Proposed Maximum Contaminant Levels (MCLs) have been set recently by the U.S. Environmental Protection Agency (USEPA) for several volatile organic contaminants and Maximum Contaminant Level Goals have been proposed for other volatile and non-volatile organic contaminants, such as pesticides. Thus, over twenty volatile organic compounds (alkanes, alkenes, and aromatics) as well as pesticides were treated by the USEPA using several types of reverse membranes. Preliminary findings indicate that reverse osmosis may be applicable for dual problems such as an organic/inorganic contamination.