Constant Rate Pumping: Constant rate pumping involves the pumping of freshwater into the aquifer at a constant rate to maintain the pressure gradient that prevents saltwater from entering the aquifer | Variable Rate Pumping: Variable rate pumping involves the pumping of freshwater into the aquifer at varying rates to maintain the pressure gradient that prevents saltwater from entering the aquifer | Reverse Osmosis: Reverse osmosis is a water treatment process that involves the removal of salt and other impurities from water |