A landfill linear is laid at elevation 50 ft msl (mean sea level) on top of a good caly unit. A clean sand unit extends from elevation 50 ft to elevation 75 ft, and another clay unit extends up to the surface, located at elevation 100 ft. The landfill can be represented by a square with length of 500 ft on a side and a vertical depth of 50 ft from the surface. The landfill has a 3 ft thick clay linear with K = = 10 -7 cm/s around the sides and bottom, as shown in Fig. P8.19. The regional ground water level for the confined sand (K = 10 -2 cm/s) is located at a depth of 10 ft below the surface, or elevation = 90 ft.
How much water will have to be continuously pumped from the landfill to keep the potentiometric surface at 60 ft elevation (msl) within the landfill? Assume mostly horizontal flow through the clay linear?

KCLAY = 10 -7 cm / s
KCLAY = 10 -2 cm / s

Pump 100 Larndfill 9d Clay Clay 75 60 50 500 ft Clay Ah Al