matlab tank containing benzene at a concentration of 1500 mg/L was overturned and spilled to a saturated layer over an area of 5 m2 . The groundwater velocity of the saturated layer is 0.45 m/day. Assume DL and DT are 2.5 and 0.25 m2 /day respectively. Assume xo = 0 and yo = 0 for the location of the tank. The monitoring well is at x =80 m and y = 5 m. What would be the concentration after 200 days of benzene spills? Assume no biodegradation and chemical reaction inside saturated zone