3. Landfills often use clay soils to control the flow of fluids in and out of the landfill. At the sides and bottom of the landfill compacted clay liners are used to contain the accumulating fluid within the landfill (called leachate). At the top of the landfill, clay cover systems keep water from rain and snow from infiltrating into the landfill and creating excess leachate. The fluid flow through these liner systems can generally be approximated as one-dimensional flow. Leachate containing trichloroethylene collects on the clay liner at the bottom of the landfill as shown in the figure below. Below the clay liner is a gravel layer that collects the leachate so it can be pumped out and treated. There is a second clay layer below the gravel layer to prevent leachate from entering the groundwater below. For the hydraulic conditions shown in the figure and a typical effective porosity of the clay of 0.10, compute: (1) The total amount of leachate that must be collected and treated each year. Assume the total area of the landfill base is 5,000 m². (2) The time it takes the leachate to penetrate through the top clay liner. 1 m Refuse Leachate collected above liner 0.5m Top clay liner k=2.1 x 10 cm/s Gravel collection layer Bottom clay liner.