Some foresee a world where clean water is one of our most precious commodities. Envirogen Technologies aims to clean up water supplies before it comes to that. The company designs, manufactures, installs, and maintains systems that treat wastewater and ground water as well as foul air nearby. It filters for selenium in coal mines, provides odor control systems for municipal wastewater, and separates chemical contaminants from groundwater at industrial sites. Envirogen provides both modular and customized units, such as ion exchange systems, coagulation filters, bioreactors, and biofilters. It is a subsidiary of Amplio Group, a UK-based investor in small renewable-energy and environmental services companies.