Texas Well Driller License Exam ACTUAL
EXAM COMPLETE QUESTIONS AND
CORRECT ANSWERS LATEST UPDATE
THIS YEAR
Q1. What is the primary purpose of a grout seal in a water well?
A. To enhance water flow
B. To prevent contamination of the aquifer
C. To reduce pump wear
D. To increase well depth
Correct ,,,,,,answer,,,,,,: B
Rationale: A grout seal, typically made of cement or bentonite, is placed in the
annular space between the casing and the borehole. Its primary function is to
prevent surface water and contaminants from migrating down the outside of the
casing and polluting the groundwater .
Q2. What is the minimum annular space required between the casing and the
borehole for proper grouting in a domestic water well in Texas?
A. 1/2 inch
B. 1 inch
C. 2 inches
D. 3 inches
Correct ,,,,,,answer,,,,,,: B
Rationale: Texas Department of Licensing and Regulation (TDLR) rules specify a
minimum annular space of 1 inch. This space is necessary to ensure that grout can
be placed properly to create a continuous, void-free seal that protects the aquifer .
Q3. Which type of pump is most commonly used in deep water wells?
A. Centrifugal pump
B. Jet pump
C. Submersible pump
D. Rotary pump
,Correct ,,,,,,answer,,,,,,: C
Rationale: Submersible pumps are placed directly inside the well casing below the
water level. They are highly efficient at lifting water from great depths without the
issues of cavitation that affect other pump types, making them the standard for
deep Texas wells .
Q4. What is the standard maximum allowable arsenic concentration in
drinking water according to EPA guidelines?
A. 5 ppb
B. 10 ppb
C. 20 ppb
D. 50 ppb
Correct ,,,,,,answer,,,,,,: B
Rationale: The Environmental Protection Agency (EPA) has set the Maximum
Contaminant Level (MCL) for arsenic in public drinking water at 10 parts per
billion (ppb). This is a health-based standard that well drillers should be aware of,
as arsenic is a common natural contaminant in some Texas aquifers .
Q5. Which of the following drilling methods uses a rotating drill bit with
drilling fluid to remove cuttings?
A. Cable tool drilling
B. Rotary drilling
C. Auger drilling
D. Percussion drilling
Correct ,,,,,,answer,,,,,,: B
Rationale: Rotary drilling is a method where a rotating bit grinds through rock
formations. Drilling fluid (mud) is continuously circulated down the drill pipe and
up the annulus to cool the bit, lift rock cuttings to the surface, and stabilize the
borehole walls .
Q6. What is the recommended minimum distance between a water well and a
septic tank in Texas?
A. 10 feet
B. 50 feet
C. 100 feet
D. 200 feet
Correct ,,,,,,answer,,,,,,: C
Rationale: TDLR and public health guidelines generally require a minimum
,horizontal separation distance of 100 feet between a water well and a septic tank to
prevent microbiological contamination of the groundwater supply .
Q7. Which type of casing is typically used for domestic water wells in Texas?
A. PVC
B. Steel
C. Fiberglass
D. All of the above
Correct ,,,,,,answer,,,,,,: D
Rationale: The choice of casing material depends on well depth, water chemistry,
and cost. PVC (polyvinyl chloride) is common for shallower wells, steel for deep
or large-diameter wells, and fiberglass for corrosive water environments. All are
acceptable if they meet TDLR standards .
Q8. What is the primary reason for disinfecting a new well with chlorine?
A. Remove minerals
B. Kill bacteria and pathogens
C. Increase water pressure
D. Prevent scaling
Correct ,,,,,,answer,,,,,,: B
Rationale: Well drilling introduces bacteria from the drilling equipment, water,
and soil into the borehole. Disinfection with a chlorine solution is mandatory to kill
these bacteria and ensure the water is microbiologically safe for human
consumption before the well is placed into service .
Q9. When must a water well driller submit a well report to TDLR?
A. Within 7 days
B. Within 15 days
C. Within 30 days
D. Within 60 days
Correct ,,,,,,answer,,,,,,: C
Rationale: Texas law requires a licensed water well driller to file a detailed well
completion report with the TDLR within 30 days of completing the well. This
report includes construction details, a well log, and pumping test data .
Q10. Which is a sign of well screen clogging?
A. Decrease in water temperature
B. Increase in water clarity
, C. Decrease in water flow
D. Increase in pump efficiency
Correct ,,,,,,answer,,,,,,: C
Rationale: The well screen is designed to allow water to enter while keeping out
sand and sediment. If the screen becomes clogged due to encrustation or fine sand,
the primary symptom will be a noticeable and progressive decrease in the well's
flow rate or yield .
Q11. Which Texas agency regulates water well drillers and pump installers?
A. Texas Commission on Environmental Quality (TCEQ)
B. Texas Department of Licensing and Regulation (TDLR)
C. Texas Water Development Board (TWDB)
D. Texas Railroad Commission
Correct ,,,,,,answer,,,,,,: B
Rationale: The TDLR is the state agency responsible for the licensing,
examination, and regulation of water well drillers and pump installers in Texas, as
outlined in Occupations Code, Chapters 1901 and 1902 .
Q12. What is the primary purpose of a casing in a water well?
A. To improve water taste
B. To prevent contamination and collapse of the well
C. To increase pump efficiency
D. To reduce drilling noise
Correct ,,,,,,answer,,,,,,: B
Rationale: The casing is the steel or PVC pipe installed in the borehole. It
provides structural support to prevent the hole from caving in and acts as a barrier
to prevent shallow, contaminated water from entering the well from the sides .
Q13. What is the main function of a well screen?
A. To prevent debris from entering the pump
B. To filter bacteria
C. To allow water entry while keeping out sediment
D. To measure water level
Correct ,,,,,,answer,,,,,,: C
Rationale: A well screen is a filtering device attached to the bottom of the casing
in unconsolidated aquifers (sand/gravel). It allows water to flow into the well but
blocks the passage of sand and fine sediment, which could otherwise damage the
pump and cloud the water .
EXAM COMPLETE QUESTIONS AND
CORRECT ANSWERS LATEST UPDATE
THIS YEAR
Q1. What is the primary purpose of a grout seal in a water well?
A. To enhance water flow
B. To prevent contamination of the aquifer
C. To reduce pump wear
D. To increase well depth
Correct ,,,,,,answer,,,,,,: B
Rationale: A grout seal, typically made of cement or bentonite, is placed in the
annular space between the casing and the borehole. Its primary function is to
prevent surface water and contaminants from migrating down the outside of the
casing and polluting the groundwater .
Q2. What is the minimum annular space required between the casing and the
borehole for proper grouting in a domestic water well in Texas?
A. 1/2 inch
B. 1 inch
C. 2 inches
D. 3 inches
Correct ,,,,,,answer,,,,,,: B
Rationale: Texas Department of Licensing and Regulation (TDLR) rules specify a
minimum annular space of 1 inch. This space is necessary to ensure that grout can
be placed properly to create a continuous, void-free seal that protects the aquifer .
Q3. Which type of pump is most commonly used in deep water wells?
A. Centrifugal pump
B. Jet pump
C. Submersible pump
D. Rotary pump
,Correct ,,,,,,answer,,,,,,: C
Rationale: Submersible pumps are placed directly inside the well casing below the
water level. They are highly efficient at lifting water from great depths without the
issues of cavitation that affect other pump types, making them the standard for
deep Texas wells .
Q4. What is the standard maximum allowable arsenic concentration in
drinking water according to EPA guidelines?
A. 5 ppb
B. 10 ppb
C. 20 ppb
D. 50 ppb
Correct ,,,,,,answer,,,,,,: B
Rationale: The Environmental Protection Agency (EPA) has set the Maximum
Contaminant Level (MCL) for arsenic in public drinking water at 10 parts per
billion (ppb). This is a health-based standard that well drillers should be aware of,
as arsenic is a common natural contaminant in some Texas aquifers .
Q5. Which of the following drilling methods uses a rotating drill bit with
drilling fluid to remove cuttings?
A. Cable tool drilling
B. Rotary drilling
C. Auger drilling
D. Percussion drilling
Correct ,,,,,,answer,,,,,,: B
Rationale: Rotary drilling is a method where a rotating bit grinds through rock
formations. Drilling fluid (mud) is continuously circulated down the drill pipe and
up the annulus to cool the bit, lift rock cuttings to the surface, and stabilize the
borehole walls .
Q6. What is the recommended minimum distance between a water well and a
septic tank in Texas?
A. 10 feet
B. 50 feet
C. 100 feet
D. 200 feet
Correct ,,,,,,answer,,,,,,: C
Rationale: TDLR and public health guidelines generally require a minimum
,horizontal separation distance of 100 feet between a water well and a septic tank to
prevent microbiological contamination of the groundwater supply .
Q7. Which type of casing is typically used for domestic water wells in Texas?
A. PVC
B. Steel
C. Fiberglass
D. All of the above
Correct ,,,,,,answer,,,,,,: D
Rationale: The choice of casing material depends on well depth, water chemistry,
and cost. PVC (polyvinyl chloride) is common for shallower wells, steel for deep
or large-diameter wells, and fiberglass for corrosive water environments. All are
acceptable if they meet TDLR standards .
Q8. What is the primary reason for disinfecting a new well with chlorine?
A. Remove minerals
B. Kill bacteria and pathogens
C. Increase water pressure
D. Prevent scaling
Correct ,,,,,,answer,,,,,,: B
Rationale: Well drilling introduces bacteria from the drilling equipment, water,
and soil into the borehole. Disinfection with a chlorine solution is mandatory to kill
these bacteria and ensure the water is microbiologically safe for human
consumption before the well is placed into service .
Q9. When must a water well driller submit a well report to TDLR?
A. Within 7 days
B. Within 15 days
C. Within 30 days
D. Within 60 days
Correct ,,,,,,answer,,,,,,: C
Rationale: Texas law requires a licensed water well driller to file a detailed well
completion report with the TDLR within 30 days of completing the well. This
report includes construction details, a well log, and pumping test data .
Q10. Which is a sign of well screen clogging?
A. Decrease in water temperature
B. Increase in water clarity
, C. Decrease in water flow
D. Increase in pump efficiency
Correct ,,,,,,answer,,,,,,: C
Rationale: The well screen is designed to allow water to enter while keeping out
sand and sediment. If the screen becomes clogged due to encrustation or fine sand,
the primary symptom will be a noticeable and progressive decrease in the well's
flow rate or yield .
Q11. Which Texas agency regulates water well drillers and pump installers?
A. Texas Commission on Environmental Quality (TCEQ)
B. Texas Department of Licensing and Regulation (TDLR)
C. Texas Water Development Board (TWDB)
D. Texas Railroad Commission
Correct ,,,,,,answer,,,,,,: B
Rationale: The TDLR is the state agency responsible for the licensing,
examination, and regulation of water well drillers and pump installers in Texas, as
outlined in Occupations Code, Chapters 1901 and 1902 .
Q12. What is the primary purpose of a casing in a water well?
A. To improve water taste
B. To prevent contamination and collapse of the well
C. To increase pump efficiency
D. To reduce drilling noise
Correct ,,,,,,answer,,,,,,: B
Rationale: The casing is the steel or PVC pipe installed in the borehole. It
provides structural support to prevent the hole from caving in and acts as a barrier
to prevent shallow, contaminated water from entering the well from the sides .
Q13. What is the main function of a well screen?
A. To prevent debris from entering the pump
B. To filter bacteria
C. To allow water entry while keeping out sediment
D. To measure water level
Correct ,,,,,,answer,,,,,,: C
Rationale: A well screen is a filtering device attached to the bottom of the casing
in unconsolidated aquifers (sand/gravel). It allows water to flow into the well but
blocks the passage of sand and fine sediment, which could otherwise damage the
pump and cloud the water .
