Wastewater Treatment Class C Exam Questions and Answers, Exams of Pathophysiology

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WASTEWATER CLASS C EXAM QUESTIONS AND

CORRECT ANSWERS VERIFIED LATEST 2024- 2025

GRADE A

What device(s) can be used as an emergency shut-off for the drive unit of a circular clarifier? - ANSWER>>>Shear Pins You are the operator-on-duty. The alarm for the fire detector in the Belt Filter Press Control Room goes off. What type of fire extinguisher would you take to respond to this alarm? - ANSWER>>>Class C When working in an area with two or more floor coverings (for example, grating and checker-plate), be sure that they are always _____. - ANSWER>>>Secured together When working in confined spaces where flammable gases may be present, use only toolsmade of - ANSWER>>>A non sparking alloy A treatment plant should have a valve exercise program in which all plant valves are exercised (opened and closed) - ANSWER>>>Once a year Immediate first aid for burns is to? - ANSWER>>>Flood with cold water

Recommended personal hygiene practices to minimize the risk of being infected by wastewater pathogens include - ANSWER>>>Changing out of your work clothes and showering before leaving work What is the best protection against the risk of exposure to infections and disease at a wastewater plant? - ANSWER>>>Personal Hygenie Regarding fire extinguisher training in the workplace. The employer must provide what? - ANSWER>>>A written and practiced emergency action plan. The combination of methane and which other gas can be very combustible? - ANSWER>>>Oxygen In what location of the sewer manhole would methane gas be found? - ANSWER>>>At the top Which type of fire is safe for a pressurized water extinguisher or water hose to be used on? - ANSWER>>>Brush Mixing dry granular chlorine (HTH) with petroleum products can cause which of the following? - ANSWER>>>Create a fire or explosive condition The fusible plugs found on a 150lb cylinders and one-ton chlorinecontainers are designed to melt at what

Waterborne diseases and illnesses common to the wastewater industryinclude dysentery, hepatitis, polio, typhoid, and what other disease? - ANSWER>>>Cholera How many fusible plugs are in a 1 ton chlorine container?

• ANSWER>>> What is the proper amount of oxygen to enter a confined space? - ANSWER>>>19.5% - 23.5% Which safety procedure can prevent accidental reenergizing of electrical energy while maintaining a piece of equipment? - ANSWER>>>Use proper LO/TO procedures If a leak of liquid chlorine occurs, one part of the liquid chlorine can expand to how many parts of gaseous chlorine at room temperature and average barometric pressure? - ANSWER>>>457 parts of gas. Chlorine gas is how many times heavier than air? - ANSWER>>>2.5 times Methane gas is lighter than air - ANSWER>>>True A pump's seal water pressure should be set at - ANSWER>>>5 to 10 psi more than the pump operating discharge pressure

What does a gradual increase in the bearing temperature of a centrifugal blower indicate? - ANSWER>>>There is a problem with the bearing lubrication or connection How often should the packing on a gate valve be replaced? - ANSWER>>>As required What is surging in a centrifugal blower? - ANSWER>>>When the blower's discharge pressure is less than the aeration system's backpressure Pumps are often required to bring wastewater into a treatment plant. What types of pumps are typically used to lift influent wastewater? - ANSWER>>>Centrifugal If a centrifugal pump loses its prime after starting, what is the most probable cause? - ANSWER>>>Air leaks into the pump through stuffing boxes The casing surrounding a pump impeller that collects the water discharged by the impeller is called a __________. - ANSWER>>>Volute A _____ is installed on the pump discharge piping to prevent water from flowing back across a pump when it is off. - ANSWER>>>Check Valve

In a centrifugal pump, leakage is prevented by - ANSWER>>>Wear rings Valves should be closed slowly to prevent: - ANSWER>>>Water Hammer The purpose of racks or screens is to remove which of the following? - ANSWER>>>large solids Which of the following indicates that the impeller of a centrifugal pump may be worn or damaged? - ANSWER>>>Pump is not delivering the design flow How often should inactive valves be exercised? - ANSWER>>>Quarterly A positive-displacement sludge pump should never be placed into operation - ANSWER>>>With the discharge valve closed A device that causes the wastewater in a vertical riser pipe to rise to an outlet using compressed air is called an - ANSWER>>>Air lift pump If packing is not maintained properly, - ANSWER>>>If packing is not maintained properly, If bearings on a centrifugal pump are running hot, over- or under-lubrication should be checked. If lubrication is satisfactory, the next preventative maintenance check

would be to - ANSWER>>>Inspect the alignment of the pump and motor A water-filled mechanical pump seal not only helps to prevent leaks but also - ANSWER>>>Acts as a lubricant for the pump shaft and keeps gritty material from entering the packing box The formation and collapse of gas pockets or bubbles when water reaches boiling point on the blade of a centrifugal pump's impeller are known as what? - ANSWER>>>Cavitation Which of the following is a type of positive-displacement pump? - ANSWER>>>Gear If the pump bearings on horizontal pumps are overlubricated, the most important effect is that the extra lubricant: - ANSWER>>>This may cause overheating and possible failure of the bearings The primary cause of motor failure is: - ANSWER>>>Moisture, and Vibration overload A water seal on a pump serves a dual purpose. - ANSWER>>>It acts as a lubricant and it keeps gritty material from entering the packing box

What is a typical application for a centrifugal pump? - ANSWER>>>Drain sump pump and reuse water How could severe damage to a positive displacement pump or its piping occur? - ANSWER>>>Starting the pump against a closed discharge valve The majority of pumps used in wastewater treatment are classified as? - ANSWER>>>Positive displacement and centrifugal In a centrifugal pump, the volute is the? - ANSWER>>>The body of the pump What is a rule of thumb regarding pump packing? - ANSWER>>>Never put rings of new packing over the old Which statement below best represents the proper removal and replacement of rope-type packing in a centrifugal pump? - ANSWER>>>Always install new packing material and stagger the packing joints Methane Anaerobic is odorless. - ANSWER>>>True One method used to minimize odor generation in sewer lines is to prevent solids deposition by designing a system with a high-flow velocity. What is the recommended design flow velocity to minimize odors? - ANSWER>>>Greater than 2.0 ft/sec

A "rotten egg" odor near a trickling filter generally indicates

• ANSWER>>>Anaerobic conditions within the filter Odor complaints are increasing at the WWTP. The operator finds most odor is coming from the primary clarifiers where bubbles and chunks are found on the tanks surface. What should be done to correct the problem? - ANSWER>>>Increase the sludge withdrawal from the primary clarifiers. If sludge is not removed frequently enough from the primary clarifier, what could occur? - ANSWER>>>If sludge is not removed frequently enough from the primary clarifier, what could occur? If a facility decides to use an alternative method of biosolids treatment that is not a part of the existing facility operating permit, and the process will be operating in a manner inconsistent with the permit, the facility should: - ANSWER>>>Notify the state regulatory agency before using a new method and modify the operating permit if necessary. FDEP Chapter 62-600 FAC, Domestic WastewaterFacilities, states that all treatment plants shall be what? - ANSWER>>>Fenced Chapter 62-601 FAC, Domestic Wastewater Treatment

domestic wastewater treatment facility," describes what? - ANSWER>>>Reclaimed (reuse) water According to Chapter 62-600, F.A.C.*, a composite sample shall be used for which test? - ANSWER>>>Effluent CBOD According to Chapter 62-600.440 (4) (c) 4,F.A.C., basic level disinfection, any ONE sample may not exceed how many fecal colonies per 100 ml sample? - ANSWER>>>80 0 This is the document that FDEP inspectors use to calculate a monetary penalty for violations of wastewater treatment regulations. - ANSWER>>>Guidelines for Characterizing Wastewater Violations A "fixed" sample is - ANSWER>>>A sample preserved in the field upon collection Which type of sample, where the sample volume or frequency of collection increases or decreases as the flow rate increases or decreases? - ANSWER>>>Composite Sample A _________ conveys waste to a wastewater facility for treatment - ANSWER>>>Collection System What is inflow and Infiltration (I&I) caused by? -

ANSWER>>>Rainwater and groundwater entering the collection system Which type of sewage collection system uses small progressing cavity grinder-type pumps? - ANSWER>>>Low pressure sewer systems Where are low-pressure sewer systems or vacuum-type sewer collection systems most likely to be found? - ANSWER>>>Low lying areas with high groundwater table What causes collection systems to generate more grit? - ANSWER>>>Wet, rainy conditions Measuring the pH of a sample must be performed within ________ after collection. - ANSWER>>>15 minutes A facility is using a ground water recharge type of effluent disposal. What is the maximum permitted total nitrogen value for this disposal? - ANSWER>>>12 mg/L What is the acceptable method of disposal of grit and screening from a WWTP? - ANSWER>>>Burial in an approved sanitary landfill Disposal of reclaimed water to a power plant for cooling towers would be an example of what kind of reuse method? - ANSWER>>>Industrial reuse

If an excess of nitrogen and carbon dioxide bubbles accumulate in the sand media of the denitrification filter, what will happen? - ANSWER>>>The filter will experience high losses Disc type filters use what type of media? - ANSWER>>>Cloth or steel mesh Plant problem: The operator returns to the treatment facility and finds the power to the RBC units has been off for an extended period of time. A generator is started and power is restored to the RBCs. The operator notices the exposed biomass has dried out due to the extended off time, however, the submerged media growth is thick and heavy. What should the operator do before restarting theRBC unit? - ANSWER>>>Remove excess media growth to prevent an unbalanced condition upon start-up. With regard to troubleshooting RBCs, choose the correct statement: - ANSWER>>>The media surface is visible, so observing biofilm thickness, and condition will help reveal clues to solve the problems. The main action of a mixed media filter is: - ANSWER>>>Straining A ________ is used to measure the weight of samples that may be on filter paper, in evaporating dishes, etc. - ANSWER>>>Analytical Balance

As per FDEP administrative code, how often must secondary devices used to report total daily plant flow to be calibrated, or verified for accuracy? - ANSWER>>>Annually What are two types of Primary flow measurement devices? - ANSWER>>>Open channel, and closed conduit If an operator is uncertain how to perform an analytical test, he or she would refer to a book called: - ANSWER>>>Standard methods for the examination of water and wastewater Which statement below is correct regarding grab samples?

• ANSWER>>>It is a single sample of wastewater taken at one instant of time from one location Solids that remain in suspension in wastewater and will not pass through a filter are called: - ANSWER>>>Total Suspended Solids (TSS) Which type of sample, where the sample volume or frequency of collection increases or decreases as the flow rate increases or decreases? A portion of a sample - ANSWER>>>A flow-proportioned composite sample

What could be the cause of short-circuiting through the primary clarifiers? - ANSWER>>>Uneven or unlevel weirs To determine detention time, you need to know the volume of the tank and what other piece of data? - ANSWER>>>Flow rate Basic data used to determine primary sludge pumping rates include experience, influent suspended solids, sludge total solids, and what other piece of information? - ANSWER>>>Sludge blanket depth What could occur if the velocity is too high in some sections of the clarifier effluent weir than in other sections?

• ANSWER>>>Increased amounts of suspended solids could be carried out with the effluent What are designed to minimize the effects of hydraulic short-circuiting caused by density currents? - ANSWER>>>Baffles What is the recommended minimum frequency of sludge blanket depth measurements? - ANSWER>>>Once per day Operators should make certain that sludge blanket measurements are measured consistently at the same time each day or shift and which of the following? - ANSWER>>>At the same location in the clarifier

If there is excessive sedimentation in the inlet channel, what action should you take to solve the problem? - ANSWER>>>Increase velocity or agitate with air or water Imhoff cones should be used to measure settleable solids for what length of time? - ANSWER>>>30 minutes Removing rags from the weirs and scum hopper is done as part of - ANSWER>>>Preventative maintenance Advanced Wastewater Treatment (AWT) includes the removal of: - ANSWER>>>Nitrogen According to the FDEP Ch 62-610.469, any utility that is practicing reuse of attached wastewater shall have: - ANSWER>>>An approved cross connection control program According to the FDEP Ch 62-600.400 FAC, when using high-level disinfectant on reclaimed water, any one sample may not exceed how many fecal coliform units, per 100 ml? - ANSWER>>>25 CFU Where is the location for collecting the TSS sample for meeting the 5mg/L TSS permitted limit when the flow is going to a reclaimed water reuse system? - ANSWER>>>After filtration but before final disinfection.