The first thing that stands out about porta-potties from Wasted* is that they’re bright orange. But there’s more than color that differentiates them from run-of-the-mill portable toilets. Wasted*, based in Williston, operates on the front end like any other sanitation company, but on the back end has a lab devoted to turning the waste it collects into fertilizer.
Wasted* was founded by Taylor Zehren, Thor Retzlaff, and Brophy Tyree – back country skiers and expeditionists – who were at base camp at Mt. Everest when they encountered the huge pits holding human waste generated by those climbing the mountain, potentially polluting water systems below. There had to be a way to mitigate that human impact there and elsewhere, they thought. So the three of them started trying to redesign back country toilets. “Their strategy was really based in biomimicry, taking inspiration from nature and designing accordingly,” explains Rachel Binstock, chief of staff at Wasted*. Basically that meant keeping #1 separate from #2. “Our bodies are biologically designed to separate the two waste streams that we produce. When we mix them, we have anaerobic digestion breaking down, we get smell, and it’s harder for systems to reintegrate the waste. When we separate them, liquids can go one place, and solids can dry out and go somewhere else.”
The back country toilet design that the trio settled on employed a slanted conveyor belt system to keep the two waste streams separate (the liquids run off one direction, while the solids are moved in the other), and that approach is still used in the off-grid toilets sold by Wasted*, which was formed in 2020 with hopes of expanding the vision for better handling and utilizing human waste. While it still serves the off-grid toilet market, the company is most visible today for the porta-potties it rents and the fertilizer products it makes with the urine collected.
How did Wasted* come to be based in Vermont? Binstock credits the pioneering work of the Brattleboro-based Rich Earth Institute. “They have done amazing research work, and they have also built a culture where they’ve really popularized and socialized people to the concept that urine is full of nutrients and should be reintegrated into agricultural systems, as it has been for millennia,” she explains. “Rich Earth has laid the stepping stones for us. They have socialized ‘pee-cycling,’ and they’ve also set up a regulatory pathway in the state of Vermont, so that pasteurized urine that comes from source separation, meaning it’s never touched fecal matter, it’s never been in contact with the solid, is understood to be ‘exceptional quality’ fertilizer in the state of Vermont.”
While it may seem counterintuitive, human urine is much more nutrient-rich than human feces, particularly in terms of macro-nutrients like nitrogen, potassium, and phosphorus. “Part of what we’re trying to do is to change hearts and minds and remind people that the human body is a part of the larger earth body…our waste belongs back in the system,” says Binstock.
Urine also doesn’t pose the same health and safety concerns as a solid waste. So, again, the goal is to keep the two streams separate. Wasted* solved that problem logistically by having specialized porta-potties designed, where the urinal tank is separate from the toilet tank. “So we only collect right now from standing pee-ers, but very soon we are hoping to introduce a ‘femme’ model that also collects from seated pee-ers,” says Binstock. That requires a slightly more complicated porta-potty design, and work is progressing.
Making fertilizer
What becomes of the urine collected? It’s brought back to the company’s hub in Williston using special trucks that also have separate tanks. (At the moment, the solid waste is sent on to a treatment plant, just as all waste would be at any porta-potty company—it’s too energy-intensive and not feasible at the current scale of the operation to make use of the solids, but there’s hope for the future, potentially making biochar, says Binstock.) Once the urine reaches the Wasted* lab, processing begins. “We bring it into storage tanks as raw urine, we pasteurize it, and that pasteurizer is built to maximize nutrient recovery, so as ammonia gasifies, it gets captured and re-submerged into the liquid and transforms back into nitrogen form,” she explains. “We try to capture and recycle as much of the nutrients as possible. The pasteurizer also heats it up to a certain level that basically deals with fecal coliform, or any of the harmful bacteria that might be found in the urine. We talk about that as cleaning the urine, and then it’s ready to go into a second stage of storage. At that point, in the state of Vermont it is understood to be ‘exceptional quality’ fertilizer and is ready for land application. Because our soils are high in phosphorus in Vermont, we do a second step, and that’s through a reactor where we just introduce a pet-friendly road salt, and that pulls out the phosphorus (which is used to make a separate product; more on that below). What’s left is a nitrogen-rich liquid product that we call Golden Grow. And we sell that to farm partners across our service radius.”
Binstock says the Golden Grow liquid fertilizer is typically supplied in bulk. “We’ve brought it to blueberry farms. We’ve brought it to hops farms. Most often it’s being applied to heavy feeders…crops that take a lot of nitrogen. And it’s a really good fit for farmers who fertigate, because they can move this product through their irrigation systems. We’ve worked with farm specialists that are doing the soil testing and the soil plans for farms … and what they’ve said to us is that it’s an excellent substitute fertilizer. The farmers really get it. They’re our biggest ally, because they understand that fertilizer comes from all kinds of places, fish guts, blood meal – the sources of nitrogen and phosphorus and potassium in our ag systems are often byproducts of other industrialized systems.”
Golden Grow is not currently certified organic, but the company is pursuing that pathway. Right now, it’s what Binstock calls “lower case organic – it’s biologically derived, it’s not mined, and it’s not chemically produced. It’s organic matter from our ecosystem.” That makes it a fit for farms that are more interested in thinking about the ecosystem and trying to bring natural nutrients and inputs back into soils. (Wasted* is actively looking for more farms and landowners to work with in that regard, and anyone interested in learning more, or supporting the concept, can email info@wasted.earth)
As mentioned earlier, Wasted* uses the phosphorus that’s isolated out during processing to produce a dry, bagged product called WeeBloom for the home and garden market. “That’s a specialty fertilizer—it’s a slow-release root booster and flower formulator,” says Binstock. “And very soon we’ll be bringing on a third product that’s more of a balanced NPK fertilizer, and that will be called Tinkle Tonic.”
A role in water quality
Utilizing the nutrients from urine not only holds benefits for growers, but importantly also helps remove those nutrients from normal municipal treatment processes. She cites work being done in France that shows how effective removing urine from the wastewater stream can be: “It’s by volume 1% of what goes into a municipal wastewater treatment plant, but in some cases it can represent up to 90% of the nutrient load.” And it’s expensive to treat the nutrients at this point: she says data shows that it can cost $200 to $280 per pound of nutrient to remove them from wastewater.
“And so if we keep them out, it’s a very effective, efficient strategy,” says Binstock. “Right now, [as a society] we are taking something that could be productive and turning it into a pollutant by putting it in our clean drinking water. It’s absolutely bonkers.”
We’re seeing that play out here in Vermont with water quality issues in Lake Champlain. “I often talk to people about the days when the beach is closed in Burlington; that’s in part because our waste treatment plants are at capacity and not able to remove the nutrients that are in them, and that causes all this eutrophication,” she notes.
And the same is happening in many places. Last year, Wasted* expanded its operations to serve both the Boston and Cape Cod markets. “There’s a huge movement of pee-cycling happening on Cape Cod, where they have a full-blown crisis. Almost everyone there is on septic, and all the septics are leaking and the soils are being polluted from the nutrients,” Binstock explains. “So they have nutrient maximums being imposed on them from the state level, and officials are scrambling to figure out how they’re going to manage their maximum loads and divert nutrients. Unfortunately, it’s usually only in moments of crisis that we wake up and say, ‘what would be a better way?’”
Could all household toilets one day separate solids from liquids? “That’s the vision when we’re sitting around talking about the sort of the places that this small company’s work could go,” says Binstock. “If we could prove that any new developer should build in plumbing to divert urine, and that could go into a collection system, and we could collect thousands of gallons of urine at one sporting event or at an airport or at amusement park or just in a residential setting, we could then recycle those nutrients and recover them at a scale that is way more impactful than running a hauling platform. She says there are examples in Europe now where this is being tried on a small scale in a few new developments.
Owning the work
While the topic is serious, if you haven’t noticed, Wasted* doesn’t shy away from the nature of its work and feels it’s best to have fun with its product names (Golden Grow, WeeBloom, Tinkle Tonic). “When people hear about what I do, they have all kinds of feelings; they sort of pause and they’re not sure if they want to keep talking!” laughs Binstock. “As humans, our waste is sort of taboo. But I could talk about pee all day. We want to normalize the idea that we are part of the ecosystem and that happens, actually, mostly through our waste. So we tell the story in a cute, cheeky way, beat people to the punch of the joke, sort of make light of something that is uncomfortable and hopefully bring them along with us as we try to reimagine waste and bring these nutrients back into the cycle. That’s fun for us.”
—Patrick White