1. A circular clearwell has a diameter of 60 feet. How many gallons of water are in the clearwell if the clearwell water level is 12 feet?
A. 2,536,618 gallons
B. 253,662 gallons
C. 1,268,309 gallons
D. 378,415 gallons
2. A water line maintenance crew much isolate and drain 100 yards of a raw water intake line in order to repair the line. If the water line has an inside diameter of 2 feet, how many gallons of water will the line contain within the 100-yard section of line that must be drained?
A. 18,352 gallons
B. 917 gallons
C. 4,688 gallons
D. 7,046 gallons
3. How many cubic inches of space are in a one cubic-foot empty box?
A. 854 cubic inches
B. 90 cubic inches
C. 1,728 cubic inches
D. 144 cubic inches
4. If a water treatment plant produces 6,132,960 gallons of finished water in twenty-four hours, what is the plant's average gpm production during this period?
A. 4259 gpm
B. 3780 gpm
C. 6133 gpm
D. 2271 gpm
5. If a water treatment plant checks finished turbidity every four hours, and the plant records a day's finished turbidity readings of .07 NTU, .11 NTU, .10 NTU, .08 NTU, .13 NTU, and .11 NTU, what is the plant's average finished turbidity for the day?
A. .09 NTU
B. .10 NTU
c. .11 NTU
D. .12 NTU
6. A water treatment plant is experiencing a dirty-water event because of unusually high levels of rainfall. During the worst day of the event, the plant produces 4,525,620 gallons of finished water, while expending 85,543 gallons of this water as backwash water. What is the plant's "percent backwash" for this day?
A. 1.24 percent
B. .86 percent
C. 2.13 percent
D. 1.89 percent
7. How is the fraction 1/20 written in decimal form?
A. .0020
B. .020
C. .05
D. .005
8. How is 90,000 gallons written in million-gallon notation?
A. .90 MG
B. .09 MD
C. .009 MG
D. .0009 MG
9. How is 826,000 gallons written in million-gallon notation?
A. .0826 MG
B. 8.260 MG
C. .00826 MG
D. .826 MG
10. A sedimentation basin holds 1,250,000 gallons of water. If the flow through the plant is 4 MGD, what is detention time through the basin?
A. 7.5 hours
B. 5.5 hours
C. 6.25 hours
D. 4.25 hours
11. A water treatment plant has ten 16-foot x 14-foot mixed-media filters. If the flow through the plant is 11.5 MGD, what is the plant's filtration rate (filter loading rate)?
A. 2.9 gpm/ft2
B. 4.3 gpm/ft2
C. 3.6 gpm/ft2
D. None of the above
12. What water pressure is exerted at the base of a standpipe by a 150-foot column of water in the standpipe?
A. 65 psi
B. 45 psi
C. 150 psi
D. 433 psi
13. What water pressure is exerted at the base of a water tank by a 12-foot level of water in the tank?
A. 4.5 psi
B. 5.2 psi
C. 8.1 psi
D. 6.3 psi
14. A sedimentation basin is nine feet wide and sixty feet long. If the flow through the basin is 540 gpm, what is the overflow rate for the basin?
A. .25 gpm/ft2
B. .50 gpm/ft2
C. .75 gpm/ft2
D. 1 gpm/ft2
15. A water treatment plant uses a ferric sulfate dose of 45 mg/l on Monday, 60 mg/l on Tuesday and Wednesday, 50 mg/l on Thursday, and 55 mg/l on Friday. What is the plant's average ferric sulfate dosage for this five-day period?
A. 52 mg/l
B. 53 mg/l
C. 54 mg/l
D. 55 mg/l
ANSWERS: 1. B; 2. D; 3. C; 4. A; 5. B; 6. D; 7. C; 8. B; 9. D; 10. A; 11. C; 12. A; 13. B; 14. D; 15. C