Natural Systems International (NSI) is a leader in applied biotechnology and ecological engineering.

NSI provides comprehensive and specialized engineering services in the area of biological wastewater treatment, stormwater treatment, water reuse, and water resources master planning. Our unique design approach utilizes natural systems, including constructed wetlands, and the applied ecologies of the pond, river, prairie, and woodland to develop sustainable projects. Our design goals include minimal energy use, the utilization of natural carbon sequestration technologies, and creating wildlife habitat and attractive landscapes. NSI is particularly adept at working with other design firms especially when participating in an integrated design process. Our broad experience in innovative wastewater treatment designs ranges from urban reuse in Washington, D.C., to zoos and wild animal parks in Australia and California, to a groundbreaking cypress wetlands restoration in Louisiana. Since 1989, NSI has designed, developed studies, specified and observed construction on more than 500 ecological engineering projects varying in size from 450 gallons per day (gpd) to 11.0 million gpd. We have firmly established our reputation for innovation and excellence with state and local regulatory agencies throughout the United States. Placing extra emphasis on both creativity and economics, NSI specializes in the implementation of natural treatment system designs using native plant species to treat municipal, commercial, residential, and industrial wastewater. Additionally the firm is experienced with stormwater, landfill leachate, agricultural wastewater, septage, sludge, and mine tailings.

The engineering staff at NSI has developed a reputation for innovation and excellence with state and local regulatory agencies throughout the United States. We possess a diverse range of professional experience and take great pride in providing our clients with innovative, cost effective, state-of-the-art engineering services. We were involved with early commercial LEED projects and continue to be leaders in the development of sustainable concepts for wastewater, storm water, and water reuse. We are in constant communication with other leading experts in the field, and are often requested to provide assistance to the environmental regulatory community in the development of guidelines for the design and permitting of various natural wastewater treatment systems.