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WOTA BOX Yosuke Maeda with solution
2021 Finalist
Build a
Waste-free World


Nominated by:

Nearly 40 percent of the world could experience “water stress” by 2050. WOTA’s technology purifies wastewater on site, meaning it can be used over and over.

Their Story

Climate change and population growth are already driving shortages across the world. WOTA, a Japanese start-up, wants to improve water security for everyone, everywhere. By improving circulation and reducing waste, it can ease global water stress.

Founded in 2014, WOTA’s unique water recycling system turns more than 98 percent of wastewater into fresh water. A fraction of the size of a typical water treatment plant, WOTA BOX is over 50 times more efficient and can be delivered at scale. Plus, installation requires no existing infrastructure.

The result means less wastewater pollution in lakes, rivers and other freshwater ecosystems, as well as reduced water scarcity in times of drought. The only invention of its kind, WOTA BOX could change the world.

It has already had an enormous impact. In Japan, between 2016 and 2020, more than 20,000 used the technology after floods, typhoons, and earthquakes cut off water supplies.  

The company’s long term hope is to develop products that are lower cost than existing water infrastructure, so they can be reasonably implemented in any region, including developing countries.  The WOTA  team hopes to make its technology as common as power generators. If it succeeds, it could help save the world from a water stressed future.   

In the time since becoming an Earthshot Prize Finalist, the team have enjoyed inbound requests from around the world, begun a new partnership with Antigua & Barbuda and are on track to launch pilot projects in multiple countries. 

They are also in ongoing discussions with their home government in Japan about introducing WOTA to rural parts of the country, with some projects already underway this year.

Other Finalists in Build a Waste-free World

Learn About the Earthshots

and Restore

By 2030, we choose to ensure that, for the first time in human history, the natural world is growing – not shrinking – on our planet. 

This Earthshot focuses on three main areas of interest: 

  1. Protecting areas of high biodiversity such as forests, wetland, peatlands and wildlife corridors
  2. Restoring damaged ecosystems
  3. Feeding people while protecting nature
Learn more about this Earthshot

Clean Our

By 2030 we choose to ensure that everyone in the world breathes clean, healthy air – at World Health Organization standard or better. 

This Earthshot focuses on three main areas of interest: 

  1. Engaging citizens in data collection and clean air policies
  2. Preventing the burning of fields, forests and waste
  3. Transitioning to clean transportation for all
Learn more about this Earthshot

Revive Our

By 2030, we choose to repair and preserve our oceans for future generations. 

This Earthshot focuses on three main areas of interest: 

  1. Protecting and restoring coastal ecosystems
  2. Replenishing fish populations
  3. Reducing demand for fishmeal
Learn more about this Earthshot

Build a

By 2030, we choose to build a world where nothing goes to waste, where the leftovers of one process become the raw materials of the next – just like they do in nature. 

This Earthshot focuses on three main areas of interest: 

  1. Reducing food loss from farm to fork
  2. Phasing out single-use and non-recycled plastics
  3. High-value circularity in fashion and electronics
Learn more about this Earthshot

Fix Our

We choose to fix the world’s climate by cutting out carbon: building a carbon neutral economy that lets every culture, community and country thrive. 

This Earthshot focuses on three main areas of interest: 

  1. Creating an equitable clean energy future
  2. Addressing non-CO2 greenhouse gas emissions
  3. Decarbonising hard to abate sectors
Learn more about this Earthshot
The Earthshot Prize