An industrial facility has a 2 acre on-site landfill for disposal of solid waste. The landfill is roughly square in planview. A 120 ft thick sandy aquifer lies beneath the facility and the upper part of the aquifer has a permeability of 35 ft /day and a porosity of 0.3. The average hydraulic gradient is 0.01. A regulatory compliance well is located on the site boundary, 1000 ft from the landfill.

Use MAGNET to answer the following questions

• What is the maximum landfill leachate concentration for a conservative species if the permissible well concentration is 10 mg/l?
• What is the maximum landfill leachate concentration for a species with a retardation factor of 2 and a hydrolysis half life of 600 days if the permissible well concentration is 0.1 mg/l?

Assume that the infiltration rate through the landfill is 6 inches per year, and the that the longitudinal, transverse, and vertical dispersivities are 90ft, 11 ft, and 0.6 ft, respectively. Neglect transport in the vadose zone. 

MAGNET/Modeling Hints: 

• Use 'Synthetic Mode' to set up your flow model ( 'Other Tools' > 'Utilities' > 'Go to Synthetic Case Area')
• Use the ‘Distance Display’ capabilities when editing geometric features and/or the ‘Ruler’ tool to properly represent distances between model features.