CWEA Environmental Compliance Exam Questions With Correct Answers

An industry operating an 8-hour shift, 5 days per week, generates 100,000 gallons of wastewater per shift. Their pretreatment system has a capacity of 150 gallons per minute. How long must the pretreatment facility operate to process the wastewater generated each day? - Answer 11.1 hours An industry has five sewer connections with the following discharge rates: 1) 300 gpd, 2) 75 gpd, 3) 725 gpd, 4) 1,200 gpd, 5) 200 gpd A flow-weighted composite sample of 5 liters is desired. How many milliliters of sample from each connection should be composited? - Answer 600, 150, 1450, 2400, 400 Prohibited discharges from industrial users to POTWs, as stipulated in the Clean Water Act, are pollutants that: - Answer create a fire or explosion hazard in the sewer or POTW. "MSDS" is an acronym for what? - Answer Material Safety Data Sheet Safety hazards associated with hydrogen sulfide in sewer systems include: - Answer toxic gasses. A significant industrial user can be defined as: - Answer a federal categorical industrial user. Lead acetate paper is used to determine the presence of: - Answer hydrogen sulfide. What is the average detention time, in minutes, for a 40,000 gpd flow going through a 1,500-gallon interceptor? - Answer 54 minutes The following type of flow measuring device can be installed in a pipe flowing full: - Answer Venturi. What total volume of spill containment capacity in gallons is needed for the following tanks if a 12-inch rainfall occurs during a 24-hour period on a common 200-foot by 200-foot spill-containment pad? Assume 100 percent containment of all tank capacity is needed. Tank I: Cube, 6 ft wide, 6 ft long, and 6 ft high. Tank II: Rectangular, 4 ft wide, 20 ft long, and 3 ft high. Tank III: Cylindrical, 8 ft in diameter and 9 ft high. - Answer 305,992 gallons 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? - Answer 0.42 lb/day What kind of container and preservative is required for samples to be analyzed for oil and grease? - Answer Glass, Cool 4°C, H2SO4 to pH<2 A chain-of-custody form: - Answer is the ability to trace sample possession and handling from collection through analysis. The BOD determination is an empirical test in which standardized laboratory procedures are used to: - Answer determine the relative oxygen requirements of wastewaters, effluents, and polluted waters. A confined space is one that: - Answer is large enough to enter and work in, has a restricted entry/exit, and is not meant for continuous occupancy. Industrial plants producing wastes with a high suspended solids content include: - Answer breweries. Whenever an inspector or sampling technician is in a manhole, how many people should there be above to respond in the event of an emergency? - Answer Two Alkalinity is reported as: - Answer alkalinity, mg/L CaCO3. What is the normality of sodium hydroxide (NaOH) solution of 25 mL if a 0.01 N sulfuric acid solution neutralizes 100 mL of the NaOH solution? - Answer 0.0025 N A major pollutant of concern from a printed circuit board shop is: - Answer copper. To find the proper protective gear to use while inspecting an area where a hazardous chemical is used, you would: - Answer check the MSDS for chemicals used. Why are gasoline and volatile solvents objectionable when present in a sewer? - Answer They can produce an explosion hazard. When inspecting a plating shop, personal protective equipment would include: - Answer eye goggles or face shield, chemical resistant gloves, and overalls. 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? - Answer 100 times higher High pH wastewater is neutralized by adding: - Answer H2SO4. When working in the street, signs and cones are needed when: - Answer over half of the street is blocked. What is the danger of asphyxiation set point for oxygen on an atmospheric monitor? - Answer 19.5 percent A common technology to recover chemicals from rinse water include: - Answer ion exchange. Is an essential part of any sampling quality control methodology: - Answer Proper cleaning techniques for sampling equipment What are the types of stormwater pollution? - Answer Sediment,BOD,Nutrients How often must SIUs be inspected? - Answer 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? - Answer 399 grams per liter Sodium hydroxide is commonly referred to as: - Answer caustic soda. Which of the following does an ultrafiltration system remove from wastewater? - Answer suspended solids. Low pH wstewater is neutralized by adding: - Answer 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? - Answer 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? - Answer 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? - Answer 10 A POTW must retain Industrial User records for a minimum of: - Answer 3 years The Federal Act that introduced the concept of cradle to grave manifesting for hazardous waste products is: - Answer Resource Conservation and Recovery Act (RCRA). Waste discharge regulations can be concentration- or mass-based except for: - Answer 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: - Answer 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? - Answer 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? - Answer 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? - Answer 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? - Answer 2,250 gallons Lead acetate paper is used to determine the presence of: - Answer hydrogen sulfide. In a normally distributed population of sampling data, what percent of the data points will fall within one standard deviation? - Answer 68.3 What kind of container and preservative is required for samples to be analyzed for oil and grease? - Answer Glass, Cool 4°C, H2SO4 to pH < 2 In open channel flow measurement, the term "primary element" is used to denote the: - Answer 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? - Answer 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? - Answer Pipe length, invert elevation at both ends, water depth at downstream end, and pipe roughness coefficient. Why are septum vials used for TTO samples? - Answer To prevent sample contact with air The scouring velocity in a sewer is the speed of wastewater that will: - Answer 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: - Answer 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? - Answer 6.0 What types of control devices are used to stop and start pumps? - Answer Floats What type of pump is used in lift station wet wells? - Answer Submersible What is the main purpose of gate valves in a lift station? - Answer To isolate the lift station from the wastewater collection system during maintenance Which of the following is not a suspended growth biological treatment system? - Answer Trickling filter Activated sludge is wasted from the reactor to: - Answer control the sludge age. A method commonly used to thicken activated sludge prior to treatment is: - Answer 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? - Answer 1,000 Which method below is not used to stabilize municipal wastewater treatment plant sludge? - Answer Contact stabilization What is the first safety planning step prior to making a pretreatment inspection? - Answer Review the facility's industrial waste permit application and correspondence file What is a common cause of oxygen deficiency in a sewer manhole? - Answer Bacterial action that replaces oxygen with other gasses How many different areas of traffic zones are there when working in roadways? - Answer Five What does "transition area" mean in traffic control? - Answer Moves traffic out of its normal path Permit space emergency personnel must have the following training - Answer Enter and rescue procedures How does sewer system confined space entry differ from other permit and non-permit entries? - Answer There rarely exists any way to completely isolate the space What is always required when working in a confined space? - Answer Continuous air monitoring Oxygen deficiency occurs when the oxygen level is less than ____ by volume - Answer 19.5% Hydrogen sulfide smells like ___________ (at high concentrations of hydrogen sulfide, however, the sense of smell is deadened and no odor is detected). - Answer Rotten eggs The lack of an unpleasant odor in a manhole, lift station, or other structures does not always mean that dangerous gases are not present because - Answer Some dangerous gases have no odor The following type of flow measuring device can be installed in a pipe flowing full: - Answer Venturi meter. An ultrafiltration system removes _______ from wastewater. - Answer suspended solids A major pollutant of concern (POC) from a printed circuit board shop is: - Answer copper Emulsified oil is commonly removed from wastewater by: - Answer dissolved air flotation. Which one of the following items is a major characteristic of the wastes produced by a cannery? - Answer High dissolved organic matter While inspecting a chrome reduction tank in a pretreatment facility, you notice that the ORP reading is out of its proper range. The first thing you should check to determine the cause of the problem is: - Answer the range of pH values. Metal plating industries use ion exchange for: - Answer byproduct recovery. A recoverable chemical from textile mill waste is: - Answer caustic soda Non-storm water discharges to storm drains that are generally not permitted under municipal NPDES storm water discharge permits include: - Answer automobile detailing. Industries discharging storm water under a General Storm Water Permit are required to sample: - Answer storm water from outside industrial activities. A representative sample is: - Answer Similar to the larger body of wastestream being sampled Pretreatment inspectors with proper credentials are authorized by _______ to enter any premises of an industrial discharger for the purposes of inspection, sampling, examination of records required to be kept by the POTW, and to set up devises necessary to conduct sampling, monitoring and metering operations. - Answer Local sewer-use ordinances What type of waste discharge into a sewer may create a toxic atmosphere? - Answer Cyanide waste from metal finishers What is the main focus of pollution prevention? - Answer Minimizing the amount of waste generated What is waste minimization? - Answer Reduction of hazardous waste What is the primary role of the pretreatment facility inspector? - Answer Enforce regulations intended to protect the POTWs and the environment What do current trends indicate regarding future job opportunities for pretreatment facility inspectors? - Answer Increasing Why do pretreatment inspectors need computer skills? - Answer Become more efficient Conventional pollutants include: - Answer BOD, Oil and Grease, Suspended Solids The objectives of the General Pretreatment Regulations are to: - Answer Improve opportunities to reclaim and recycle sludge, reduce the health and environmental risks from pollution, and prevent the :interference with use or disposal of sludge, operation of POTW and introduction of pollutants which pass through treatment works What is the purpose of an industrial waste pretreatment program? - Answer The protection of agency personnel, capital facilities, the community, and the environment and to provide pollution prevention guidance to industry.