The Shadow of Groundwater: The Tokorozawa Disaster Prevention Well Contamination Incident and Environmental Anxiety in the 1990s (June 1998)

The Shadow of Groundwater: The Tokorozawa Disaster Prevention Well Contamination Incident and Environmental Anxiety in the 1990s (June 1998)

In the late 1990s, Japanese society was in a period of stagnation following the collapse of the bubble economy, and environmental and health concerns overshadowed the lives of citizens. In particular, the risks posed by chemical substances attracted much attention, and along with environmental hormones and dioxin, the safety of groundwater and drinking water became a major concern. The case of the detection of the carcinogen chloroethylene in disaster prevention wells in Tokorozawa City, Saitama Prefecture, sent shockwaves through the residents, highlighting the contradiction of a water source that should be a lifeline in times of disaster, but instead became a symbol of anxiety.

This problem was closely related to the development of laws and regulations as well as environmental technology that was advancing at the time. In groundwater remediation, technologies such as activated carbon adsorption, air sparging, soil cleaning, and bioremediation using microorganisms were attracting attention, and efforts were being made to eliminate contamination and prevent recurrence. On the other hand, the development of related laws and regulations has been an issue.

First, the Water Pollution Control Law (enacted in 1970 and revised and strengthened in the 1990s) became the foundation for regulations to prevent pollution of groundwater and public waters. In addition, the Waste Disposal and Public Cleansing Law (Waste Disposal and Public Cleansing Law) was strengthened to address illegal dumping and mismanagement of industrial waste, which can cause groundwater contamination. In 1997, the Environmental Impact Assessment Law (Environmental Assessment Law) was enacted, institutionalizing studies of the impact of large-scale development on groundwater and ecosystems, and accelerating the development of the legal framework.

In addition, the Environmental Agency (now the Ministry of the Environment) promoted the introduction of the PRTR (Pollutant Release and Transfer Register) system, which required businesses to report the release and transfer of chemical substances in an effort to understand the flow of substances that had previously been opaque. This system was spreading internationally in response to OECD recommendations, and the Tokorozawa case strongly impressed upon society the need for its introduction in Japan.

This case embodied an environmental problem in the form of the intersection of technology, laws and regulations, and citizens' movements. The reality that groundwater, a resource closely linked to daily life, had been contaminated showed that the destruction of ecosystems was directly related to human life, and provided an opportunity to strengthen environmental administration and promote technological development.