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CWEA Collection Systems Maintenance
QUESTIONS WITH 100% CORRECT
ANSWERS. NEW UPDATE!!
Why are gasoline and volatile solvents objectionable when present in a sewer? -
CORRECT ANSWER -They produce an explosion hazard
You should never attempt to install, maintain, repair or replace electrical equipment
panels, controls, wiring or circuits unless - CORRECT ANSWER -You know what
you are doing, are qualified and are authorized
What are the different areas of traffic zones? - CORRECT 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!
why should hydrogen sulfide be controlled? - CORRECT ANSWER -to protect
from corrosion and odors Personnel entering a Permit Required Confined Space must have the following training
- CORRECT ANSWER -entry and rescue
To find protective gear before application of a product, you should: - CORRECT
ANSWER -look at the MSDS
The gas most commonly associated with septic wastewater is - CORRECT
ANSWER -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: - CORRECT
ANSWER -some dangerous gasses are odorless (for example, carbon monoxide)
What are the four conditions necessary to create an explosion? - CORRECT
ANSWER -combustible gas, adequate oxygen, heat and proper mixing of gas and
oxygen
what does the "transition area" mean in traffic control? - CORRECT ANSWER -It
moves traffic out of its normal path what elements should be considered to improve worker safety in High speed Temporary
Traffic control Zones? - CORRECT ANSWER -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? - CORRECT ANSWER -Traffic Control Plan, By-Pass
connections, and Spill containment
What tools are used with a power rodder? - CORRECT ANSWER -Spring Blades
Tools used for sewer rodding include: - CORRECT ANSWER -porcupine, root
saw, square bar cork screw
What tool would you use to cut VCP pipe? - CORRECT ANSWER -Chain Pipe
Cutter
Which conditions should a gas detection device test for? - CORRECT
ANSWER -Hydrogen sulfide, explosive/flammable gases, oxygen
What does "LEL" mean on a gas detection meter? - CORRECT ANSWER -Lower
Explosive Limit
The oxygen level alarm normally goes off if oxygen levels are below: - CORRECT
ANSWER -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? - CORRECT
ANSWER -The L.O.T.O Program
What does L.O.T.O. Stand for? - CORRECT ANSWER -Lock out tag out
What document would you require to be referenced when developing an S.O.p. for
hazardous substace spill clean up? - CORRECT ANSWER -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? - CORRECT ANSWER -Placement of the blower
and a weather forecast
protective shoring systems options include: - CORRECT ANSWER -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: -
CORRECT ANSWER -keeping wastewater flowing through pipes
What is minimum design velocity for a sewer? - CORRECT ANSWER -a
minimum of two feet per second
Vitrified clay pipe is what type of pipe? - CORRECT ANSWER -Rigid
What is another name for a manhole? - CORRECT ANSWER -Maintenance hole
What are the four parts of a manhole? - CORRECT ANSWER -lid, cone, barrel
and base
What are some sewer testing methods? - CORRECT ANSWER -Air, water,
mandrill, smoke, dye, lamping
What are some hydraulic cleaning methods? - CORRECT ANSWER -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? - CORRECT ANSWER -Length x
width
The main advantage of using CCTV is what? - CORRECT ANSWER -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: - CORRECT
ANSWER -an offset joint
What is the formula for the volume of a cube? - CORRECT ANSWER -Length x
Width x Height
What is the formula for the area of a circle? - CORRECT ANSWER -0.785 x
Diameter x Diameter
What is the formula for the volume of a pipe? - CORRECT ANSWER -0.785 x
Diameter x Diameter x Length
A flow of 650 pgm would be how many mgd? - CORRECT ANSWER -0.
How can the members of a balling crew communicate with each other? - CORRECT
ANSWER -Hand Signals
Why must you always know where a cleaning tool is in a sewer? - CORRECT
ANSWER -so you know where obstructions or difficulties are encountered
emergency stoppages in pipelines may be cleared safely by use of: - CORRECT
ANSWER -high velocity cleaners
rodents and insects can be controlled by - CORRECT ANSWER -spraying
manholes with an approved pesticide Sources of excessive clear water in a collection system are usually caused by: -
CORRECT ANSWER -infiltration from a high water table
How many types of common shoring are there? - CORRECT ANSWER -
What is the "dirt" formula? - CORRECT ANSWER -distance = rate x time
What is the total volume (in gallons) of 1,000 feet of 8-inch pipeline? - CORRECT
ANSWER -2,611 gallons
What is the most critical task in operation and maintenance of wastewater collection? -
CORRECT ANSWER -Keeping wastewater flowing through pipes
Once enrolled in CIWQS, the "Collection System Questionnaire" must be updated at
least every: - CORRECT ANSWER -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? - CORRECT ANSWER -162 gallons
What would cause a pump to deliver less than its expected rate of discharge? -
CORRECT ANSWER -clogged impeller
Why are wear rings installed in a pump? - CORRECT ANSWER -To concentrate
wear on rings instead of volute and impeller
When a citizen wants information regarding a maintenance operation you should: -
CORRECT ANSWER -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: - CORRECT ANSWER -contact the resident and politely
ask permission to enter their backyard
Maintenance programs are based on: - CORRECT ANSWER -Preventative and
corrective maintenance principles
The goal of preventative maintenance is to? - CORRECT ANSWER -Avoid
breakdowns, severe damage, or harmful depreciation
What is the definition of a sanitary sewer system? - CORRECT 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
What is the definition of "hydraulic capacity"? - CORRECT ANSWER -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? - CORRECT ANSWER -
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? - CORRECT ANSWER -
Manholes, Lift stations, Building connections, junction chambers, terminal cleanouts
What is an Easement? - CORRECT ANSWER -The legal right that allows
placement of sewer in privately owned property
What is the springline? - CORRECT ANSWER -The theoretical center of the pipe
What is the top of the pipe called? - CORRECT ANSWER -The crown
What is the lowest point inside of a pipe called? - CORRECT ANSWER -The
invert
What are some examples of rigid pipe? - CORRECT 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
What are some examples of flexible pipe? - CORRECT ANSWER -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? - CORRECT ANSWER -Mandrel Inspection, also know as
"pigging"
What is an Operating Range? - CORRECT ANSWER -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)? - CORRECT ANSWER -Bubbler Level Gauge,
Mercury/Mechanical Float Switches, Ultra Sonic Sensor
What are some common types of valves? - CORRECT ANSWER -Plug, Gate,
Butterfly, Ball, Check
What is infiltration? - CORRECT ANSWER -water ENTERING a sewer through
pipe joints, cracks or voids
what is ex-filtration? - CORRECT ANSWER -leakage OUT of pipes through
joints, cracks or voids
What is a confined space? - CORRECT ANSWER -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? -
CORRECT ANSWER -23.5%
How long do you have to report a category 2 or 3 SSO? - CORRECT ANSWER -
3 days 550 gallons of sewage overflow and do not reach any surface waters. What category of
overflow is this? - CORRECT ANSWER -Category 3
What does FOG stand for? - CORRECT ANSWER -Fats, oils and greases
employees AND who has the authorization to take prompt corrective measure to eliminate them
what are some characteristics of a competent person? - CORRECT ANSWER -
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? - CORRECT ANSWER -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? - CORRECT ANSWER -Safe Work Procedures
What does PPE stand for? - CORRECT ANSWER -Personal Protective
Equipment
What does PPE do? - CORRECT ANSWER -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? -
CORRECT ANSWER -Head Protection
When is hearing protection required? - CORRECT ANSWER -When noise could
induce hearing loss
When is foot protection required? - CORRECT ANSWER -When there is
potential for serious injury to the foot from daily job duties
When is hand protection required? - CORRECT ANSWER -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? - CORRECT ANSWER -
Flammability, Toxicity, Corrosivity, Reactivity
What is the scale for the level of hazard for chemicals - CORRECT ANSWER -0-
4, 0 being minimal and 4 being extreme
What precautions should be taken for a chemical with a high flammability hazard? -
CORRECT ANSWER -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? - CORRECT ANSWER -
disinfectants, insect repellent, antifreeze, ammonia, mothballs, motor oils, rat poison, windshield wiper fluid, weed killers
What factors create a reactivity hazard? - CORRECT ANSWER -peroxide-
forming chemicals, water-reactive chemicals, self-reactive chemicals, incompatibility.
What is corrosivity? - CORRECT ANSWER -chemicals that can cause tissue
damage (permanent bodily harm to the skin, eyes or respiratory tract)
What are the routes of exposure for chemicals? - CORRECT ANSWER -
Inhalation, injection, absorption, ingestion
What are the characteristics of a permit required confined space? - CORRECT
ANSWER -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? - CORRECT
ANSWER -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? - CORRECT ANSWER -1. 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)
What is the difference between a trench and an excavation? - CORRECT
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)
What is the minimum length of a taper in a temporary traffic control setup? -
CORRECT ANSWER -50'
How high do your traffic cones need to be if the speed limit around your work zone is 35
MPH? - CORRECT 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 how many flaggers are REQUIRED to perform a basic flagging operation? -
CORRECT ANSWER -one
