Environment A Green Future for the Northern Harbor: Hokkaido Tomakomai Industrial Zone Environmental Improvement Plan, June 1996.

Environment A Green Future for the Northern Harbor: Hokkaido Tomakomai Industrial Zone Environmental Improvement Plan, June 1996.

In the mid-1990s, Tomakomai developed as a port city with heavy and chemical industries, mainly in the petroleum, paper, and chemical industries, but years of industrial activity had resulted in air and water pollution in the port area. In particular, organic matter contained in wastewater from paper mills, chemicals generated in bleaching processes, and oil spills from large tankers have contributed to the deterioration of water quality and bottom sediment pollution in the port area. Furthermore, with the introduction of the ISO 14000 series internationally, companies were required to strengthen their environmental management.

An important pillar of this plan was the expansion of the buffer greenbelt. The planting of a combination of salt-preventive tree species and evergreen broad-leaved trees was designed to provide wind protection, salt protection, and dust dispersal prevention, as well as to improve the port's landscape. The greening infrastructure used permeable soil and improved materials, and was designed to withstand the strong winds and tidal damage typical of coastal areas.

In addition to the conventional activated sludge method, sand filtration, activated carbon adsorption, and advanced oxidation treatment (ozone and ultraviolet oxidation) were introduced for wastewater treatment technology to significantly improve COD, color, and SS removal rates. For oil removal, oil-water separation tanks and flotation separators as well as centrifugal separation systems were added for higher efficiency. In addition, ships entering the port were required to properly treat ballast water, and the control of alien organisms and oil spills was promoted.

As measures to improve the sea area, dredging and disposal of polluted sediments were planned, and at the same time, facilities to introduce tidal currents were considered to improve the water circulation in the port. In addition, an on-line water quality monitoring system was installed to monitor pH, dissolved oxygen, oil concentration, and turbidity in real time. If any abnormality is detected, an alarm is automatically issued, and a system is in place for the port management office and related companies to respond quickly.

These measures went beyond mere pollution control and attracted nationwide attention as a model case of how to maintain port functions while preserving the environment, and had a technical impact on the environmental improvement plans of Muroran City and Niigata East Port at the same time.