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CWEA ECI Grade 1 practice questions

Number of questions: 150

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About the CWEA ECI Grade 1 exam

The CWEA Environmental Compliance Inspector (ECI) exams are designed for people currently working as, or aspiring to become, Environmental Compliance Inspectors in California.

The exams are administered by the California Water Environment Association (CWEA), a professional organization dedicated to wastewater professionals in California.

The CWEA ECI exams are categorized into four grades: Grade 1, Grade 2, Grade 3, and Grade 4:

While CWEA certification isn't mandatory for a job as an Environmental Compliance Inspector, it can help you get a job and can also lead to a pay raise and other benefits.

Practice questions

1) 0.5 mol of solute is dissolved in 250 cm³ of solution. What is the concentration in mol/dm³?
  1. 0.002 mol/dm³
  2. 2 mol/dm³
  3. 12.5 mol/dm³
  4. 125 mol/dm³
 2) A hydrogen chloride solution has a concentration of 0.5 mol/dm³. Given that the molar mass of hydrogen chloride is 36.5, what is the solution's concentration in g/dm³?
  1. 0.065 g/dm³
  2. 18.25 g/dm³
  3. 36.55 g/dm³
  4. 73 g/dm³
 3) Calculate the volume of a 0.5 mol/dm³ solution that contains 1 mol of solute.
  1. 0.5 dm³
  2. 0.75 dm³
  3. 1 dm³
  4. 2 dm³
 4) 8.0 g of magnesium oxide contains 4.8 g of magnesium and 3.2 g of oxygen. If the atomic mass of magnesium is 24 and the atomic mass of oxygen is 16, what is the empirical formula of magnesium oxide?
  1. MgO
  2. MgO₂
  3. MgO₃
  4. Mg₃O
 5) What is the concentration in ppm of 0.001 g of lead dissolved in 1 kg of water?
  1. 1 ppm
  2. 10 ppm
  3. 100 ppm
  4. 1,000 ppm
 6) Calculate the amount of solute dissolved in 4 dm³ of a 0.2 mol/dm³ solution.
  1. 0.05 mol
  2. 0.8 mol
  3. 3.8 mol
  4. 4.2 mol
 7) What volume of solute is required to prepare 950 mL of an acetic acid solution made from 7 parts solute and 10 parts solvent?
  1. 58 mL
  2. 101 mL
  3. 391 mL
  4. 559 mL
 8) What does 5% w/v mean?
  1. 5 grams of solute dissolved in 100 mL of solution
  2. 5 grams of solute dissolved in 100 mL of solvent
  3. 5 mL of solute dissolved in 100 mL of solution
  4. 5 mL of solute dissolved in 100 mL of solvent
 9) Calculate the density of a liquid that has a volume of 40 mL, a weight of 50 grams, and a boiling point of 110°C.
  1. 0.8 g/mL
  2. 0.9 g/mL
  3. 1.25 g/mL
  4. 1.5 g/mL
 10) Parts per million (ppm) can also be expressed as:
  1. cm³
  2. dm³
  3. mL/billion
  4. mg/L
 11) A pH of 2 is how many times more acidic than a pH of 5?
  1. 3
  2. 6
  3. 256
  4. 1,000
 12) 200 microliters is how many milliliters?
  1. 0.2 mL
  2. 2 mL
  3. 20 mL
  4. 2,000 mL
 13) What is 10 mg in micrograms?
  1. 0.0001 mcg
  2. 0.001 mcg
  3. 10,000 mcg
  4. 100 mcg
 14) In the equation KOH + CO₂ → K₂CO₃ + H₂O, which molecule needs a coefficient for the equation to be balanced?
  1. KOH
  2. CO₂
  3. K₂CO₃
  4. H₂O
 15) Balance the equation Ag + H₂S → Ag₂S + H₂.
  1. 2Ag + H₂S → Ag₂S + H₂
  2. 4Ag + 2H₂S → 2Ag₂S + H₂
  3. 2Ag + 2H₂S → Ag₂S + 4H₂
  4. 4Ag + H₂S → 2Ag₂S + H₂
 16) How many gallons of a 0.1 M KOH solution will neutralize 30,000 gallons of 0.5 M HCl?
  1. 15,000
  2. 75,000
  3. 150,000
  4. 450,000
 17) If 25 mL of LiOH is needed to neutralize 20 mL of 0.500 M HBr, what is the concentration of the LiOH?
  1. 0.4 M
  2. 0.5 M
  3. 0.6 M
  4. 0.75 M
 18) 1 L of a 0.1 M potassium hydroxide solution neutralizes 50 mL of a sulfuric acid solution. What is the molarity of the sulfuric acid solution?
  1. 0.005 M
  2. 0.045 M
  3. 0.5 M
  4. 1 M
 19) What is the TLV-C?
  1. The concentration a worker can be exposed to for one hour without adverse effect
  2. The concentration a worker can be exposed to over a working lifetime without adverse effects
  3. The concentration a worker can be exposed to up to 4 times per day
  4. The concentration that should never be exceeded
 20) During an eight-hour shift, an employee is exposed to zinc oxide fumes at a concentration of 150 ppm for two hours, 75 ppm for another two hours, and 50 ppm for four hours. Calculate the 8-hour time-weighted average.
  1. 81.25 ppm
  2. 88.515 ppm
  3. 91.75 ppm
  4. 95 ppm
 21) What is the duration of the STEL?
  1. 5 minutes
  2. 15 minutes
  3. 1 hour
  4. 8 hours
 22) What is the lower flammability limit of carbon monoxide?
  1. 2%
  2. 4%
  3. 7%
  4. 12%
 23) What is the lower flammability limit of methane?
  1. 1%
  2. 5%
  3. 10%
  4. 17%
 24) Under OSHA and GHS, which category of liquids has flashpoints between 23°C and 60°C?
  1. Category 1
  2. Category 2
  3. Category 3
  4. Category 4
 25) What is an upper flammability limit?
  1. The amount of fuel that will burn before the fuel burns itself out
  2. The highest concentration of a vapor that can catch fire
  3. The highest temperature at which a liquid can be stored safely
  4. The highest temperature that a chemical can reach when ignited
 26) In 2015, OSHA adopted the Globally Harmonized System (GHS) for classifying and labeling of chemicals. This resulted in flammable liquids being redefined as liquids with a flashpoint lower than:
  1. 37.8°C
  2. 67.3°C
  3. 93°C
  4. 100°C
 27) In the context of occupational health and safety, what does STEL stand for?
  1. Short-term exposure limit
  2. Standard task exposure limit
  3. Standard task equipment list
  4. Short-term emergency lighting
 28) Safety goggles fall under which of the four levels of PPE?
  1. Level A
  2. Level B
  3. Level C
  4. Level D
 29) What is the term for a substance with the potential to produce cancer in humans or animals?
  1. Carcinogen
  2. Caustic substance
  3. Nosocomial substance
  4. Pathogenic substance
 30) Which pH buffer solution is typically used first when calibrating a pH meter?
  1. pH 1
  2. pH 4
  3. pH 7
  4. pH 10
 31) What is the chemical formula for methane?
  1. CH₄
  2. C₂H₈
  3. C₈H₂
  4. C₈H₈
 32) Complete the following reaction: HCl + Mg(OH)₂ → MgCl₂ + _______
  1. CO₂
  2. H₂O
  3. O₂
  4. O₃
 33) What is the chemical formula for hydrogen sulfide?
  1. HS
  2. HS₂
  3. H₂S
  4. H₂S₂
 34) What is the purpose of a custody seal on a sample container?
  1. To help identify the sample if the container is misplaced
  2. To prevent air from entering the container
  3. To show whether the container has been tampered with
  4. To show who currently has custody of the container
 35) A courier delivers a chain of custody sample to a technician at a laboratory. Who needs to sign and date the chain of custody form?
  1. Only the courier
  2. Only the laboratory technician
  3. The courier and the laboratory technician
  4. The laboratory manager and the laboratory technician
 36) What are class 8 hazardous materials?
  1. Corrosive
  2. Explosive
  3. Poisonous
  4. Radioactive
 37) What are class 1 hazardous materials?
  1. Explosive
  2. Infectious
  3. Poisonous
  4. Radioactive
 38) What type of hazard are OSHA action levels for?
  1. Ergonomic hazards
  2. Hazardous substances
  3. Psychosocial hazards
  4. Slips, trips, and falls
 39) According to OSHA standard 40 CFR 136, wastewater samples for organic tests must be stored below what temperature?
  1. −5°C
  2. 2°C
  3. 6°C
  4. 10°C
 40) Which danger must employers inform workers about under OSHA’s Hazard Communication Standard?
  1. Bloodborne pathogens
  2. Dangerous chemicals
  3. General safety hazards
  4. Miscommunication
 41) Most OSHA permissible exposure limits (PELs) are time-weighted averages of how many hours?
  1. 1
  2. 2
  3. 4
  4. 8
 42) OSHA considers a confined space as oxygen-deficient if its oxygen level is below:
  1. 19.5%
  2. 20.1%
  3. 20.4%
  4. 20.9%
 43) According to OSHA standard 1910.95, employers must implement a noise monitoring program when an employee's noise exposure equals or exceeds an 8-hour time-weighted average of how many decibels?
  1. 85 dB
  2. 90 dB
  3. 95 dB
  4. 100 dB
 44) Which ion does pH measure?
  1. Carbon
  2. Hydrogen
  3. Nitrogen
  4. Oxygen
 45) A pH of 6.6 is:
  1. very acidic
  2. slightly acidic
  3. neutral
  4. slightly alkaline
 46) Which pH is neutral?
  1. 0
  2. 1
  3. 3
  4. 7
 47) Which device is typically used to separate grit from organics in grit slurries?
  1. Aerated grit chamber
  2. Air lift
  3. Clarifier
  4. Hydrocyclone
 48) A wastewater treatment plant has 150,000 lbs of mixed liquor volatile suspended solids (MLVSS) in the aeration tank. The primary effluent has a BOD of 75,000 lbs per day. Calculate the F/M ratio.
  1. 0.5
  2. 1
  3. 1.5
  4. 2
 49) Which of these water indicators is reported in μg/L?
  1. Temperature
  2. Total toxic organics
  3. Turbidity
  4. pH
 50) Which dye is used to detect the presence of anionic surfactants in water samples?
  1. Methylene blue
  2. Nile red
  3. Oil red
  4. Thymolphthalein
 51) An environmental inspector collects a sample of water for a BOD₅ test but cannot start the test until tomorrow morning. How should the sample be stored in the meantime?
  1. At room temperature
  2. In a freezer
  3. In a refrigerator
  4. In a vacuum flask
 52) An aeration tank has a volume of 100 m³ and an influent flow rate of 10 m³/hour. Calculate the hydraulic retention time of the aeration tank.
  1. 0.1 hours
  2. 10 hours
  3. 100 hours
  4. 1,000 hours
 53) What are the three characteristics of a confined space?
  1. Has a restricted entry and exit, contains serious safety hazards, and is large enough to work in
  2. Has a restricted entry and exit, contains serious safety hazards, and is too small to work in
  3. Has a restricted entry and exit, is not meant for continuous occupancy, and is large enough to work in
  4. Has a restricted entry and exit, is not meant for continuous occupancy, and is too small to work in
 54) An aeration basin has a dark brown, almost black sudsy foam that covers the entire basin. The foam smells sour. What is the most likely cause?
  1. Anaerobic conditions in the aeration basin
  2. Filamentous organisms are present
  3. The RAS flow is too low
  4. The aeration basin has excessive solids due to insufficient wasting
 55) Which stage of wastewater treatment separates readily settleable and floatable solids from the wastewater?
  1. Primary
  2. Secondary
  3. Tertiary
  4. Quarternary
 56) Which of these units is a typical unit used to measure flow?
  1. CFS
  2. MPH
  3. liters
  4. mg/L
 57) Total Kjeldahl nitrogen (TKN) is the total concentration of:
  1. nitrate and ammonia
  2. nitrate and nitrite
  3. organic nitrogen and ammonia
  4. organic nitrogen and nitrite
 58) Which section of the Code of Federal Regulations sets the standards for the use and disposal of sewage sludge?
  1. 20 CFR Part 136
  2. 20 CFR Part 1910.1450
  3. 40 CFR Part 403
  4. 40 CFR Part 503
 59) Workers can warn traffic of their presence in the street with signs, cones, and:
  1. banners
  2. billboards
  3. chairs
  4. flagmen
 60) What is the typical unit for reporting water alkalinity?
  1. mEq OH−
  2. mEq/kg
  3. mg/L CaCO₃
  4. mol NaOH
 61) An industry has three sewer connections with the following discharge rates: 1) 100 gpd 2) 300 gpd 3) 600 gpd. A flow-weighted composite sample of 2 liters is needed. How many milliliters of sample from each connection should be composited?
  1. 0.1 mL, 0.3 mL, 0.6 mL
  2. 100 mL, 300 mL, 600 mL
  3. 200 mL, 600 mL, 1,200 mL
  4. 500 mL, 750 mL, 750 mL
 62) Which of these wastewater components takes the longest to biodegrade?
  1. Carbohydrates
  2. Fats
  3. Glucose
  4. Proteins
 63) Why is chlorine added during water treatment?
  1. To accelerate sedimentation
  2. To destroy microorganisms
  3. To enhance water taste and odor
  4. To reduce water hardness
 64) A rectangular pond has a length of 500 feet, a width of 200 feet, and a depth of 10 feet. Calculate the surface area of the pond in acres.
  1. 1.7 acres
  2. 2.3 acres
  3. 3.8 acres
  4. 4.5 acres
 65) PSI is a unit of:
  1. distance
  2. energy
  3. pressure
  4. time
 66) What does the unit MGD refer to?
  1. Milligallons per day
  2. Milligrams per day
  3. Million gallons per day
  4. Thousand gallons per day
 67) VCP stands for ________ ________ pipe.
  1. vacuum channel
  2. verified capacity
  3. vinyl chloride
  4. vitrified clay
 68) As per 40 CFR 403.5, what is the maximum holding time for wastewater samples intended for salmonella testing?
  1. 30 minutes
  2. 8 hours
  3. 28 hours
  4. 7 days
 69) Grab samples are also known as __________ samples.
  1. composite
  2. discrete
  3. sequential
  4. time-proportional
 70) What is the difference between nitrate and nitrite?
  1. Nitrate has three hydrogen atoms while nitrite has two
  2. Nitrate has three oxygen atoms while nitrite has two
  3. Nitrate has two hydrogen atoms while nitrite has three
  4. Nitrate has two oxygen atoms while nitrite has three
 71) What is the term for the liquid between the sludge and scum in a digester?
  1. Filtrate
  2. Sewage
  3. Slush
  4. Supernatant
 72) The following copper results, in mg/L, were taken throughout the day: 4.7, 5.1, 5.4, 6.2, 6.1, 5.9, 4.2, 3.5, 3.5, 3.4. Calculate the mean of these results.
  1. 4.5
  2. 4.6
  3. 4.7
  4. 4.8
 73) What is graywater?
  1. Water from sinks, showers, bathtubs, and washing machines
  2. Water that contains soil
  3. Water that has been cleaned at a water treatment plant
  4. Water that has come into contact with feces
 74) 40 CFR 136 of the Federal Code of Regulations contains:
  1. guidelines establishing test procedures for the analysis of pollutants
  2. hazardous waste injection restrictions
  3. state UIC program requirements
  4. toxic pollutant effluent standards
 75) Denitrification is the ____________________ to nitrogen gas.
  1. oxidation of ammonia
  2. oxidation of nitrate
  3. reduction of ammonia
  4. reduction of nitrate
 76) Which wastewater treatment process is typically accomplished by adding sulfur dioxide?
  1. Dechlorination
  2. Digestion
  3. Disinfection
  4. Thickening
 77) What do the terms "Schedule 40" and "Schedule 80" refer to?
  1. Employer workplace rights
  2. The storage of dangerous chemicals
  3. The thickness of pipes
  4. Wastewater legislation
 78) Which of these types of waste is found in food industry effluents?
  1. BOD
  2. Cyanide
  3. Nitrates
  4. Polychlorinated biphenyl
 79) What is the first step of wastewater treatment?
  1. Grit removal
  2. Screening
  3. Sedimentation
  4. Trickling filters
 80) What is 100 feet of head in PSI?
  1. 2.9 PSI
  2. 14.0 PSI
  3. 28.2 PSI
  4. 43.3 PSI
 81) Which of these is required on an inspection report for a wastewater treatment plant?
  1. Contact details of the maintenance contractor
  2. HHE-200 septic permit number
  3. Name of the inspector
  4. Signature of the plant manager
 82) A clarifier has a volume of 200,000 gallons and a flow rate of 2.4 MGD. Calculate the detention time of the clarifier.
  1. 2 hours
  2. 2.5 hours
  3. 3.5 hours
  4. 3 hours
 83) Calcium hydroxide is also known as:
  1. caustic soda
  2. lye
  3. quick lime
  4. slaked lime
 84) Which agency is responsible for administering and enforcing the General Pretreatment Regulations?
  1. Department of Energy (DOE)
  2. Environmental Protection Agency (EPA)
  3. Food and Drug Administration (FDA)
  4. Occupational Safety and Health Administration (OSHA)
 85) A wastewater sample of 100 mL is diluted to 300 mL with water. The initial DO of the sample is 50 mg/L. After 5 days, the DO has fallen to 10 mg/L. Calculate the BOD₅ of the sample in mg/L.
  1. 120 mg/L
  2. 245 mg/L
  3. 500 mg/L
  4. 600 mg/L
 86) Which of these is a conventional pollutant?
  1. Ammonia
  2. Chromium
  3. Cyanide
  4. Oil
 87) What are field blanks?
  1. Bottles of clean water
  2. Collection systems of unknown water quality
  3. Disposable, single-use sampling devices
  4. Water samples taken upstream from incoming pollutants
 88) A developer anticipates that a new site will produce 500 gallons of wastewater per day. The sewer impact fee is $31.23 per gallon of wastewater per day. Calculate the total daily sewer impact fee.
  1. $10,835
  2. $15,615
  3. $20,935
  4. $25,815
 89) Electromagnetic flowmeters measure flow by measuring the _________ created by the movement of water.
  1. area
  2. depth
  3. pressure differential
  4. voltage
 90) Goggles, earplugs, and gloves are needed when using a:
  1. gas detector
  2. pH meter
  3. power grinder
  4. sampling pump
 91) What is the most oxidized form of nitrogen found in wastewater?
  1. Ammonia
  2. Nitrate
  3. Nitrite
  4. Organic nitrogen
 92) A factory generates 0.12 MGD of wastewater. The treatment system can treat 200 GPM. How many hours would it take the treatment system to process one day’s wastewater?
  1. 2
  2. 6
  3. 10
  4. 14
 93) Which of these items of safety equipment is NOT required in an inspector's vehicle?
  1. Fire extinguisher
  2. First aid kit
  3. Spill control pillows
  4. Stop signs
 94) What organization enforces the pretreatment requirements of the Clean Water Act?
  1. EPA
  2. NOAA
  3. The Department of Energy
  4. The Department of Health and Human Services
 95) What is the main difference between primary clarifiers and secondary clarifiers?
  1. The density of the sludge handled
  2. The flow rate through the clarifiers
  3. The number of clarifiers required
  4. The sludge removal systems
 96) An industrial discharger has a wastewater flow of 50,000 liters per day containing 4.5 mg/L of copper. What is the mass emission rate of copper in grams per day?
  1. 12.5 g/day
  2. 225 g/day
  3. 5 g/day
  4. 90 g/day
 97) What is the most common toxic gas encountered during sampling work?
  1. Carbon monoxide
  2. Hydrogen cyanide
  3. Hydrogen sulfide
  4. Methane
 98) The following calcium results, in mg/L, were taken throughout the day: 200, 241, 231, 242, 192 What is the range of these results?
  1. 50
  2. 100
  3. 150
  4. 200
 99) Which of these has the lowest BOD?
  1. Rainwater
  2. Treated municipal water
  3. Unpolluted river water
  4. Untreated municipal water
 100) A circular spill has a radius of 10 feet and an average depth of 2 feet. Estimate the volume of the spill in gallons.
  1. 2,100
  2. 3,800
  3. 4,700
  4. 5,300
 101) Composite samples are collected by combining two or more __________ samples.
  1. time-proportional
  2. discrete
  3. aggregate
  4. flow-proportional
 102) What is Manning's formula?
  1. V = (1.49/A) × n²ᐟ³ × S × √R
  2. V = (1.49/n) × A × R²ᐟ³ × √S
  3. V = (A/1.49) × n × R²ᐟ³ × √S
  4. V = (n/1.49) × A²ᐟ³ × S × √R
 103) What is the term for a chemical that lowers the surface tension of a liquid?
  1. Liquefactant
  2. Liquescent
  3. Surfactant
  4. Tensile
 104) Water hardness is a measure of the amount of which two minerals in water?
  1. Calcium and magnesium
  2. Iron and phosphorous
  3. Nitrogen and oxygen
  4. Sodium and fluoride
 105) What is the main purpose of the General Pretreatment Regulations?
  1. Ensure safe drinking water
  2. Prevent damage to POTWs
  3. Promote wildlife conservation
  4. Regulate air quality
 106) What is the term for a sample collected at a single location at a single point in time?
  1. Composite
  2. Flow-proportional
  3. Grab
  4. Time-proportional
 107) What is the Venturi principle?
  1. Fluid pressure reduces when the fluid flows through a constricted section of a pipe
  2. Fluids have constant densities, regardless of pressure variations in the flow
  3. Fluids passing from higher to lower elevations maintain a steady velocity
  4. In a steady flow, the sum of all forms of energy in a fluid along a streamline is the same at all points on that streamline
 108) Which of these industry types generally produces a very high suspended solids content?
  1. Breweries
  2. Laundries
  3. Oil fields
  4. Textile dyehouses
 109) How should an inspector be able to activate emergency response procedures?
  1. By calling the police and fire departments
  2. By contacting local TV and radio stations
  3. By making one call to a person in the home office
  4. By phoning the collection system and treatment plant superintendents
 110) Which of these items should an inspector examine at high-risk industrial facilities with regard to emergency response?
  1. Chemical ordering plan
  2. Future expansion plan
  3. Spare parts inventory plan
  4. Spill prevention plan
 111) The EPA recognizes what types of dischargers in its efforts to control the flow of pollutants into water?
  1. Direct and indirect
  2. Municipal and industrial
  3. Raw and treated
  4. Sanitary and storm
 112) A sodium chloride solution contains 25% sodium chloride and has a density of 2 g/mL. How many grams of sodium chloride are in one liter of the solution?
  1. 0.5 grams
  2. 2 grams
  3. 500 grams
  4. 2,000 grams
 113) Which of these chemicals may cause explosions in sewers?
  1. Acetic acid
  2. Carbon tetrachloride
  3. Gasoline
  4. Hexavalent chromium
 114) A flow rate of one cubic foot per second is equal to how many gallons per hour?
  1. 26,928
  2. 37,818
  3. 42,470
  4. 58,915
 115) A POTW must retain Industrial user records for a minimum of how many years?
  1. 2
  2. 3
  3. 5
  4. 10
 116) What is the average detention time for a 100,000 GPD flow going through a 3,000-gallon interceptor?
  1. 12 minutes
  2. 28 minutes
  3. 37 minutes
  4. 43 minutes
 117) The reason inspectors must keep notes during an emergency is because they will be useful in preparing:
  1. a briefing for public officials
  2. a case for court if enforcement action is initiated
  3. a meeting for reporters
  4. an informational pamphlet for the public
 118) What is the best method to determine the pollutants that industrial dischargers are placing in collection systems?
  1. Field test kits
  2. Laboratory chemical tests
  3. Results of industrial self-monitoring
  4. Visual observations
 119) A batch tank has a water depth of 8 ft, a diameter of 6 ft, and a discharge rate of 10 GPM. How many hours will it take for the batch tank to empty?
  1. 2.8 hours
  2. 4.2 hours
  3. 7.4 hours
  4. 9.6 hours
 120) A representative sample is:
  1. collected during minimum flows
  2. obtained when industrial representatives are present
  3. similar to the larger body of the waste stream being sampled
  4. transported to a laboratory for analysis
 121) What is meant by chain of custody?
  1. A record of criminal action against an industrial discharger
  2. A record of each agency action leading to a notice of violation
  3. A record of every person who has access to a sample
  4. A record of every sample submitted to the laboratory
 122) BOD is a measure of the amount of _______________ in water.
  1. biological organisms
  2. bound oxygen
  3. dissolved oxygen
  4. organic material
 123) Which type of water stabilization pond has an aerobic zone at the top and an anaerobic zone at the bottom?
  1. Facultative
  2. Aerobic
  3. Anaerobic
  4. Maturation
 124) In the context of wastewater treatment, what does FOG mean?
  1. Fats, oils, and grease
  2. Filamentous organisms
  3. Free oxygen grade
  4. Fully organic grade
 125) The focus of pollution prevention is to ______________ waste generated.
  1. dispose of
  2. minimize
  3. recycle
  4. treat
 126) Which Federal Act introduced the concept that waste generators are responsible for their waste from cradle to grave?
  1. Comprehensive Environmental Response, Compensation and Liability Act
  2. Resource Conservation and Recovery Act
  3. Superfund Amendments and Reauthorization Act
  4. Toxic Substances Control Act
 127) Industrial wastewater discharge permits grant permission to discharge wastewater into:
  1. a pretreatment facility
  2. the centralized waste treatment facility
  3. the environment
  4. the wastewater collection system
 128) Which of these is a danger of hydrogen sulfide in sewers?
  1. Pipe corrosion
  2. Pathogen growth
  3. Carcinogenicity
  4. Toxic gas
 129) The wastewater discharge of a factory is sampled every 300 gallons. What is the term for this type of sampling?
  1. Continuous
  2. Discrete
  3. Flow-proportional
  4. Time-proportional
 130) The figure below shows the horizontal cross-section of a water tank in the shape of a rectangle with a semi-circle at one end. If the water in the tank is 7 meters deep, then what is the volume of water in the tank in gallons?
  1. 110,547 gallons
  2. 222,938 gallons
  3. 319,937 gallons
  4. 483,885 gallons
 131) Lead acetate paper is used to determine the presence of which dangerous gas?
  1. Carbon monoxide
  2. Hydrogen sulfide
  3. Methane
  4. Nitrogen dioxide
 132) The main pollutants from the production of printed circuit boards are organic matter, ammonia, and:
  1. copper
  2. mercury
  3. silicon
  4. steel
 133) For how long is the BOD₅ test run?
  1. 5 minutes
  2. 5 hours
  3. 5 days
  4. 5 weeks
 134) A pretreatment system has a capacity of 100 gallons per minute. In how many hours can the facility process 60,000 gallons?
  1. 10 hours
  2. 12 hours
  3. 14 hours
  4. 16 hours
 135) Maturation ponds are:
  1. aerobic on the top and anaerobic on the bottom
  2. anaerobic on the top and aerobic on the bottom
  3. wholly aerobic
  4. wholly anaerobic
 136) In the context of water treatment and purification, MLSS is the:
  1. amount of solids removed from an activated sludge reactor
  2. concentration of suspended solids in mixed liquor of an aeration tank
  3. mixture of wastewater and microorganisms returned to the head of an aeration tank
  4. underflow from a secondary sedimentation tank
 137) In the context of wastewater treatment, what does SSO stand for?
  1. Sanitary sewer overflow
  2. Single source outlet
  3. Surface-to-surface outfall
  4. Suspended solids and organics
 138) In the context of wastewater treatment, what does F/M ratio mean?
  1. Fat-to-mineral ratio
  2. Flotsam-to-mixture ratio
  3. Flow-to-mass ratio
  4. Food-to-microorganism ratio
 139) Who is responsible for holding and maintaining an SPCC (Spill Prevention, Control, and Countermeasure) Plan for a facility?
  1. The Environmental Protection Agency
  2. The facility's safety officer
  3. The local government
  4. The owner or operator of the facility
 140) Calculate the total storage capacity, in gallons, of the following three tanks. Tank I: Cuboid tank measuring 5 feet on all sides. Tank II: Rectangular tank measuring 30 × 10 × 3 feet. Tank III: Cylindrical tank measuring 18 feet in diameter and 10 feet in height.
  1. 21,308 gallons
  2. 22,839 gallons
  3. 24,810 gallons
  4. 26,703 gallons
 141) An inspector needs to enter an area where a hazardous chemical is in use. How can the inspector find out which protective gear they need to wear?
  1. Ask a supervisor
  2. Ask an employee who works there
  3. Check the PPE policy
  4. Check the SDS
 142) An environmental compliance inspector records the following pH values at five locations of a wastewater influent: 9.1, 9.5, 8.9, 9.5, 10.0 What is the average of these five results?
  1. 9.4
  2. 9.5
  3. 9.6
  4. 9.7
 143) What is the main danger of polychlorinated biphenyls (PCBs)?
  1. Carcinogenicity
  2. Combustibility
  3. Flammability
  4. Toxicity
 144) What is the psi of a column of water with a height of 110.8 inches?
  1. 1
  2. 2
  3. 3
  4. 4
 145) What is the purpose of unannounced industrial inspections?
  1. To check the effluent quality
  2. To meet with a POTW's normal contact person
  3. To review paperwork
  4. To test the response of the industry
 146) Which of these chemicals can be used to neutralize acidic wastewater?
  1. CH₃COOH
  2. Ca(OH)₂
  3. HCl
  4. HNO₃
 147) The effluent from Significant Industrial Users should be sampled at least every _____ months.
  1. 2
  2. 4
  3. 6
  4. 12
 148) If three pounds of sodium bisulfite are needed to reduce one pound of hexavalent chromium, then how many pounds of sodium bisulfite are needed to reduce 10,000 kg of hexavalent chromium?
  1. 10,001
  2. 28,376
  3. 48,103
  4. 66,138
 149) Which preservative is needed when collecting a sample for TKN (Total Kjeldahl Nitrogen) analysis?
  1. HCl to pH < 9
  2. HNO₃ to pH > 9
  3. H₂SO₄ to pH < 2
  4. Zinc acetate + NaOH to pH < 2
 150) Which preservative is needed when collecting a sample for total phosphorus analysis?
  1. HCl
  2. H₂SO₄
  3. KOH
  4. NaOH

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