Figure 2-3 Changes in Achievement of Nitrogen Dioxide EQS (FY 2005 to FY 2009)

Source: Ministry of the Environment, "FY 2009 Monitoring Results of Hazardous Air Pollutants,"

real-time observation data gained at a monitoring network composed of the LIDAR equipment installed in Japan and other countries has been provided on a website of the Ministry of the Environment, since FY 2007.

## (2) Measures to Conserve Water Environment

### A. Setting Environmental Quality Standards

Currently, the Environmental Quality Standards for water pollution covering substance related to health items, include 27 substances set for public waters and 28 substances set for groundwater, such as cadmium, lead and other heavy metals, trichloroethylene and other organochlorine compounds, and simazine and other agricultural chemicals. In FY 2010, the government made a reassessment of the cadmium standard values. Also, the government conducted the water quality measurements and gathering of knowledge and experiences for items other than those covered by water quality EQSs, such as specified monitoring items (currently 26 substances for public waters and 24 items for groundwater).

As for substances related to the conservation of the living environment, various standards have been established for items such as BOD, COD, dissolved oxygen (DO), total nitrogen, total phosphorus, and total zinc. For the purpose of water-utilization, the environmental quality standards are specified for each type of designated water area. Also, the government studied the nation-wide soundness indicators of water environment. "Mizube-no-Sukoyakasa-Shihyou (Mizu-Shirabe)," which had been organized as indicators for realizing good water environment according to regional characteristics, as well as the assessment of water quality. The government also conducted long-term continuous measurements for setting environmental standards such as lower-layer DO in oceans and lakes.

### B. Measures for Conserving Water Environments in Public Waters (Lakes and Enclosed Coastal Seas)

As a measure against eutrophication in lakes, the Water Pollution Control Law regulates the nitrogen and phosphorus in charged effluent. There are 320 lakes under the nitrogen control, and 1,393 lakes under phosphorus control. The Environmental Quality Standards (EQS) of nitrogen and phosphorus in lakes are specified for each type of designated water area for a total of 115 water regions including Lake Biwa.

For the lakes whose water quality could be sufficiently conserved by the regulations of the Water Pollution Control Law alone, the regulation will be applied based on the Law concerning Special Measures for Preservation of Lake Water Quality (Law No. 61 of 1984), and the lake will be designated as a lake that requires the emergency restoration of lake water quality, followed by the development of a plan for the conservation of water quality and measures such as construction of sewage systems, water quality conservation projects such as river purification, and regulations for various sources of pollution. Also, the government conducted studies in order to clarify the pollution structure of lakes including Lake Biwa and to understand the relationship between phytoplankton and changes in ratios of nitrogen and phosphorus.

Among area-wide enclosed coastal areas, the Total Pollutant Load Control System (TPLCS), with COD, nitrogen and phosphorus as the target reduction items (designated items), has been implemented in the Tokyo Bay, Ise Bay, and the Seto Inland Sea, where populations and industries are concentrated and it is therefore difficult to achieve and maintain EQSs for water pollution by effluent concentration control alone. Specifically, with respect to the pollution amounts emitted from factories and businesses which are larger than a certain scale in designated areas, the measures for industrial water