November 27, 2003
The Ministry of the Environment has put together the results of the nationwide water quality survey of public water areas implemented by the national and local governments in FY 2002 pursuant to the Water Pollution Control Law.
1. Health Items
Most of the monitoring points have achieved the environmental quality standards (hereinafter referred to as EQSs) for the 26 human health items, with the compliance rate reaching 99.3% (Table 1).
2. Living Environment Items
BOD and COD are typical indicators of water quality for organic contamination. In terms of the compliance rates of EQSs for BOD and COD, the overall compliance rate was 81.7%--the highest on record, with rivers at 85.1%, lakes and reservoirs at 43.8%, and sea areas at 76.9%. In enclosed water areas such as lakes and reservoirs, the compliance rate remains low (Table 2).
Although the compliance rate of EQSs for total nitrogen and total phosphorus in lakes and reservoirs is still at a low level of 33.3%, the concentrations of total nitrogen and total phosphorus have both shown a slight improvement in water areas where monitoring has been conducted since FY 1991 (Fig. 1).
As for sea areas, the compliance rate of EQSs is at a high 80.3%. The concentrations in water areas where monitoring has been conducted since FY 1998 have indicated improvement. Among the three enclosed sea areas, the Seto Inland Sea shows an especially remarkable improvement in the compliance rate of EQSs (Fig. 2).