Introducing a totally new, solid state technology—the Electronic Water Purifier (EWP) from Water Resources Co., of San Antonio. EWP is in no way similar to RO, DI, EDI or EDR. The purifier represents the most advanced water purification technology in existence. It’s designed for all types of water and wastewater applications. Membrane pre-treatment is not an issue. Plus, the purifier works on a broader range of contaminants than any of the other technologies.