NJS Consultants Co. Ltd. (NJS) was established in 1951 in Tokyo, Japan, and is a major independent international multidisciplinary engineering consulting firm, specializing in environmental engineering, water supply, sanitary and civil engineering, together with institutional development, training and financial management activities related to environmental projects.

As one of the pioneering sanitary engineering firms in Japan with almost 60 years of worldwide experience, NJS enjoys a reputation for providing technical excellence and a superior quality of work to its clients. Having carried out almost one-third of the sewerage and sewage treatment schemes in Japan as the country invested heavily in urban sanitation upgrading in the 1950s and 1960s, NJS is now rated as one of the top Japanese consulting firms providing water and wastewater consultancy services to its worldwide clients.

The services provided by NJS cover the complete range of environmental engineering disciplines over the full project cycle, from initial project identification studies; master planning; technical, economic and financial feasibility studies; engineering design; cost estimation; preparation of tender documents and tender evaluation; construction supervision and contract management; system commissioning and operations; and institutional development, capacity building and training.