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136 Cards in this Set
- Front
- Back
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Which of the following soil conditions is most favorable for removal of viruses? |
b. fine loamy sand over course sand and gravel
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Which of the following organisms are most resistant to unfavorable environmental conditions and indicate past or possibly intermittent pollution?
a. fecal streptococci b. Escherichia coli c. Aerobacter aerogens d. clostridium sporulates |
d. clostridium sporulates
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Which of the following wells is considered the most dependable source of water and is less likely to become contaminated?
a. driven well b. bored well c. drilled well d. dug well |
c. drilled well
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Which of the following is not considered a satisfactory solution to the problem of chemical contamination in well systems?
a. abandoning the well b. boiling the water c. connecting to a public water system d. building a new, properly constructed, drilled well |
b. boiling water
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Which of the following chemicals is the most widely used to destroy microorganisms?
a. chlorine b. copper sulfate c. chloramine d. hydrogen sulfate |
a. chlorine
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Which of the following is the best method of backflow control?
a. air gap separation b. vacuum breaker c. backflow preventer d. barometric loops |
a. air gap separation
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Microscopic photosynthetic plants of the simplest forms, having neither roots, stems, nor leaves, that are associated with taste and odor, filter clogging, and other water problems are known as
a. yeasts b. algae c. protozoa d. rotifers |
b. algae
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Control of infectious, intestinal diseases of humans requires
a. provisions of safe water supplies b. proper waste disposal c. personal hygiene d. all of the above |
d. all of the above
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Drinking water standards generally specify that a water is safe provided that testing in a specified manner does not reveal more than an average of
a. 10 positive samples out of 100 samples taken b. 50 coliform organisms per 100 ml c. 1 positive sample out of 40 samples taken d. 50 coliform organisms per 200 ml |
c. 1 positive sample out of 40 samples taken
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What does it mean when a body of water has a high JTU?
a. it has a low amount of organic matter b. it has no bacteria c. no one is swimming at this time d. it has high turbidity |
d. it has high turbidity
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The presence of which of the following is most easily identified by laboratory analysis in water contaminated by feces?
a. shigella dysenteriae b. coliform c. entamoeba histolytica d. salmonella typhosa |
b. coliform
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Nephelometric Turbidity Units (NTU) are most commonly used to
a. determine the type of pollution or contamination present in natural waters b. estimate the amount of dissolved oxygen in surface waters c. define the strength of waste waters d. determine turbidity |
d. determine turbidity
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The safe distance between a well and a waste disposal system is dependent on
a. chemical processes b. physical processes c. biological processes d. all of the above |
d. all of the above
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What is the first step in evaluating the safety of a potential water system?
a. the frequency with which source and distribution system ware samples are collected b. a detailed sanitary survey of the water supply c. the standard plate count for bacterial examination d. the results of a bacterial chemical examination |
b. a detailed sanitary survey of the water supply
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What are examples of ground water systems?
a. dug, bored, driven, drilled wells; rock , sand or earth springs; infiltration galleries b. water located no deeper than 400 feet c. direct municipal wastewater systems d. lake, reservoir, stream, pond, river, and creek supplies |
a. dug, bored, driven, drilled wells; rock, sand or earth springs; infiltration galleries
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What causes water hardness?
a. high concentrations of iron b. pond, creek or other surface water c. well-water supplies that are improperly constructed, protected or located d. dissolved calcium and magnesium bicarbonates, sulfates, and chlorides |
d. dissolved calcium and magnesium bicarbonates, sulfates, and chlorides
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What is desalination?
a. the detection of detergents in water by laboratory examination b. the process of removing undesirable tastes and odors from domestic water supplies c. one of the classifications of springs d. the conversion of seawater or brackish water to fresh water |
d. the conversion of seawater or brackish water to fresh water
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The quality of surface water depends on
a. the use of chemicals for disinfection of drinking water b. the elimination of coliform organisms c. the watershed area drained, land use, location and sources of pollution, and the natural agencies of purification d. the injecting of a chlorine solution into water at its source |
c. the watershed area drained, land use, location and sources of pollution, and the natural agencies of purification
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Which of the following is not commonly used for disinfection of water?
a. chlorine b. silver nitrate c. chlorine-ammonia compounds d. ozone |
b. silver nitrate
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Hydro penumatic or pressure-tank water systems are suitable for
a. providing sufficient water to meet peak demands for domestic, commercial, and industrial purposes b. small communities, housing developments, private homes and estates, camps, food service operations, and hotels c. water storage requirements d. helping to control watershed runoff |
b. small communities, housing developments, private homes and estates, camps, food service
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The hydro pneumatic tank typically contains ___ of its volume as water.
a. 50 percent b. 80 percent c. 20 percent d. does not contain water only compressed air |
c. 20 percent
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Water containing nitrates generally indicates
a. a nearby cesspool b. evidence of previous pollution c. a chemical leak d. a nearby slaughterhouse |
b. evidence of previous pollution
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Diatomaceous earth filters
a. should be integrated into pressure-tank systems b. can be used for public water supplies c. should be augmented by chlorination d. can be left unattended for long periods of time. |
c. should be augmented by chlorination
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Hydrogen sulfide can be fatal at exposure of
a. 100 ppm b. 150 ppm c. 225 ppm d. 300 ppm |
d. 300 ppm
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The most practical method for removing nitrates from water is
a. reverse osmosis b. ion exchange c. reverse osmosis d. double reverse osmosis |
b. ion exchange
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Which of the following is not a practical method for removal of cadmium?
a. ion exchange b. lime softening c. reverse osmosis d. iron coagulation |
c. reverse osmosis
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Back-siphonage may be prevented by all of the following methods except
a. barometric loop b. vacuum breakers c. air gap separation d. back pressure units |
a. barometric loop
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Of the following, which is not a variable to be considered when deciding upon a safe distance between a well and a sewage disposal system?
a. well construction, tightness of pump connection, depth of well casing and sealing of the annual space b. the number of individuals utilizing the well c. the volume, strength, type and dispersion of the polluted material d. the soil structure and texture |
b. the number of individuals utilizing the well
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Microbial pollution travels only a short distance through
a. solution channels in limestone b. fissured rock c. dried-out, cracked clay d. sandy loam or clay |
d. sandy loam or clay
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Typically, an abundant supply of groundwater may be yielded from
a. sedimentary rocks b. molten rocks c. igneous rocks d. metamorphic rocks |
a. sedimentary rocks
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An example of a surface water supply would be
a. a well b. a rock and sand spring c. an earth spring d. a reservior |
d. a reservoir
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Which of the following is used to properly seal a drilled well to prevent contamination of the water supply?
a. epoxy b. bentonite clay c. grouting d. a rubber seal |
c. grouting
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Which of the following compounds would not contribute to water hardness?
a. calcium sulfate b. magnesium c. calcium chloride d. sodium chloride |
d. sodium chloride
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The quiescent settling of water such as would occur in a reservoir, lake or basin without the aid of chemicals is known as
a. plain sedimentation b. coagulation c. settling d. flocculation |
a. plain sedimentation
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Which of the following is not a commonly accepted method or device to prevent back siphonage?
a. vacuum breakers b. cross-connections c. air gap separation d. back pressure units |
b. cross-connections
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Which of the following disinfecting compounds can be used full strength for disinfection?
a. perchloron b. calcium hypochlorite c. chlorinated lime d. sodium hypochlorite |
d. sodium hypochlorite
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The type of filter that is recommended for use at small communities and rural places is the
a. rapid sand filter b. pressure filter c. slow sand filter d. diatomaceous earth filter |
c. slow sand filter
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All of the following will generally vary directly with the quantity of water used for domestic purposes except
a. availability b. habits of the people c. cost of water d. amount of minerals in the water |
d. amounts of minerals in water
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Groundwater in the soil travels up through a plant's root system and then comes out from the leaf structure as
a. transpiration b. sublimation c. evaporation d. condensation |
a. transpiration
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The type of water that makes it difficult to produce suds or to rinse laundry, dishes or food equipment is
a. soft water b. hard water c. spring water d. distilled water |
b. hard water
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A sanitary survey of a water system is necessary for what reason?
a. to determine the safety and the adequacy of the water supply b. to determine how much iron is in a water supply c. to determine what size pump is needed for the water system d. to determine whether the water in the system is hard or soft |
a. to determine the safety and the adequacy of the water supply
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The sources of water supply are divided into which of the following major classifications?
a. spring water and well water b. groundwater and surface water c. rainwater and river water d. demineralized water and lake water |
b. groundwater and surface water
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The gas causing the distinct "rotten egg" odor in many water sources is
a. hydrogen sulfide b. carbon dioxide c. chlorine gas d. hydrogen carbonate |
a. hydrogen sulfide
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High concentrations of nitrates in drinking water are
a. detrimental to adults b. considered safe to drink c. the cause of a blood disease in teenagers d. a possible cause of methemoglobinemia |
d. a possible cause in methemoglobinemia
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Turbidity of water will
a. interfere with proper disinfection b. harbor viruses c. causes tastes and odor d. all of the above |
d. all of the above
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This substance is the first product of the decomposition of organic matter. Its presence in water usually indicates "fresh pollution" of sanitary significance. What is it?
a. ammonia b. sugar c. carbon dioxide d. hydrogen sulfide |
a. ammonia
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The presence of which of the following elements in water treatment plant effluent is used as a measure of filtration efficiency?
a. copper b. aluminum c. zinc d. lead |
b. aluminum
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One of the most common reasons for the contamination of wells drilled through rock, clay, or hardpan is
a. seepage of pollutants through soil b. failure to seal well casings properly c. porosity of the rock d. use of inferior quality well casings. |
b. failure to seal well casings properly
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Proper disinfection of water using chlorine depends on the concentration of chlorine plus which of the following?
a. temperature of the water b. pH of the water c. contact period d. all of the above |
d. all of the above
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Which of the following is used to control the growth of algae and protozoa?
a. addition of copper sulfate b. aeration of the water c. addition of nitrates d. filtration |
d. filtration
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The gases frequently found in water that encourage corrosion are
a. methane and oxygen b. oxygen and carbon dioxide c. chlorine and carbon dioxide d. methane and hydrogen sulfide |
b. oxygen and carbon dioxide
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In emergencies, small quantities of water can be disinfected by boiling or using
a. aluminum salts b. tincture of iodine c. salt tablets d. direct exposure to sunlight for 22 hours |
b. tincture of iodine
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Which of the following is not used to disinfect water?
a. chlorine b. bromine c. flourine d. iodine |
c. flourine
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Porosity is
a. measurement of the amount of water that can be held by a rock in its pores or voids, expressed as a percentage of the total volume b. the rate of water at 60 degrees F, in gallons per day, through a cross section of 1 ft2 under a head of 1 ft/ft of water travel c. the amount of water that will drain out of saturated rock or soil by gravity d. the direct relationship between permeability and specific yield |
a. measurement of the amount of water that can be held by a rock in its pores or voids, expressed as a percentage of the total volume
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The presence of which of the following in water would indicate past or possibly intermittent pollution?
a. Streptococcus fecalis b. Escherichia coli c. Clostridium perfringens d. Enterococci |
c. Clostridium perfringens
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Which of the following is a measure of the amount of light scattered by particles suspended in a water test sample?
a. Formazin Turbidity Units (FTU) b. Nephelometric Turbidity Units (NTU) c. Jackson Turbidity Units (JTU) d. Lincoln Turbidity Units (LNU) |
b. Nephelometric Turbidity Units (NTU)
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In testing for residual chlorine, which of the following determines free available chlorine with minimal interference from combined chlorine, iron, nitrates, and nitrites?
a. leuco crystal violet method b. stabilized neutral orthotolidine (SNORT) method c. DPD-Colorimetric method d. DPD-titrimetric method |
c. DPD-colorimetric method
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Granular activated carbon (GAC) filters are used to
a. treat water for soft drinks and bottled drinking water b. remove taste and odor producing compounds c. remove synthetic organic chemicals (suspected carcinogens) d. all of the above |
d. all of the above
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Ozone is effective against
a. amoebic cysts b. bacteria and phenols c. viruses d. all of the above |
d. all of the above
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Which of the following is (are) fundamental to the control of inorganic chemicals in drinking water?
a. sanitary survey b. identification of the sources c. determination of amounts of pollutants d. all of the above |
d. all of the above
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Often over 90% of sodium arsenate can be removed by
a. filtration b. coagulation c. ion exchange d. all of the above |
b. coagulation
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Reduction of the level of fluorides in drinking water can be accomplished by
a. coagulation b. lime softening c. ion exchange d. all of the above |
d. all of the above
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What are the fundamental steps involved in the control of organic chemcials in drinking water?
a. conduct sanitary surveys to identify sources, types and amounts of pollutants b. identify pollutants and select treatment methods c. contact higher level regulatory authorities for consultation d. upgrade water treatment plants |
a. conduct sanitary surveys to identify sources, types and amounts of pollutants
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Trihalomethanes are synthetic organic chemicals primarily created
a. during the coagulation process b. during the pre-chlorination process c. during reverse osmosis d. during the post-chlorination process |
b. during the pre-chlorination process
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The Langelier index is used to determine the point of stability of
a. aluminum sulfate b. calcium carbonate c. water pH d. HOC1 |
b. calcium carbonate
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A hydraulic ram is used to elevate a quantity of water to a higher elevation. Rams are powered by
a. wind b, electricity c. water d. heat |
c. water
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A well casing should be equipped with a vent and installed
a. with a sampling tap b. in a pit to prevent freezing c. with a turbine type pump d. with concrete used as grout |
d. with concrete used as grout
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Cross-connections are frequent causes of disease resulting from
a. back-siphonage of contaminated chemicals b. backflow of biologically contaminated liquids c. connection of the water supply to the sewer system d. all of the above |
d. all of the above
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Backflow of nonpotable materials into the potable water system may occur by
a. backpressure b. back-siphonage c. vacuum in the volume d. a and b above |
d. a and b above
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The flushometer valve is typically portected by
a. a non-pressure -type vacuum breaker b. a pressure-type vacuum breaker c. a backflow prevener d. a reduced pressure zone backflow preventer |
a. a non-pressure-type vacuum breaker
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Which of the following statements is (are) true?
a. all surface water must be considered unsanitary unless given adequate treatment b. all groundwater supplies may be considered safe as a potable water supply c. when considering surface water as a water supply, the entire watershed must be surveyed d. a and c above |
d. both a and c above
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Which of the following statements is (are) true concerning the presence of coliform organisms in drinking water?
a. drinking water may also be used as a varnish remover b. the drinking water should be considered unsanitary c. the drinking water does not contain toxic chemicals d. all of the above |
b. the drinking water should be considered unsanitary
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When using presettling reservoirs to eliminate heavy turbidity of pollution before treatment, what is the desirable retention time?
a. 8 hours b. 1 week c. 2 to 3 days d. 1 month or longer |
c. 2 to 3 days
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If sufficient amounts of activated carbon in the powdered form are used, practically all tastes and odors are removed from water by
a. absorption b. polymerization c. adsorption d. oxidation |
c. adsorption
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It has been estimated that waterborne disease worldwide accounts for in excess of
a. 250 million illnesses per year b. 20 million illnesses per year c. 150 million illnesses per year d. 400 million illnesses per year |
a. 250 million illnesses per year
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Residential cesspool and septic tank soil absorption systems discharge
a. 400 million gallons of sewage into the ground each year b. 800 billion gallons of sewage into the ground each year c. 800 million gallons of sewage into the ground each year d. 2 billion gallons of sewage into the ground each year |
a. 400 million gallons of sewage into the ground each year
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In a test conducted in North Carolina by the PHS in sandy soil, sewage organisms traveled
a. only 10 feet b. 450 feet c. in excess of 200 feet d. 1,200 feet |
c. in excess of 200 feet
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Leachate from a garbage dump has been found to pollute wells
a. 2000 feet away b.1400 feet away c. 100 feet away d. 50 feet away |
a. 2000 feet away
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Hardness in drinking water is desirable at levels of
a. 80 to 150 mg/l b. 50 to 80 mg/l c. 0 to 50 mg/l d. 600 to 800 mg/l |
b. 50 to 80 mg/l
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Alkalinity of water is desireable at levels of
a. 0 to 30 mg/l b. o to 500 mg/l c. 30 to 100 mg/l d. 0 to 5 mg/l |
c. 30 to 100 mg/l
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Which of the following would be classified as a non-transient, non-community water system (NTNCWS)?
a.water supply serving a campground b. water supply serving a small city c. water supply serving a highway rest area d. water supply serving a factory with at least 25 employees |
d. water supply serving a factory with at least 25 employees
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A water system serving one apartment building with three apartments, having a total of six residents is a Public Water Supply (PWS).
a. True b. False |
b. False
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Of the following, which are included as a major regulatory requirements in the Safe Drinking Water Act (SDWA)?
a. sampling b. record keeping c. public information d. a and b e. b and |
c. public information
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The Primary Drinking Water Standards
a. apply to community water systems only b. apply to community water systems and non-transient, non-community water systems c. are health related and enforceable d. a and c e. b and c |
e. b and c
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The Maximum Contaminant level (MCL) is the highest concentration of a contaminant that is allowable in a water system.
a. True b. False |
a. True
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Any time a MCL is exceeded the NTNCWS must give notice by continuous posting in a conspicuous location within the area served by the water system.
a. True b. False |
a. True
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Which of the following is not included in the nine contaminant groups?
a. microorganisms b. volatile organic chemicals c. turbidity d. Lead and copper e. Nitrate and nitrite |
a. microorganisms
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Which would not be classified as a sedimentary formation?
a, limestone b. peat c. olivine d. loess |
c. olivine
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Rocks such as serpentine, slate, soapstone, and marble belong to which class?
a. igneous b. sedimentary c. metamorphic d. limestone |
c. metamorphic
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Which soil has the greatest % porosity?
a. silt b. uniform gravel c. gravel d. sandstone |
a. silt
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Which is included in the sanitary survey of groundwater supplies?
a. aquifer drainage area and local geology b. nature of soil, rock strata, and local geology c. land use and habitation, sources of pollution and local geology d. all of the above |
d. all of the above
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When collecting bacteriological samples that have been chlorinated, what chemical is used to dechlorinate the water?
a. sodium sulfate b. sodium thiosulfate c. sodium bisulfate d. sodium bisulfite |
b. sodium thiosulfate
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What is the purpose of using a forward sweeping motion when collecting water samples from a stream or lake?
a. allows equal mixing of sample b. prohibits contamination from sampler hands c. prohibits collection of trash in water d. creates a current that will collect visible contaminants for ID |
b. prohibits contamination from sampler hands
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Which bacterial group is indicative of fecal contamination or sewage pollution?
a. pseudomonas b. coliform c. salmonella d. all |
b. coliform
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What water constituent has been associated with staining plumbing and clothing dark brown or black?
a. Zn b. Mn c. Ag d. Ca |
b. Mn
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Methylene Blue Active Substance (MBAS) is a test to identify:
a. hardness of water b. iron in water c. presence of detergents containing phosphates d. presence of coliform bacteria |
c. presence of detergents containing phosphates
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In domestic water wells supplies, which two elements cause most hardness?
a. Zn and Mg b. Na and Mg c. Ca and Mg d. Ca and Na |
c. Ca and Mg
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Which residual test for chlorine would be least deisrable?
a. SNORT b. Methyl orange c. OTA d. DPD |
c. OTA
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Which would not be used as a coagulant?
a. black alum b. chlorinated copperas c. ferric chloride d. sodium hypochlorite |
d. sodium hypochlorite
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Which organism is not known as an iron bacterium?
a. crenothrix b. Giardia lamblia c. gallionella d. leptothrix |
b. Giardia lamblia
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What conditions would result in the worst case of pipe damage due to corrosion?
a. hard water, low alkalinity, presence of oxygen b. soft water, low alkalinity, presence of oxygen c. hard water, high acidity, presence of oxygen d. soft water, low acidity, presence of oxygen |
b. soft water, low alkalinity, presence of oxygen
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Which statement is more correct?
a. facultative bacteria live in aerobic conditions only b. facultative bacteria live in anaerobic conditions only c. facultative bacteria live in either aerobic or anaerobic conditions d. facultative bacteria produce their own oxygen |
c. facultative bacteria lice in either aerobic or anaerobic conditions
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Which increases the chance of pollution travel?
a. acidic soil conditions b. lack of organic materials c. lack of Fe, Mg, C d. all |
d. all
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Measure of the amount of water held by a rock or soil in pores or voids, expressed as % of total volume:
a. permeability b. specific retention c. porosity d. specific gravity |
c. porosity
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What is the primary organism identified in the fecal coliform test?
a. Fecal streptococci b. Enterobacter aeroaenes c. Salmonella typhosa d. Escherichia coli |
d. Escherichia coli
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Which is not a measure of water turbidity?
A. nephelometric turbidity unit b. siple turbidity unit c. formazin turbidity unit d. jackson turbidity unit |
b. siple turbidity unit
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Which is the standard measure for water turbidity?
A. nephelometric turbidity unit b. siple turbidity unit c. formazin turbidity unit d. jackson turbidity unit |
A. nephelometric turbidity unit
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Another name for Epsom salts is:
a. sodium sulfate b. calcium sulfate c. zinc sulfate d. magnesium sulfate |
d. magnesium sulfate
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The final product in biochemical oxidation of ammonia yields:
a. nitride b. nitrite c. nitrate d. nitrogen |
c. nitrate
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Which contaminant in water is associate with methemoglobnemia?
a. zinc b. lead c. copper d. nitrate |
d. nitrate
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Which will cause taste and odor in water supplies?
a, coke oven emissions b. oil refinery wastes c. algae d. all |
d. all
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What statement concerning ozone is incorrect?
a. ozone residual can last several hours b. ozone is faster disinfectant than chlorine c. ozone is more expensive than chlorine d. all statements are correct |
a. ozone residual can last several hours
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Regulation of drinking water additives is the responsibility of:
a. FDA b. EPA c. Dept. of Labor d. PHS |
b. EPA
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Which conditions indicate organic stream pollution?
a. water has foul odor and is turbid b. fish counts decrease or disappear c. increase in worms and snails d. all |
d. all
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Lakes having characteristics of being clean, high DO, deep, and receiving few nutrients:
a. oligotrophic b. mesotrophic c. euphoric d. eutrophic |
a. oligotrophic
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Algae development will cause all conditions except:
a. reduced water clarity b. increased chlorine consumption c. rapid fall in pH d. slimy growth |
c. rapid fall in pH
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The presence of bacteria responsible for typhoid fever in a public water supply could be traced to:
a. fecal contamination b. excessive water aeration c. pus from skin lesions d. rotting animal and fish remains |
a. fecal contamination
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Objectionable tastes and odors in public water supplies are, in a great majority of cases, due to the presence of:
a. algae and protozoa b. animal remains c. dissolved oxygen d. yeasts and molds |
a. algae and protozoa
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Infectious Hepatitis A (HAV) is a disease caused by:
a. bacteria b. protozoa c. rickettsia d. virus |
d. virus
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The pH of a solution in which the apparent hydrogen ion concentration is equal to 1 x 10-8 moles per liter:
a. 2 b. 4 c. 6 d. 8 |
d. 8
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The substance commonly used as a coagulant in water treatment is:
a. aluminum sulfate b. calcium sulfate c. potassium chloride d. sodium phosphate |
a. aluminum sulfate
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A sample of water taken for bacteriological analysis is usually packed in ice, if the sample cannot be analyzed immediately. The main reason for this procedure is to retard changes in the:
a. amount of oxygen dissolved in the water b. mineral content of the water c. number of bacteria in the water d. pH of the water |
c. number of bacteria in the water
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The disinfecting ability of chlorine is affected most by:
a. BOD b. temperature c. hydrogen ion concentration d. dissolved oxygen |
c. hydrogen ion concentration
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Alkalinity exists in three forms. Which is not one of these forms?
a. bicarbonate b. hydroxide c. carbonate d. hypochlorite |
d. hypochlorite
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Which of the following compounds would not contribute to water hardness?
a. calcium sulfate b. magnesium sulfate c. calcium chloride d. sodium chloride |
d. sodium chloride
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Improperly located wells, allowing fecal pollution of the water supply, may lead to outbreaks of:
a. botulism, leptospirosis, typhus fever, malaria b. brucellosis, strep infections, cholera, yellow fever c. salmonellosis, shigellosis, cholera, hepatitis d. relapsing fever, histoplasmosis, psittacosis |
c. salmonellosis, shigellosis, cholera, hepatitis
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Viral hepatitis B (HBV) is most often associated with:
a. contaminated dairy products b. uncooked shellfish c. administration of blood products d. fecal contamination of water |
c. administration of blood products
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Historically in the US, most of the impetus for adequate water treatment came from the need to control:
a. infectious hepatitis b. TB c. malaria d. typhoid |
d. typhoid
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Communicable diseases such as typhoid fever, cholera, shigellosis, and infectious hepatitis are most commonly transmitted by the:
a. vector-borne route b. respiratory route c. direct contact route d. fecal/oral, or vehicle-borne route |
d. fecal/oral, or vehicle-borne route
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Which of the following chemicals that can be used for the disinfection of water does not provide a residual?
a. iodine b. bromine c. ozone d. chlorine |
c. ozone
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Aeration is advantageous in the treatment of water containing:
a. phosphorous and manganese b. dissolved iron and manganese c. magnesium and iron d. phosphorus and iron |
b. dissolved iron and manganese
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Masonry reservoirs of rural water supplies are called"
a. leaching pits b. cisterns c. cesspools d. seepage pits |
b. cisterns
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The liquid form of chlorine used for emergency disinfection of small volumes of
a. calcium hypochlorite b. sodium hypochlorite c. bromide hypochlorite d. potassium hypochlorite |
b. sodium hypochlorite
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A general rule when surface waters are used for drinking water supplies is:
a. that they must be considered contaminated b. that fluorides must be used c. that they require softening d. aeration is usually required |
a. that they must be considered contaminated
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If you had to rely on only one of the following to determine the safety of a drinking water supply, which one would you choose?
a. three consecutive samples showing no coliform b. no chlorides or nitrates in the water c. watershed area remote and isolated d. sanitary survey of supply (source, equipment, etc.) |
d. sanitary survey of supply (source, equipment, etc.)
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The general type of subsurface formation in which groundwater contamination is likely to travel the farthest is:
a. clay b. granite c. limestone d. gravel |
c. limestone
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