As an environmental public health major, I am highly interested in water quality and how water impacts health. Exploring the underground regulating reservoir in Tokyo was highly interesting and introduced me to new ideas about floodwater management. Tokyo Metropolitan Government implemented the Kanda River/ Loop Road No. 7 Underground Regulating Reservoir to protect against flood waters that the Kanda River and Zenpukuji Rivers cannot handle during flooding events. 

Allowing flood waters to collect in an underground reservoir like this reduces damage to downstream basins. Water is collected via the intake facilities which receive the water and guide it to the underground tunnel. Connecting ducts, discharge pumps, and shafts lead the water underground to be held in the reservoir tunnel. The total storage volume of both stages of the regulating reservoir project is 540,000 m^3. The 4.5 km tunnel has three intake facilities located at the Kanda, Zenpukuji, and Myoshoji Rivers.

While we explored the underground tunnel it was impressive to see the massive diameter. The inner diameter of the tunnel was 12.5 meters. It was mind-blowing to realize we were 57 meters below ground in a massive tunnel. The tunnel needed to be placed so deep within the Earth to avoid subway lines and plumbing, while also being deep enough to sit below the flow of the rivers. 

During our tour of the regulating reservoir, we got to visit the control room where the control boards and monitors are located. This control center operates and monitors water inflow from the rivers and handles discharge pumping. The control facility can raise and lower the gates of intake spots to control when and how much water flows into the tunnel. 

The intake facilities are equipped to handle the mass flow of water in a way that redirects the water and reduces noise. If water is allowed to freely flow into the reservoir, there are loud noises, vibrations, and other disturbances. By forcing the water to instead spiral down the drop shaft, it gets quieter and flows faster.

Walking around the facility and seeing the control room with the models of the reservoir was very impressive but it still didn’t prepare me for seeing the real thing. After going down 11 flights of stairs, I was amazed at the size of the tunnel. I can’t even begin to comprehend the amount of water that would fill a tunnel that big. I think reservoir tunnels such as this one are a great way to protect the community from massive amounts of rainfall that can cause flooding. 

One of our first program activities was visiting Azabu University. Here, we met with faculty and students to present our projects and learn about Japanese student culture, lifestyle, cuisine, and public health issues. Our trip to Azabu University began with meeting Dr. Oui and other faculty such as the chairman and English teacher. The staff at Azabu University were all so welcoming and kind, it seemed like they were very excited to have us students from OSU visit their university. 

After the introduction of the university from the faculty, it was our turn to present our projects on different Japanese topics. My group presented about earthquakes in Japan and preparedness strategies. Other groups included topics like water quality and the aging population of Japan. We used this as a practice to share our work and receive feedback before being evaluated on the actual presentation a few days later. After the OSU students presented, we listened to the Japanese student’s poster presentations. At this time, we met students in smaller groups and I listened to many presentations from students such as Ann, Rui, and Shinosuke, who became great friends! Some of the Azabu student’s topics included “foods you may find weird but should try,” “daily life of a Japanese college student,” “Oendan; the samurai cheer boys,” and, “Japanese pets.” The students did an incredible job presenting their posters in English and it was fun to learn more about the culture through a personal connection.

After our presentations, we took a lunch break. Many of us decided to take a trip to the grocery store down the street. At this grocery store, I had Shinosuke show me around, translate, and give recommendations on foods I should try. It was amazing to go to the grocery store, pick up microwaveable meals, and warm them up in the store. One of my favorite aspects of Japan was the price and quality of food. The food was affordable, fresh, and delicious. Once we made it back from the grocery trip, we ate lunch as a large group with more Azabu students. At this time, we met Takuya, and he became a close friend with our group. He was so friendly, outgoing, and easy to talk to. He met with us many times outside of program activities to hang out with us.

During our lunch, Dr. Oui held a presentation about the aftereffects of earthquakes and how besides the immediate dangers of shaking from quakes, they can have huge public health implications. He discussed the struggles that Japanese people faced after the 2011 Tohoku earthquake, such as rotting fish, building damage, and resource scarcity. Following lunch, we toured the Life Museum which held many skeletons of various animals like anteater, dog, fish, sloth, elephant, snake, etc. At the museum, I met Yosuke and we immediately became great friends. I talked to him about biology and his life in Japan, and I asked him any questions I had. He even went to Tokyo University with us that evening. Yosuke met with our group many times and even surprised us on our visit to Hiroshima.

After we toured the museum we headed to Tokyo University to see the students we met there the previous day. Azabu University had an incredible campus and a lovely atmosphere. Our first day of visiting Azabu had me extremely excited to go back the next day. 

One of the first things I noticed about Japan upon arrival was how clean it is. Every street, park, train station, playground, and sidewalk was in impeccable condition with no litter. However, I was baffled by how they keep their surroundings so clean with minimal public trashcans. As I got accustomed to Japan, I loved seeing the appreciation the people have for their environment. It was great to learn how Japan burns the majority of its trash at incineration plants. While visiting the Hikarigaoka Incineration Plant, we learned how the Clean Authority of Tokyo collects, transports, processes, and disposes of Japan’s trash. 

Within the 23 Cities, each municipality is responsible for waste management, this change was enacted in 2000 when responsibility shifted from Tokyo Metropolitan Government to the 23 Cities. The Clean Authority of Tokyo has authority for intermediate waste treatment such as incineration, and must comprehensively plan with the Cities for processing. Each city determines collection days for household waste disposal and is free of charge. Chargeable waste removal includes business and large-scale wastes. 

One of the first operations we observed while at the plant was garbage trucks dumping their waste into the combustible waste platform. The trucks backed up to extremely large doors which opened to a waste pit that could hold up to 20 meters of trash. In the pit, a large claw reached down, picked up trash, and dropped it back down in order to mix the waste and make the trash more uniform and level. When it was time to incinerate garbage, the claw would grab it and carry it to a large hole that led to the incinerator. The incinerator burns the waste at a temperature of over 800℃. Burning at such a high temperature has environmental benefits such as limiting dioxin release. Within the incineration plant are giant boilers that use the heat energy to produce electricity which is used to power the plant itself and sold to power companies. 

Dangerous gases such as dioxins, mercury, and hydrogen chloride are byproducts of burning trash. These gases are removed from the exhaust by moving through a series of filters and a gas scrubber which cleans the gas with water and neutralizing chemicals. The clean gases are then released into the environment through the tall stack. 

Japan’s cleanliness can be explained by many reasons; education, cultural values, government involvement, recycling, and religious influence. Children are taught in schools and their homes to keep their spaces clean and take responsibility for their surroundings. This responsibility continues into adulthood and is a large aspect of Japanese culture. Government initiatives encourage people to reduce, reuse, and recycle. Charging extra for shopping bags and separating their trash into components are ways that Japan reduces and recycles their waste effectively. I was surprised the first time I went to a 7-Eleven and they asked if I needed a bag and then charged me for it. However, I came to appreciate using my own reusable shopping bag and it’s a practice I will apply in America. If America could implement an incineration system like Japan does, I think we could see less litter in the streets and decrease our reliance on landfills. Urging the importance of cleanliness and enforcing fines, extra charges, and increasing waste education could all benefit the environment. I hope America learns from Japan in this regard.