## 3 ) Conservation of water, soil, and ground environment

## (1) Water environment

The result of national public water quality monitoring in 2000 indicates that the environment standard achievement rate regarding human health such as cadmium is 99.2%, however, the environmental standard achievement rate regarding conservation of living environment such as COD, which is a typical water quality index of organic pollution, is 79.4%. In particular, the achievement rates in the enclosed waters such as lakes, swamps, and bays are still low. The COD indexes, which are the typical indicators, indicate 63% for Tokyo Bay, 56% for Ise Bay, 76% for Seto Inland Sea, and 42.3% for lakes and swamps. To take the proper measures for such a condition, the Government decided to reduce COD indexes of Tokyo Bay, Ise Bay, and Seto Inland Sea further. The Government also decided to implement the 5th Areawide Total Pollutant Load Control targeting 2004 as the implementation year by adding nitrogen contents and phosphorus contents as the specification items as well as COD, in order to promote comprehensive reduction measures combining nitrogen and phosphorous, which are the causes of eutrophication.

Transition of rate of specimens exceeding environmental standard associated with health items (8th item)

Transition of environmental standard (BOD or COD) achievement rate

Notes: 1. The rate of a specimen of alkyl mercury exceeding the environmental standard is 0% since 1971.

2. As a result of revision of the environmental standard made in March 1993, the environment standard value of lead was revised from 0.1mg/l to 0.01mg/l, the standard value of arsenic was revised from 0.05mg/l to 0.01mg/l, and the standard value of organic phosphorus was deleted (not detected). Presentation: Prepared by the Ministry of the Environment based on "National public water quality monitoring in 2000".

Groundwater quality monitoring result of 2000

Remarks: 1. BOD for rivers and COD for lakes and swamps, and sea areas

2. Achievement rate (%) = (Number of water areas achieved/number of water areas applied) × 100

Presentation: Prepared by the Ministry of the Environment based on "National public water quality monitoring in 2000".

Substance	Number of wells tested (wells)	Number of wells exceeded the standard (wells)	Excess rate %	Environmental standard
Cadmium	2,997	0	0.0	0.01 mg/l or less
Total cyanogen	2,616	0	0.0	not detectable
Lead	3,360	10	0.3	0.01 mg/l or less
Chromium(VI)	3,187	1	0.03	0.05 mg/l or less
Arsenic	3,386	65	1.9	0.01 mg/l or less
Total mercury	2,833	2	0.1	0.0005 mg/l or less
Alkyl mercury	1,048	0	0.0	not detectable
PCBs	1,818	0	0.0	not detectable
Dichloromethane	3,534	0	0.0	0.02 mg/l or less
Carbon tetrachloride	3,675	2	0.1	0.002 mg/l or less
1,2-dichloroethane	3,301	0	0.0	0.004 mg/l or less
1,1-dichloroethylene	3,650	2	0.1	0.02 mg/l or less
cis-1,2-dichloroethylene	3,657	12	0.3	0.04 mg/l or less
1,1,1-trichloroethane	4,219	0	0.0	1 mg/l or less
1,1,2-trichloroethane	3,286	0	0.0	0.006 mg/l or less
Trichloroethylene	4,225	22	0.5	0.03 mg/l or less
Tetrachloroethylene	4,225	17	0.4	0.01 mg/l or less
1,3-dichloropropene	3,039	0	0.0	0.002 mg/l or less
Thiuram	2,528	0	0.0	0.006 mg/l or less
Simazin	2,508	0	0.0	0.003 mg/l or less
Thiobencarb	2,453	0	0.0	0.02 mg/l or less
Benzene	3,436	0	0.0	0.01 mg/l or less
Selenium	2,634	0	0.0	0.01 mg/l or less
Nitrate nitrogen and nitrite nitrogen	4,167	253	6.1	10 mg/l or less
Fluoride	3,276	25	0.8	0.8 mg/l or less
Boron	3,210	16	0.5	1.0 mg/l or less
Total (Number of wells)	4,911	398	8.1

Transition of water quality in three sea areas

Presentation: Ministry of the Environment "Groundwater Quality Monitoring Result in 2000"

Presentation: Prepared by the Ministry of the Environment based on "National public water quality monitoring during the period from 1995 to 2000".