A recharge well receives a conservative contaminant in the effluent from a treatment plant. The contaminant is present at a concentration of 10 mg/l over duration of 14 days. Recharge from the well is captured by a river located 500 m downgradient through an aquifer with a porosity n = 0.35 and a saturated thickness of b = 10 m. The regional aquifer flux is U = 5 m2/day, and the recharge well injection rate is Q = 500 m3/day.
Use MAGNET to determine the contaminant influx (loading) to the river as a function of time. In particular, determine the maximum influx in kg/day.
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.
- Represent the stream as a constant head zone feature.