Efforts to tackle environmental issues gained worldwide momentum from around 1970. In the US, the Environmental Protection Agency was established in 1970, and a series of major environmental protection laws were enacted. One of these was the Clean Water Act, which set forth regulations and standards for the quality of contaminated wastewater discharged into rivers and territorial waters. As tighter water quality standards were introduced, aging facilities in the US were expanded and reorganized, and sewage treatment facilities increased in size. However, with an increase in size came an increase in costs. From then on, the biggest challenge was to develop advanced wastewater treatment methods that could satisfy water quality standards while keeping costs down.

From the latter half of the 1980s, Kubota began development on submerged membranes^*2 to be used as membrane separation devices in MBRs. These membranes were compact, consumed little energy, and boasted advanced treatment capabilities, and were ideally suited to small- and medium-sized facilities. In 2005, Kubota established Kubota Membrane U.S.A. Corporation. Utilizing the wastewater treatment and engineering capabilities it developed over many years in Japan, Kubota successfully developed technologies that were optimized for large-scale treatment facilities in the US. Elsewhere, with improved energy efficiency, and a diverse range of submerged membranes sizes, use of Kubota’s membranes technologies increased. One such example was in Canton City in Ohio, where in 2013 Kubota received an order for submerged membranes at a water recycling and treatment facility, which at the time was the largest MBR in North America.

In 2016, Kubota set up the Kubota Water and Environment R&D Center USA within the water recycling and treatment facility, which was its first overseas research hub specializing in the water and environment business. The aim was to design MBR treatment systems that were optimally suited to the local climate and water quality, as well as the types, availability, and characteristics of local microorganisms. Research and development is also underway on ways to increase operational efficiency, such as by improving membrane performance at low water temperatures and enabling low-energy operation. Kubota continues to provide water treatment systems that conform to the necessary standards while being optimized to local needs, thereby helping to protect water environments in countries across the world.