Wastewater Treatment Certification Practice Exam: New 2023-2024, Exams of Water and Wastewater Engineering

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Wastewater Treatment Certification Practice Exam

(New 2023 – 2024) With Verified Answers

If a consumer complains about the drinking water characteristics, the operator should record the complaint and - Investigate immediately. What term is used when a water utility divides its total operating expenses into the total revenue? - Operating ratio How often should operating data, such as flow rate, amount of water treated, dosage of chemical, and reservoir levels be recorded? - Daily Which of the following is the most important reason to keep daily records of operational data? - Document that safe drinking water has been delivered to customers Under the requirements of the Safe Drinking Water Act, it is the duty of the water purveyor to deliver potable water of proper quantity only as far as the - Consumer's tap inside the home. According to the Safe Drinking Water Act, the basic definition of a public water supply system is any water system that supplies water for human consumption that serves - 15 service connections or over 25 persons for over 60 days a year. What agent is responsible for for reporting lab results to the regulatory agency? - Water system owner According to the USEPA drinking water regulations, the owner or operator of a public water system which fails to comply with applicable monitoring requirements must give notice to the public within - 3 months of the violation in a daily newspaper in the area served by the system. What federal law is designed to protect the safety and health of operators? - OSHA What federal law regulates public water supplies? - Safe Drinking Water Act What causes water to move through pores in soil and rocks? - Gravity What is commonly used indicator of possible health problems found in plants, soil, water and the intestines of humans and warm-blooded animals? - Coliform bacteria What are disease producing bacteria called? - Pathogenic What are the two main causes of hardness in water? - Calcium and Magnesium

Which source of water has the greatest natural protection from bacterial contamination? - Deep well in gravel What device measures the flow rate of gases? - Rotameter How often should preventative maintenance for equipment be performed? - According to the manufacturer recommendations Dynamic head is best described as the - total energy that a pump must develop for pumping to take place. Which of the following terms refers to the excessive internal pressure, which may be several times the normal operating pressure and can seriously damage hydropneumatic tanks, valves, and the piping network? - Water hammer Which of the following should an operator investigate first when the well pump and control problems occur? - Electricity Most pumps must be primed before startup in order to - start the flow of water. What is the purpose of a check valve? - Act as an automatic shutoff valve when the pump stops What is the primary purpose of a preventative maintenance program? - Avoid future equipment problems A mixture of air and gas is considered hazardous when the mixture exceeds what percentage of the lower explosive limit (LEL)? - 10% Which of the following duties should NOT be performed by a small system operator? - Wire pumps, compressors, and electrical components of the water system What are the most important methods of ensuring operator safety? - Alerting operators of unsafe acts and conducting mandatory safety training What safety procedure should an operator always follow when mixing a solution of sodium hypochlorite (liquid bleach) and fresh water? - Wear goggles and gloves when handling hypochlorite Which form of hypochlorite is the most dangerous to handle? - Calcium What are the two most important safety concerns when entering a confined space? - Oxygen deficiency and hazardous gases What piece of equipment must an operator wear when entering a confined space? - Harness

What type of fire extinguisher should be used for fires with live electricity present? - Class C Which document provides a profile of hazardous substances? - MSDS What safety measures must an operator follow prior to working on electrical equipment? - Lock out and tag out all electrical switches What is the correct procedure for mixing acid and water? - Acid is added very slowly to the water What is the purpose of a pump guard? - Protects operators from rotating parts The most important responsibility of an operator is to provide - safe drinking water. To ensure that the water supplied by a public water system meets federal and state requirements, the water system operator must regularly collect samples and - send all analysis results to the State periodically. The major source of error when obtaining water quality information is improper - sampling. A composite sample should never be used when sampling for which contaminant? - Bacteria When should water quality samples for chlorine residual be analyzed? - Immediately How many coliform samples are required per month for a water system serving a population between 25 and 100? - 1 Water laboratory test calculations and results use which system? - Metric Factors of what numbers are used in the metric system? - 10 What is the chemical formula for sulfuric acid? - H2SO Which of the following should NOT be used to draw a sample into a pipet? - Mouth Which of the following are two types of samples? - Grab and composite What two types of devices are used to collect samples? - Automatic and manual How should samples that cannot be analyzed immediately be maintained until the analysis is conducted? - Preserved

What is the most common method used in labs to test for total coliform and E. Coli? - Colilert What test method best determines chemical feed/dosage rates? - Jar An empty atmospheric shortage tank is 8 feet in diameter and 32 feet high. How long will it take to fill 90% of the tank volume if a pump is discharging a constant 24 gallon per minute into the tank? - 7 hours 3 minutes Two columns are filled completely at sea level to a height of 88 feet. Column A is 0.5 inches in diameter. Column B is 5 inches in diameter. What will two pressure gauges, one attached to the bottom of each column, read? - Column A: 38.0 PSI Column B: 38.0 PSI A ditch that is 4.5 feet wide, 6 feet deep, and 120 feet long has to be dug for a water line. How many cubic yards of material must be removed? - 120 cubic yards How many cubic feet of water will a rectangular tank that is 20 feet long by 15 feet wide and 10 feet high hold? - 3,000 cubic feet Calculate the chlorine demand using the following data. -Raw water flow is 0.75 MGD. -Chlorinator feed rate is 4.0 mg/L. -Chlorine Residual is 1.8 mg/L. - 2.2 mg/L Convert 60.5 degrees Fahrenheit to degrees Celsius. - 15.8 degrees Celsius Calculate drawdown, in feet, using the following data. -The water level in a well is 20 feet below the ground surface when the pump is not in operation. -The water level is 35 feet below the ground surface when the pump is in operation. - 15 feet Calculate the volume, in gallons, of a tank that is 75 feet long, 20 feet wide, 10 feet deep. - 112,200 gallons How many pounds of a chemical applied at the rate of 3 mg/L are required to dose 200, gallons? - 5 lbs Calculate the average weekly flow for a system with the following data. SUNDAY: 3,000 gallons MONDAY: 4,000 gallons TUESDAY: 3,500 gallons WEDNESDAY: 2,000 gallons THURSDAY: 3,000 gallons FRIDAY: 3,500 gallons SATURDAY: 2,000 gallons - 3,000 gpd

After a new water main is installed and pressure tested it should be - Filled with a solution of 25 ppm to 50 ppm free chlorine for at least 24 hours prior to flushing Chlorine demand is satisfied at the point when - the reaction of chlorine with organic materials stops. What chlorine concentration should be produced when disinfecting a well or well pump? - 50 mg/L When disinfecting a new or repaired main, what is the minimum chlorine residual at the extreme end of the main after standing for 24 hours? - 25 mg/L Chlorine will destroy bacteria most rapidly at what pH? - 7. What is the process of adding chlorine to water until the chlorine demand has been satisfied called? - Breakpoint chlorination Which of the following pH ranges would deposit a thin film of calcium carbonate on the inside surface of a pipe? - 8.0 - 9. Where should sodium hypochlorite (liquid bleach) be stored? - Away from equipment that is susceptible to corrosion What is the most important reason for maintaining a continuous positive pressure throughout the distribution system? - Prevent contamination from backflow A weir should be used to measure water in which of the following locations? - Open channels The pumping water level is best defined as the distance from the top of the well to the - water after the pump has been operating for a period of time. The space between the inner or protective casing and the outer casing or drill hole should be filled with cement grout to a minimum of how many feet? - 10 feet When bringing community water service to a home with a private well, what is the most positive method of preventing a cross connection between the two systems? - Complete isolation between the two systems using an air gap What is the physical connection, direct or indirect, which provides the opportunity for nonpotable water to enter a conduit, pipe or receptacle containing potable water? - Cross connection Which of the following causes taste problems and has a rotten egg odor? - Hydrogen sulfide