ADEQ Water Treatment 2 Practice Test

These questions are part of the practice quiz. Start practicing

• The flow through a sedimentation basin should not exceed
• What are the three forms of carbonate hardness?
• Which is a limitation of softening?
• Reverse osmosis units also have cartridge filters installed immediately ahead of the RO unit to remove suspended matter down to _____.
• Lamella plate or tube settlers with angles of ______ would require backflushing or manual cleaning to remove built-up sludge?
• Chelation controls _______, and sequestration controls _______.
• What is the approximate open-circuit voltage per cell in a lead-acid battery?
• The concentration of a disinfectant multiplied by the contact time from application to first customer must be calculated ______.
• Which substances serve as precursors to disinfection by-products when disinfectants are used?
• The Filter Backwash Recycling Rule is intended to minimize health risks associated with recycling backwash water, particularly with respect to which pathogen?
• Hardness is generally expressed as the total concentration of which ions?
• What unit is used to report arsenic concentration in drinking water standards?
• The Langelier Saturation Index is used to assess the tendency of water to precipitate or dissolve calcium carbonate.
• What indicates that water produced by a well is being drawn from more than one aquifer?
• Which chemical lowers pH when added to water?
• What is the major reason that turbidity is undesirable?
• Which statement best describes the focus of the primary drinking water regulations?
• Which agency defines the risk bins used to classify surface water sources under LT2?
• What type of aerators have riffle plates?
• What is caustic alkalinity?
• Which option lists the correct formula for caustic soda?
• Which factor is most commonly cited as the benefit of pressure filtration for small water systems?
• For conductivity measurements, which sampling option is correct?
• In the completed test of the multiple-tube fermentation method, a small portion of a coliform colony from the confirmed test that is positive is transferred to a growth medium and inoculated for _______, and a second portion is transferred to _______ and incubated for _______.
• Which source water type is commonly associated with iron and manganese presence?
• What is a potential concern when ozone is used as a primary disinfectant?
• Which pairing of membrane processes is effective for removing hardness from water?
• Which device best measures total suspended solids?
• In a lead-acid battery, each of the battery cells produces an open circuit voltage of approximately ______
• In a two-stage recarbonation process, CO2 is added after lime to lower the pH to approximately which range?
• The chlorine-measuring method that uses a chlorine gas-permeable membrane is the polarographic method.
• Which type of process control uses a mode where the output is directly proportional to the deviation from the set point?
• Chlorinating before a microstrainer may cause a sticky, jelly-like coating to form on the microstrainer. What is present in the water that causes this problem?
• Which action is NOT recommended when working around machinery with moving parts?
• Which chemical is primarily responsible for precipitating magnesium hydroxide during lime-softening?
• Continuous regeneration (CR) is usually used in greensand filters when ________ is mostly being removed and intermittent regeneration (IR) when __________ is mainly being removed. The _________ regeneration is used while the filter is offline.
• In 2003, the USEPA revised the drinking water standard for arsenic from which range to which range?
• To eliminate hydrogen sulfide (H2S), the pH of the water should be lowered to _______ or less before beginning aeration.
• What is an operating factor that would affect floc formations?
• Separate refrigerators should be used for the storage of which items because fumes of some chemicals may be harmful to the organisms?
• In lime-soda ash softening, what are used to help gather the fine calcium and magnesium precipitates into particles that will readily settle?
• Define divalent.
• Molecular weight is expressed in which units?
• In the Lead and Copper Rule, if a water system exceeds the 90th percentile for the lead action level, the system must also _______.
• Which statement best describes circuit breakers in relation to switches?
• PDVF membranes have excellent chemical resistance to which substance, and what is their typical service life?
• Which pipette type is used for performance monitoring and should be Class A?
• The optimum fluoride level in drinking water, as recommended by the Department of Health and Human Services and the USEPA, is what?
• Why are drinking water regulations sometimes called interim regulations?
• In the brine regeneration process, which cations are exchanged on the resin by sodium?
• Bar or wire-mesh screens typically encounter the largest amount of debris in which season?
• Which coliform test methods have three distinct steps: presumptive, confirmed, and completed?
• A Leopold filter bottom is a patented filter underdrain system using a series of perforated _______ with channels to carry the water.
• If a particular section of the distribution system suddenly has a drop in chlorine residual, what most likely has occurred?
• Which instrument has a fixed light source and provides a qualitative measurement but cannot detect particles that do not scatter light?
• What is the percentage of copper in copper sulfate (CuSO4)?
• What should be done to a new shaft sleeve before it is put on a shaft if it uses an o-ring?
• What is hardness caused by?
• During manganese greensand bed regeneration, which chemical is used to regenerate the media?
• When can wearing gloves be a hazard?
• The reason that a sample has a holding time is usually because the sample's ____ .
• An electric current in a wire travels from end to end at _______. However, individual electrons within the wire move ______ and over ________.
• A conical tank in which the softening reactions take place as the water passes upward through the unit is described as what type of reactor?
• In the Long-Term 2 Rule, the bin scenario represents source water concentrations used to assess what?
• In the Long-Term 2 Rule, which pairing correctly matches 'pack' to the concentration concept?
• Sodium hypochlorite is usually purchased at 12% to 12.5% and is then distributed down to a more stable percentage of ______.
• What will a coagulant aid not achieve from the following?
• What are the primary reasons that more small water systems are installing pressure filters?
• The Long-Term 2 Enhanced Surface Water Treatment Rule also calls for continuous monitoring at the entry point to the distribution system with a minimum of ______ of chlorine residual.
• Which method is listed as another approach for the modified Winkler method?
• What is used to coat the walls of sedimentation basins to rid the basin of slime growth?
• Which statement is true about the Contaminant Candidate List (CCL)?
• The slime layer prevents deposition of calcium carbonate. When the slime sloughs away, it carries away which substance and leaves the pipe surface bare?
• In HPC testing, which plating incubation duration applies for plate-count agar?
• After the Long-Term 2 Surface Water Treatment Rule testing, a system is put into a ________, which are ______ concentrations in the source water for the theoretical potential for contamination.
• The fluoride injection point should be as far away as possible from any _____.
• Although _______ can be added to lime-soda ash rapid-mix basins, better results are usually obtained if they are added _______ in a separate rapid-mix basin.
• What material is commonly used to cap greensand filters to improve performance?
• Iron bacteria, such as which organism, cause red water, tastes and odors, clogged pipes, and pump failure?
• In coagulation, once zeta potential forces are reduced below the ______________, the particles in suspension will start to coalesce?
• Waterborne disease outbreaks have historically been traced to inadequate disinfection of drinking water. Which disease among the following has been linked to this issue?
• For manganese oxidation in surface water, which pH value would be sufficient to make the process effective?
• Fluoride injection should be kept away from which type of chemical?
• In the oxidation of iron and manganese, the pH must be adjusted to an optimal level. What must be determined to accomplish the optimal pH?
• Using dry ice or liquid CO2 as a diffuser gas results in smaller diffuser pipes.
• Chelation is a chemical treatment process used in water treatment to control what?
• In water treatment, which compound is described as looking like broken glass crystals?
• The Radionuclides Rule added for the first time an MCL, for uranium of ______
• Under the Interim Enhanced Surface Water Treatment Rule, what Giardia log reduction credit is given for conventional treatment with disinfection credits?
• In nanofiltration and reverse osmosis, membrane compaction rates increase when membranes are operated at which conditions?
• In the multiple-tube fermentation method, as presumptive positives are inoculated into BGB, 0.1 mL of presumptive broth is also transferred into which broth?
• What are the effects of high iron and or manganese in water?
• The ____ process is used in the water industry primarily for the removal of ______.
• What type of pump has the ability to rotate its discharge 360 degrees?
• Superchlorination is typically used when ______ are excessive
• Gas chromatography-mass spectrometry is used to determine which category of compounds in a sample?
• Which chemical family is used to regenerate ion-exchange systems and lower the pH of water treated by membrane processes?
• Even after equipment is locked out and tagged, why might it still be unsafe to repair?
• Which component of the softening system is primarily responsible for removing suspended solids before the main treatment?
• What does the Unregulated Contaminant Monitoring Regulation provide the EPA?
• Which alum sludge dewatering method can attain at least 20% solids by weight?
• The best way to remove H2S is by scrubbing at about _______ by bubbling CO2 through the water before aeration to reduce the pH
• The ripening of a filter after it backwashes depends on ________.
• An organic contaminant from coagulants would most likely include which compound?
• The 1996 Risk Management Rule was issued to protect public health and safety for which group?
• A low-cost radioactive scan is first done to determine if the level of radioactivity is high enough to progress to further analyses. The level of radioactivity that would call for further analysis is normally the ______ for ______ or _________ but can be varied by the particular state drinking water agency.
• In the EC-MUG test, if the tube _______, it is positive for E. Coli.
• Which pump configuration allows the discharge to be oriented in any direction around the axis?
• Garnet sand is used at the bottom medium in multimedia filters. What characteristics does garnet sand have compared to the other sand in the filter?
• Which regulation includes Giardia reduction credits for conventional treatment with disinfection?
• In microfiltration operation, stable flux is maintained while recovery is kept at or above what percentage?
• Chlorine dioxide is how many times more powerful than chlorine?
• Besides oxidizing iron and manganese, potassium permanganate has been found to be most effective in controlling...
• Which errors often cause inaccurate iron and manganese test results?
• Alternate statement about the cations usually present in water in significant concentration: Which ions are usually the primary hardness contributors in water?
• Cyanide affects which body systems?
• What is the correct order of parts that follows a pump for the listed components?
• When did the Long-Term 2 Enhanced Surface Water Treatment Rule take effect for large systems?
• To address algae growth in sedimentation basins, which combination is applied per liter when drains are used?
• What should you base a safe stopping distance behind the vehicle in front of you on?
• Where in the treatment plant is nitric acid most commonly used?
• What indicates whether the small amount of fluid in the tip of a pipette that remains after it has drained should be blown out?
• Which particle size range is recommended for tracking by particle counters as a surrogate for Cryptosporidium?
• Which factors contribute to the difficulty of inactivating all microorganisms with a single treatment method?
• How is aluminum oxide activated?
• A calcium sulfate molecule would be considered a dissolved solid.
• Why is ozone treatment often followed by granular activated carbon, which removes assimilated organic carbon caused by the action of the ozone treatment?
• In mass spectrometry identification, the key signature used is which?
• Why do some water treatment plants avoid addressing iron, manganese, arsenic, and disinfection byproducts in their treatment operations?
• If algae or slime growth in sedimentation basins are a problem, drain the basin and apply a solution of ______ per liter of water using a brush to remove the growth.
• In HPC testing, where are the diluted water samples placed and how long are they incubated?
• Actinomycetes are a group of organisms usually associated with tastes and odors. This group has the characteristics of _______.
• Soft water is defined as CaCO3 equivalents below what value?
• Ozone is more stable in water when the water has which condition?
• Which method is the least reliable for detecting hydrogen sulfide?
• For nomographic determination of CO2 in water, which additional properties must be known?
• Separate refrigerators should be used for the storage of _____ and ______ because the fumes of some chemicals may be harmful to ______.
• What genus type or organism has killed the most people because of its high mortality rate when contracted?
• The abbreviation LT2 stands for which designation?
• When iron alone is treated using manganese greensand filters, the chlorine feed rate should be about ______.
• Alum sludge dewatered in a lagoon for a year may still contain more than ______ of the original water.
• What is the purpose of using granular activated carbon after ozone treatment, as described?
• Which device would best measure total suspended solids?
• What happens when the brine solution is fed into the resin?
• Synthetic organic compounds would more likely contain _____ than natural organic compounds
• What type of automation control would work best if the chlorine demand varies but the flow is constant?
• Why is electrical power entering a water treatment facility usually routed through transformers?
• The precipitative softening process uses _____ that render _______ calcium and magnesium ______
• The regulatory framework that includes a limit for chlorite is part of which EPA rule?
• Adjustments to the carbon dioxide dosage in recarbonation should be based on both the Langelier saturation index and results of coupon testing.
• If dissolved oxygen increases and the pH and alkalinity do not increase, the corrosion rate will generally:
• The ideal alkalinity for manganese greensand filters for the removal of iron and manganese is _______ as CaCO3.
• What is the primary purpose of routing power through transformers at a water treatment facility?
• What will most likely exhaust GAC first?
• The most used conductor metal is?
• Groundwater systems at high risk for fecal contamination must provide a 4.0-log inactivation of viruses.
• The low-cost radioactive scan threshold for further analysis is normally the ______ for ______ or ______ but can be varied by the state agency.
• Which of the following correctly reflects the health concern associated with turbidity as described in the material?
• In the Ground Water Rule for systems that disinfect, large systems are required to monitor ______ and small systems are required to monitor ______.
• When disinfecting with chloramines, when can the ammonia be added to the process?
• What is alkalinity?
• Which colors are not assigned numerical color units?
• In a concentration cell corrosion, what gas is produced?
• The Long Term 2 Enhanced Surface Water Treatment Rule specifies that UV disinfection must provide at least what level of log removal for Cryptosporidium?
• Which condition indicates poor floc formation?
• Under the Stage 1 Disinfectants and Disinfection Byproduct Rule, the maximum contaminant level for haloacetic acids is 60 micrograms/L.
• Which phrase best describes the crystals that resemble broken glass in certain compounds?
• Which organism obtains energy for growth from the chemical reaction that spontaneously occurs between iron and manganese and dissolved oxygen?
• Which unit correctly identifies the unit expressing electrical potential?
• Which statement best describes the factors that influence cleaning protocols for microfiltration membranes?
• Under favorable conditions, combined chlorine, such as monochloramine and dichloramine, compared to the bactericidal action of free chlorine would require ____ times more combined chlorine residual.
• Microfiltration sits between ultrafiltration and multimedia filtration based on pore size. Which option correctly lists those adjacent stages?
• What is the result of overexposure to hypochlorite compounds?
• A special problem with granular activated carbon filters is the rapid growth of which microorganisms?
• In water chemistry, what aspect of pH is of interest to chemists?
• In the chemical precipitation process, the hardness causing ions are converted from [blank] forms. Calcium and magnesium become [blank] as the pH increases.
• Electric energy is usually expressed in _______, and power is expressed in ______
• Which chemical is used to remove noncarbonate hardness in chemical precipitation softening?
• Which statement best describes manganese dioxide (MnO2) in soils?
• What NSF/ANSI Standard covers coatings, construction materials, and components?
• Slow sand filters are cleaned by scraping the top ____ off the top of the sand filter.
• In a corroding pipe, the electrons released at the anode will combine with which species in the pipe at the cathode?
• What is the main purpose of presedimentation following screening?
• ______ or small streams at the upper end of a reservoir can help reduce _____
• In an electrolyte solution, an anion is attracted to which electrode?
• The Surface Water Treatment Rule requires that the turbidity of the water entering the distribution system be equal to or less than ______ in at least ____ of measurements each month.
• In dual media filtration, if the ratio of anthracite size to sand size is close to 2, which outcomes may occur?
• Mineral acids are measured by titration to a pH of 4.3 using which indicator?
• If raw water is pre-chlorinated, what color on the inside walls of filters and the filter media indicates the presence of both iron and manganese?
• In a dual media filter, it is best to have ____ backwash rates because each type of media has a different ____.
• A hazardous measuring device would most likely be _______
• It is recommended that operators using particle counters track particles in the size range ______ because they are a possible surrogate for _______.
• Stage 2 DBPR includes a provision to reduce or eliminate the use of chlorine disinfectants at the beginning of the treatment process if TOC exceeds 2.0 mg/L.
• The current travels end-to-end at high speeds; electrons move relatively slow over short distances. Which option correctly reflects this statement?
• Lamella plates create flow by
• In order to achieve similar disinfection, combined chlorine residual must be greater than free chlorine by how many times under favorable conditions?
• Lamella plates work by
• Which health indicator may suggest a child has been exposed to high lead levels?
• Which filter has an unstratified media distribution?
• When chlorine dioxide is generated on site, a small amount of which species can be formed?
• Which statement about pH and magnesium hydroxide precipitation is true?
• Caustic soda is commonly known as sodium hydroxide with formula NaOH. Which of the following options correctly pairs the name with its formula?
• What are some uses of synthetic organic chemicals (SOCs)?
• Which skin condition provides more resistance to electrical current flow?
• The platinum-cobalt method measures which property in water?
• Which protozoan parasite is a key target in modern drinking water treatment due to resistance to disinfection methods?
• What is the best-known solution for excessive algae growth in a presedimentation impoundment?
• Which regulation addresses backwash water recycling in filtration plants?
• No preliminary contact or sedimentation chambers are necessary for which oxidation process?
• What is CaCO3 known as?
• If coliforms are present, the gas they produce will begin to form bubbles in each inverted vial within what period?
• What information can particle counters provide?
• If a water system exceeds the 90th percentile of either the lead or copper action levels, it must also assess _______.
• A metal rod should be used to probe the filter on a grid system to locate and record the depth to gravel. At a minimum, how often should this be done?
• Which agency promulgated the Final Groundwater Rule?
• What membrane configurations are currently available and used in drinking water treatment plants?
• Breathing hydrogen sulfide gas at low concentrations can be fatal. Which combination is listed as fatal?
• During greensand regeneration, continuous regeneration is typically used while the filter is offline.
• In variable declining-rate filtration, what is placed in the effluent line of each filter to prevent excessive flow rates?
• To provide adequate protection, what should the noise reduction rating (NRR) of the hearing protection device be?
• How many grains are in 1 pound?
• At pH levels associated with softening chemical precipitation, which component in the treated water may increase?
• Electrolytic flotation uses which gas mixture as a byproduct?
• What type of pretreatment must be cleaned manually when the amount of debris is relatively small?
• In groundwater systems that disinfect and have deficiencies, 4-log inactivation of viruses must be demonstrated with adequate C x T.
• While converting carbonate back to bicarbonate, how does recarbonation affect the pH?
• Which term refers to the EPA program that surveys unregulated contaminants in drinking water?
• A low-cost method of feeding PAC is to use a _____ where precise feed in ____
• Caustic hypochlorite used in disinfection ranges in available chlorine from which percentage?
• The depth to which submerged plants will grow is primarily limited by ______
• What is the typical service life range for PDVF membranes in oxidants?
• What happens when high chlorine residual levels are applied to the softening units?
• Why is nitrate regulated?
• What is a disadvantage of using chlorine dioxide in water treatment?
• Slow sand filtration cleaning involves removing how many inches from the top of the filter?
• An organic compound from components of pipe, coatings, and joint adhesives would most likely include...
• What was the primary concern for why the Final Groundwater Rule was promulgated?
• After screening and presedimentation, there should be a significant reduction in which parameter?
• Which material sits on the top in the standard bottom-to-top arrangement of higher-rate filter media?
• What is a limitation of the ion exchange softening process?
• What pH level is required to precipitate magnesium hydroxide?
• After water has been softened, it is close to pH 11; thus it needs to be stabilized by a process known as recarbonation. What small amount of hardness chemical is formed and what is precipitated in this process?
• The C x T value is calculated using most or part of the treatment plant, some distribution piping, and to the _______.
• Besides using carbon dioxide, encrustation can also be prevented by adding ______
• What do the routine monitoring requirements of the Stage 1 DBPR include?
• Monomedium filters are best suited for which filtration approach?
• The precipitative softening process uses which mechanism to render calcium and magnesium insoluble?
• Electrical conductivity meter readouts are in what units at what temperature?
• Before installing a new shaft sleeve, it should be heated to _______.
• The analysis of a water sample yielded a result of 4.0 mg/L CO2. What is the most likely source of this water sample?
• In dual-media filtration, if the ratio of anthracite size to sand size is close to 2, what is a likely outcome?
• What does valence refer to in chemistry?
• What is an ion?
• Which problem is commonly associated with hardness?
• Which are usually the only cations present in water in significant concentration?
• What piece of laboratory equipment can be made of polycarbonate and is clear, such that there is no confusion over reading the meniscus?
• Reverse osmosis membranes need cleaning if the pressure drop through the unit increases by what percent?
• How often should amperage and voltage tests be performed on three-phase motors?
• Which material is commonly used as a sacrificial anode to protect iron components from corrosion?
• Dissolved air flotation has achieved a ______ removal of cryptosporidium, which compares to a removal rate of less than 0.5 log using conventional sedimentation.
• What is the Stage 1 Disinfectants and Disinfection Byproducts Rule maximum contaminant level for chlorite?
• In reporting the water quality, turbidity is expressed in which unit?
• How can an operator accept responsibility for an active role in the safety program?
• What byproduct is most associated with chlorine dioxide used for disinfection?
• Engineers usually design the height of a filter's backwash collection trough to allow for _____ bed expansion without loss of media into the troughs
• How often must an ozone-using system monitor bromate at the distribution system entry point?
• Which type of process control can be used if accuracy is not critical?
• Which pair of colors is not assigned numerical color units?
• Which process is used in the water industry primarily for the removal of organic substances?
• Under the Surface Water Treatment Rule, the turbidity entering the distribution system must not exceed _____.
• What should the operator do for best results in a plant with six flocculators?
• TOC removal requirements increase as alkalinity decreases. Which of the following best describes this relationship?
• Which membrane process combination removes hardness?
• For source water at or below 10 NTU, the sedimentation effluent should meet which turbidity criterion for 95% of the time?
• Which parameter is not part of the Langelier saturation index calculation?
• What is a common disadvantage of using caustic soda to soften hard water?
• The DBPR focuses on which group of contaminants?
• Scale is formed from the combination of which?
• Which term describes a water's buffering capacity?
• What is the chemical formula for hydrated ferric sulfate?
• When do bar or wire-mesh screens usually encounter the largest amount of debris?
• Water becomes capable of _______ iron and manganese when the oxygen levels ________.
• What is the MCL for radon in drinking water?
• Which chemical looks like broken glass crystals?
• Ammonia is fed at about what percent of the amount of chlorine used?
• Stage 2 Disinfectants and Disinfection Byproducts Rule uses sampling sites based on what evaluation approach?
• In the multiple-tube fermentation method, as presumptive positives are inoculated into Brilliant Green Broth (BGB), 0.1 mL of the presumptive broth is also transferred into which medium?
• What is skeletal fluorosis?
• The optimum pH for the removal of excess fluoride by activated alumina is _____.
• Air binding can cause which of the following effects on flow?
• What is under the state-level aquifer protection standard setting?
• In calculating the C x T value, the contact time is extended to which point in the system?
• The solubility of calcium carbonate in water decreases as temperature increases.
• What scale prevention chemical can loosen existing deposits and cause red-water complaints?
• Carbonate hardness relative to total hardness
• Chlorine dioxide has gained popularity because it:
• Which arrangement describes lamella plate flow?
• The process of removing organics from a water sample and concentrating them in a solvent suitable for injection into the ______ is called ______.
• Jar tests are used to determine the powdered activated carbon dose. The glassware used need to be cleaned with _____ and rinsed with _____ water.
• Hypochlorous acid is favored over hypochlorite ion when the pH is _____ and the temperature is ________.
• Why is polyphosphate added to softening process water?
• Regarding the USEPA sampling frequency for radionuclides in drinking water for individual contaminants at each entry point: If results of testing are below the detection limit of an approval method, what is the frequency of sampling?
• Because the gas generated from _______ is pure CO2, the pipes from the diffusers can be _________ than those needed for CO2 generated on site by combustion.
• What factor explains why the bulk density shipping weight differs from laboratory density?
• Lime precipitation of noncarbonate hardness forms which noncarbonate salts?
• What is the maximum contaminant level (MCL) for arsenic in drinking water?
• Rapid pressure changes in a distribution system can cause red water due to precipitation of which iron species?
• When iron corrodes, it converts from which form?
• Threshold odor tests on the raw water and finished water while PAC is being fed should be performed at least
• In the lime-soda ash softening process, smaller plants find that ______ is less expensive to purchase; regardless of size, ______ needs to be mixed long enough because it dissolves slowly.
• Which combination is used to coat sedimentation basin walls to rid the basin of slime growth?
• What is the purpose of turning off surface washers before the end of the backwash?
• Which statement about pump lubrication is false?
• Which statement about high iron and manganese in water is true?
• A gravity thickener would include which of the following components?
• To determine a safe stopping distance behind the vehicle in front, you should consider
• Where is arsenic found naturally?
• What is the function of bases in a treatment plant?
• In greensand filtration, CR is usually used when which contaminant is mostly removed?
• What membrane process will remove hardness?
• What are glassy phosphates?
• A common problem with hyperchloronators is ________
• What is the most common unit of hardness?
• Which softening process would probably not meet the Surface Water Treatment Rule requirements?
• A bacterial slime layer prevents the deposition of ______, and when the slime occasionally gets sloughed away, the slime carries away ______ and leaves the pipe surface bare.
• A water that does not form scale or corrosive is stable; this condition is called what?
• Surface washers should be turned off ____ min before the end of the main backwash.
• Which statement correctly describes HOCl versus hypochlorite at low pH and low temperature?
• How can the problem of poorly formed floc be solved?
• How is magnesium noncarbonate hardness removed?
• Where is the heater located that vaporizes any chlorine liquid that may develop downline from an online one-ton container?
• Actinomycetes are commonly linked to which water quality issue?
• Methyl orange used as an indicator in titrations is ______ on the alkaline side and _______ on the acid side.
• Before installing casing wear rings, what preparation step is recommended?
• Which year range best represents a long-range planning horizon for a water system's source of supply?
• Caustic soda is also known as which option?
• Beneath the slime layer of certain iron bacteria in a pipe, what is produced that reduces pH and speeds up the corrosion rate?
• Which temperature-time combination is used to heat a shaft sleeve prior to installation?
• It is recommended that the free chlorine residual at a customer's tap should be at least ________.
• The most common higher-rate filter media consists of the following (bottom to top)
• To ensure adequate contact time before chlorine addition, PAC should have at least ______ minutes.
• Circuit breakers, compared to _______, have a much _______. This means that they are capable of interrupting the flow of considerably _____ than could be interrupted by _______.
• If a radionuclide is above the MCL in finished water, how often must sampling be done and for how long?
• The dosage of lime and soda ash at a softening plant is based on which of the following alkalinities?
• Which statement about carbonate hardness is correct?
• HPC method, and how long are samples incubated?
• What pH is needed to form the magnesium hydroxide precipitate?
• What does total hardness represent?
• Which material would be best to use as caps on iron bolts so the caps become the sacrificial anodes and the iron bolts the protected cathodes?
• Point-of-use activated carbon filters are most effective for removing ______.
• Which action best reduces siltation in a reservoir?
• Unlike reverse osmosis and nanofiltration, the recovery of the microfiltration process is not limited by the formation of _____ or the precipitation of _____.
• Which of the following is not a part of a bearing?
• Absolute ratings for membranes are based on which pore-size measure?
• To address iron problems when using resin exchange, which pre-treatment step is recommended?
• An organic compound from components of pipe coatings and joint adhesives would most likely include which class of compounds?
• Because bromine is not as stable as chlorine, if it were used to treat public water supplies, how much more would be needed?
• In the lauryl tryptose broth test, which combination describes the bacteria associated with a positive result?
• What can greatly reduce fire hazards?
• When ozone reacts with organic contaminants to form organic acids, what may this eventually contribute to the distribution system?
• To preserve sediments from presedimentation for analysis, which sampling method is recommended?
• What is the most common disinfection byproduct when chlorine is added to water containing natural and inorganic matter?
• Cleaning protocols for microfiltration membranes vary according to the membrane tolerance to changes in which parameter and resistance to which chemical?
• Mass spectrometry identifies organic compounds by which characteristics?
• Which water treatment chemicals lower the pH when added to water?
• Point-of-use activated carbon filters are most effective for removing _________.
• What is the typical detention time for the recarbonation process?
• What process is currently used for softening brackish water?
• What is titration?
• Water that is highly colored with organic material requires a _______ pH for coagulation; therefore, ________ before _________ may be necessary.
• What best describes an operator taking an active role in safety?
• If THMs are still a problem after softening, and changing the disinfectant is not an option, what other treatment process can be used and what is its disadvantage?
• Which structural feature do buttress dams rely on to transfer the water load?
• Which factor will cause problems for chlorination?
• Bicarbonate alkalinity is caused by which species?
• Which measuring and transmitting level device works readily on a 4-20 mA system but needs a temperature correction?
• Which of the following is not a part of a bearing?
• Why can rapid sand filters handle higher filtration rates compared to slow sand filters?
• Turbidity is typically measured in what units?
• Before making corrosion control changes, with which state authority should utilities coordinate first?
• Which of the following salts is not typically a hardness-causing salt?
• In SUVA calculation, which pairing is correct?
• What is the main source of chlorite in drinking water?
• A calcium sulfate molecule would be considered a dissolved solid.
• If any stains or chemical residues remain after normal cleaning of labware, the glassware should be washed with a cleaning solution such as acid-dichromate.
• One key element of LT2 is to use monitoring results to classify surface water sources into USEPA-defined risk levels called bins. How many bins are defined?
• What is molecular weight?
• A treatment plant's effluent water quality would be best shown from a sample collected _____.
• Which statement about the lime-soda ash process is true?
• There are two types of acidity: phenolphthalein acidity, which is prevalent ___________, and mineral acid acidity, which tends to be in the ________.
• Which fires require a Class D fire extinguisher?
• Which chemical is commonly added to provide alkalinity and facilitate precipitation of iron in water treatment?
• If dissolved oxygen increases, the corrosion rate changes as well as the effect of increasing pH and alkalinity on corrosion rate.
• If a water system exceeds the action level for lead and copper, which parameter must be measured in the laboratory?
• Chloramines will be used when tastes and odors are a problem, particularly when the source water contains
• Nitrite interferes with which chlorine residual measurement method?
• According to best practices, tip speed of the last flocculator should be about ______ and operate in the range of _______.
• Backwash bed expansion to prevent media loss is designed to reach what percentage?
• In manganese greensand filtration, what is the typical layer above greensand?
• A condenser will allow which type of current to flow through it, but block the other? One use is to suppress voltage surges.
• In the two-stage recarbonation process, the raw water pH is elevated to ____ or greater with lime; after that stage, carbon dioxide is added to lower the pH to ____
• Under LT2, surface water sources are classified into how many USEPA-defined risk levels called bins?
• What are the principal precursors that react with disinfectants to produce disinfection by products?
• Garnet sand is used at the bottom medium in multimedia filters because it is finer and greater density compared to the other sand in the filter. Which option best describes this characteristic?
• Which regulation protects public health by limiting levels of contamination in drinking water under the Safe Drinking Water Act?
• What is the primary advantage of placing a properly sized anthracite coal layer over manganese greensand?
• What should be done to a shaft after an old sleeve is removed and before a new sleeve is installed?
• What treatment chemical is corrosive, dense, and an oily liquid and is available in strengths of 62%, 78%, and 93%?
• Under USEPA radionuclide sampling frequency for entry point testing, if results are greater than or equal to one-half the MCL and less than the MCL, sampling frequency is every how many years?
• Riparian rights are a common-law doctrine, which body of law are they part of?
• When temperature increases, the corrosion rate usually ________, and when the water is corrosive and the velocity increases, the corrosion rate ______?
• If a water system exceeds the action level for lead and copper, it must measure other contaminants as well. What parameter must be measured in the field?
• What is a disadvantage of using caustic soda to soften hard water compared to other chemicals?
• When analyzing samples for haloacetic acids 5 (HAA5), what is added to the sample container to quench more HAA5 formation?
• What are hearing protection devices given to evaluate their effectiveness?
• Under the Emergency Response Planning Guidelines #2, what is the maximum airborne concentration of chlorine below which nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects that could impair an individual's ability to take protective action?
• Which parameter most strongly influences permanganate reactions in water treatment?
• Bentonite clay improves coagulation by which mechanism?
• Iron complexes with organic matter are anionic and are not removed by which type of exchange?
• Chelation is a chemical treatment process used in water treatment to control which condition?
• Drinking water containing copper well above the action level will most likely cause _______.
• Which hazard pair is most associated with handling activated carbon?
• Ozone may convert large organic molecules into smaller ones. These BDOC compounds serve as food for which organisms?
• Manganese is naturally found in soils primarily as _______ and in the two forms of _______.
• What should an operator do if hardness leakage is excessive immediately following a regeneration stage?
• What type of pretreatment settling units can use coagulants because it has been showing to be very effective?
• What is the chemical formula corresponding to caustic soda?
• What is the best solution for iron problems when using exchange resins?
• The excess lime-softening process is used so that which compound will precipitate out of the water?
• Emergency response at a water treatment facility generally means responding to a _______. This response is governed under the ______ and under _______.
• Before reinstalling a shaft sleeve or impeller, which cleaners should be used?
• Which organization issued the Risk Management Rule in 1996 in an effort to protect public health and safety (nonemployees)?
• To prevent algae growth, which action is most appropriate?
• Cryptosporidium and Giardia typically range in size from which of the following?
• In the presence-absence test, the presence of total coliforms is indicated by the medium turning yellow and the formation of what?
• The best packing for medium pressures and temperatures is ______
• A filter core sample is best collected for solids retention analysis when
• In regenerating ion-exchange systems and lowering the pH of water treated by membrane processes, which chemical family is used?
• The rationale for dividing public water systems into three groups is the ______ of persons using the water.
• In the Stage 2 Disinfectants and Disinfection Byproducts Rule, new sampling sites are based on what evaluation?
• Synthetic organic compounds are more likely to contain which halogen than natural organic compounds?
• Which type of aerators have riffle plates?
• What chemical is used for oxidizing iron and manganese that needs a reaction basin?
• The rate of formation of _____ increases with increasing pH
• Color in the ______ range is determined by a visual comparison of the sample with either a known colored chemical solution or a calibrated color disk.
• If hardness leakage is excessive after regeneration, which action is most appropriate?
• As the TOC increases, the TOC percentage removal required from a source water supply _______.
• If the pH of a water sample increases, the calcium carbonate level will ________, and as the temperature increases, the solubility of the calcium carbonate ________.
• What information can particle counters provide about particles?
• Disinfection byproducts increase as ______ increases, and low pH favors ______ and high pH favors ______.
• Which regulatory rule explicitly includes monitoring for TTHM and HAA5 by Stage 1 DBPR?
• The primary purpose of covering an algae-prone impoundment is to
• Which option shows the correct pairing for caustic soda?
• Driven wells are practical only when the water-bearing formations are relatively close to the surface and no contaminants exist in the soil. Which statement best describes this condition?
• Small and medium sized utilities are deemed to have optimal corrosion control if they meet lead and copper levels for how many consecutive sampling periods?
• In groundwater, the total dissolved solids will change ______ and the dissolved oxygen will change _______, with the dissolved oxygen lowest most probably around ________.
• Chlorite is regulated under the _______ and has maximum contaminant level of ______.
• In the lauryl tryptose broth test, which observation corresponds to a positive result?
• Permanganate reactions are largely dependent on ________.
• Ammonia is an inorganic compound occurring ______
• One benefit of softening water
• Interferences to aerometric chlorine residual measurement come from nitrite.
• The oxidation of manganese in surface water is not effective until the pH goes to or surpasses which value?
• Phenolphthalein acidity is prevalent above which pH value?
• During HAA5 analysis, which chemical is used to quench further HAA5 formation?
• The final RCTR requires which entity to notify the public if a test exceeds the MCL for E. coli in drinking water?
• Which chemical used for oxidizing iron and manganese will react with hydrogen sulfide, cyanides, phenols, and other taste and odor compounds and will not form trihalomethanes?
• What is an ion?
• What is another name for hydrochloric acid?
• Which byproduct is formed when ozone is used for disinfection and is commonly monitored for public health protection?
• Which color range is used for color assessment by visual comparison with a color disk?
• Powdered activated carbon dosing: which feed system reduces handling problems?
• The solubility of calcium carbonate decreases as temperature increases.
• After a routine sample tests positive for total coliforms, which analyses are required?
• _____ pipettes are used for performance monitoring and should be ______
• Microfiltration membranes made from PDVF have excellent chemical resistance to which substance, and what is their typical service life?
• ______ and ______ should not be stored in the same refrigerator.
• A coagulant aid primary benefit is to reduce the amount of coagulant used.
• If a UV reactor is operating outside of the validation limits by more than _____ of the water treated, it is considered off-specification.
• Under the Ground Water Rule, large systems disinfecting must monitor continuously while small systems must monitor daily.
• The best packing material for medium pressures and temperatures is which?
• Under Stage 1 disinfection byproduct rules, haloacetic acids are measured in which unit?
• In the described extraction method, the analytes are concentrated for injection into which instrument?
• When dewatering alum sludge using mechanical equipment, pretreatment is typically done with which device and feature?
• Point-of-use activated carbon filters are most effective for removing which of the following?
• Air binding is caused by pressure in the filters ______ than atmospheric pressure, and it can cause ______ flow.
• What is the one objective of a safety program?
• The Information Collection Rule is designed to support the development of which types of regulations?
• Which feed system reduces handling problems with powdered activated carbon?
• Driven wells are practical only when the water-bearing formations are relatively close to the surface and no contaminants exist in the soil. Which option best reflects this condition?
• Emergency response at a water treatment facility is governed under which combination?
• Which of the following is the correct alternative name for hydrochloric acid?
• Compared to Stage 1 Disinfectants and Disinfection Byproducts Rule (DBPR), what major change was made when Stage 2 DBPR was promulgated?
• In manganese greensand filters, the greensand is usually capped with at least _____
• Which treatment chemical raises pH?
• Which type of sample is specifically excluded from mailing to a laboratory for transport?
• What is produced after colloids have just become charge neutralized?
• How does cyanide affect the human body?
• Which statement best describes the focus of the discussed rules in relation to drinking water?
• Lubrication used on the bearings of line shaft turbines can be _____
• A special problem with granular activated carbon filters is the rapid growth of which microorganisms?
• A gravity dam resists both ______.
• If TOC removal percentages cannot be met, a utility can comply with the EPA rule by removing at least ______ of _______, as CaCO3, measured monthly and calculated quarterly as an annual running average.
• When using chlorine disinfectants, lower temperatures favor the formation of _______. Lower temperatures also show _______ to persist somewhat longer.
• What is the required minimum alkalinity (as CaCO3) for manganese greensand filters?
• Diatomaceous earth filtration is used for raw water that has a maximum turbidity of ____.
• Which oven is used to burn solids?
• Which two items are specifically targeted by LT1ESWTR turbidity performance standards?
• What is the main, easiest way to identify a confined space?
• Hardness has any unwanted health effects?
• Among the VOCs found in groundwater, which are encountered most frequently and in the highest concentrations?
• What compounds are formed when calcium and magnesium are precipitated out of water in the lime softening process?
• Methane dissolved in water will cause which taste?
• Which statement is true about the Saybolt Universal Seconds (SUS) unit?
• The chlorine-measuring method that uses a gas-permeable membrane is the polarographic method.
• Equivalent weight is defined as the weight that will react with, displace, or is equivalent to one gram of hydrogen.
• Under the Stage 1 Disinfectants and Disinfection Byproducts Rule, which compound has an MCL of 1.0 mg/L?
• Which solvent is used to clean an old bearing?
• Under LT2, UV disinfection is specified to provide at least a log removal/inactivation for which organism?
• Which option is NOT a purpose of polyphosphate addition in softening water?
• Which chemical is used to raise alkalinity but requires the most maintenance?
• Powdered Activated Carbon (PAC) is used in water treatment to achieve removal of contaminants primarily through which mechanism?
• In determining a safe following distance, you should primarily consider
• In lime softening, the precipitated solids are which of the following?
• What is the new MCL for uranium established by the final Radionuclides Rule?
• Which source water is most likely to contain iron and manganese?
• The Information Collection Rule requires large water systems to collect information to build a database to assist in the development of which regulations?
• Cartridge pre-filters installed ahead of a reverse osmosis unit serve what purpose?
• All sedimentation basins should be equipped with which of the following safety features?
• After microscreening, there should be a significant reduction in _________.
• At a softening plant, the most severe carryover of sludge in a sedimentation basin occurs when which condition?
• What is the main consideration in determining the length of the service stage of an ion exchange softener?
• What corrosion prevention chemical may be the best overall treatment approach?
• Airline supplied air is not commonly used for emergency response because they are limited to only _______ ft.
• Greensand filters are often capped to enhance filter performance and backwash efficiency. It is common to cap them with...
• Which statement describes a common natural form of manganese (Mn) in soils and is not MnO?
• When is the best time to start using a destratification equipment to overturn a lake?
• The sediment from presedimentation systems can be kept if samples are collected _________.
• Which chemical is used as a corrosion inhibitor in water treatment?
• The flocculation and settling of calcium carbonate and magnesium hydroxide precipitates occur more quickly in the presence of what?
• Which two hardness-forming cations are most commonly present in significant concentrations?
• Which regulation requires performance goals for filters, data collection, and reporting exceptions for any filter not performing in accordance with the turbidity values stated in the rule?
• Noncarbonate hardness is defined as
• Which statement about the lime-soda ash process characteristics is correct?
• What filter types would be best for direct filtration?
• Which oxidant used for iron and manganese will react with hydrogen sulfide and will not form trihalomethanes?
• In open filters, which pairing of media is associated with superior organics removal?
• Which process is currently used for softening brackish water?
• Which unit is commonly used to express viscosity in the Saybolt Universal system?
• Under LT2, which three parameters were added for testing?
• The filtration ripening process is driven by which phenomenon?
• The LT2 Enhanced Surface Water Treatment Rule added tests that were not in the original rule. Which tests were added?
• Which organism was introduced to the United States from Southeast Asia and has become a significant pest in almost every river system?
• Large bubble diffusers can be cleaned with which method?
• What acid is more corrosive when it is diluted?
• If PAC does not remove tastes and odors, what is a likely explanation?
• Stage 2 DBPR compliance is evaluated at each monitoring location using which metric?
• Which skin condition has lower resistance to electrical current flow?
• What is the typical backwash rate for resin beds?
• Why are primary standards or MCLs enforceable by law?
• Which list identifies contaminants not regulated by current standards and monitored for potential future regulation?
• Under current regulations, what type of samples must be collected from the source water supply?
• In the lime-soda ash process, what will cause increased solubility of taste and odor causing compounds?
• Hydraulic fracturing uses pressure to force ______ into existing fractures to open and separate different _____.
• When using calcium hypochlorite, calcium carbonate scaling can occur on the suction and discharge sides of the pump. What is the best solution?
• What instrument is used to measure the depth to gravel in a filter bed?
• Which statement describes how aluminum oxide is activated?
• What does the optimal pH establish when applying oxidation to iron and manganese?
• Which radon removal method is most effective considering cost and footprint?
• Greensand filters are often capped to enhance filter performance and backwash efficiency. It is common to cap them with...
• Which agencies are recommended to set the optimum fluoride level in drinking water?
• When natural gas and air are used to make CO2 for recarbonation, good ventilation is required because dangerous concentrations of which gas are produced?
• Which organization established regulations for new chemical contaminant testing?
• Which compound is commonly used to prevent encrustation by sequestering metal ions?
• In the lime-soda ash softening process, coagulants are used to gather which substances into particles that settle readily?
• Methyl orange used as an indicator in titrations is ______ on the alkaline side and _______ on the acid side.
• ________ is often added to provide _______ and facilitate iron precipitation
• Carbonate alkalinity is caused by which ion?
• Which regulation governs microbial monitoring in drinking water distribution systems?
• Define anion.
• For conductivity sampling, which statement is correct?
• What is the CT value?
• What should be used to clean an old bearing?
• In water treatment, chelation is applied primarily to prevent which condition?
• Which of the following defines carbonate alkalinity?
• In the simplest terms, what is hardness?
• Which gas(es) does electrolytic flotation use?
• What membrane process will remove dissolved solids?
• Excessive algae growth in a presedimentation impoundment is best controlled by:
• Destratification is most effective when the lake has a stable layer of warm surface water over cooler bottom water.
• Define cation.
• Which chemical is used to raise alkalinity in water treatment?
• Chlorine dioxide can revert to chlorite and chlorate under which conditions?
• What is the minimum free chlorine residual at the customer tap that is considered acceptable for ongoing disinfection?
• Why are cold-weather conditions an added hazard when working around water?
• Excessive up-thrust on line shaft turbines is caused by
• How are manganese greensand beds regenerated in typical treatment systems?
• What is the filter bed used for in the softening process?
• What is the primary purpose of pressure aerators in water treatment?
• Which contaminants make up the Contaminant Candidate List (CCL)?
• In a buttress dam, the impounded water's weight is used to resist which forces?
• If a routine or repeat sample tests positive for total coliforms, it must also be analyzed for _______.
• Which alum sludge dewatering method can attain at least 20% solids by weight?
• What is the best way to deal with accidents or safety incidents?
• Which two test methods for coliform bacteria include a three-step process?
• In viscosity testing, which unit is commonly used to express viscosity?
• In the wellhead protection program, which technical step is essential?
• Which genus has killed the most people because of its high mortality rate when contracted?
• If there is no pretreatment, what membrane processes will remove dissolved organic matter?
• Lime slakers should be equipped with a _______ that will stop the lime feed before _______.
• Which results are used to develop the Langelier saturation index?
• Alkalinity definition and units
• Which concept defines that the proportion by weight of elements in a compound is constant regardless of the method used to form the compound?
• How do the Surface Water Treatment Rules define surface water?
• Chlorine dioxide can revert to chlorite and chlorate under which conditions?
• During lime softening, the hardness-causing ions are transformed into which form as pH rises?
• When ozone is used as a primary disinfectant, which byproducts may form that require monitoring?
• If too much aeration occurs after clarification and filtration, which process will most probably suffer?
• Lime-soda ash softening can reduce water hardness to approximately which range?
• Point-of-use activated carbon filters are most effective for removing which contaminant?
• Which compound looks like broken glass crystals?
• The iodometric method is a variation of which method for dissolved oxygen determination?
• Microfiltration is considered to be intermediate between _______ based on pore size
• To demonstrate 4-log inactivation of viruses, adequate C x T must be provided.
• Mechanical mixers should never be used in conjunction with which component?
• A specific-ion meter resembles a _______ except for the addition of a ______ and a provision for a selective-ion electrode.
• Jar tests are used to determine the dose of which material in water treatment?
• In open filters, which media arrangement provides superior removal of organics?
• Phenolphthalein is colorless at low pH and pink or red at higher pH. How does it appear at pH below 8.3 and above 8.3?
• Long-range planning for a water system's source of supply should be approximately which range?
• Increasing which factors together will decrease corrosion rate?
• Titration is best described as a method used to determine the composition of a sample by incrementally adding a standard solution until what occurs?
• What are the potential hazards when handling activated carbon?
• Where is nitric acid most commonly used within a water treatment facility?
• Under the ______, nonuse for a long period of time may result in loss of water right by forfeiture or abandonment.
• How often are the maximum daily temperatures determined to establish the optimal fluoride levels for any particular state?
• The specific ultraviolet absorbance (SUVA) is calculated using the absorbance of UV light at 254 nm ______ the concentration of _______
• In lime-soda ash softening, which compound is formed by reaction of lime with carbonate hardness?
• Diatomaceous earth filtration maximum turbidity value?
• Which statement about pumps is false?
• Alternate description of glassy phosphates: Glassy phosphates are best described as which of the following?
• Which statement correctly pairs acidity types with pH ranges?
• An advantage of using ozone treatment is....
• The LT2 rule requires a minimum chlorine residual at the entry to the distribution system. Which value is specified?
• In a filtration system, adding an anthracite coal layer over greensand primarily improves which performance aspect?
• What is the only reliable method of detecting hydrogen sulfide in the air?
• When alum is added to water, it causes the pH to _______, and when ferric salts are added to water, it causes the pH to ________.
• This parameter is used to determine if the Disinfectants and Disinfection Byproducts Rule is in compliance.
• In a presedimentation impoundment, which option would most directly limit algae growth by reducing light exposure?
• A gas chromatography-mass spectrometer would be used to determine ______ in a sample.
• What is the most common radionuclide anion?
• What has caused a significant increase in environmental aluminum exposure?
• The cleaning of microfiltration membranes helps maintain a stable ______ while keeping recovery at or above _______.
• Which pairing of units correctly describes electrical energy and power?
• What is the mechanism by which potassium permanganate works when used to control algae?
• What corrosion prevention chemical may actually cause tuberculation in iron pipe in the pH range of 7.5-9.0?
• Caustic soda is also known as
• Some systems using aeration towers are required to install air scrubbers. These scrubbers use _____.
• Minimum hardness achievable by lime-soda ash process
• Without pretreatment, which membrane processes must be used to remove dissolved organic matter?
• In the context of softening, floc is often composed mainly of which precipitate?
• Which parameter is used to quantify disinfection effectiveness as the product of concentration and time?
• The major provisions of the LT1ESWTR include the control of ____ and ______ turbidity performance standards.
• In an electrolyte solution, a cation is attracted to which electrode?
• The flow through a sedimentation basin should not exceed...
• The Lead and Copper Rule is different from the other rules in that it deals with ______ to determine compliance.
• Ammonia is a dangerous gas and is readily detectable at concentrations of ______.
• Which combination describes a low-cost PAC feed method suitable for secondary treatment?
• Chlorite monitoring is required only for systems using ______
• Lime softening effect on disinfection
• The suction side of a pump's piping should be ______ pipe size ______ than the intake side of the pump.
• Which chemical is used to regenerate manganese greensand beds?
• Compared to conventional sedimentation, dissolved air flotation achieves what with cryptosporidium removal?
• What loads are applied to a pump's shaft?
• In the presumptive test, if gas is produced after either the 24-Hour or 48-Hour incubation period, the sample must undergo the confirmed test.