A Report from the Rich Earth Summit

January 1, 2020

PHLUSH President Hayley Joyell Smith, currently a PhD student at the University of Georgia, reports on the Rich Earth Summit held at the University of Michigan, November 7-8, 2019. She was among the experts – entrepreneurs, engineers, farmers, regulators, researchers and practitioners – who explored the theme “Policy, Regulation, and Moving to Implementation of New Technologies” as applied to urine diversion and reuse.


Nancy Love, University of Michigan Professor of Engineering and co-host of the Rich Earth Summit, opened the event with the powerful quote from Buckminster Fuller

Pollution is nothing but the resources we’re not harvesting. We allow them to disperse because we are ignorant of their value.

Love’s introduction set the tone for this two-day summit dedicated to the resource potential human urine as well as the social impediments to successfully capturing and processing it for agricultural use.

Hayley Joyell Smith (right) with Nazneen Ahmed, Director of Global Projects at Laufen Bathrooms, whose team has developed a plumbable urine diversion toilet called Save!.

At the summit, 41 invited participants representing a range of science, social science, and humanities fields were asked to imagine an infrastructure that harvests thousands of people’s urine and then supplies farmers with a local fertilizer instead of the synthetic products or raw non-renewable resources, such as the phosphorous mined in Morocco. While that vision may seem radical, the participants agreed that creating a more resilient and sustainable world must involve a significant overhaul of the standard wastewater system. Toward that end, diverting human urine away from the wastewater stream to concentrate nitrogen and phosphorus, mitigate water pollution, and contribute to agricultural productivity, must become a priority.

Presentations and panels explored both the physical science of harvesting human urine and converting it into a fertilizer and the social and political aspects of promoting a paradigm shift from viewing urine as a waste to valuing it as a resource.

The Science

Discussions around the science of producing fertilizer tended to focus on ways to maximize the nutrients available in urine and determining the risk of using urine as a fertilizer. In addition to nutrients and salts, urine can contain traces of pharmaceuticals. When discharged into the natural environment via water treatment, these compounds remain and bio accumulate. Concentrating the urine is one way to capture and treat the resource. Scientists at the University of Michigan and State University of New York, Buffalo are working with Rich Earth Institute to determine methods for safe removal of pharmaceuticals and measuring any uptake of synthetic compounds into the plants. The innovative group of researchers are invested in furthering the effort to use renewable resources (human urine) as a fertilizer for sustainably growing crops.

Abe Noe-Hays with his newly-patented freeze concentration urine treatment device installed at the University of Michigan. (REI photo)

One of the highlights of the Summit was touring the experiment for plumbed urine harvesting. In the G.G. Brown building on campus there is a waterless urinal in the men’s restroom and a urine diverting toilet in the women’s restroom. Both have pipes leading to a containment and processing room. At several steps along the way, sensors monitor different parameters such as pH, nitrogen, temperature, and salts. One of the goals of this experiment is to derive a higher concentration of the nutrients to produce a fertilizer product that is not recognizable as human urine. The most recent iteration of the experiment is to freeze the urine in order to concentrate nutrients and separate the water. The excitement of Abraham Noe-Hays, co-founder and Director of Research of Rich Earth Institute was tangible. Earlier in the week he had installed this latest version and it was functioning as anticipated. The next day the patent for the urine freezing apparatus was approved. 

Social and Political Factors

While knowing the statistics and science of harvesting human nutrients is an essential aspect of the work, those at the summit clearly agreed that the implementation of appropriate technology is dependent upon social acceptance.  The general population needs to be enlightened about the benefits of urine diversion and the harmful effects of standard wastewater systems. Repeatedly, it was acknowledged that until people identify a clear problem there is no incentive to adopt a solution. In other words, increasing awareness that our freshwater resources are being polluted with our flushed toilet water is a precursor to soliciting support for implementing urine diversion as part of the solution.

For social change to take place it is imperative that social scientists gain a better understanding of the values and ideas held by the general populace.  In a presentation of doctoral research, Alex Cohen shared results from an extensive study (n=2,000) indicating that people expressed less “disgust” at the concept of urine diversion and use of urine as a fertilizer than predicted. Further, that people thought others would be more disgusted than they were at the concept; one of several findings, which encouraged the group that the paradigm shift is possible. Along with the general public’s approval and acceptance of urine diversion (UD) technology, regulators are a necessary population of people that need to be supportive of UD adoption.

There are also many political and regulatory impediments.  Each state and in some cases, each county may have different regulatory practices inhibiting the implementation of urine diverting toilets, onsite wastewater treatment, and/or application of human derived fertilizers. Regulators are charged with adherence to codes, which are hypothetically designed to protect pubic and environmental health. In essence, they are responsible for following pre-established laws that often do not reflect modern scientific understanding.

There is no set category for urine. The lack of clarity of how urine differs from other biosolids or from grey water is a problem. Further, the department or individual authorized to make decisions regarding toilet systems varies, meaning different education and perspectives. The person who can approve or block UD implementation might be working in public utilities, health departments, or environmental agencies. Clearly education must extend beyond the general public to regulators and decision makers.

Putting it all Together

Real change will require innovations in technology, creative education, social adaptation, and regulations that reflect scientific evidence. All of those topics were discussed in various settings during the Summit.  
Paula Kehoe, Directory of Water Resources, San Francisco Public Utilities inspired attendees with her success in melding science with social and political action. She discussed transforming the modus operandi of building practices under her jurisdiction from “business as usual” to innovative. By listening to the concerns of stakeholders in public health, building management, and public works she was able to establish a path to embracing onsite wastewater systems for new construction projects. The San Francisco Public Utilities Commission Building was the first to implement a living system that treats and reuses all water onsite. It is now expected that any new building in the urban area will follow suit and treat its water onsite. Kehoe also explained the process undertaken by the National Blue Ribbon Commission for Onsite Non-Potable Water Systems, which drew from institutional knowledge, scientific evidence, and governance norms to create the is blueprint to “progress innovative solutions for One Water management.”

A Path from Here

Rich Earth Summit participants will continue the work until they reconvene at next year’s event. (REI photo)

Meetings of this nature often share the same pitfall—participants leave inspired and energized for the short term, until their enthusiasm dissipates in the wake of daily work and life. Because Rich Earth Summit organizers and participants are on a mission, this Summit is a part of a longer journey not an end in itself. As an example, due to the complexity of the decision-making on the part of regulators, summit participants decided to create a manual for the wastewater treatment. A taskforce for composing the document was named and given the charge to provide educational information, case study examples, regulatory suggestions, risk-based analyses, and protocols for implementing urine diversion systems.

The Summit clarified the path forward so the necessary science and social science can continue in earnest.

One Response to A Report from the Rich Earth Summit

  1. Lorraine Hains on January 6, 2020 at 3:12 pm

    Inspiring group of people on a worthy mission. Well written article and I look forward to following the progress.

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Our Mission Through education and advocacy, PHLUSH helps local governments and citizen groups to provide equitable public restroom availability and to prepare for a pipe-breaking seismic event with appropriate ecological toilet systems.

Our Vision Toilet availability is a human right and well-designed sanitation systems restore health to our cities, our waters and our soils.

Public Hygiene Lets Us Stay Human (PHLUSH) was founded in Portland, Oregon and today collaborates with groups across North America.

PHLUSH is a member of the World Toilet Organization and a partner in the Sustainable Sanitation Alliance.

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