Residential reverse osmosis (RO) water treatment systems provide an excellent means to reduce contaminants found in drinking water by utilizing a semipermeable membrane to remove ions, molecules, and particles. To function properly, these systems need a certain amount of rinse water, which is typically sent to the drain. Manufacturers of RO systems and components have been working to improve the efficiency of RO systems by reducing the amount of rinse water needed. The purpose of this standard is to aid water conservation efforts by providing manufacturers an efficiency target for their RO system designs.

ASSE 1086 covers water efficiency for residential RO systems and performance testing to address the membrane life concerns of high efficiency RO systems and membranes. The standard includes test requirements for complete systems or components, including system manifolds, RO membranes, pre- and post-filtration assemblies, supply and drain connections, among others.