An apparatus for purifying water according to one embodiment of the present invention may include a feed line fluidically connected to a reverse osmosis module containing a semipermeable membrane. The semipermeable membrane produces purified water and a concentrate. A drain line is also connected to the reverse osmosis module configured to transport concentrate. A product line is connected to the reverse osmosis module for transporting purified water. Operatively associated with the product line and drain line is a shut-off mechanism containing a pressure sensor or gasket operatively associated with an appliance configured to activate the shut-off mechanism.