This is a brief talk I gave at a symposium sponsored by The Walrus magazine late in 2015, on the topic of Innovation. I chose the not very glamorous subject of sewage; it refers to a theme introduced in my book, Back to the Well: Rethinking the future of water.
I had briefly considered calling the talk, “The Excitement of Sewage”, but even to me that seemed a little over the top.
But not by much …
It may be hard to think of something so, well, basic as being ripe for innovation, but that just makes it overdue for rethinking. And by this I mean the very real possibility that neighborhoods and even cities may be able to dispense with sewer systems entirely, thus no sewage charges, no costly installations and maintenance fees, no infrastructure breakdowns, greatly reduced water usage and costs … and more…
Consider this: about a decade ago in Windhoek, the capital of Namibia, a water manager pressed into my hand a tumbler of recycled sewage and urged me to drink it. Which, of course, I did; it would have been churlish not to, for the water manager was endearingly upbeat about what he had wrought.
I drank the water knowing what it was because I had just toured the treatment plant where it was produced. I already knew that Windhoek was the first city, anywhere, to fully recycle all its water, whatever the source, into drinking water … Other places have since followed suite. Singapore, for example, now get almost 40 per cent of its drinking water from such recycling. They carefully call this product “Newwater”, so as not to offend still-delicate sensibilities.
Well, yuck factor aside, this is surely a Purely Good Thing. But it is really only a half-hearted first step. It’s not yet innovation.
After all, the water that carried the sewage to the treatment plant was potable water to start with. Why are we flushing our toilets with water that has previously been expensively cleaned? It makes no sense. We’re stuck with it because traditional distribution grids, including Windhoek’s, use only one set of pipes in and one out. Some communities have already shifted away from this one-pipe-for-all-purposes mode; Orlando, for example, bedroom community for Walt Disney World, has two distribution grids — a regular one for potable water and a purple-pipe one for reused water, called grey water in the trade. In water-stressed areas, recycling water in this way is by far the cheapest and easiest way of increasing supply.
But this isn’t good enough either. Sure. We can save water by recycling it – but why do we need to use water at all?
As the water guru Peter Gleick points out, toilet flushing is the largest indoor use of water in most Western urbanized countries. He points out that “new technology . . . can manage human wastes without water. . . . Electrically mixed, heated, and ventilated … toilets have no odors or insect problems and produce a finished compost that does not endanger public health. These devices safely and effectively biodegrade human wastes into water, carbon dioxide, and a soil-like residue.”
The makers of these toilets have latched onto this notion, and an industry website gets positively giddy at the possibilities: “If a community were to embrace the total use of composting toilets and appropriate gray water systems, it would have no sewage charges, no sewage pipe installations and no maintenance costs. The community would also have greatly reduced water usage and costs. It could also … produce valuable compost and worm castings for sale or reuse in community and private gardens.”
All true, but as one who actually owns an early generation composting toilet, I can attest that it is not yet quite as convenient as advertised and that the “soil-like residue” remains an issue, keeping you closer than you would like to what you would like to get away from.
But the technology is already better. Retrofit kits already exist to convert residential septic systems into treatment systems. And where urban densities don’t allow septic systems, it is still possible to have household or apartment-block wastewater treatment systems in-house, so to speak. A paper in the journal Water Research reported on a so-called membrane bioreactor in the basement of a four-person house that treated all outgoing water, including sewage, into “de-watered sludge” plus usable water. A Canadian company, H2O Innovation, is a leading developer of membrane bioreactor technologies for wastewater treatment, but there are many others. See? Sludge management is also an industry ripe for innovation,
But can this work in densely-populated cities? Or even in suburbs?
The answer is yes, given the political will. A number of college dorm apartment houses in the U.S., for example, have installed building-wide waterless toilet systems. They report that the workers employed to remove that “soil-like residue” from the basement and distribute it on surrounding gardens have found their work odorless and not unpleasant, more like gardening than anything … And the resulting compost has become a profit center.
In Brooklyn, New York, a sustainable solutions company called Rosie’s Natural Way has installed a Swedish composting toilet system called the Aquatron in a new 12-apartment building. The solid waste generated by the residents is composted by worms, which produce fertilizer for the building’s rooftop gardens, which produce food for the residents, who then … complete the cycle.
Rosie’s has also developed a bio-filter that filters liquid waste to drinking water quality. The water so produced is then recycled into a home’s water system. As the company puts it, “the bio-filter is the final component for creating a [totally] independent sewage system. Residential homes and facilities will no longer [need to] rely on [centralized] sewage systems.”
This is not just hippy-dippy stuff either. There is some serious money invested into sewage innovation, by the Bill and Melinda Gates Foundation among others. One result of their Reinvent the Toilet challenge is the Blue Diversion device developed by Swiss scientists; it is a dry toilet that requires no piped water or wired-in electricity. As the writer Sallie Tisdale wrote in a piece for Harper’s, “it has been thoroughly tested by its end users …” (Her pun, not mine). A pilot project in Nairobi is used by 27,000 people every day.
In Australia, the Victoria Smart Water Fund has a five year project to design, build and assess dry composting toilet (DCT) technology applied in urban areas, including inner city apartments. The advantages, so far, include a 30 percent reduction in household water use; a 65 per cent reduction in nutrient loads to sewers; and the recovery of safe-to-handle nutrient-rich fertilizer.
Well, there’s lots more. In Bristol, England, the Number 2 commuter bus is now widely known as the Poo Bus. (It’s really the Bio-Bus, but nobody calls it that.) It is powered entirely by bio-methane produced by anaerobic digestion by micro-organisms from a nearby sewage treatment plant. Mohammed Siddiq, the CEO of the company that runs the bus, points out that “it is actually powered by people living in the local area – including quite possibly those on the bus itself.” Oh, by the way … it takes the annual waste from five people to drive the bus 300 kilometers.
And in Washington DC, a town some think is over-full of crap, is now putting some of it to good use, employing the same micro-organisms to treat 15 million gallons of sewage daily and generate enough bio-methane to power about 10,000 homes, saving around $14 million annually.
So is everything smelling of roses, so to speak? Not quite. There is still one serious problem that none of these systems have yet solved, and that is how to compost the “other stuff” that routinely gets deposited in toilets (this is a real list, from a real site) – plastic kids’ toys, a teddy bear, goldfish, styrofoam containers, expired credit cards, shopping bags, egg shells, swiffers, dental floss, cosmetics dispensers, diapers, and at least one stash of cocaine hastily dropped into the toilet after a loud knock at the door …
If you can fix consumer behavior, we’re home free…