Conservation of soil environment

Conservation of soil environment

Conservation of Soil Environment

1 Countermeasures for Soil Pollution

Since soil plays important roles such as filtration of water

quality, groundwater, recharge and production of foods, it is

indispensable to protect the soil from contamination and conserve

it in proper manner

(1) Environmental quality standards for soil pollution

The soil, together with the water and air, is a key component

of the environment and plays an important role as basis for living

things including human beings and as integral part of the material

cycle Once the soil is contaminated, the impacts last for a long

period

Therefore, environmental quality standards are presently defined for 27 items based on the Basic Environment Low These standards are standards compliance with which is desirable in terms of protecting human health and conserving living envirouments, and reviewed according to the accumulated scientific data on the "as-necessary" basis

The soil environmental quality standards stipulate the elution standard aiming at filtration of water quality and purification of groundwater, and the farmland standard aiming at conservation of food production functions These two standards are used to judge whether the soil is contaminated or not and give targets for designing the countermeasures against the pollution

■Environmental Quality Standards for Soil Pollution

cadmium 0.0lmg/ in sample solution and less* than 1mg/kg in rice for agricultural land

total cyanide not detectable in sample solution

organic phosphorus** not detectable in sample solution

lead 0.0lmg/ or less* in sample solution

chromium (VI) 0.05mg/ or less* in sample solution

arsenic 0.0lmg/ or less* in sample solution, and less than 15mg/kg in soil for agricultural land

(paddy field only) total mercury 0.0005mg/ or less* in sample solution

alkyl mercury not detectable in sample solution

PCB not detectable in sample solution

copper less than 125mg/kg in soil for agricultural land (paddy field only)

dichloromethane 0.02mg/ or less in sample solution

carbon tetrachloride 0.002mg/ or less in sample solution

1,2-dichloroethane 0.004mg/ or less in sample solution

1,1-dichloroethylene 0.02mg/ or less in sample solution

cis-1,2-dichloroethylene 0.04mg/ or less in sample solution

1,1,1-trichloroethane 1mg/ or less in sample solution

1,1,2-trichloroethane 0.006mg/ or less in sample solution。

trichloroethylene 0.03mg/ or less in sample solution

tetrachloroethylene 0.0lmg/ or less in sample solution

1,3-dichloropropene 0.002mg/ or less in sample solution

thiram 0.006mg/ or less in sample solution

simazine 0.003mg/ or less in sample solution

thiobencarb 0.02mg/ or less in sample solution

benzene 0.0lmg/ or less in sample solution

selenium 0.0lmg/ or less* in sample solution

fluorine 0.8mg/ or less* in sample solution

boron 1mg/ or less* in sample solution

* When involving those environmental limits concerning the concentration of cadmium, lead, chromium(VI), arsenic, total mercury, selenium fluorine, or boron in liquid samples, when the soil contamination is alway from the groundwater level and the concentration of the substance dose not exceed 0.01mg, 0.01mg, 0.05mg, 0.01mg, 0.0005mg, 0.01mg, 0.8mg, or 1mg, respectively, in the original condition, then the limit per

1 liter of liquid sample shall be 0.03mg, 0.03mg, 0.15mg, 0.03mg, 0.0015mg, 0.03mg, 2.4mg and 3mg respectively

** Organic phosphorus means parathion, methylparathion, methyldimeton, and EPN

Note: The above standards are not applicable to (1) the soil in those places where natural toxic substances exist such as the vicinities of mineral veins and (2) the soil in those places designated for storage of toxic materials such as waste disposal sites with respect to the items listed

in the above table

(2) Agricultural land soil pollution control measures

The soil pollution is one of the oldest pollution types and the

agricultural land soil pollution in the Watarase River Basin area

generated social concern around 1877 In 1968 "Itai-Itai disease"

in the Jinzu River Basin area proved to be a case of chronic

cadmium poisoning and again generated social concern to the

agricultural land soil pollution problem Finally, in 1970 the

Agricultural Land Soil Pollution Prevention Law was enacted and remedial projects by methods such as clean soil dressing were initiated

Cancellation of

designated

special area

Implementation of special land improvement work for environmental pollution prevention/removal

Cancellation of designated agricultural land soil pollution policy areas

Planning of cost-bearing plan

(Pollution Control Public Works Cost Allocation Law)

Request for Application of Financial Special Measures Law

(Law on Special Financial Arrangement by the Government for Public Pollution Control Projects)

Implementation of measures against polluters

・ Water Pollution Control Law

・ Air Pollution Control Law

・ Mining Safety Law

・ Law on Special Measures for Mine Damages Caused by the metal mining industry, etc.

Designation of

special area

Implementation of Survey of Policy Area

Planning of agricultural land soil pollution policy project

- Detailed survey for planning countermeasures

- Survey for confirming the result of project

Prefecture (Subsidy of MOE)

Prefectures (Subsidy of MOE)

Prefectures, municipalities (Subsidy of MAFF)

Prefecture (Subsidy of MOE)

Prefectural Governors: Article 8 of the Law

Prefectural Governors: Article 9 of the Law

Prefectural Governors: Article 4 of the Law

Prefectural Governors: Article 5 of the Law

Prefectural Governors: Article 3 of the Law

Consent of Minister of the environment and Minister of agriculture, forestry and fisheries

Report to Minister of the environment

[Agricultural Land Soil Pollution Prevention Law]

(Law No.139 of December 25, 1970)

Central Environment Council Possible polluted area

(1) Designation of specific harmful substances (Cd, Cu, As) (2) Establishment of requirements for designation of policy areas Designation of

agricultural land soil pollution policy areas

Fact-finding survey of

possible polluted area

Fact-finding survey

of soil pollution

Surveillance and monitoring

for recurrence of pollution

Report to Minister of the environment

■System of Implementing Agricultural Land Soil Pollution Control Measures

■Progress in Recognizing and Restoring Sites

(3) Urban type soil pollution control measures

In 1975, a large quantity of soil contamination with

hexavalent chromium was found in Tokyo and it became a serious

social problem Since then, the number of so-called "urban" type

soil pollution cases discovered has been rapidly increasing

throughout Japan mainly due to accelerated urban redevelopment

of sites such as those of former factories and the installation of groundwater quality monitoring activities required by the Water Pollution Control Law The major soil polluters are the chemical and electroplating industries and the major contaminants are lead, arsenic, and trichloroethylene

■Discovered Number of Urban Type Soil Pollution Cases

(1) Area of site exceeding EQS 7,156ha

(2) Designated site area 6,266ha (3) Planned site area 6,181ha (4) Restored site area 5,818ha

(5) Area to be cleaned in the future

1,338ha

(ha)

0

20

40

60

80

100

120

140

160

180

200

Establishment of soil environment standards

Number of events exceeding the standards

Number of survey events

Addition of soil environment standard items

FY

On and

before 1974

'75 '76 '77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99

Number of survey events 2 7 6 2 10 5 3 10 2 17 10 18 12 16 23 20 26 38 34 43 44 44 56 58 197 183

Number of events

exceeding the standards − − − − − − − − − − − − − − − − − 8 12 13 26 36 50 47 122 117

Number

of

events

■Number of Events Exceeding the Standards Per Substance (Accumulation)

2 Survey and Policy Planning of Soil and

Groundwater Pollutions

With respect to the soil pollution (caused by the pollutants

except for dioxins) in the urban area, the business owners have

been taking voluntary activities according to the Survey and

Countermeasure Guidelines for Soil and Groundwater

Countamination enacted in January 1999

Each business owner is required to survey the soil whenever it modifies the land properties and, if it is proved that the soil fails

to comply with the environmental quality standards, take any necessary action so that the soil will meet the standards

120

102

64 55

15 7 1

140

110

79

0

20

40

60

80

100

120

140

160

Elution standard item

Number of events

LeadArsenic

Chromium (VI)Total mercury

Cadmium Total cyanideSelenium

ＰＣＢ

Thiobencarb Trichloroethylene Tetrachloroethylene Cis-1,2-dichloroethylene1,1-dichloroethyleneCarbon tetrachloride

1,2-dichloroethane1,1,1-trichloroethane

Benzene Dichloromethane 1,1,2-trichloroethane1,3-dichloropropene

Discovery of pollution

Document survey of subject area (fact-finding)

Prefectural governments

General Survey of subject area

Countermeasures Guidance Detailed survey of subject area

Report

Guidance

Guidance

Guidance

Guidance (Temporary measures is needed when permanent measures cannot be taken immediately)

■Outline of Technical Guideline of the Ministry of Environment

(Survey and Guideline Contermeasure for Soil and

Groundwater Contamination enacted in January 1999)

- The Ministry of Environment notifies prefectural governments of the

guidelines.

- Content

The Guideline stipulates the techniques on how to develop surveys

and countermeasures in handling of heavy metals (such as cadmium)

and volatile organic compounds (such as trichloroethylene) so that these

techniques will be helpful to implement surveys and countermeasures for

soil and groundwater pollutions.

(1) Survey procedure and evaluation of result

The Guideline defines three survey phases: document survey,

general survey, and detailed survey.

(2) Techniques

The Guideline describes the techniques for use in

countermeasures and summarizes their availability.

(3) Surrounding environment conservation and monitoring techniques

The Guideline describes the necessity of scattering and discharge

preventive measures and monitoring of surrounding groundwater.

(4) Communication with prefectural governments

If the land administrator discovers the pollution of soil and/or

groundwater through the voluntary survey, it shall report the fact to

the appropriate prefectural government(s).

(5) Preparation and control of records

The Guideline stipulates the necessity of preparing and controlling

■Excavation of Polluted Soil

■Flow of Guideline-based Survey and Countermeasures