Urbanization and the Geoenvironment - Sustainable Practices in Geoenvironmental Engineering - page 231

complaints of disposal of oil, shredder waste and open burning of wastes and a conse-
quent investigation, the company halted disposal operations on the island but left large
amounts of waste at the site. Leaching of the contaminants from the landill and proper
disposal of the contaminants (more than 600,000 tonnes) had to be addressed. Analyses
showed contamination in the soil and leachate, surface, and groundwater (Table 7.4).
Lead, benzene, and PCB in particular were notable. An impermeable wall was con-
structed on the north coast of the disposal area to prevent contaminated water from
lowing out to sea. The industrial waste was then excavated (Figure 7.7) and brought to
Naoshima Island where a melting furnace was constructed. The slag was to be reused
as aggregate in concrete. Comprehensive environmental preservation measures and
full environmental monitoring of sewage and emission gas are planned in Teshima

TABLE 7.4
Average Concentrations of Hazardous Contaminants in the Waste Leachate, Groundwater, and
Surface Water at Teshima

Component Leachate (mg/L) Groundwater (mg/L) Surface Water (mg/L)

Arsenic 0.048 0.004 0.02

Benzene 1.2 1.1 ND

Cadmium 0.022 ND ND

1,3 dichloropropylene 0.54 ND ND

Chromium (VI) 0.1 ND 0.03

Dioxins (ng TEQ/L) 8.0 0.031 0.18

Lead 6.1 0.804 0.12

Mercury 0.0017 ND ND

PCBs 0.016 ND 0.0005

Tetrachloroethylene 0.19 0.0041 ND

Trichloroethylene ND 0.003 ND

Source: Takatsuki, H., Journal of Material Cycles and Waste Management , 5, 26-30, 2003.
Note: ND, not detected.

FIGURE 7.7
Two views of the Teshima waste site with retaining wall where the waste and contaminated soil are contained
before transfer to the treatment plant.