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• A drawdown of 1.9 feet was measured in observation well MW-3-13 (A-zone well), suggesting a
hydraulic connection between the A- and B-zones.
• Little to no response was observed in the C-zone wells, indicating no direct hydraulic connection.
• Calculated radius of cross-gradient capture for each B-zone well is listed below:
- MW-3B = 40 feet
- MW-5B = 15 feet
- MW-1B = 5 feet
The test data demonstrated that an elliptical drawdown area reflects the horizontally anisotropic nature of
the B-zone water-bearing zone. The B-zone is equivalent to a porous media where the upper portion of
bedrock is highly fractured and jointed. In areas where it is less jointed, the aquifer responds as a
fracture flow system with both primary and secondary porosity.
The results of the pumping test conducted in the B-zone were used in selecting appropriate wells to
monitor the effectiveness of the IRM system.
3.2.3 Aquifer Testing in C-Zone
During the constant rate pumping testing conducted in the C-zone in 2008, hydraulic responses were
observed in the majority of the C-zone wells monitored (Figure 8). This included well EXB-07, which is
located over 130 feet downgradient of the pumping well (EXB-06/EW-8-62). No measurable drawdown
was detected in the upgradient observation well EXB-02. A summary of the key results from the constant
rate test are presented below:
• The extraction rate in the pumping well EXB-06 ranged from 0.30 to 0.40 gpm throughout the
pumping phase of the test, with an average rate of 0.35 gpm.
• Approximately 4.3 feet of drawdown was measured in cross-gradient exploratory boring EXB-05,
which is located 135 feet to the northeast of the pumping well.
• Approximately 4.2 feet of drawdown was measured in cross-gradient exploratory boring EXB-10,
which is located approximately 80 feet to southwest of the pumping well.
• Approximately 1.5 feet of drawdown was measured in downgradient exploratory boring EXB-07,
which is located approximately 140 feet to the north.
• Approximately 0.85 foot of drawdown was measured in D-zone well EXB-11, which is located north of
EXB-06.
The test data demonstrated that an elliptical drawdown area primarily reflects the horizontally anisotropic
nature of the C-zone. Over 370 feet of cross-gradient influence was observed and over 130 feet of
downgradient influence was observed with respect to the pumping well. The data indicated that the
predominant source of flow within the C-zone is from the open bedding plane fractures, which respond
significantly under pumping conditions.
The results of the pumping test conducted in the C-zone were used in selecting appropriate wells to
monitor the effectiveness of the IRM system.
3.2.4 B-Zone Well Selection
The wells selected to monitor the groundwater within the B-zone are shown in Figure 3 and include MW-
1B, MW-4B, MW-5B, MW-7B, MW-8B, MW-23B, and MW-32B. The selected wells are screened in the
intensely fractured B-zone bedrock (typically between 10 and 20 feet bgs) and correlate with the B-zone
extraction wells (EW-4-25B, EW-5-25B, EW-7-25B, and EW-10-25B). These selected wells will be used
to demonstrate hydraulic capture and long-term reduction of VOC mass in the groundwater within the B-
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