Class D Water Exam Illinois
1. For a water storage tank, cathodic protection is only effective for the < > tank
areas covered by water
For a water storage system, the purpose of an altitude valve is to prevent < > overflow
2. Before using a water storage tank that has been disinfected, water from the tank
must not show the presense of < > coliforms
3. High trihalomethane (THMs) levels may cause < > cancer
4. A finished water with a negative Langelier Index may be < > corrosive
5. Water with pH scale less than 7 is considered < > acidic
6. pH scale of 7 is considered < > neutral
7. pH scale of 8-14 is considered < > basic
8. How many gallons of water are in 1 cubic ft < > 7.48 gallons
9. How many gallons of water are in 15 cubic ft < > 15 x 7.48 = 112.2 gallons
10. How many cubic ft of water is 20 gallons < > 20/7.48 = 2.67 cubic ft
11. 1 gallon of water equals how many lbs < > 8.34 lbs
12. 16 gallons of water is how many lbs < > 16 x 8.34 = 133.44 lbs
13. A 180 ft water tower would show what psi on the gauge located at the base
1/
17
,< > 180/ 2.31 = 77.92 psi
14. Pump cavitation is most likely to occur when < > the top of the water source
level is lower than the impeller
15. 1 pound per square inch is equal to how many feet of elevated water < > 2.31 feet
16. For most centrifugal pumps, if the total dyanmic head decreases, the pump will < >
pump water at a faster rate in gpm. (less head to push against)
17. The velocity of water is measure in < > Feet per Second
Distance (feet)/Time (sec)
18. When water lines in a distribution system are installed parallel to sewer lines,
they should be located how far apart from the sewer lines < > 10 ft
19. Air relief valves in the distribution system should be located where < > at the high
point on a main
20. What is the minimum psi that needs to be continually maintained in all parts
of a water distribution system < > 20 psi
21. What could occur if the minimum distribution system pressure is not
maintained < > backsiphonage
22. A ground storage tank is 50 feet in diameter and 30 feet high. If the tank is being
filled at a 10 feet rise in level per hour, how many gallons per minute are flowing into
2/
17
, the tank < > 2,447 gpm
(Ignore the heighth)
3/
17
1. For a water storage tank, cathodic protection is only effective for the < > tank
areas covered by water
For a water storage system, the purpose of an altitude valve is to prevent < > overflow
2. Before using a water storage tank that has been disinfected, water from the tank
must not show the presense of < > coliforms
3. High trihalomethane (THMs) levels may cause < > cancer
4. A finished water with a negative Langelier Index may be < > corrosive
5. Water with pH scale less than 7 is considered < > acidic
6. pH scale of 7 is considered < > neutral
7. pH scale of 8-14 is considered < > basic
8. How many gallons of water are in 1 cubic ft < > 7.48 gallons
9. How many gallons of water are in 15 cubic ft < > 15 x 7.48 = 112.2 gallons
10. How many cubic ft of water is 20 gallons < > 20/7.48 = 2.67 cubic ft
11. 1 gallon of water equals how many lbs < > 8.34 lbs
12. 16 gallons of water is how many lbs < > 16 x 8.34 = 133.44 lbs
13. A 180 ft water tower would show what psi on the gauge located at the base
1/
17
,< > 180/ 2.31 = 77.92 psi
14. Pump cavitation is most likely to occur when < > the top of the water source
level is lower than the impeller
15. 1 pound per square inch is equal to how many feet of elevated water < > 2.31 feet
16. For most centrifugal pumps, if the total dyanmic head decreases, the pump will < >
pump water at a faster rate in gpm. (less head to push against)
17. The velocity of water is measure in < > Feet per Second
Distance (feet)/Time (sec)
18. When water lines in a distribution system are installed parallel to sewer lines,
they should be located how far apart from the sewer lines < > 10 ft
19. Air relief valves in the distribution system should be located where < > at the high
point on a main
20. What is the minimum psi that needs to be continually maintained in all parts
of a water distribution system < > 20 psi
21. What could occur if the minimum distribution system pressure is not
maintained < > backsiphonage
22. A ground storage tank is 50 feet in diameter and 30 feet high. If the tank is being
filled at a 10 feet rise in level per hour, how many gallons per minute are flowing into
2/
17
, the tank < > 2,447 gpm
(Ignore the heighth)
3/
17
