This research proposes a nanoporous silicon membrane for use as a household water treatment filter in India and other regions of the developing world. As a robust and tunable material capable of rejecting contaminants based primarily on size, nanoporous silicon is capable of removing both bacteria and heavy metals from drinking water in a single stage. Produced via a cheap and scalable process, the targeted cost of the membrane is 10X cheaper than existing alternatives, while its physical and chemical properties render it less prone to biofouling, allowing for operation over a lifetime of multiple years with minimal monthly maintenance.