Japan's Sewerage System Expansion and Water Quality Conservation - February 1996

Background and Current Situation:
As of the end of 1994, Japan's sewerage system coverage reached 51%. However, this coverage varies significantly by region. While the coverage rate in major metropolitan areas, such as designated cities, is as high as 95%, it remains at 39% in ordinary mid-sized cities and as low as 14% in towns with populations of less than 50,000.

Importance of Sewerage Development:
The sewerage system collects and treats wastewater and rainwater from homes and factories, purifying it before discharging it into rivers and seas. The development of this system is essential for improving living conditions, maintaining public health, and conserving water quality. Particularly in densely populated areas, lack of a sewerage system can lead to direct discharge of untreated wastewater into rivers, causing water pollution and potentially harming the health of residents and ecosystems.

Challenges in Rural Areas:
Rural areas and smaller cities have significantly lagged in sewerage system development. This delay is partly due to lower population densities and the high costs of installation, which place considerable financial strain on local governments. However, sewerage system expansion is critical even in these regions to protect water quality. In particular, wastewater from livestock farming can contribute to water pollution, necessitating the spread of sewerage systems as a countermeasure.

Future Goals:
The Japanese government aims to increase the national average sewerage system coverage to 70% by the year 2000 and further to 90% in the early 21st century. Achieving this goal requires accelerating sewerage system development, not only in urban areas but also in rural regions. Local governments, with the support of national subsidies and technical assistance, need to formulate and implement efficient development plans.

Impact on Water Quality Conservation:
Expanding the sewerage system enables proper wastewater treatment, leading to improved water quality in rivers, lakes, and coastal areas. This improvement helps protect the habitats of aquatic organisms, thus maintaining the overall health of ecosystems. Additionally, purified water can be reused, promoting the sustainable management of water resources.

Technical Challenges:
Developing the sewerage system involves more than just laying pipes; it also requires establishing wastewater treatment facilities and improving sludge treatment methods. Additionally, building a resilient infrastructure to withstand disasters such as earthquakes and floods is a crucial challenge. Addressing these technical challenges is necessary to introduce an efficient and environmentally friendly sewerage system.