Countermeasures for PCBs - PowerPoint Presentation

Slide1

Countermeasures for PCBs Taken by Hyogo Prefecture（Takasago West Port）

Hyogo Prefectural Government

Agricultural and Environmental Affairs Dept. Environmental Management Bureau,

Water and Air Quality Control Division

Kotoko

UENISHISlide2

What are PCBsPCB stands for Poly Chlorinated Biphenyl, a class of poly chlorinated compounds. Theoretically 209 isomers exist depending on the number of chlorine atoms in the molecular and substituent positions. Particularly Coplanar PCB (coplanar means shapes, structures that lie on the same plane) is extremely toxic and belongs to the class of so-called Dioxins.PCBs are chemically stable compounds, having low water solubility, high boiling temperature, hardly degradable by heat, and non-burnable as well as electrically insulated. Therefore, they had been widely utilized as insulating oil for electrical equipment and heat catalyst for heat exchanger

as well as carbonless paper

.

1Slide3

Since PCBs have superior characteristics such as insulating (preventing electricity from passing through), and incombustible (hardly burn), they have been used for a wide variety of products including electrical equipment such as trans-condenserWhen Kanemiyusho (

Kanemi

rice oil disease) incident

occurred in 1968, growing social attention had been paid to their toxicities and the use of PCBs had come to a social issue. As a result, the manufacturing of PCBs was banned in 1972Slide4

１　

Great attentions had been paid to PCBs inspired by

Kanamiyusho

(Kanemi rice oil disease) incident.

This incident was caused by PCBs, etc. that were used as heat catalyst and accidentally mixed into rice oil during a deodorization process.In October of 1968, food poisoning caused by rice oil broke out in wide areas with a focus on the west Japan. The number of patients were estimated to be about 13,000. ２　

General symptoms of PCB poisonings such as eye mucus, pigmentary deposit on nails and oral cavity membrane as well as chloro-acne, deformation of nails, swelling of eye lids and joints are reported.

Deodorization process for rice oil

Kanemi

rice oil incident

heating

a hole

Rice oilSlide5

1968

Kanemiyusho

(Kanemi rice oil)

disease incident

1972

～

PCBs surveys for bottom sediments in coastal seas and rivers carried out

throughout the country

1972

PCBs contamination was found in the bottom sediments dredged from

Takasago West

Port

PCB Contaminations in Takasago West PortSlide6

Dredging in Takasago West Port (1974～1975) Slide7

The details of the treatment of PCB-containing bottom sediments　　１　PCB-containing bottom sediments piled up in the port were dredged and solidified, then, banked in the area owned by the alleged manufacturing company.

　①　

The 1

st

phase of construction: September, 1974～March, 1975　　　The 2nd phase of construction: August, 1975～August, 1976

　②　

Amount of the dredged soil: 301,000

ｍ

３

　③　

Amount of banked soil: 283,000ｍ３　　　（Dredged & solidified soil 224,000ｍ３, Amount of covering soil

59,000ｍ３）　④　Area for banking: 51,000ｍ２　　２　The surface and the bottom of the banked area were covered by asphalt, and the area has been controlled completely cut off from outside areas.

Survey results for PCBs contained in bottom sediments in the Takasago West Port　

１ 　Bottom sediment survey before dredging（June, 1972～April, 1973）　　　　　19 survey points Maximum 3,300ppm～Minimum 20ppm

　２　

Bottom sediment survey immediately after dredging

（

January, 1976

）

40 survey points

４

cross points

Average value

4.53ppm～0.02ppm　　　　（Tentative removal standard for bottom sediments: 10ppm）Slide8

PCB related standards

Parameters

Standard values, etc.

Remarks

Water quality

Environmental standards regarding water pollution

-

Not detected

（＜

0.0005mg/L

）

Environmental Basic Law

Environmental standards regarding groundwater

-

Not detected

（＜

0.0005mg/L

）

Effluent standards

-

0.003mg/L

Water Pollution Control Law

Tentative removal standards for bottom sediments

content

10

ｐｐｍ

Notification made by Director General of Water Quality Preservation Bureau, Environment Agency in 1975

Environmental standards with regard to soil pollution

elution

Not detected

（＜

0.0005mg/L

）

Environmental Basic Law

Standards with regard to specification of soil pollution (standards for elution volume)

elution

Not detected

（＜

0.0005mg/L

）

Soil Contamination Countermeasure Act

Standards with regard to actions for removal of polluted soil, etc. (The 2

nd

standards for elution volume)

elution

0.003mg/L

Standards with regard to judgment for industrial wastes (sludge)

elution

0.003mg/L

Law Concerning Waste Treatment and Clean-up

Concentrations in the atmosphere (guideline values)

－

0.05μg/m3

Tentative allowable limit for PCBs release in exhaust gas when PCBs are incinerated (Notification by Director General of Atmospheric Preservation Bureau, Environment Agency in 1972

）

. Guidelines regarding treatment and disposal of bottom sediments

（

Notification by Director of Water Environment Dept. , Ministry of Environment in 2002

）Slide9

Takasago West Port in 1980

400m

100mSlide10

Restoration and improvement ofTakasago West Port

③　

Enhance

accessibilities

④　

Create

water-front park

①　

Enhance

Port functions

②　

Permanent protective measures and effective utilization strategies for

the bankSlide11

Permanent protective measures for banking site

PCB-containing solidified soil

Carbide scum, bank

（

sand, gravel

）

Sandy soil

Clay

（

non-permeable layer

）

Non-permeable underground soil retaining wall

Reinforced

protective

wall

Surface

cover

SeaSlide12

PCB Surveys for Atmosphere and Water

PCB survey for atmosphere and water (Takasago city, Hyogo

prefecture & related companies

)

○Atmosphere

○

Rain water

○

Ground water

○

Sea water

●Continuous monitoring of public water bodies

○○○○PCB tracing survey by Takasago city and companies (twice a year) ●Continuous monitoring by Hyogo Prefecture (4 times a year)

All the measured values have been below quantitation limit since 1976.

For

banking

Dredging

Takasago West Port

LandfillSlide13

PCB Survey for Bottom Sediments

PCB survey for bottom sediments (Takasago City) once a year

All the survey points have shown PCB concentrations below tentative removal standards for PCB

For

banking

Landfill

Dredging

Takasago West

portSlide14

Thank you very much for your kind attention