Achievement rate for water quality standards in Japan FY 2022, by category

In the fiscal year 2022, the achievement rate for the overall water quality standards in Japan amounted to around 87.8 percent. Lakes recorded the lowest achievement rate of approximately 50.3 percent. The achievement rate was based on biochemical oxygen demand (BOD) for rivers and chemical oxygen demand (COD) for lakes and sea areas.

在2022财年，日本整体水质标准达标率约为87.8%。湖泊的达标率最低，约为50.3%。该达标率以河流的生化需氧量（BOD）和湖泊及海域的化学需氧量（COD）为基准。