Nubian Water Systems. The company manufactures and installs high-end greywater treatment systems for single-family, multifamily, and commercial applications. Its residential system, the Nubian GT600, meets requirements for indoor reuse (where allowed) and for above-ground sprinklers. A four-stage treatment process, including coarse-through-fine filtration, adsorption media, biological treatment, and UV-light disinfection completes the treatment process before the treated water is stored for recycling. Nubian is headquartered in Australia and provides service in the western United States. www.nubian.com.au.