As of 2023, approximately 18% of Japan's population was not connected to public sewerage or independent wastewater treatment. The anticipated forecasts indicate a declining trend in this segment, with percentages reducing from 17.44% in 2024 to 15.34% in 2028. Year-on-year, the share declines consistently by an average of about 3%, highlighting a continuous effort towards infrastructural improvements in wastewater management.

Future trends to watch for:

Investment in modern sewerage infrastructure and independent wastewater solutions could accelerate this trend.
Technological innovations may further decrease the share of the population without such facilities.
Government policies aimed at sustainability and environmental protection will likely support these improvements.