Waste Water Certification Test Questions With CORRECT Answers

Surface water runoff, storm water, sanitary and industrial. -ANSWER A collection system that is called "combined" may carry this kind of wastewater: 2 -ANSWER The flow in a collection system should be a minimum of ____ feet per second (FPS)? Solids will settle. -ANSWER What will happen if the flow is too slow in a collection system? Odors, Corrosion, Hydrogen Sulfide Gas (all of the above) -ANSWER A short detention time in the collection system will help prevent which of the following problems? Low areas must be sewered. -ANSWER When are lift (pumping) stations installed in a collection system? Parentheses, Exponents, Multiplication, Division, Addition, Subtraction -ANSWER The order of operations to solve math problems is: (from first to last) 27 -ANSWER 3^3 24 -ANSWER (5+7)x4/2= 19 -ANSWER 7+6X4/2= 4 -ANSWER 2X+12=20. What is "X" equal to? 3,000,000gal/1,500,000MGD = 2 days = 48 hours -ANSWER The volume of a tank is 3,000,000 gallons (3MG) and the flow rate into the tank is 1,500,000 gallons per day (1.5 MGD). Calculate the detention time in hours. (750 GPM)(60 min/hr)(24 hr/day)/1,000,000 = 1.08 MGD -ANSWER A pump is rated at 750 gpm. Calculate the flow rate in million gallons per day (MGD). 1.5MG/1MLSS x 3.785L/1gal = 5.6775MG/1gal x 1lbs/453,592.37MG = 25.04 lbs/day -ANSWER A secondary clarifier discharges 2 MGD and the effluent contains 1.5 mg/l of mixed liquor suspended solids (MLSS). Calculate the pounds per day of MLSS discharged. (F012, F017, F022, F035) (200 mg/L - 15 mg/L)/(200 mg/L) x 100% = 92.5% -ANSWER The influent to a clarifier contains 200 mg/l of total suspended solids (TSS). What is the efficiency in % if there is 15 mg/l of TSS in the effluent? (F011 , F018) x= 0.785 x (100)^2 x (20) = 157,000 cf x 7.481/gal = 1,174,517 gal -ANSWER A clarifier is 100 ft. in diameter and 20 ft. deep. How many (ft^3) of water does the clarifier