protect operator health and safety when working in dry wells?
Ensure regular preventive maintenance activities are performed to minimize any engulfment hazard; Install ventilating fans that are activated as soon as the light switch is turned on; Monitor the fan exhaust for hazardous atmospheric conditions; Provide for air monitoring capability;
Which items should be checked by operators when troubleshooting cavitation problems?
Examine the wet well level and ensure the pump is not sucking in air or pumping to low before shutting off; inspect the bottom of the wet well for grit deposits; inspect the suction line to make sure it is not partially plugged with grease or foreign material such as sand, grit, and rocks; look for places where air could be leaking in at the packing; make sure the suction valve is all the way open;
T or F: A high suction lift will dramatically increase centrifugal pump discharge volume.
False
T or F: A rod driven into dry ground is very effective as a ground for electrical tools and equipment.
False
T or F: Electric motors are the machines most commonly used to convert mechanical energy into electrical energy.
False
T or F: Every centrifugal pump operates at 100 percent efficiency.
False
T or F: Few communities have regulations to control stormwater runoff to minimize sediment and debris from entering local water ways.
False
T or F: Heavy equipment operators normally dig trenches from the high end to the low end(i.e, the trench slopes away from the equipment) to stay on grade.
False
T or F: If the pump shaft rotation is in the wrong direction, the amp reading will be higher than the motor rating due to more work being done by the pump by rotating backwards.
False
T or F: Lift station pumps are designed to move the wastewater with a maximum of energy consumption.
False
T or F: Lift station wet well installations typically have limited access to the pumping equipment and if anything goes wrong, they can be easy to repair.
False
T or F: Location and design of the lift stations depend on economic factors that are analyzed by operators.
False
T or F: Most mechanical seals are designed to run dry.
False
T or F: Native backfill material is the material excavated from a sewer trench and is not the best choice for use as backfill.
False
T or F: Sewer pipe must be laid by machine.
False
T or F: Submersible pump motors are an integral part of the pump and are external to the pumping unit.
False
T or F: T or F: If a pump has a mechanical seal, there should be some leakage(approximately one drop per second).
False
T or F: Viscosity increases with temperature rise because oil becomes thinner as it warms.
False
T or F: When megging a motor and a high reading is observed, the motor winding insulation is breaking down.
False
T or F: When reviewing lift station prints and specifications, it is the operator's job to tell the engineer how to design the facility.
False
Before starting repair of a main line, the supervisor must perform which tasks?
Identify potential problems; make a preliminary field investigation; obtain necessary permits; plan the repair job
Participation by the operator during the planning and design of a lift station will result in which positive contributions?
Identify problems in existing stations to ensure that those problems are eliminated in new stations; increase operator safety; make the station more reliable, reducing the number of emergency call outs, provide for sufficient space to safely operate and maintain the facility; reduce the maintencance required, including emergency maintenance (EM), corrective maintenance (CM), and preventive maintenance (PM);
Why should operators meg motors and wiring after a pump station has been flooded?
If the insulation is wet, excessive current could be drawn and cause the pump motors to "kickout" (shutoff)
Pumps are used by collection system operators in which capacities?
In backhoes as hydraulic pumps; in high-velocity cleaners for cleaning collection systems; to dewater trenches or excavations while installing pipe-lines or repairing them; to lift wastewater from a low elevation to a higher elevation;
Magnetic starter maintenance consists of at least an annual inspection of the equipment, including which tasks?
Inspect and replace, if necessary, the stationary and movable contacts; Inspect line and load conductors for evidence of high temperatures as indicated by bubbling or discoloring of the wire insulation; tighten all line and load connection terminals, including all low-voltage terminals (control, auxiliary switches);
Which items are important facts about transite pipe?
It is also called asbestos-cement (AC) pipe; It is cement pipe made with asbestos fibers to improve pipe strength; it might release harmful asbestos fibers into the air if it is crushed, cut, or trapped
What is the first task when preparing a lubrication schedule?
Make a list of everything that needs lubrication.
As final point of inspection of a new lift station, which housekeeping items are needed to maintain an acceptable station that will satisfy the public or the surrounding area?
Make sure all fences are complete and have a neat appearance; make sure all openings on the building roof are adequately covered or louvered; Make sure all paved areas have proper drainage; make sure metal chain-link fences are grounded in case a power line drops across them;
Why is asbestos cement (AC) pipe no longer in favor with the building industry?
It was found that asbestos is a leading contributor to asbestosis or other forms of cancer.
What are the advantages of using mechanical seals to seal the stuffing box area of a centrifugal pump?
Leakage of raw wastewater into the pump station out of the top of the stuffing box is eliminated; Less power consumption; less wear on the pump shaft or shaft sleeve; Mechanical seals are virtually maintenance free with no adjustment required or normally available; When installed and operated properly, mechanical seals will last for several years before replacement is required;
Controls to start, stop, or change pumping rates in a station are used to tell the pumps when to operate based on which factors?
Level of wastewater to be pumped from the wet well.
Where should all manhole gauges and valve be?
Located outside the manhole to avoid injury to those reading gauges or adjusting valves if a plug should be blown out of the pipe.
Pumping wastewater with entrained air can cause which problems?
Loss of efficiency; reduction of pump capacity; rough and noisy operation; vibration; wasted power
Who inspects and certifies that the manufacturer of large-diameter pipes is testing representative samples of pipe?
Many sewer utilities send an observer to manufacturing plants to observe and certify that the manufacturer is testing representative samples of pipe to demonstrate that the specification requirements are being met.
What is sheeting?
Metal plates, plywood sheets, or wooden planks used in excavations to hold back soil and prevent cave-ins.
What are the differences between mortar and grout?
Mortar often contains lime instead of gravel; The size of the aggregates in grout and mortar are different.
What should be done when manual reset solves an electrical failure temporarily but the reset or breaker switches trip again after a few moments of lift station operation?
Perform a thorough inspection of the pumping equipment, find the problem, and correct the situation before attempting to restart the pumps.
In referring to the actual maintenance or operational types of lift station visits, which types of visits and activities are included? Visits to:
Perform scheduled routine preventive maintenance on the equipment and the station; respond to a lift station alarm or emergency condition to restore the station to operation;
What are the considerations for selecting a nozzle?
Objective of the operation, type of the cleaning or stoppage, type of environment, type of traffic control
Most electrical equipment used in wastewater collection systems is labeled with nameplated information indicating which items?
Proper voltage and allowable current in amps
Which items are important safety considerations when performing underground sewer repair?
Protecting operators from injury; Protecting operators from cave-ins; Protecting operators from falling objects; Protecting operators from toxic, irritating, or flammable and explosive gases; Protecting operators from traffic.
What should be done before using an ammeter to record the current or amps in a circuit?
Read the motor nameplate data and find what the amperage reading should be for the particular motor or device you are testing.
Which tools are required for repairing service lines?
Round point shovel; six-foot digging bar;square point shovel; the wonder bar
What is locked-rotor current?
The current drawn by the motor the instant the power turned on while the rotor is still at rest.
What is voltage?
The electrical pressure available to cause a flow of current(amperage) when an electric circuit is closed;
What is sewer pipe bedding?
The material upon which the pipe is laid and which provides firm support around the pipe walls.
Which items are essential for effective grounding?
The path to ground has ample current-carrying capacity to conduct safely any currents liable to be imposed on it; the path to ground has impedance(opposition to current flow) sufficiently low to facilitate the operation of the overcurrent devices in the circuit; The path to ground has impedance(opposition to current flow) sufficiently low to limit the potential above ground; The path to ground is permanent and continuous;
What is an analog readout?
The readout of an instrument by a pointer (or other indicating means) against a dial or scale.
What should be done if a leak develops from the gland of a mechanical seal?
The seal may require relapping or it may have to be replaced.
What is the net positive suction head?
The total absolute suction head at the inlet of the pump mines the vapor pressure of the water.
What could be a problem with flat-bottomed manholes?
They do not have channels through the bottom.
What are the functions of flexible couplings?
To absorb shock loads and pulsations; To accommodate the slight shaft misalignment's that develop in service; to dampen vibrations; to decrease wear on shaft bearings and driven equipment; to transmit power efficiently and effectively from one shaft to the other.
Why are new wastewater collection system construction materials and procedures inspected?
To alert the design engineers to any modifications of plans required to meet unexpected conditions found during construction; to ensure compliance with the plans, specification, and safety regulations governing the work; to minimize the need for future maintenance of the wastewater collection system that is mostly buried; to provide critical records of the construction progress and as-built drawings of the wastewater collection system that is mostly buried
Why is it necessary for operators to read, understand, and interpret centrifugal pump curves?
To correctly diagnose problems and ensure that the hydraulic systems are operating at maximum efficiency
Why should a tailgate safety and preconstruction meeting be held?
To discus safety and work assignments with all personnel assigned to the project.
Why compact the initial backfill under the bottom of the pipe?
To eliminate voids in this critical area of pipe support according to the bedding specifications.
Why must manholes be maintained and kept in working condition?
To ensure bottom flow channels are smooth; to ensure frames and covers are secure and the top is at the same grade as the surrounding street or other surface; to keep the manhole cone and barrels free from cracks and deterioration from corrosion; To provide easy access for operators to the collection system.
Operators must be able to read, understand, and interpret centrifugal pump curves in order to perform which tasks?
To evaluate pump repairs; to evaluate pump replacement needs; to troubleshoot existing pump systems; to verify pump operating conditions;
Which of the following items are objectives of cleaning equipment maintenance?
To increase the efficiency and safety of maintenance operations; to prevent equipment failure on the job; to prolong the life of the equipment.
When repairing a main line, why should a mirror and flash-light be lowered into the trench after the broken pipe has been removed from the trench?
To inspect the main line for cracks, roots, and bad taps and joints in both directions from the cut.
Why are mechanical seals always flushed in some manner?
To lubricate the seal faces and minimize wear.
Why should the equipment located in the lift station wet well be minimized?
To make accessibility and maintenance easier for the operator.
T or F: A protruding tap may be avoided by cutting a hole in the main line with a core drill and installing a saddle.
True
T or F: A tee-shaped channel causes the flow to run directly into the main channel flow, called deadheading.
True
T or F: Always be sure that motor belt guards are in place and covering all exposed portions of belts whenever the equipment is operating.
True
T or F: Always change the pump lubricant before it is too worn or too dirty.
True
T or F: An advantage of using pressurized air to test sewers is that air can leak through a smaller crack than wastewater, which helps find vapor leaks that may attract roots.
True
T or F: Be sure that the pump and motor flanges are parallel vertically and axially and that they are kept that way.
True
T or F: By keeping accurate cost records, the costs for operating and maintaining a lift station provide the information needed to prepare next year's annual budget.
True
T or F: Check valves in the discharge piping for each pump prevent backflow through the pump back into the wet well.
True
T or F: Effective equipment and sewer maintenance is the key to successful system performance.
True
T or F: Entrained air in wastewater frequently contributes to pump cavitation, which can rapidly destroy the impeller or wear rings and other pump components in the liquid end of the pump.
True
T or F: Excessive greasing can cause as much damage to motor bearings as undergreasing.
True
T or F: Extreme care must be taken to protect underground utilities when you are excavating near them.
True
T or F: Failure to adhere to motor nameplate guidelines frequently results in excessive heat buildup, damaged motor insulation, and eventual motor failure.
True
T or F: If a pump loses its suction and is allowed to operate, the pump could be seriously damaged.
True
T or F: If the air test fails, one or both of the seals made by the plugs may be defective.
True
T or F: If the protective device on an electric motor blows or trips, the potential source of the problem should be investigated, identified, and corrected.
True
T or F: Once a lift station preventive maintenance program has been defined, there must be a procedure that notifies the crew to perform the required maintenance at the station.
True
T or F: Proper tools, equipment, and materials to do the job must be on the repair crew's truck before they drive to the job site.
True
T or F: Pump stations may have provisions for connecting a portable standby power system, which is an engine-driven generator that can be towed to the site and plugged in.
True
T or F: Spot liners and pipe bursting are two trenchless techniques used by collection system agencies to replace failing sewer lines.
True
T or F: The approach to solving any problem must be made with logic and caution.
True
T or F: The maintenance operator should be able to explain how the equipment is supposed to work and what it is doing or is not doing when it fails.
True
T or F: The submersible pump motor is waterproof and mechanical seals are used for keeping out the water being pumped.
True
T or F: Turn off the circuit breaker when using a megger.
True
T or F: Underground sewer repair work can be very dangerous.
True
T or F: When a manhole settles, sewers connected to the manhole may crack or break and the connection joints may develop leaks.
True
T or F: When laying large-diameter pipe, care must be used to provide uniform support under the entire length of pipe.
True
T or F: When preparing to repair underground sewers, all underground utilities should be located and marked and some thought should be given to overhead utility conflicts.
True
What is a typical feature of a small-diameter pipe?
Up to 15 inches in diameter
When arriving at the job site, what is the first task of the repair crew?
Verifying that the address and map location are correct.
