NGWA AUGERING AND MONITORING
WELL PROFESSIONAL CERTIFICATION
EXAM
1. What is the primary technical advantage of using Hollow Stem Augers (HSA) for monitoring
well installation in unconsolidated formations?
A. It allows for the continuous collection of rock cores in lithified formations.
B. It provides the highest torque efficiency for drilling through glacial till.
C. It minimizes the generation of drill cuttings compared to direct push methods.
D. It acts as a temporary casing to prevent borehole collapse during well construction.
Answer: D
Conceptual Explanation: HSA acts as a temporary casing, allowing the well screen and
casing to be inserted through the center of the augers, which prevents the borehole from
collapsing in unstable soils.
2. When designing a filter pack for a monitoring well, what is the standard practice for
selecting the grain size relative to the formation?
A. The filter pack should have a D30 size that is 3 to 6 times the D30 of the formation.
,B. The filter pack should be 10 times finer than the formation D50.
C. The filter pack must always be composed of angular crushed stone.
D. The filter pack D60 should be exactly equal to the formation D10.
Answer: A
Conceptual Explanation: A common design criteria is that the filter pack grain size (D30)
should be approximately 3 to 6 times the D30 size of the formation to effectively bridge and
filter fine particles.
3. In the context of well development, what is the main goal of surging the well?
A. To increase the pH of the groundwater for better sampling results.
B. To compact the filter pack against the borehole wall.
C. To move water in and out of the screen to break down the filter cake and remove fines.
D. To sterilize the screen surface from microbial growth.
Answer: C
Conceptual Explanation: Surging creates a flow reversals (in and out of the screen) that
helps remove fine materials from the formation and the filter pack, improving hydraulic
connectivity.
4. Which material is most recommended for well casing when monitoring for trace levels of
volatile organic compounds (VOCs) to minimize sorption?
A. Stainless steel (304 or 316) or Fluoropolymer (Teflon)
, B. Galvanized iron
C. High-density polyethylene (HDPE)
D. Low-carbon steel
Answer: A
Conceptual Explanation: Stainless steel and Teflon are relatively inert and have low
sorption potential compared to polymers or carbon steel, making them ideal for high-
sensitivity VOC monitoring.
5. What is the minimum recommended thickness for a bentonite seal above the filter pack in
a monitoring well?
A. 6 inches
B. 10 feet
C. 5 feet
D. 2 feet
Answer: D
Conceptual Explanation: Industry standards generally recommend a minimum of 2 feet of
bentonite pellets or chips to provide an effective seal against grout migration into the filter
pack.
6. During the Standard Penetration Test (SPT), what does the ‘N-value’ represent?
A. The number of blows required to drive the sampler through the first 6 inches.
WELL PROFESSIONAL CERTIFICATION
EXAM
1. What is the primary technical advantage of using Hollow Stem Augers (HSA) for monitoring
well installation in unconsolidated formations?
A. It allows for the continuous collection of rock cores in lithified formations.
B. It provides the highest torque efficiency for drilling through glacial till.
C. It minimizes the generation of drill cuttings compared to direct push methods.
D. It acts as a temporary casing to prevent borehole collapse during well construction.
Answer: D
Conceptual Explanation: HSA acts as a temporary casing, allowing the well screen and
casing to be inserted through the center of the augers, which prevents the borehole from
collapsing in unstable soils.
2. When designing a filter pack for a monitoring well, what is the standard practice for
selecting the grain size relative to the formation?
A. The filter pack should have a D30 size that is 3 to 6 times the D30 of the formation.
,B. The filter pack should be 10 times finer than the formation D50.
C. The filter pack must always be composed of angular crushed stone.
D. The filter pack D60 should be exactly equal to the formation D10.
Answer: A
Conceptual Explanation: A common design criteria is that the filter pack grain size (D30)
should be approximately 3 to 6 times the D30 size of the formation to effectively bridge and
filter fine particles.
3. In the context of well development, what is the main goal of surging the well?
A. To increase the pH of the groundwater for better sampling results.
B. To compact the filter pack against the borehole wall.
C. To move water in and out of the screen to break down the filter cake and remove fines.
D. To sterilize the screen surface from microbial growth.
Answer: C
Conceptual Explanation: Surging creates a flow reversals (in and out of the screen) that
helps remove fine materials from the formation and the filter pack, improving hydraulic
connectivity.
4. Which material is most recommended for well casing when monitoring for trace levels of
volatile organic compounds (VOCs) to minimize sorption?
A. Stainless steel (304 or 316) or Fluoropolymer (Teflon)
, B. Galvanized iron
C. High-density polyethylene (HDPE)
D. Low-carbon steel
Answer: A
Conceptual Explanation: Stainless steel and Teflon are relatively inert and have low
sorption potential compared to polymers or carbon steel, making them ideal for high-
sensitivity VOC monitoring.
5. What is the minimum recommended thickness for a bentonite seal above the filter pack in
a monitoring well?
A. 6 inches
B. 10 feet
C. 5 feet
D. 2 feet
Answer: D
Conceptual Explanation: Industry standards generally recommend a minimum of 2 feet of
bentonite pellets or chips to provide an effective seal against grout migration into the filter
pack.
6. During the Standard Penetration Test (SPT), what does the ‘N-value’ represent?
A. The number of blows required to drive the sampler through the first 6 inches.
