Overview of Water Pollution Countermeasures in Shimane Prefecture

Overview of Water Pollution Countermeasures in Shimane Prefecture

Since 1999, Shimane Prefecture has been addressing the issue of pollution from household wastewater and nitrogen and phosphorus from agriculture, and has focused on the development of sewage systems and the diffusion of household septic tanks. In the 2010s, new technologies such as biofilter technology were adopted, and by the 2020s, sewerage system penetration reached about 80%, which greatly improved pollution in urban areas. In Lake Shinji, total phosphorus concentrations have decreased to about 0.05 mg/L, while purification of rural areas and improvement of small rivers remain a challenge. Wetland restoration and public awareness raising are being promoted through public-private sector cooperation, and environmental conservation is underway.