Japan
Last Updated : 16 November 2022.

Japan is located in the eastern monsoon region of Asia and noted for having one of highest accumulations in the world. Most of the available water is discharged to the ocean unused due to the steep topography, very short streams as well as intensive rainfall in rainy and typhoon seasons.
State of water environment
Legal framework
Conservation of Water Quality in Public Water
- Basic Environment Law (In Japanese)
The law governing “Environmental Quality Standards for Water Pollutants”
General Measures
- Water Pollution Control Law (In Japanese)
The law governing “Factory effluent control, notification of factory establishment, monitoring orders, continuous monitoring, measures for domestic wastewater”
- Sewerage Law (In Japanese)
The law governing “Construction of sewerage”
- Johkasou Law (In Japanese)
The law governing “Installation of Johkasou , regulation of desludging and production, registration system of johkasou installation worker, licence system of Johkasou desludging technician, etc.”
Special Measures in Enclosed Water Bodies
Lakes and Reservoirs
Special regulations for Planning of plan for the preservation of lake water quality.
Estuaries
- Water Pollution Control Law (In Japanese)
Control of total pollutant load, and countermeasures against eutrophication.
Seto Inland Sea
- The Law Concerning Special Measures for Conservation of the Environment of the Seto Inland Sea (In Japanese)
Ariake Sea/ Yatsushiro Sea
- The Law Concerning Special Measures for the Re juvenation of the Ariake Sea and Yatsushiro Seas (In Japanese)
Biwa Lake
Potable Water Sources
Groundwater Quality Conservation
- Basic Environment Law (In Japanese)
Environmental quality standards for groundwater
General Measures
- Water Pollution Control Law (In Japanese)
Regulations for toxic substances from factories, purifying orders for polluted groundwater, and continuous monitoring
Sound Water Cycle
- Basic Law on Water Cycle (In Japanese)
Holistic and integrated implementation of policies on water cycle
Other Laws Related to Water Environment
- Law Concerning Special Measures against Dioxins (In Japanese)
- River Law (In Japanese)
- Drinking Water Sources Law (In Japanese)
- Water Supply Law (In Japanese)
Institutional Arrangement of water
Water quality standards
Technical standards and related information
Water management practices
Domestic wastewater governance: A case study from Lake Teganuma, Japan
Policies for Watershed Management for Controlling Municipal Wastewater in Japan
Groundwater Pollution Control in Japan
Regulations of Wastewater Discharge in Japan
On-site Inspection and Administrative Direction to Business Establishment
Pig Waste and Wastewater Management in Japan
Multistage Hybrid Wetland Systems for Pig Wastewater Treatment
Link / Country specific
Ministry of Environment, Japan
Ministry of Land, Infrastructure, Transport and Tourism
Japan Education Center of Environmental Sanitation
Water quality database by MOEJ (In Japanese)
Johkaso related data by MOEJ (In Japanese)
Sewerage related data by MLIT (In Japanese)
Comprehensive survey on pollutant loads (In Japanese)