Water reclamation, water conveyance technologies

Needs Address

The need to compensate for a shortage of water arising from changes in rainfall patterns due to climate change. 

Adaptation effects

Securing water resources to deal with water shortages resulting from climate change

Overview and Features

Reclaimed water is supplied to public facilities, a wide-area disaster preparedness center and an incineration plant, as well as to private sector facilities such as groupings of large companies, and clusters of small and medium-sized enterprises. During non-emergency times, the water is used as general service water such as for toilet flushing, watering, and also for cooling and other industrial purposes. This technology system provides water in quality and in quantities that respond to multiple demand-side needs. It Is able to efficiently provide a stable supply of water for urban uses. 

Fire hydrants are installed on some of the water mains, making water available for firefighting during emergencies, thereby providing greater safety to the community. 

The technology supplies two categories of water from reclaimed water in terms of quality and quantity produced, depending on the water use. The system designed incorporates the following facilities to supply 33,000 m3 per day of water filtered by no-contact fiber, and 1,000 m3 per day of contact ozonated water: 

• One water pumping station
• Two satellite water treatment facilities (ozonators)
• About 12 kilometers of water main pipes

Cost

Initial cost+ 3.76 billion yen (Phase 1 construction of Sakaihama Water Reclamation and Distribution Project)

Energy source

Electricity

Ease of maintenance

• Daily inspections of the pumps and electrical system must be conducted by electrical and equipment technicians. 
• Daily water quality inspections are required. 

Technology performance

Quality, quantity of reclaimed water

• Water filtered by no-contact fiber: 33,000 m³ per day
• Contact ozonated water: 1,000 m³ per day

Considerations

• It is important to design the system to match supply to the demand for reclaimed water.
• Consideration/analysis is required of the various uses/applications for reclaimed water. 
• Cost is expensive. 

Co-benefit, suitability for developing countries

• Creation of employment for technicians able to conduct routine water quality testing, as well as inspections of pumps and electrical systems.
• Technology is beneficial for increasing community safety (by provision of water for firefighting)

Information Resources

• Sakai City Waterworks and Sewerage Project Discussion Group, Fourth Meeting Documents (October 31, 2008) (in Japanese only)
  http://water.city.sakai.lg.jp/torikumi/konwakai2.html
• Japan Institute of Wastewater Engineering Technology (JIWET)
  http://www.jiwet.jp/quarterly/pdf1/2010/n013-013.pdf