NGWA (K) WATER SYSTEMS LESS THAN 100 GPM EXAM QUESTIONS AND ANSWERS FINAL VERSION WITH STEP-BY-STEP SOLUTIONS INCLUDED

1. What is the primary purpose of a well screen?

• A) To filter sediment from water
• B) To allow water to enter while keeping formation material out
• C) To increase water pressure
• D) To prevent corrosion ANSWER : B

2. Which material is most commonly used for modern well casing?

• A) Wood
• B) Concrete
• C) PVC or steel
• D) Copper ANSWER : C

3. What is the typical minimum distance a well should be from a septic
system?

• A) 25 feet
• B) 50 feet
• C) 100 feet
• D) 200 feet ANSWER : C

4. What does a pitless adapter do?

• A) Reduces water pressure
• B) Provides sanitary below-ground connection through casing
• C) Increases pump efficiency
• D) Filters contaminants ANSWER : B

5. What is the recommended minimum well casing diameter for most
residential wells?

• A) 2 inches

, • B) 4 inches
• C) 6 inches
• D) 8 inches ANSWER : C

6. What is the annular space in well construction?

• A) The space between casing and borehole wall
• B) The screen opening size
• C) The water storage capacity
• D) The pump chamber ANSWER : A

7. What material is typically used for annular sealing?

• A) Sand
• B) Gravel
• C) Bentonite or cement grout
• D) Clay ANSWER : C

8. What is a sanitary well seal?

• A) A pressure relief valve
• B) A cap preventing contamination at wellhead
• C) A water treatment device
• D) A flow meter ANSWER : B

9. What is the purpose of a gravel pack?

• A) To increase water storage
• B) To support formation and filter sediment around screen
• C) To seal the well
• D) To prevent corrosion ANSWER : B

10. What is drawdown in a water well?

• A) The pump installation depth
• B) The difference between static and pumping water levels
• C) The well depth
• D) The casing diameter ANSWER : B

Pumps & Motors

11. What type of pump is most common for wells deeper than 25 feet?

• A) Centrifugal
• B) Submersible

, • C) Jet pump
• D) Hand pump ANSWER : B

12. What is the maximum practical suction lift for a shallow well jet pump?

• A) 10 feet
• B) 15 feet
• C) 25 feet
• D) 40 feet ANSWER : C

13. Where is a submersible pump located?

• A) At ground level
• B) In the pressure tank
• C) Below water level in the well
• D) In the basement ANSWER : C

14. What voltage is standard for most residential submersible pump
motors?

• A) 110V
• B) 220-240V
• C) 440V
• D) 12V ANSWER : B

15. What component converts electrical energy to mechanical energy in a
pump?

• A) Impeller
• B) Motor
• C) Diffuser
• D) Check valve ANSWER : B

16. What is the function of pump stages?

• A) To filter water
• B) To increase pressure incrementally
• C) To cool the motor
• D) To reduce noise ANSWER : B

17. How many stages might a typical residential submersible pump have?

• A) 1-2
• B) 3-15

, • C) 20-30
• D) Over 50 ANSWER : B

18. What is the purpose of the pump's check valve?

• A) To regulate flow rate
• B) To prevent backflow when pump stops
• C) To filter debris
• D) To measure pressure ANSWER : B

19. What does TDH stand for in pump terminology?

• A) Total Dynamic Head
• B) Total Discharge Height
• C) Total Depth Horizontal
• D) Thermal Dynamic Heat ANSWER : A

20. What factor does NOT affect pump selection?

• A) Required flow rate
• B) Total dynamic head
• C) Well diameter
• D) Color of the house ANSWER : D

Pressure Systems

21. What is the typical residential pressure tank setting?

• A) 10/30 psi
• B) 20/40 psi
• C) 30/50 psi
• D) 40/60 psi ANSWER : C

22. What does the cut-in pressure represent?

• A) Maximum system pressure
• B) Pressure when pump starts
• C) Pressure when pump stops
• D) Tank capacity ANSWER : B

23. What is the typical pressure differential in a residential system?

• A) 5 psi
• B) 10 psi
• C) 20 psi