The sketch below represents an industrial site where there is a high potential for a hy­dr...

The sketch below represents an industrial site where there is a high potential for a hy­drocarbon product spill to occur over an aquifer. The sand and gravel aquifer is very permeable and a spill would result in the product reaching the water table aquifer and

seeping into the bay. APED represents a constant head boundary (bay) with elevation of 96.0 m (315.0 ft). ABCD represents a barrier boundary. The bottom of the aquifer has an elevation of 91.5 m (300.0 ft). The wells are equipped with switches so that the pumped wells turn off when the water level drops below 93.0 m (305 0 ft) and the recharge wells turn off when the water level exceeds 99.1 m (325.0 ft). Determine the time for an effective barrier to form.