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Table 11 ESTIMATED RATE OF AQUIFER REFRESHING BY PUMPING Special Studies - Delivery of Water to Mexico Time After Pumping Began (Years) 1/ Estimated Salinity of Pump Effluent (ppm) Aquifer Porosity 40% 35% 30% 40% 35% 30% 2.4 2.1 1.8 6,000 6,000 6,000 3.0 3.0 3.0 5,650 4.0 4.0 4.0 5,130 5.0 5.0 5.0 4,710 4,440 4,120 6.0 6.0 6.0 4,340 7.0 7.0 7.0 4,020 8.0 8.0 8.0 3,760 9.0 9.0 9.0 3,520 10.0 10.0 10.0 3,330 3,100 2,860 15.0 15.0 15.0 2,710 2,560 2,430 20.0 20.0 20.0 2,370 2,340 2,280 25.0 25.0 25.0 2,300 2,260 2,230 1/ Pumping began late in 1959. 55Epson Perfection 4870 Photo, 400 dpi, 8 bi