EVALUATION 2026 QUESTION BANK FULL
SOLUTION SET
◉ The term pathogenic means.
Answer: Capable of causing disease
◉ The minimum separation between sewer lines and potable water
lines is.
Answer: Ideally, 9 feet. At least 2 feet above and 4 feet horizontal.
Separate trenches.
◉ A licensed wastewater operator is a professional.
Answer: consistently does best job possible, practices personal
safety, strives to improve job knowledge, strives to keep the plant
and collection system in the best appearance and working order
◉ An important step in testing a sample for Total Suspended Solids
is.
Answer: Filtering a sample
◉ The Biochemical oxygen Demand (BOD) of a sample is based on.
,Answer: Measuring the dissolved oxygen (DO) used
◉ The results of Biochemical Oxygen Demand (BOD) sample taken
at a treatment plant tells the operator.
Answer: How the plant was operating 5 days ago
◉ Which of the following are dangerous gasses that are likely to be
present in lift stations and manholes?.
Answer: Natural gas, gasoline fumes, hydrogen sulfide and carbon
monoxide
◉ A preferred hydraulic method of cleaning sewer lines is.
Answer: Hydro Jet Cleaner
◉ Ways to reduce bad odors coming from a collection system.
Answer: routinely cleaning slow running or low flow lines, adding
chlorine or hydrogen peroxide to the collection system
◉ Types of pipe that are commonly used in wastewater collection
system.
Answer: Ductile iron, concrete pipe, vitrified clay, PVC, ABS
◉ Before entering a confined space a worker should.
,Answer: Use approved monitoring device and check for the presence
of dangerous gasses, ventilate the space with a blower, wear a safety
harness and attach a life line
◉ A properly designed and operated primary sedimentation tank
should remove _____ percent of incoming BOD.
Answer: 30-40%
◉ Devices that may be used to determine the level of sewage in a lift
station.
Answer: air bubbler, floats, electrodes, Acoustic (sonic)
◉ What is the most important role of aerobic bacteria in the
treatment of wastewater?.
Answer: decompose organic matter
◉ The hydraulic loading of a trickling filter may be determined by.
Answer: flow rate and filter area
◉ These can be used to dewater sludge.
Answer: belt press, drying beds, solid bowl centrifuge, gravity
thickener
, ◉ Most important to providing adequate sewage treatment in a
stabilization pond.
Answer: sunlight, algae, bacteria and time
◉ Offensive and objectionable odors which sometimes occur in
trickling filters usually indicate.
Answer: septic conditions are present
◉ Dissolved Oxygen (DO) in aeration tank of an activated sludge
plant should be maintained at or about.
Answer: 2 to 4 mg/L
◉ Contributes to the infiltration in a collection system.
Answer: breaks in the main lines, high ground water levels, heavy
rains
◉ When a centrifugal pump loses prime the.
Answer: pump is no longer moving liquid
◉ A Rotating Biological Contactor (RBC) is.
Answer: fixed film biological treatment process