An organic contaminant is disposed of continuously in a long narrow trench that fully penetrates a shallow, semi-infinite aquifer (see figure below). For this aquifer, groundwater seepage velocity v = 2.31 x 10^-6 m/s, and dispersivity in the flow direction is 4.3m. The retardation factor = 3.0. The contaminant concentration at the source remains constant with time at 1.0 mg/l.

Use MAGNET to simulate the contaminant migration and calculate concentration distribution after three years.

MAGNET/Modeling Hints:

• Use ‘Synthetic mode’ in MAGNET to create a model domain.
• Use the ‘Distance Display’ capabilities when editing geometric features and/or the ‘Ruler’ tool to properly represent distances between model features.
• Represent the rivers as constant head zone features.