Japan’s Wastewater Treatment Coverage at FY2025 Year-End
Overview
The Ministry of Agriculture, Forestry and Fisheries, the Ministry of Land, Infrastructure, Transport and Tourism, and the Ministry of the Environment jointly surveyed and released nationwide wastewater treatment coverage at the end of fiscal year 2025. The wastewater treatment population coverage rate was 94.0%, an increase of 0.3 percentage points from the end of the previous fiscal year. Treatment facilities served 116.02 million people, while about 7.4 million people could not use wastewater treatment facilities. In municipalities with populations under 50,000, the coverage rate was 85.1%.
Key points
- Nationwide wastewater treatment population coverage reached 94.0% at the end of fiscal year 2025.
- Wastewater treatment facilities served 116.02 million people nationwide.
- About 7.4 million people could not use wastewater treatment facilities.
- The coverage rate in municipalities with populations under 50,000 was 85.1%.
Overview
The Ministry of Agriculture, Forestry and Fisheries, the Ministry of Land, Infrastructure, Transport and Tourism, and the Ministry of the Environment jointly surveyed the nationwide availability of wastewater treatment facilities at the end of fiscal year 2025. The wastewater treatment population coverage rate is a standardized indicator expressed as the share of the total population served by wastewater treatment, and the three ministries publish it annually.
Nationwide wastewater treatment population coverage was 94.0%, up 0.3 percentage points from 93.7% at the end of fiscal year 2024.
Impact
In municipalities with populations under 50,000, wastewater treatment population coverage rose by 0.6 percentage points from the previous survey to 85.1%, but it still trails the national average.
The Japanese government will advance support for building sustainable wastewater treatment systems, enabling municipalities to optimize collective and individual treatment in line with local conditions for an era of population decline.
Details
By facility type, agricultural community wastewater treatment facilities and related systems served 2.76 million people, with a coverage rate of 2.2%; sewer systems served 101.41 million people, or 82.2%; septic tanks served 11.71 million people, or 9.5%; and community plants served 140,000 people, or 0.1%.
The survey covered agricultural community wastewater treatment facilities and related systems, sewer systems, septic tanks, and other facilities under the jurisdiction of the Ministry of Agriculture, Forestry and Fisheries, the Ministry of Land, Infrastructure, Transport and Tourism, and the Ministry of the Environment. Agricultural community wastewater treatment facilities and related systems include fishery community wastewater treatment facilities, forestry community wastewater treatment facilities, and simple drainage facilities. Septic tanks and related systems include septic tanks and community plants.