Ready. Set. Go! The race to the high-tech toilet of the future is officially on. In early October, the International Organization for Standards, better known by its English acronym of ISO, published the first technical standard for the attributes and performance of a toilet that fully treats human waste on site, without connection to a sewer or drainage system, and by implication, without connection to a dedicated water supply.
Less than two months later, Bill Gates, the philanthropist and former chief of Microsoft, was “toasting” the attendees at the Reinvented Toilet Expo in Beijing with a beaker of human feces. Gates’ malodorous prop made a telling point — every human on the planet has to “go,” and there is an enormous market awaiting new products that can safely address the universal human need for sanitation without requiring costly sewers and squandering fresh water simply to transport human waste.
The alternative to the traditional toilet — defined by ISO as a “Non-Sewered Sanitation System”— is a manufactured product the will serve an individual household, a small apartment building, or a public restroom. It must accept and treat all manner of human biological waste, and may accept additional types of household and personal waste if so designed by the manufacturer.
ISO has established rigorous standards for the destruction of human pathogens and for limits on noise, air emissions, and odor. And manufacturers must subject their products to a challenging set of tests to demonstrate attainment of these standards. All surfaces of the device are to be cleanable, and there can be no visibility of the deposits of previous users. From the consumer perspective, using a reinvented toilet will not be noticeably different from using a conventional toilet.
New products are very close to reality
So is a Reinvented Toilet a real thing? “Very close to being real” is the best answer. Various teams, some with the support of the Bill & Melinda Gates Foundation, have products under development, and several devices are out of the lab and undergoing field trials.
There are several technical pathways for meeting the ISO standards: electrochemical, biological, and combustion-based approaches are all in contention. It’s not clear yet whether one approach will prevail, or whether all these approaches can find their niche in a worldwide market. Service requirements, warranties, supply and distribution chains, and — notably — purchase price, are all unknown as of yet.
The Beijing Expo was intended to showcase those products that are closest to being market-ready, but it could be another couple of years before bona fide commercial shipments take place.
Meanwhile, testing and evaluation will continue, and companies and public officials will begin to familiarize themselves with the requirements of the ISO standard. In the U.S., the International Association of Plumbing and Mechanical Officials (IAPMO) has signaled its intention to undertake the adoption of the ISO standard as a U.S. national standard, which should ease the way for recognition of the standard in health and building codes across the country. Canadian national adoption is under initial discussion as well.
For the last two years, I had the opportunity to serve on the U.S. technical advisory group that participated in the development of the ISO standard. At the final plenary meeting of the ISO committee in Nepal last May, I recorded a few thoughts about the threshold we’re soon to cross.
It’s logical to ask whether composting toilets — commercially available for many years— might qualify. The answer is probably not.
The new ISO standard — and the goal for the “reinvented toilets” as originally scoped by the Gates Foundation — calls for complete treatment on site. The treatment standards are demanding, not only for bacteria like E. coli, but for viruses, protozoans, and worm eggs. Today’s generation of composting toilets may be a good solution for some locations, but it does not achieve the level of treatment called for in the standard. It is possible for biologically based treatment systems to be tested for qualification under the standard, as no particular technical approach is ruled out. But traditional composting alone is unlikely to meet the standard. Perhaps an enhanced approach will emerge in the years ahead.
Potential for public health benefits
The public health benefits of reinvented toilets will be enormous for the developing world, leapfrogging over the lack of wastewater infrastructure and saving thousands of lives now lost each year to preventable diseases, among both settled populations and those displaced by conflicts and natural disasters.
But perhaps unexpectedly, reinvented toilets are likely to play the role of disruptive technology in many parts of the developed world as well, including North America. To begin with, remote and arid locations that attract large numbers of people are obvious candidates — music festivals like California’s Burning man, or the Grand Canyon, for instance.
But we also have many full-time residents here in rural communities marked by poor drainage, water scarcity, permafrost conditions, or inadequate infrastructure — any of which can make traditional sanitation technology prohibitively expensive.
On an even larger scale, cities across the continent are facing the vagaries of climate change and its effects on the reliability of traditional sources of water. According to a recent survey of U.S. and Canadian cities, nearly 25% of all indoor water use in single-family homes is still devoted to flushing toilets, a luxury that may not be sustainable. And with our water and wastewater infrastructure suffering from decades of deferred maintenance, strategic placement of toilets that operate independent of these aging networks may well factor into the solutions we seek for resilient communities and just access to essential services.
The need for a new technology is acutely evident in cities such as Cape Town, South Africa, today. But before long, reinvented toilets may be finding their way to places like Atlanta, Los Angeles, or any other community in North America that wants to start capturing the benefits of this new technology.
Get ready. Reinvented toilets are on their way.
Ed Osann is director of national water use efficiency, Water Initiatives, Healthy People & Thriving Communities program, at the the Natural Resources Defense Council. This post was originally published at the NRDC Expert Blog.