Download Water Distribution and Treatment Fundamentals and more Exams Water Resources Planning and Management in PDF only on Docsity!
OIT WATER TREATMENT TEST | OPERATOR-IN-
TRAINING EXAM | ALL QUESTIONS AND
CORRECT ANSWERS (GRADED A+) | VERIFIED
ANSWERS | JUST RELEASED
When flushing a water main, operators should ensure that the pressure in nearby areas does not drop below _______. a) 60 kPa b) 140 kPa c) 350 kPa d) 550 kPa ---------CORRECT ANSWER-----------------b) 140 kPa Which of the following best describes the largest volume of water a distribution system would normally supply during a day? a) minimum demand (L/hour) b) average demand (L/hour) c) peak demand (L/hour) d) average demand per person (L/hour/person) ---------CORRECT ANSWER-----------------c) peak demand (L/hour) Distribution lines are flushed periodically to: a) increase water pressure in the system b) reduce the risk of water hammer c) ensure that chlorine does not accumulate in pipes d) remove deposits from the pipeline ---------CORRECT ANSWER------------- ----d) remove deposits from the pipeline What is NOT one of the main purposes of distribution storage?
a) to help satisfy peak demand b) to allow for a uniform water treatment and pumping rate c) to provide water for firefighting needs d) to store a large volume of water for long periods of time --------- CORRECT ANSWER-----------------d) to store a large volume of water for long periods of time What is the name of the valve which connects the customer's service line to the municipal water line? a) bypass valve b) control flume c) curb stop d) check valve ---------CORRECT ANSWER-----------------c) curb stop In an activated sludge process, some of the sludge collected in the secondary sedimentation tank is returned to the _______ to maintain the mass of the mixed liquor. a) grit channel b) aeration tank c) primary sedimentation tank d) digester ---------CORRECT ANSWER-----------------b) aeration tank Why does untreated sewage cause serious problems to streams and lakes? a) sewage will deplete the water of oxygen required by fish and other animals b) sewage creates unpleasant odours for water animals c) sewage decreases the temperature of the water d) sewage will decrease the amount of nutrients in the water --------- CORRECT ANSWER-----------------a) sewage will deplete the water of oxygen required by fish and other animals
Secondary treatment typically removes ______ of the BOD and suspended solids. a) 20-39% b) 40-59% c) 60-79% d) 80-99% ---------CORRECT ANSWER-----------------d) 80-99% Water entering a wastewater treatment plant will pass through a bar screen. The bar screen is designed to remove which of the following items? a) dissolved solids b) grit and sand c) large objects d) nutrients ---------CORRECT ANSWER-----------------c) large objects Define the term 'supernatant' a) a solution which is supersaturated b) a substance used to reduce odour in polluted waters c) the liquid located above a sediment or precipitate d) an operator who is extremely proficient in fulfilling their duties --------- CORRECT ANSWER-----------------c) the liquid located above a sediment or precipitate A __________ is used to move wastewater from a wastewater lift station to an elevated gravity sewer: a) sewer lateral b) force main c) sanitary trunk main d) transmission main ---------CORRECT ANSWER-----------------b) force main
What happens when a sewer is surcharged? a) infiltration of ground water into sewers b) flushing a sewer with clean water to clean debris away c) hydraulically overloading a sewer d) taxing a customer's water bill to pay for collection devices --------- CORRECT ANSWER-----------------c) hydraulically overloading a sewer Which of the following infectious diseases can be transmitted through domestic wastewater? a) hepatitis b) giardiasis c) cryptosporidiosis d) all of the above ---------CORRECT ANSWER-----------------d) all of the above What is meant by the term "combined sewers"? a) industrial sewage and domestic sewage are collected in the same sewers b) stormwater and sewage are collected in the same sewers c) the main sewer line which takes all of a city's sewage to the treatment plant d) a sewer which contains both gravity sewers and force mains --------- CORRECT ANSWER-----------------b) stormwater and sewage are collected in the same sewers Why is hydrogen sulphide gas a problem in sewers? a) results in an increase in rodent populations b) the gas can block the flow of sewage
b) Any operational duties if not in the presence of another operator c) Anything which could effect the quality of the water/wastewater d) Be the operator with overall operational responsibility of the system ------ ---CORRECT ANSWER-----------------d) Be the operator with overall operational responsibility of the system Define the term "head" as used in hydraulic systems. a) The block of an internal combustions engine b) The ability of a piston pump to overcome the force of gravity c) The height or energy of water above a specified point d) The distance between the liquid level and the cover of a well --------- CORRECT ANSWER-----------------c) The height or energy of water above a specified point Which of the following statements accurately describes some of the properties of chlorine? a) I a colourless gas which is toxic to plants and animals; is flammable and explosive b) Is a greenish/yellow gas with a penetrating odour; is heavier than air c) Is a yellowish gas with an irritating odour; insoluble in water d) Is lighter than air; soluble in water and forms a salt which is lethal to microorganisms ---------CORRECT ANSWER-----------------b) Is a greenish/yellow gas with a penetrating odour; is heavier than air What happens when two or more different elements combine? a) chemical compound is formed b) atom is created c) molecule is formed d) concentration is created ---------CORRECT ANSWER-----------------a) chemical compound is formed
What is the definition of a confined space? a) Any space which is not actively ventilated by an electrical ventilation system b) Any space from which exit by an injured worker is difficult c) Any space where hazardous gas can accumulate or an oxygen deficient atmosphere can occur d) Any space where the distance from floor to ceiling is less than 3 metres - --------CORRECT ANSWER-----------------a) Any space which is not actively ventilated by an electrical ventilation system The flow of electrical current is measured in a) Amperes b) Ohms c) Volts d) Watts ---------CORRECT ANSWER-----------------a) Amperes What is meant by the term 'organic compounds'? Chemical compounds that are: a) not made from carbon b) contain carbon, hydrogen and oxygen c) can easily oxidize d) can dissolve in water ---------CORRECT ANSWER-----------------b) contain carbon, hydrogen and oxygen The volume of chlorine increases ______ times when it is depressurized into gas a) 100 b) 200
c) Hydrogen sulphide gas in all concentrations is only an irritant, so proceed with the task d) Do not enter the confined space until there is no hydrogen sulphide detected, and then only when all safety equipment is in place --------- CORRECT ANSWER-----------------d) Do not enter the confined space until there is no hydrogen sulphide detected, and then only when all safety equipment is in place What is the main purpose of the Safe Drinking Water Act? a) Certify operators b) Protect human health c) Supervise drinking water systems d) Sample and test drinking water ---------CORRECT ANSWER----------------
- b) Protect human health What does a sample with a high BOD level indicate? a) Low organic material content b) High organic material content c) High level of inorganic suspended solids d) Low level of pathogenic bacteria ---------CORRECT ANSWER--------------- --b) High organic material content Which of the following statements is the most accurate concerning a "Certificate of Approval" (C of A), issued by the Ministry of Environment? a) The terms and conditions stated in a C of A are legally enforceable b) The terms and conditions stated in a C of A are recommendations on how the facilities should be operated c) A C of A is only required for facilities built before 1965 d) Once a facility has been built the C of A is no longer required and can be discarded ---------CORRECT ANSWER-----------------a) The terms and conditions stated in a C of A are legally enforceable
Coagulation is the mixing of coagulants with water to: a) disperse colloidal material b) form floc c) inactivate colloids d) suspend floc ---------CORRECT ANSWER-----------------b) form floc Trihalomethanes are produced when chlorine reacts with: a) inorganic materials b) chlorine dioxide c) organic materials d) ultra violet light ---------CORRECT ANSWER-----------------c) organic materials What is the chlorine residual in water? a) the amount of chlorine applied to the water daily b) low concentrations of chlorine gas c) chlorine salt which is left after water evaporates d) amount of chlorine that remains in water after disinfection --------- CORRECT ANSWER-----------------d) amount of chlorine that remains in water after disinfection The chlorine dosage of a town's water source is 4.0 mg/L. The chlorine demand for the water is 3.7 mg/L. What is the chlorine residual? a) 0 mg/L b) 0.3 mg/L c) 3.7 mg/L d) 4.3 mg/L ---------CORRECT ANSWER-----------------b) 0.3 mg/L
a) infiltration from a high water table b) exfiltration from a high water table c) excessive recirculation d) inverted siphon ---------CORRECT ANSWER-----------------a) infiltration from a high water table Who is primary responsible for your safety? a) you b) employer c) MOE d) government ---------CORRECT ANSWER-----------------a) you When operating a pump, an operator feels a vibration and hears a slight hammering noise. a) water hammer b) cavitation ---------CORRECT ANSWER-----------------b) cavitation when monochloramines reacts with hypochlorous acid, the product is? ------ ---CORRECT ANSWER-----------------Dichloramine a chemical used to dechlorinate water quality samples is? --------- CORRECT ANSWER-----------------sodium thiosulfate How long are you required to keep the tap closed before you grab a sample for lead and copper? ---------CORRECT ANSWER-----------------6 hours
Which water source typically has the highest concentration of dissolved solids? ---------CORRECT ANSWER-----------------Groundwater What is the purpose of the lantern ring? ---------CORRECT ANSWER--------- --------Cools and lubricates the packing What occurs in the first stage of the breakpoint chlorination curve? --------- CORRECT ANSWER-----------------Chlorine is destroyed by reducing compounds Which of the following is a strong acid? ---------CORRECT ANSWER--------- --------pH = 1 A food supply for microorganisms can be measured in the laboratory as? -- -------CORRECT ANSWER-----------------Assimilable organic carbon Bromate formation can be reduced by the addition of which of the following, prior to ozonation? ---------CORRECT ANSWER-----------------Ammonia Ozone is a major component of? ---------CORRECT ANSWER----------------- Smog When no chlorine is added prior to the filtration processes, this process can be used to? ---------CORRECT ANSWER-----------------Consume BDOC
Of the four chemicals approved for water disinfection by the Surface Water Treatment Rule, the one most associated with chlorite formation is? --------- CORRECT ANSWER-----------------Chlorine dioxide Of the four chemicals approved for water disinfection by the SWTR, the one that produces the highest bromate levels is normally? --------- CORRECT ANSWER-----------------Ozone Of the four chemicals approved for water disinfection by the SWTR, the one that produces the highest trihalomethane levels is normally? --------- CORRECT ANSWER-----------------Free chlorine How many carbon atoms are present in a molecule of a trihalomethane? --- ------CORRECT ANSWER----------------- 1 Halogens within the regulated THMs and HAAs are chlorine and? --------- CORRECT ANSWER-----------------Bromine The current MCL for bromate is? ---------CORRECT ANSWER----------------- 10 ug/L Form a DBP perspective, a high level of TOC would be a concentration in excess of? ---------CORRECT ANSWER-----------------4 mg/L
The precursors for THMs and HAAs are collectively known as? --------- CORRECT ANSWER-----------------Natural Organic Matter The current MCL for Haloacetic Acids is? ---------CORRECT ANSWER------- ----------60 ug/L A chemical that is applied to drinking water mainly to provide a residual disinfection benefit is referred to as a? ---------CORRECT ANSWER---------- -------Secondary disinfectant The term for the attached microbiological growth in a distribution system is the? ---------CORRECT ANSWER-----------------Biofilm Which of the following chemicals is commonly used for the formation of chloramines? ---------CORRECT ANSWER-----------------Aqueous ammonia A problem in distribution systems associated with chloramination is? --------- CORRECT ANSWER-----------------Nitrification The optimum chlorine-to-ammonia ratio for chloramine operations is? ------- --CORRECT ANSWER-----------------5: What is the MRDL for free chlorine in the distribution system? --------- CORRECT ANSWER-----------------4 mg/L
Which of the following may be present in commercial sodium hypochlorite solutions? ---------CORRECT ANSWER-----------------All of the above The MCL for trihalomethanes is? ---------CORRECT ANSWER----------------- 80 ug/L Which of the following is the least potent disinfectant? ---------CORRECT ANSWER-----------------Chloramines The main advantage of chloramination over chlorination is? --------- CORRECT ANSWER-----------------Reduced by-product formation The most commonly used drinking water disinfectant in the United States is? ---------CORRECT ANSWER-----------------Chlorine Which of the following is the most potent disinfectant? ---------CORRECT ANSWER-----------------Ozone Haloacetic acids may be formed when natural organic matter reacts with? - --------CORRECT ANSWER-----------------Free chlorine The organic precursors of disinfection by-products are measured as? ------- --CORRECT ANSWER-----------------Total Organic Carbon
An effective way to increase disinfection without increasing disinfectant dosage is to? ---------CORRECT ANSWER-----------------Increase disinfectant contact time When free chlorine reacts with NOM, which of the following is likely to be formed? ---------CORRECT ANSWER-----------------Haloacetic acids The disinfectant residual used for calculating "CT" is from the? --------- CORRECT ANSWER-----------------Process effluent The running annual average for bromate is calculated from samples that are collected? ---------CORRECT ANSWER-----------------Monthly Compared to chlorine, what is the mass of bromine? ---------CORRECT ANSWER-----------------More than twice as much Which of the following is a product of the reaction of chlorine and sodium chlorite? ---------CORRECT ANSWER-----------------Chlorine dioxide A disinfection by-product associated mostly with chlorine dioxide is? --------- CORRECT ANSWER-----------------Chlorite The MCL for haloacetic acids is? ---------CORRECT ANSWER----------------- 60 ug/L
