According to data from the Cabinet Office,*1 natural disasters are on the rise in many parts of the world, with approximately 160 million people*2 affected every year since 1970. In Japan, where earthquakes and floods are frequent, a major disaster occurs somewhere every year. Evacuation centers are opened whenever such disasters occur. In evacuation centers, where people are forced to live in an unfamiliar environment, many people fall ill due to the stress of using temporary toilets. According to the Guidelines for Securing and Managing Toilets in Evacuation Shelters,*3 “The number of disaster victims who feel uncomfortable due to unhygienic toilets is increasing. On top of this, some people are hesitant to use these toilets, which can lead to worsening nutritional status, dehydration, venous thromboembolism (economy class syndrome), and other health problems.” In other words, the problems caused by uncomfortable toilet environments during disasters are not only psychologically stressful but also pose serious health risks. Just like water and food, it is a serious issue that can be a matter of life or death.

Kubota, which has been solving various water-related problems, focused on the potential for manhole toilets, one kind of toilet system used in times of disaster. In 2007, the city of Higashi Matsushima in Miyagi Prefecture, which had been grappling with the problem of providing toilets during disasters as a countermeasure against large-scale earthquakes, adopted Kubota’s manhole toilet because of its hygiene and ease of operation, working to ensure clean and comfortable toilets in times of disaster for all. The basis of this project was the Disaster Toilet Piping System, a technology that we have been developing since 2001.

Kubota (now Kubota ChemiX Co., Ltd.) conducted research based on the basic concepts of “flushing” and “a simple structure connecting the manhole to the sewage pipe.” The result was the development of a new manhole toilet connected to the Disaster Toilet Piping System. By installing manholes directly connected to the sewage lines of evacuation centers such as parks and schools, and installing simple toilet seats and private rooms in them, the toilets can be used as flush toilets, even though they are temporary. The installation of these manhole toilets at five of the 16 designated evacuation centers in Higashi Matsushima was completed in December 2010. Just three months later, the Great East Japan Earthquake struck. The manhole toilets were immediately put to use, and were extremely well received, especially by women and the elderly, for their hygienic and odorless condition during evacuation, and the fact that there are no steps at the entrance.

Kubota’s manhole toilets were also put to use for a certain period following the Kumamoto Earthquake in 2016, once again demonstrating their excellent functionality. In cooperation with municipalities, Kubota has also begun to install manhole toilets in parks and evacuation facilities so that stress-free manhole toilets can be used quickly during disasters. Kubota, which has been working to maintain environmental sanitation through the construction of sewage infrastructure, will continue to actively work on the development of social infrastructure in preparation for natural disasters.