ft2/day. The thickness of the aquifer in the storage zone is 105 ft. Thus, the average
horizontal hydraulic conductivity is equal to 89.52 ft/day. Ambient water quality data
were collected from storage and monitoring wells. The chloride concentration of ambient
water at this site was about 1950 mg/L and for the injected water it was reported to be 50
mg/L. Aquifer porosity is reported to be 0.3 for this site.
Table 3-1. Duration and flow rates for three cycles of ASR operation in Boynton Beach,
Florida.
Cycle 1 Cycle 2 Cycle 3
Injection Time (day) 12.690 41.376 41.547
Storage Time (day) 0.130 0.010 8.768
Recovery Time (day) 6.981 15.979 21.750
Delay Time (day) 1.000 18.543 ---
Injection Flow Rate (ft3/day) 131140.6 181875.7 179629.6
Injection Flow Rate (ft3/day) 183408.6 144955.7 195192.3
The numerical model consists of 101 columns and 101 rows and one confined layer
with the thickness of 105 ft. A regular grid spacing of 10 ft is used for each row and
column. The horizontal hydraulic conductivity of this layer is 89.52 ft/day and storativity
is set to 0.0005. The effective porosity is 0.3. The flow field was first calculated with
MODFLOW. The 3rd-order TVD scheme (Ultimate) with Courant number 0.75 was used
in the simulation for the advection term and the GCG solver is used to solve the system
equations. No dispersion is considered in the model. To obtain the desired hydraulic
gradient, the cells in the first and last columns of the model are specified as fixed-head
boundaries. Water of a constant concentration, CI, is injected into the well at the cell [51,
51, 1]. The initial concentration, CB, is set to 1950 mg/L. Eleven stress periods are