The Shadow of Industry Left Underground: Shudo Town's Story of Underground Time (1993)

The Shadow of Industry Left Underground: Shudo Town's Story of Underground Time (1993)

The tetrachloroethylene level of 7,301 times the level recorded in Shuto-cho, Yamaguchi Prefecture, was not merely an abnormal value, but rather the result of the time gap between Japan's industrial history and environmental administration that has continued from the Showa to the Heisei Era (Showa to Heisei Era). While Shuto-cho was an agricultural area with fields spreading out, an industrial area was formed around it with small and medium-sized metalworking, woodworking, and chemical-related factories. According to a survey conducted by Yamaguchi Prefecture in 1991, tetrachloroethylene and trichloroethylene were detected in drinking water wells in Shuto Town out of 99 wells, far exceeding the evaluation standard values, and the reality of the situation had already taken deep root in the region.

Before regulations were put in place, the handling of tetrachloroethylene was surprisingly lax by today's standards, with storage in outdoor tanks, spilled solvent seeping into the ground, and waste liquid being treated in bare tanks as a matter of course. The geology of the area surrounding Shuto Town is characterized by a combination of valley-like topography and sand and gravel beds, and unevenly distributed groundwater veins, so it is highly likely that the conditions were such that volatile chlorinated organic compounds were easily concentrated at a single point. The Ministry of the Environment records a case in which the concentration reached approximately 220 milligrams per liter, or 730 times the environmental standard, in a well in the Shimokuhara area, and there are maps and interview records of the area around the business that is believed to be the source of the contamination.

From the end of the Showa period to the beginning of the Heisei period, environmental awareness increased nationwide, and with the revision of the Water Pollution Control Law, volatile organic compounds became the subject of full-scale regulation, and groundwater contamination, which had previously been overlooked, became visible all over the country. The 7,000 times higher concentration in Shuto-cho came to light as part of this trend, and was symbolic of a pre-regulation practice in a local industrial area that, over time, became an environmental problem that stuck out. After the investigation, guidance was given to stop drinking the water, and the water supply system was switched over and monitoring of the wells continued. Since then, Shuto-cho has become part of Iwakuni City, and the current annual water quality test report shows no detection of tetrachloroethylene, indicating that good water quality is being maintained.

The figures rising in the wells of Shuto-cho show us how deeply the shadow of industry has sunk into the land and will appear in another form in another time. What is meant to be sunk underground never disappears. It moves slowly in the strata and is pushed back into the future as a more concentrated record of time.