There is hope for arid countries and those with access to sea water.
Scientists in Italy claim they are working on water purification that will cut filtering costs in half. It’s all in the membrane evidently. They have developed a filtering membrane that looks a little like saran wrap and mimics our own bodies’ membranes, and is selective about what goes through and what is left behind.
One application: undrinkable sea water, passed through this membrane will come out the other side minus the salt and potable. What an incredible gift for areas with undrinkable water.