Grey Water Recycling in New California Homes

Our solution reduces water & sewer infrastructure by 30% and 70%, respectively, with technology that can be applied in drought-prone regions

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I confirm that I am fully aware of the eligibility criteria, and based on its description, I am eligible to apply to the CSV Prize 2017.

  • Yes, I'm eligible

Preferred language

  • English

Organization name

Nexus eWater, Inc.

Year founded


Initiative stage

  • Start-Up (a pilot that has just started operating)

Annual budget in 2017 (USD)

  • $500k - $1m

Number of beneficiaries impacted so far

  • 10 - 50

Organization type

  • For-profit

Secondary Focus Area

  • Rural development

Headquarters location: Country

  • United States of America

Headquarters location: City

San Diego

Location(s) of impact

United States: San Diego, Los Angeles, Bakersfield, Fresno (California)


Facebook URL

Twitter URL

Problem: What problem is this initiative trying to address?

According to a Pew Research Survey, drought and water shortage top the list of things people around the world are most concerned about regarding the issue of climate change -- 44% globally in 2015. Indeed, there is plenty of evidence that indicates drought is both drier and lasting longer than ever thanks in part to climate change. In the developed world, one of the most frivolous uses of water is the use of potable water for residential needs such as landscaping, car washing, and in toilets for flushing.

Solution Summary: What is the proposed solution? What do you see as its most promising aspects for creating shared value?

Our solution reduces residential potable water use by 30% and sewer flow by 70% by reusing certain flows from the home, what we call "grey water", for nonpotable applications like irrigation, car washing, and toilet flushing. Grey water, which is the wash water from showers and laundry, makes up approximately 2 out of 3 gallons of all indoor water. For municipalities in drought-prone regions, this reduction could allow cities to reach population growth targets without having to expand existing water or sewer infrastructure. For builders and housing developers, this could mean securing building permits in cities that are already drought-prone or drought-stressed. For environmentalists, this could mean preserving or increasing existing water supply for wildlife. For homeowners, this could mean meeting potable water reduction targets -- all without changing any of their behavior. In short, our solution allows homeowners the water they want and the environment the water it needs

Impact: What is the impact of the work to date? Specify both the social and the environmental impact of your work

The NEXtreater was the first product in a new category of grey water, what is being called NSF350 treated grey water. First certified to NSF350 in 2015, we are now in the process of delivering our first 50 systems to various markets in California. Early data indicates that homes are saving roughly 30% on potable water and 70% on sewer. Extrapolated, this translates to over 50,000 gallons of potable water saved per home per year -- over 2.5 million gallons, total! -- all without homeowners having to change any of their water-use behavior. In addition to being a leader in a new category, by being one of the few experts available we have taken an active role in shaping new grey water policy and regulations across various areas of the United States, most successfully in California and Colorado.

Financial sustainability plan: How is this initiative financially supported? How will you ensure its financial sustainability long-term?

Nexus eWater is largely VC funded with an annual operating budget of approximately $1 million. Our product, the NEXtreater, retails for roughly $10,000. It is anticipated that financing through 2018 will be approximately 50% investor funded and 50% earned revenue. As for 2019 and beyond, we plan to secure contracts for larger projects by first demonstrating the effectiveness of the solution with our first 50 unit deliveries. In the future, with scale, we will be able to reduce our costs related to manufacturing by upwards of 75%. The price of our system at that time will then be a "no-brainer" for California homebuyers, much like with solar panels, as there will be a return on investment (ROI) of just a few years.

Unique value proposition: What makes your initiative innovative? How does your project differ from other organizations working in the same field?

Our product differs from other products in the category because it meets an international standard called NSF350. The California State Plumbing Code, among other codes, allows NSF350 treated water to be reused for any irrigation need (including spray and garden use) and even for toilet flushing and car washing. Our product, the NEXtreater, was the first product to meet this international standard and remains one of only two grey water products available in the world.

Founding story: Share a story about the "Aha!" moment that sparked the beginning of this initiative.

Our founders originally developed the NEXtreater technology during the Millenial Drought in Australia. After the Millenial Drought ended they began pivoting the idea to the much larger California market (roughly 40 million people compared to Australia's roughly 24 million people). The timing of this pivot was a bit serendipitous, as it just so happened to coincide with the beginning of what would become a severe, 6-year drought in California. Our story only reinforces the view that drought truly is a world-wide issue.

Where did you hear about the Nestlé Creating Shared Value Prize?

  • Ashoka page or contact
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Attachments (2)


NEXtreater spec sheet


Join the conversation:

Photo of Mouhamadou Moustapha Seck

Great idea.

Photo of Mirana Francoise Razafindramboa

What a brilliant idea! Let us know if you plan to extend your project globally in countries like Madagascar. We'd be interested in! Fill free to reach us for any idea:

Photo of Tom Wood

Thanks for the support!


What a U.S. house saves in one year will suffice a rural family in India for ten years.

Photo of Tom Wood

Indeed lots of wasted water we MUST change how homes in developed countries are built!

Photo of Tom Wood

Questions? Ask me anything!