CWEA ENVIRONMENTAL COMPLIANCE EXAM 2025/2026
QUESTIONS WITH ANSWERS GRADED A+
✔✔What are the types of stormwater pollution? - ✔✔Sediment,BOD,Nutrients
✔✔How often must SIUs be inspected? - ✔✔Once a year
✔✔A solution of ferrous chloride used at a pretreatment facility contains 30 percent
ferrous chloride and has a density of 1.33 g/mL. How many grams of ferrous chloride
are in one liter of the solution? - ✔✔399 grams per liter
✔✔Sodium hydroxide is commonly referred to as: - ✔✔caustic soda.
✔✔Which of the following does an ultrafiltration system remove from wastewater? -
✔✔suspended solids.
✔✔Low pH wstewater is neutralized by adding: - ✔✔NaOH.
✔✔A solution with a pH of 5 has a concentration of hydrogen ions that is how many
times higher than a solution with a pH of 7? - ✔✔100 times higher
✔✔What is the normality of a sodium hydroxide solution of 25 ml if 0.01 N sulfuric acid
solution neutralizes 100 mL of the NaOH solution? - ✔✔0.0025 N
✔✔A cyanide destruction process is designed to treat 30 pounds of cyanide per 24-hour
operational day. How many pounds of cyanide can be treated during an 8-hour shift? -
✔✔10
✔✔A POTW must retain Industrial User records for a minimum of: - ✔✔3 years
✔✔The Federal Act that introduced the concept of cradle to grave manifesting for
hazardous waste products is: - ✔✔Resource Conservation and Recovery Act (RCRA).
✔✔Waste discharge regulations can be concentration- or mass-based except for: -
✔✔pH and temperature.
✔✔New Categorical Dischargers must submit a Baseline Monitoring Report to the
POTW control authority prior to the planned commencement of discharge by at least: -
✔✔90 days
✔✔The State NPDES General Permit for storm water from Industrial Activities covers
industries subject to federal storm water effluent limitation guidelines under 40 CFR,
,Subchapter N. Which of the following industries falls under this category? - ✔✔Cattle
feedlot
✔✔An industry has a wastewater discharge of 10,000 gallons per day containing 5 mg/L
of copper. What is the industry's mass emission rate of copper in pounds per day? -
✔✔0.42
✔✔An industry has five sewer connections with the following discharge rates: 1) 300
gpd, 2) 75 gpd, 3) 725 gpd, 4)1,200gpd, 5) 200 gpd. A flow-weighted composite sample
of 5 liters is desired. How many milliliters of sample from each connection should be
composited? - ✔✔600, 150, 1450, 2400, 400
✔✔An industry has a 36,000-gpd discharge in a sixteen-hour day. A composite sample
of 2 liters is needed. The sampler is set to take 125 ml. Each time the pump is activated.
For a flow proportional sample, at what gallon interval should the sampler activate to
take a sample? - ✔✔2,250 gallons
✔✔Lead acetate paper is used to determine the presence of: - ✔✔hydrogen sulfide.
✔✔In a normally distributed population of sampling data, what percent of the data points
will fall within one standard deviation? - ✔✔68.3
✔✔What kind of container and preservative is required for samples to be analyzed for
oil and grease? - ✔✔Glass, Cool 4°C, H2SO4 to pH < 2
✔✔In open channel flow measurement, the term "primary element" is used to denote
the: - ✔✔measuring structure that contains the water.
✔✔A solution of ferrous chloride used at a pretreatment facility contains 30 percent
ferrous chloride and has a density of 1.33 g/mL. How many grams of ferrous chloride
are in one liter of solution? - ✔✔399
✔✔19. You want to measure the flow in an 8-inch diameter city sewer line. If you use
the Manning formula, what additional data will you need to gather to calculate the flow
rate in the downstream manhole? - ✔✔Pipe length, invert elevation at both ends, water
depth at downstream end, and pipe roughness coefficient.
✔✔Why are septum vials used for TTO samples? - ✔✔To prevent sample contact with
air
✔✔The scouring velocity in a sewer is the speed of wastewater that will: - ✔✔Prevent
the deposition and buildup of solids.
, ✔✔22. Flatter sewer line grades may cause added sewer maintenance expense and
odor nuisance. The problem is most likely cased by: - ✔✔A decrease in velocity
allowing organic and inorganic solids to settle out
✔✔A cyanide-bearing waste is to be treated by a batch process using the alkaline
chlorination method. The cyanide holding tank contains 6,000 gallons with a cyanide
concentration of 15 mg/L. Seven pounds of caustic soda and eight pounds of chlorine
are required to oxidize one pound of cyanide to nitrogen gas. How many pounds of
chlorine are needed? - ✔✔6.0
✔✔What types of control devices are used to stop and start pumps? - ✔✔Floats
✔✔What type of pump is used in lift station wet wells? - ✔✔Submersible
✔✔What is the main purpose of gate valves in a lift station? - ✔✔To isolate the lift
station from the wastewater collection system during maintenance
✔✔Which of the following is not a suspended growth biological treatment system? -
✔✔Trickling filter
✔✔Activated sludge is wasted from the reactor to: - ✔✔control the sludge age.
✔✔A method commonly used to thicken activated sludge prior to treatment is: -
✔✔dissolved air flotation.
✔✔A metal finishing facility generates nickel-plating sludge from the clarifier of its
pretreatment system. The clarifier sludge is 6,000 mg/L and 2 percent of the treatment
plant inflow of 50,000 gallons per day. The sludge is dewatered in a filter press, 5 days
per week, and shipped off site for disposal as hazardous waste once per week. If the
filter press cake is 25 percent solids, how many pounds of dewatered sludge should be
manifested as hazardous waste each week, assuming a cake density of 8.34
lbs/gallon? - ✔✔1,000
✔✔Which method below is not used to stabilize municipal wastewater treatment plant
sludge? - ✔✔Contact stabilization
✔✔What is the first safety planning step prior to making a pretreatment inspection? -
✔✔Review the facility's industrial waste permit application and correspondence file
✔✔What is a common cause of oxygen deficiency in a sewer manhole? - ✔✔Bacterial
action that replaces oxygen with other gasses
QUESTIONS WITH ANSWERS GRADED A+
✔✔What are the types of stormwater pollution? - ✔✔Sediment,BOD,Nutrients
✔✔How often must SIUs be inspected? - ✔✔Once a year
✔✔A solution of ferrous chloride used at a pretreatment facility contains 30 percent
ferrous chloride and has a density of 1.33 g/mL. How many grams of ferrous chloride
are in one liter of the solution? - ✔✔399 grams per liter
✔✔Sodium hydroxide is commonly referred to as: - ✔✔caustic soda.
✔✔Which of the following does an ultrafiltration system remove from wastewater? -
✔✔suspended solids.
✔✔Low pH wstewater is neutralized by adding: - ✔✔NaOH.
✔✔A solution with a pH of 5 has a concentration of hydrogen ions that is how many
times higher than a solution with a pH of 7? - ✔✔100 times higher
✔✔What is the normality of a sodium hydroxide solution of 25 ml if 0.01 N sulfuric acid
solution neutralizes 100 mL of the NaOH solution? - ✔✔0.0025 N
✔✔A cyanide destruction process is designed to treat 30 pounds of cyanide per 24-hour
operational day. How many pounds of cyanide can be treated during an 8-hour shift? -
✔✔10
✔✔A POTW must retain Industrial User records for a minimum of: - ✔✔3 years
✔✔The Federal Act that introduced the concept of cradle to grave manifesting for
hazardous waste products is: - ✔✔Resource Conservation and Recovery Act (RCRA).
✔✔Waste discharge regulations can be concentration- or mass-based except for: -
✔✔pH and temperature.
✔✔New Categorical Dischargers must submit a Baseline Monitoring Report to the
POTW control authority prior to the planned commencement of discharge by at least: -
✔✔90 days
✔✔The State NPDES General Permit for storm water from Industrial Activities covers
industries subject to federal storm water effluent limitation guidelines under 40 CFR,
,Subchapter N. Which of the following industries falls under this category? - ✔✔Cattle
feedlot
✔✔An industry has a wastewater discharge of 10,000 gallons per day containing 5 mg/L
of copper. What is the industry's mass emission rate of copper in pounds per day? -
✔✔0.42
✔✔An industry has five sewer connections with the following discharge rates: 1) 300
gpd, 2) 75 gpd, 3) 725 gpd, 4)1,200gpd, 5) 200 gpd. A flow-weighted composite sample
of 5 liters is desired. How many milliliters of sample from each connection should be
composited? - ✔✔600, 150, 1450, 2400, 400
✔✔An industry has a 36,000-gpd discharge in a sixteen-hour day. A composite sample
of 2 liters is needed. The sampler is set to take 125 ml. Each time the pump is activated.
For a flow proportional sample, at what gallon interval should the sampler activate to
take a sample? - ✔✔2,250 gallons
✔✔Lead acetate paper is used to determine the presence of: - ✔✔hydrogen sulfide.
✔✔In a normally distributed population of sampling data, what percent of the data points
will fall within one standard deviation? - ✔✔68.3
✔✔What kind of container and preservative is required for samples to be analyzed for
oil and grease? - ✔✔Glass, Cool 4°C, H2SO4 to pH < 2
✔✔In open channel flow measurement, the term "primary element" is used to denote
the: - ✔✔measuring structure that contains the water.
✔✔A solution of ferrous chloride used at a pretreatment facility contains 30 percent
ferrous chloride and has a density of 1.33 g/mL. How many grams of ferrous chloride
are in one liter of solution? - ✔✔399
✔✔19. You want to measure the flow in an 8-inch diameter city sewer line. If you use
the Manning formula, what additional data will you need to gather to calculate the flow
rate in the downstream manhole? - ✔✔Pipe length, invert elevation at both ends, water
depth at downstream end, and pipe roughness coefficient.
✔✔Why are septum vials used for TTO samples? - ✔✔To prevent sample contact with
air
✔✔The scouring velocity in a sewer is the speed of wastewater that will: - ✔✔Prevent
the deposition and buildup of solids.
, ✔✔22. Flatter sewer line grades may cause added sewer maintenance expense and
odor nuisance. The problem is most likely cased by: - ✔✔A decrease in velocity
allowing organic and inorganic solids to settle out
✔✔A cyanide-bearing waste is to be treated by a batch process using the alkaline
chlorination method. The cyanide holding tank contains 6,000 gallons with a cyanide
concentration of 15 mg/L. Seven pounds of caustic soda and eight pounds of chlorine
are required to oxidize one pound of cyanide to nitrogen gas. How many pounds of
chlorine are needed? - ✔✔6.0
✔✔What types of control devices are used to stop and start pumps? - ✔✔Floats
✔✔What type of pump is used in lift station wet wells? - ✔✔Submersible
✔✔What is the main purpose of gate valves in a lift station? - ✔✔To isolate the lift
station from the wastewater collection system during maintenance
✔✔Which of the following is not a suspended growth biological treatment system? -
✔✔Trickling filter
✔✔Activated sludge is wasted from the reactor to: - ✔✔control the sludge age.
✔✔A method commonly used to thicken activated sludge prior to treatment is: -
✔✔dissolved air flotation.
✔✔A metal finishing facility generates nickel-plating sludge from the clarifier of its
pretreatment system. The clarifier sludge is 6,000 mg/L and 2 percent of the treatment
plant inflow of 50,000 gallons per day. The sludge is dewatered in a filter press, 5 days
per week, and shipped off site for disposal as hazardous waste once per week. If the
filter press cake is 25 percent solids, how many pounds of dewatered sludge should be
manifested as hazardous waste each week, assuming a cake density of 8.34
lbs/gallon? - ✔✔1,000
✔✔Which method below is not used to stabilize municipal wastewater treatment plant
sludge? - ✔✔Contact stabilization
✔✔What is the first safety planning step prior to making a pretreatment inspection? -
✔✔Review the facility's industrial waste permit application and correspondence file
✔✔What is a common cause of oxygen deficiency in a sewer manhole? - ✔✔Bacterial
action that replaces oxygen with other gasses
