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100 Cards in this Set

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When organic wastes are discharged to receiving water, oxygen is depleted by:

a. algae during the day
b. bacteria
c. pathogens
d. limestone rocks
b. bacteria
Hydrogen sulfide gives off an odor similar to:

a. ammonia
b. chlorine gas
c. rotten eggs
d. decayed wood
c. rotten eggs
Three diseases potentially carried by wastewater are:

a. mumps, measles, colds
b. scarlet fever, pneumonia, hay fever
c. typhoid fever, dysentery, chlorea
d. tuberculosis, diptheria, chickenpox
c. typhoid fever, dysentery, chlorea
Immediate first aid for burns is to:

a. bandage tightly
b. apply warm, moist compress
c. immerse in warm water
d. flood with cold water
d. flood with cold water
How much does 7.5g of water weigh in lbs:

a. 50.8lbs
b. 62.5lbs
c. 75.6lbs
d. 77.3lbs
b. 62.5lbs
Of the following, which is most likely cause of electric motor failure:

a. dust
b. new connection
c. no friction
d. moisture
d. moisture
A pump runs continuously for 24hrs at full speed and delivers 288,000gal. The capacity of the pump is___g/min.

a. 100gpm
b. 200gpm
c. 1000gpm
d. 12,000gpm
b. 200gpm
Approximately how many gallons of wastewater would 600ft of 6in pipe hold?

a. 740g
b. 880g
c. 900g
d. 930g
b. 880g
Before repairing a pumps electical circuit, which of the following actions should you take:

a. disconnect the circuit breaker, place a red tag and lock out
b. post a notice in the break room
c. tell all the operators not to activate the circuit
d. turn the pump switch to standby
a. disconnect the circuit breaker, place a red tag and lock out
A valve that allows water to flow in one direction only is a ___ valve.

a. check
b. gate
c. globe
d. plug
a. check
Centrifugal pump parts include:

a. diaphragm
b. impeller
c. piston
d. rotor
b. impeller
What mixed liquor characteristics indicate a healthy activated sludge process?

a. black color and a strong, unpleasant odor
b. brown color, frothy appearance, and musty odor
c. brown color and thick, dark brown foam
d. light tan and light fluffy foam
b. brown color, frothy appearance, and musty odor
Which of the following forms of plant life is necessary for the proper functioning of a stabilization or oxidation pond:

a. algae
b. cattails
c. water lillies
d. weeds
a. algae
Chlorine gas is:

a. colorless
b. heavier than air
c. nontoxic
d. odorless
b. heavier than air
The highest concentration of algae growth in a facultative lagoon is usually observed:

a. near middepth
b. near the bottom
c. near the top
d. in the sludge layer
c. near the top
Common hydraulic detention times for primary clarifiers range from:

a. 15 to 30min
b. .5 to 1hr
c. 2 to 3hrs
d. 4 to 5hrs
c. 2 to 3hrs
Which gas is produced in anaerobic digesters and can be used as a fuel:

a. propane
b. methane
c. ethane
d. carbon dioxide
b. methane
Compute the lagoons detention time:
Surface area = 6 acres
Avg Depth = 3ft
Avg Daily flow (Influent) = .25MGD

a. 3days
b. 8days
c. 24days
d. 29days
c. 24days
How many pounds of chlorine gas are necessary to treat 4MGD of wastewater at a dosage of 2 mg/L:

a. 61lbs
b. 65lbs
c. 67lbs
d. 69lbs
c. 67lbs
Your wastewater treatment plant serves 1100 people. the flow avg is 80,000gpd. the approximate daily flow contribution per person is:

a. 14gpd/cap
b. 73gpd/cap
c. 80gpd/cap
d. 140gpd/cap
b. 73gpd/cap
The rock in a trickling filter is usually placed:

a. directly in the ground
b. directly in a concrete slab
c. on a tile underdrain system
d. on a rubber tile floor
c. on a tile underdrain system
Chlorine is primarily used to:

a. disinfect
b. prevent corrosion
c. raise pH
d. stabilize organics
a. disinfect
What is the purpose of heating and mixing a primary anaerobic digester:

a. to eliminate all oxygen present
b. to increase the digestion rate
c. to keep methane gas in suspension
d. to prevent grit from settling to the bottom of the digester
b. to increase the digestion rate
Which of the following devices is used to measure the flow of wastewater:

a. cocmminutor
b. comparator
c. parshall flume
d. sluice gate
c. parshall flume
Exhaust from a chlorinator room should be taken from:

a. anywhere
b. at floor level
c. close to the entrance
d. in the cieling
b. at floor level
Chlorine residual may be determined using the reagent:

a. DPD
b. EDTA
c. PCB
d. Na2S2O3
a. DPD
What test is typically never performed on wastewater influent:

a. BOD
b. fecal coliform
c. suspended solids
d. pH
b. fecal coliform
Considering the layout and flow diagram for the complete treatment plant, oxidation ditch plants would be most similar to which of the following:

a. completely mixed activated sludge
b. contact stabilization
c. conventional activated sludge
d. extended aeration
d. extended aeration
The pressure against which a pump must operate is measured in terms of:

a. ft-lb
b. gal
c. hp
d. psi
d. psi
an air-gap device is used to:

a. increase oxygen content in manholes
b. prevent contamination of potable water systems
c. prevent excessive vibration in pipe joints
d. ventilate manholes
b. prevent contamination of potable water systems
A horizontal centrifugal pump has "rope" packing. When the pump is operating, water slowly drips from the packing gland. This indicates that the:

a. packing bolts or nuts on the packing gland should be tightend
b. packing bolts or nuts on the packing gland should be loosend
c. packing bolts or nuts on the packing gland are properly adjusted
d. packing should be replaced
c. packing bolts or nuts on the packing gland are properly adjusted
Why are check valves used in conjunction with centrifugal pumps:

a. to equalize the pressure on both sides of the impellar
b. to prevent wastewater in the suction line from becoming air-locked
c. to prevent wastewater in the discharge line from flowing back through the pump
d. to regulate the rate of wastewater flow through the discharge pipe
c. to prevent wastewater in the discharge line from flowing back through the pump
If a fuse continues to blow, an operator should:

a. replace it with a higher capacity fuse
b. provide a jumper in the box
c. inspect the affected equipment to determine the cause
d. contact the power company to check for power surges
c. inspect the affected equipment to determine the cause
A single piston reciprocating pump has a 6in diameter piston with a 6in length stroke. If it makes 16 discharge strokes per minute, the pumping rate is____gpm.

a. 6gpm
b. 12gpm
c. 25gpm
d. 47gpm
b. 12gpm
Valves should be closed slowly to avoid:

a. excessive head loss
b. excessive wear
c. injury to the operator
d. water hammer
d. water hammer
Assuming a constant suction head, the disharge of a centrifugal pump:

a. decreases with an increase in discharge head
b. increases with the head increase only at the start of pumping
c. increases with the increase of discharge head
d. is independent of the discharge head
a. decreases with an increase in discharge head
A positive displacement sludge pump should never be placed into operation:

a. without being primed
b. with the discharge vavle closed
c. with the discharge valve open
d. without checking for proper impeller rotation first
b. with the discharge vavle closed
The addition of chlorine, acid, carbon dioxide, or sulfuric acid will ____ the pH of wastewater.

a. neutralize
b. lower
c. increase
d. have no effect on
b. lower
Activated sludge generally ____ than raw sludge.

a. settles more slowly
b. is more granular
c. is saltier
d. is denser
a. settles more slowly
Controlling the sludge wasting rate by constant MLSS concentration involves maintaining a certain concentration of:

a. suspended solids in the reactors (aeration tanks)
b. volatile suspended solids in the reactors (aeration tanks)
c. volatile suspended solids in the return sludge
d. volatile suspended solids in the waste sludge
b. volatile suspended solids in the reactors (aeration tanks)
Which of the following organisms should not be present in a healthy lagoon treatment system:

a. aerobic bacteria
b. anaerobic bacteria
c. algae
d. fungi
d. fungi
Under ice and snow cover, the BOD level in ponds will normally:

a. decrease rapidly
b. decrease slowly
c. increase slowly
d. remain the same
c. increase slowly
The rotational speed of air-driven rotating biological contactor (RBC) is controlled by:

a. air temp
b. air velocity
c. air volume
d. diffuser head setting
c. air volume
Chloramines are:

a. combined chlorine
b. enzymes
c. found in polluted air
d. free chlorine
a. combined chlorine
Which one of the following are normal conditions for a manual control gas chlorination system:

a. increase alkalinity
b. increase in organic matter
c. increase in phosphate concentration
d. decrease in pH
b. increase in organic matter
Which of the following are normal conditions for a manual control gas chlorination system:

a. line free of ice
b. pressure reading slowly decreasing
c. rotameter float fluctuating over a range of 10lbs/24hrs
d. vacuum gauge fluctuating over a range of 10in. Hg
a. line free of ice
Calculate the weir loading for a primary settling tank that has an outlet weir that is 480ft long and recieves a flow of 5MGD.

a. 9220gpd/ft
b. 9600gpd/ft
c. 9920gpd/ft
d. 10420gpd/ft
d. 10420gpd/ft
A settling tank that is 60ft long by 20ft wide and 12ft deep is used to treat a flow of 2.4MGD. What is the detention time?

a. 15min
b. 30min
c. 1.1hr
d. 2.3hr
c. 1.1hr
Calculate pounds of BOD per day entering the trickling filter.
influent wastewater flow is 1.5MGD
influent wastewater BOD is 150mg/L
There is a 30% reduction in BOD through primary treatment.

a. 560lb/day
b. 879lb/day
c. 1310lb/day
d. 1880lb/day
c. 1310lb/day
The part of the chlorine cylinder designed to melt at 150 to 162F to prevent the cylinder from exploding in the event of a fire is the:

a. fusible plug
b. needle valve seat
c. tank head
d. needle valve
a. fusible plug
When high organic waste load reaches an activated sludge plant, the operators first indicator is a decrease in:

a. COD in plant influent
b. DO residual in the aeration tanks
c. floatables in the primary clarifiers
d. flow to the treatment plant
b. DO residual in the aeration tanks
Disaster planning is:

a. having manuals ready so they can be read if a disaster occurs
b. something that, if properly done, will not need to be revised
c. useful in reducing confusion in the event of a disaster
d. only necessary if your facility is located near a coast or fault line
c. useful in reducing confusion in the event of a disaster
Turbidity in wastewater is caused by:

a. color
b. dissolved calcium
c. hardness
d. finely divided suspended material
d. finely divided suspended material
The gas most commonly associated with septic wastewater is:

a. carbon dioxide
b. carbon monoxide
c. hydrogen sulfide
d. methane
c. hydrogen sulfide
Industrial waste that can be treated by biological processes includes:

a. metal finishing waste
b. paper product waste
c. plating waste
d. pesticide waste
b. paper product waste
Mechanical ventilation of a lift station is required to:

a. lower the temperature
b. reduce chlorine demand
c. minimize the presence of harmful gases
d. increase DO in raw wastewater
c. minimize the presence of harmful gases
In electrical circuits a ____ is used to reduce the voltage where necessary.

a. ammeter
b. thermal overload
c. transformer
d. voltmeter
c. transformer
Which of the following causes the greatest pipe friction loss:

a. decreasing the rate of flow
b. increasing the temp of wastewater
c. increasing the velocity of wastewater
d. decreasing the pressure
c. increasing the velocity of wastewater
Wastewater is flowing thourgh a 42in diameter pipe at a rate of 6.5ft/sec. What is the flow in ft3/sec?

a. 18ft3/sec
b. 36ft3/sec
c. 62ft3/sec
d. 520ft3/sec
c. 62ft3/sec
If the bearings on horizontal centrifugal pumps are overlubricated, the most important effect is that the extra lubricant:

a. will result in smoother and more efficient operation of the pump.
b. will not make any difference in the operation of the pump.
c. will be wasted.
d. may cause overheating and possible failure of the bearings.
d. may cause overheating and possible failure of the bearings.
If packing is not maintained properly,:

a. cavitation damage will result
b. the impeller will corrode
c. loss of suction will occure due to air being allowed to enter pump
d. the pump efficiency will increase
c. loss of suction will occure due to air being allowed to enter pump
Which of the following is the most likely casue of rising sludge in clarifiers:

a. low DO and pH levels in the aeration tanks
b. young sludge
c. overaeration in the aeration tanks has sheared the floc
d. denitrification occuring
d. denitrification occuring
The amount of BOD in sludge entering a digester is an indirect measure of the:

a. amount of the sample that will evapourate when standing
b. "food" available for bacteria in the digester
c. number of bacteria entering the digester
d. primary effluent suspended solids
b. "food" available for bacteria in the digester
What organisms will be found in a balanced, good settling mixed liquor:

a. flagellate and amoeboid organisms
b. flagellates and free-swimming ciliates, but no stalked ciliates and rotifers
c. free swimming and stalked ciliate, some flagellates, and rotifers
d. nematodes, rotifers, ciliates, flagellates, and amoeboids
c. free swimming and stalked ciliate, some flagellates, and rotifers
Chemical coagulation doses can be initially estimated by:

a. jar tests
b. measurments of zeta potential
c. oxidation reduction investigations
d. stoichiometric calculations
a. jar tests
Given the following data, calculate the average veloctiy in the channel.
Data: 2.5ft wide channel
flow depth is 1.4ft
flow rate is 7.2MGD

a. 1.2ft/sec
b. 3.2ft/sec
c. 11.2ft/sec
d. 32.2ft/sec
b. 3.2ft/sec
A 240gpm mixed media filter operated at a rate of 2gpm/ft2 is backwashed at a rate of 15gpm/ft2. The backwash lasts for 5min. How many gallons of washwater were used:

a. 8000g
b. 9000g
c. 6000g
d. 6200g
b. 9000g
Given the data below, what is the most likely cause of a low DO level in an activated sludge aeration tank with a diffused aeration system problem?
Data: Blower air rate output is high
organic load is normal
hydraulic load is normal
high turbulance in a specific area of aeration tank

a. aeration system has leaking or broken pipes
b. excessive air bubble shearing by diffusers
c. return sludge rate too high
d. underaeration because of low blower speed
a. aeration system has leaking or broken pipes
An incubator for the BOD test should be controlled at ___ C.

a. 15
b. 20
c. 25
d. 30
b. 20
In certain situations, a supervisor encourages the employees to make their own decisions. this is considered to be:

a. against the rules to follow past experiences in decision making
b. bad form because the supervisor eventually loses control
c. highly desirable because it encourages employee growth and frees the supervisor for other tasks
d. passing the buck
c. highly desirable because it encourages employee growth and frees the supervisor for other tasks
If the sewer rate is $25 for the first 500ft and all wastewater generated over that amount is billed at the rate of $2.50 per 100ft3, how much would a customer generating 1200ft2 of wastewater be billed?

a. $25
b. $32
c. $36
d. $42.50
d. $42.50
Which of the following pieces of equipment should be calibrated daily at a treatment plant:

a. fixed location dissolved oxygen probe
b. continuous recording chlorine residual analyser
c. continuous recording pressure gauges
d. portable dissolved oxygen probe
d. portable dissolved oxygen probe
Information on preventive maintenance procedures, recommended maintenance frequencies and replacement parts for a specific piece of equipment installed at a plant can be obtained from:

a. record drawings
b. experience at the particular plant
c. lab records
d. manufacturer's operation and maintenance manuals
d. manufacturer's operation and maintenance manuals
Word has just come down from the top that operating funds are being cut. How should this be handled?

a. cut the supplies and repairs to balance the budget
b. fire some of the less productive, older employees
c. keep it quite and do what you have to do, "the less said is better"
d. let the other personnel know what the situation is and ask for their help
d. let the other personnel know what the situation is and ask for their help
One Opening has become available that would be an advancement to any one of three qualified eager employees. What is the best way to handle this situation?

a. hire an outsider to fill the position
b. pick one and normally all personnel of the change
c. split the work between the three and leave the position open
d. talk to the three as a group, explain the situation, interview them individually, and make your selection, then notify all personnel of the change
d. talk to the three as a group, explain the situation, interview them individually, and make your selection, then notify all personnel of the change
the ash content remaining at the end of a VSS test is the same as the:

a. difference in raw sludge and the sludge after air drying
b. inorganic solids
c. organic solids
d. volatile solids
b. inorganic solids
The weight of a chemical compound is 1/8 of the total weight of a chemical solution. the percent, by weight, of the chemical in solution is:

a. 6.4%
b. 8.3%
c. 10.5%
d. 12.5%
d. 12.5%
given the data below, what is the most likely cause of the problem?
Data:
wet well influent flow is high due to rain
wet well level is remaining high
lead pump is running
lag pump is running
lead pump check valve arm is up
lag pump check valve arm is down
force main pressure remains at normal range for one pump
low level pressure switch is normal
high level pressure switch is normal
electrical controls are in automatic mode

a. lead pump is clogged
b. force main pressure is too high
c. lag pump is clogged
d. both pumps are clogged
c. lag pump is clogged
A chlorine demand test will show the:

a.safe amount of chlorine that may be fed without killing fish
b. number of kilograms or pounds of chlorine required to kill 100% of coliforms
c. amount of chlorine required to give a desired residual after a given time
d. amount of chlorine required to satisfy the biochemical oxygen demand
c. amount of chlorine required to give a desired residual after a given time
Calculate the foot to microorganism (F:M) loading ration.
Data:
flow is 1MGD
Average BOD to aeration tank is 140 mg/L
Aeration tank capacity is 250000gal
MLVSS concentration mg/L

a. .25
b. .28
c. .30
d. .32
b. .28
A rotating biological contractor treats a flow of 2.2MGD with a BOD of 110mg/L. The surface area of the media is 550000ft2. What is the organic loading?

a. 2.7lbs BOD/1000ft2
b. 3lbs BOD/1000ft2
c. 3.5lbs BOD/1000ft2
d. 3.7lbs BOD/1000ft2
d. 3.7lbs BOD/1000ft2
Jar tests may be used to determine the optimum dosage of:

a. polymer
b. BOD
c. oil and grease
d. volatile acids
a. polymer
Which of the following process changes is most likely to improve the settling performance of primary settling tanks that are being operated at flows greater than their design flow

a. chlorinate the supernatant return from sludge handling processes
b. install flow equalization basins ahead of primary tanks
c. preaerate raw wastewater flow
d. recycle sludge from the secondary clarifiers to the primary tanks for settling
b. install flow equalization basins ahead of primary tanks
Which activated sludge process could handle shock loads of dairy waste most effectively:

a. a plug flow system
b. a high rate system
c. a complete mix system
d. a tapered aeration system
c. a complete mix system
When chlorine reacts with hydrogen sulfide gas, the hydrogen sulfide is:

a. amplified and made worse
b. diluted
c. not affected by the chlorine
d. oxidized and made odorless
d. oxidized and made odorless
Granular filter media used to filter wastewater can become coated with a biological slime due to the ___ in the wastewater.

a. alkalinity
b. hardness
c. pH
d. soluble BOD and ammonia
d. soluble BOD and ammonia
In the membrane filter method, the number of coliforms is estimated by the:

a. number of colonies grown
b. number of negative tubes
c. number of positive tubes
d. sum of positive and negative tubes
a. number of colonies grown
One method that generally is helpful in encouraging an employee to derive satisfaction from work is giving the employee a(n):

a. change in position whenever a need for self expression is indicated
b. opportunity to demonstrate efficiency in various types of work
c. realization that job security depends on manifest interest in the job
d. understanding of the relationship of the job to the work of the whole organization
d. understanding of the relationship of the job to the work of the whole organization
The span of supervision is the:

a. average length of time required to be in the organization before becoming a supervisor
b. number of levels between the employee with the least amount of responsibility and the employee with the most responsibility
c. number of subordinates for each manager
d. number of supervisors in an organization
c. number of subordinates for each manager
If departments are definedbased on jobs to be done, this is known as organization by:

a. customer
b. function
c. product
d. territory
b. function
Decentralized authority describes the process of:

a. changing an organization from centralized to decentralized
b. delegating authority to ones supervisors instead of ones subordinates
c. delegating power for decisions to lower levels
d. retracting authority that has been previously delegated an d probably changing functions and duties
c. delegating power for decisions to lower levels
What term means that the employee reports to one specific supervisor and that the delegation of authority comes from one particular supervisor to the employee?

a. unity of command
b. span of supervision
c. organizational chart
d. formal organization
d. formal organization
Steel tanks may be protected from rusting by:

a. alternately wetting and drying the walls
b. maintaining humidity in tank
c. protective coating
d. washing tanks walls
c. protective coating
What should be an operators top priority when making operational decisions?

a. protecting aquatic life
b. cleanup procedures
c. protecting the publics health
d. preventing odors
c. protecting the publics health
If chlorine costs $.21/lb, what is the daily cost to chlorinate 5MGD of wastewater to an initial concentration of 2.6mg/L?

a.. $1.95
b. $3.25
c. $10.84
d. $22.77
d. $22.77
Disaster plans should be developed to deal with which of the following events?

a. broken sewers
b. floods
c. power outages
d. pump stoppages
b. floods
When preparing for a public open house, what following in plant arrangements must be made:

a. a printed handout is available and up to date
b. adequate coffee cups and ash trays are available
c. all pump casings are repainted
d. visitor safety is ensured
d. visitor safety is ensured
When an employee breaks the rules and requires discipline, who is responsible for administering it?

a. fellow staff
b. personnel office
c. supervisor
d. upper mgt
c. supervisor
The best approach to resolving complaints involving the operation of a wastewater plant is to:

a. explain the problem and proposed solution and offer to conduct a tour of the plant for those complaining
b. keep all persons except operating personnel out
c. never admit there is a problem or cause for the complaint
d. publicize the problem as much as possible
a. explain the problem and proposed solution and offer to conduct a tour of the plant for those complaining
Your systems billing is based on water usage rate. Given the following data, calculate the bill to be recieved by a customer that uses 35000gal/quarter.
Data:
$1/1000gal for the first 10000gal
$.75/1000gal for the next 15000gal
$.50/100gal for more than 25000gal

a. $21.75
b. $26.25
c. $34.50
d. $40.75
b. $26.25