Texas Well Driller License Practice Exam
Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a well casing?
A) To increase water pressure
B) To prevent sediment buildup
C) To support the well bore and prevent collapse
D) To filter water
The casing supports the well bore walls and prevents collapse, ensuring the
well remains structurally sound.
2. What is the minimum distance a well must be located from a septic
tank according to Texas regulations?
A) 50 feet
B) 100 feet
, C) 25 feet
D) 75 feet
Texas regulations typically require wells to be at least 50 feet from septic
tanks to prevent contamination.
3. Which drilling method uses a rotating drill bit and drilling mud?
A) Cable tool drilling
B) Jetting
C) Percussion drilling
D) Rotary drilling
Rotary drilling involves a rotating drill bit and drilling mud to remove
cuttings and stabilize the borehole.
4. What is the purpose of a sanitary seal in a well?
A) To improve water flow
B) To prevent surface contaminants from entering the well
C) To support the pump
D) To increase well depth
A sanitary seal prevents contaminants from seeping down along the
outside of the casing into the well.
5. Which material is commonly used for well casings?
A) Wood
B) Aluminum
, C) Steel
D) Plastic
Steel is a common casing material because of its strength and durability,
especially in deep wells.
6. What is the typical pump setting depth for a shallow well?
A) Less than 25 feet
B) 25 to 50 feet
C) Over 50 feet
D) More than 100 feet
Shallow wells typically have pump settings less than 25 feet deep.
7. What is the main hazard of drilling through contaminated soil?
A) Equipment damage
B) Loss of drilling fluid
D) Contamination of the water supply
Drilling through contaminated soil can introduce pollutants directly into
the well water.
8. How often should a well be disinfected after drilling?
A) Every 6 months
B) Immediately after drilling
C) Only if water is cloudy
D) Once a year
, Disinfection immediately after drilling removes bacteria introduced during
the drilling process.
9. Which agency regulates well drilling in Texas?
A) EPA
B) TCEQ
C) Texas Department of Licensing and Regulation (TDLR)
D) Texas Water Development Board
The TDLR regulates well drilling licenses and standards in Texas.
10. What is the correct depth to place a sanitary seal?
A) Within the upper 50 feet of the well
B) At the bottom of the well
C) Below the water table
D) Above the pump intake
Sanitary seals must be placed near the surface, typically within the top 50
feet, to prevent surface contamination.
11. What is the primary function of drilling mud?
A) To increase drilling speed
B) To cool the drill bit
D) To stabilize the borehole and remove cuttings
C) To disinfect the well
Drilling mud stabilizes the borehole walls and carries cuttings to the
surface.
Questions And Correct Answers
(Verified Answers) Plus Rationales
2025|2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a well casing?
A) To increase water pressure
B) To prevent sediment buildup
C) To support the well bore and prevent collapse
D) To filter water
The casing supports the well bore walls and prevents collapse, ensuring the
well remains structurally sound.
2. What is the minimum distance a well must be located from a septic
tank according to Texas regulations?
A) 50 feet
B) 100 feet
, C) 25 feet
D) 75 feet
Texas regulations typically require wells to be at least 50 feet from septic
tanks to prevent contamination.
3. Which drilling method uses a rotating drill bit and drilling mud?
A) Cable tool drilling
B) Jetting
C) Percussion drilling
D) Rotary drilling
Rotary drilling involves a rotating drill bit and drilling mud to remove
cuttings and stabilize the borehole.
4. What is the purpose of a sanitary seal in a well?
A) To improve water flow
B) To prevent surface contaminants from entering the well
C) To support the pump
D) To increase well depth
A sanitary seal prevents contaminants from seeping down along the
outside of the casing into the well.
5. Which material is commonly used for well casings?
A) Wood
B) Aluminum
, C) Steel
D) Plastic
Steel is a common casing material because of its strength and durability,
especially in deep wells.
6. What is the typical pump setting depth for a shallow well?
A) Less than 25 feet
B) 25 to 50 feet
C) Over 50 feet
D) More than 100 feet
Shallow wells typically have pump settings less than 25 feet deep.
7. What is the main hazard of drilling through contaminated soil?
A) Equipment damage
B) Loss of drilling fluid
D) Contamination of the water supply
Drilling through contaminated soil can introduce pollutants directly into
the well water.
8. How often should a well be disinfected after drilling?
A) Every 6 months
B) Immediately after drilling
C) Only if water is cloudy
D) Once a year
, Disinfection immediately after drilling removes bacteria introduced during
the drilling process.
9. Which agency regulates well drilling in Texas?
A) EPA
B) TCEQ
C) Texas Department of Licensing and Regulation (TDLR)
D) Texas Water Development Board
The TDLR regulates well drilling licenses and standards in Texas.
10. What is the correct depth to place a sanitary seal?
A) Within the upper 50 feet of the well
B) At the bottom of the well
C) Below the water table
D) Above the pump intake
Sanitary seals must be placed near the surface, typically within the top 50
feet, to prevent surface contamination.
11. What is the primary function of drilling mud?
A) To increase drilling speed
B) To cool the drill bit
D) To stabilize the borehole and remove cuttings
C) To disinfect the well
Drilling mud stabilizes the borehole walls and carries cuttings to the
surface.
