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Honda Engineering Co., Ltd.Business Administration Division, Facilities Management Department

Yuji Omori, Staff Engineer, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

Yuji Omori, Staff Engineer, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.
The integrated domestic water treatment facilities (above) and the ozone treatment system introduced after the disaster (below)
The integrated domestic water treatment facilities (above) and the ozone treatment system introduced after the disaster (below)

A evolutionary redesigned closed-loop system after the Great East Japan Earthquake

 About one year after its completion, the closed-loop water recycling system sustained damage in the Great East Japan Earthquake. Staff Engineer Yuji Omori looked back on the event.
 “Given that even the buildings were damaged, restoration took considerable time. The most troublesome issue was repairing the damage to underground drainage pipes. The length of all domestic and industrial drainage pipes running from each structure to the water treatment facilities totaled 14 kilometers, and we had to check all of it. All water use was suspended, because damaged pipes could leak dirty water into the ground and pollute the soil and river. During this period, we used portable toilets and replaced services in the cafeteria, which discharges the most wastewater, with lunch boxes."
 Drainage pipe inspection was a daunting task, said Omori. The work to put cameras into the pipes via manholes and check for damage continued until every inch of the drainage pipes had been inspected. Inspections finally finished three months after the disaster and the water supply was partially restored.
 The damage, however, was not limited to the piping. A tank in the No. 1 Domestic Water Treatment Facility was cracked, making operation impossible. Repairing the crack was prohibitively expensive, so the associates struck upon the idea of expanding the undamaged No. 2 Domestic Water Treatment Facility and integrating the two. Completed in 2004, the No. 2 facility was more technologically advanced and more compact than the No. 1 facility, which was built in 1990, meaning that integration led to an economization of space.
 In addition, a new piece of equipment called an ozone treatment system was installed during the repair work.
  Sakurai said, “We introduced this system to eliminate the odor of water and sludge that occurs during drainage. Clarity is a measured indicator for water, but there are no legal standards relating to smell. In other words, water that passes quality standards can still give off a faint odor. This was becoming an issue for us, particularly in summer. Passing the water through the ozone system clarifies it and eliminates the odor in just two to three minutes. This also helps reduce the amount of chemicals used, providing the added benefit of shortening the purification process and saving power.”
 The ozone system is one of the most significant features of the current closed-loop water recycling system. It is an advanced technology that has not yet been introduced at other Honda plants and has only been adopted at a few locations across Japan.
 After the repairs and integration, restoration of the entire system was finally completed on March 25, 2012, about one year after the disaster.

Kenichi Tasaki, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

Kenichi Tasaki, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

The next issues to tackle were the treatment of concentrated water and optimal year-round water management.

 Having survived the disaster and been repaired and updated with the latest technologies, the closed-loop water recycling system at the Honda Engineering’s Plant has begun to attract the attention of other companies, as well as a growing interest from the rest of the Honda Group. Even so, there are still issues to be worked out, explained Sakurai.
 “One issue is the treatment of concentrated water. We can purify wastewater with current technologies but we still can’t remove the salt content. So when wastewater is recycled over and over again, the salinity gradually increases until it reaches a certain level of salinity and must be discharged (1). A technological breakthrough to eliminate all discharge is our next task. It’s quite a challenge.”
 Another issue is the difficulty of balancing the supply and demand of reclaimed wastewater through the year. “We purchase almost the same volume of potable water throughout the year, but reclaimed wastewater is primarily used as industrial water and the quantity of this required by the facilities differs significantly in summer and winter. For this reason we have a situation where reclaimed wastewater is insufficient in summer and must be replenished by potable water (2), whereas in the winter there is an excess which can only be discharged (3).”
Notes (1), (2), (3): Refer to the Technical Report: Water flow in the closed-loop recycling system for wastewater
 However, this is not to say that there are absolutely no prospects for a solution.
 “We plan to expand the capacity of the rainwater cistern to compensate for the water deficiency in summer. By storing more rainwater, we hope to be able to supplement the industrial water with rainwater rather than potable water. We expect to be able to implement this in the first half of 2013. As for the excess of reclaimed wastewater in winter, all we can really do is reduce the amount of reclaimed wastewater itself, which means saving potable water to reduce the quantity of wastewater produced. We hope to save water used in restrooms, showers, and kitchens as much as possible.”
 According to Hayashida, the plant has long since been united in promoting water conservation.
  “We’ve installed water-saving values on approximately 250 taps at all the hand-wash stations within the plant. Kitchen staff are also cooperating with us on water conservation. Many are housewives, so they have lots of ideas about how to save water. For example, previously, dishwashers were used to wash dirty plates and utensils as they came. But the housewives remarked that at home, they wash everything in one load. So we figured we could do the same thing here, and in fact we were able to reduce the number of washes from four times to three times a day.”
 Hayashida went on to explain carefully that saving water saves resources, which helps reduce costs. He said that associates who had not known this were extremely cooperative when they realized that their efforts would produce benefits for the company. The result was a 22% reduction in the purchase of potable water, from 60,600 tons in fiscal 2010 to 47,400 tons in fiscal 2013.

Takenori Narita, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

Takenori Narita, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

Promoting water conservation by expanding the system to the entire Honda Group

 Nearing four years since the completion of the closed-loop water recycling system, the team spoke about future targets.
 “Introducing the RO membrane and ozone systems early on allowed us to create a state-of-the-art system.
Moving forward, we hope to contribute to environmental conservation by picking up on trends and maintaining the system so that it can respond flexibly to R&D operations. I hope to make the system more efficient in cooperation with other team members.” (Tasaki)
 “I’ve only been here since April and still have a lot to learn. I’d like to quickly put into practice what I’ve been taught by my seniors and help create methods to maintain a steady supply of reclaimed wastewater in a more balanced manner.” (Narita)
 “I provide support to Tasaki and Narita. When we run into trouble I try to use my experience to provide back-up.” (Omori)
 “My final goal is to run the cycle without purchasing potable water and using rainwater alone. I would also like to deploy this technology overseas. There are many regions where discharge standards are low and awareness of water treatment is low compared to Japan. Even if facilities could be brought in, most places lack the know-how to operate them. First, I think we should raise global awareness of water resource conservation by communicating the importance of fully recycling industrial wastewater and industry’s responsibility to do so. I hope to actively challenge myself in future opportunities using my experiences to date.” (Hayashida)
 “The current state of the system is one that the Honda Group should be proud of, even internationally. Still, although theoretically we’ve closed the loop, we still have to discharge some of the concentrated water, from which the salt content cannot be removed. My hope is that in the future we can eliminate this discharge and realize a true closed cycle in both name and substance. We must not forget that a closed cycle itself is not our objective but only a means by which to preserve water resources. Once we’ve fully recognized this objective, I hope we can actively deploy this system to other Honda companies and minimize the use of resources across the Honda Group for the sake of the global environment.” (Sakurai)

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