Laura Allen, a 33-year-old teacher from Oakland, California, has a famous toilet. To be honest, it’s actually a box, covered in decorative ceramic tiles, sitting on the cement floor of her bathroom like a throne. No pipes lead to or from it; instead, a bucket full of shavings from a local wood shop rests on the box next to the seat with a note instructing users to add a scoopful after making their “deposit.” Essentially an indoor outhouse, it’s a composting toilet, a sewerless system that Allen uses to collect her household’s excrement and transform it into a rich brown material known to fans as “humanure.”
Allen is a founding member of an activist group devoted to the end of sewage as we know it. Her toilet recently made an appearance in the Los Angeles Times—which might explain why she didn’t seem surprised when I emailed her out of the blue to ask if I could use it.
Lifting the seat, she showed me a seal of insulating foam tape she’d put around its edges to prevent odors from wafting into the bathroom and then pointed out a funnel-like contraption hanging from the front of the toilet that diverted urine away from crap. The separated waste collected in two containers sitting several feet below the toilet seat, accessible through a hatch cut into the side of the house: the urine flowed into a plastic jug formerly used for olive oil, the feces into a bucket labeled “feta cheese.” A year from now, once it’s composted, Allen and her roommates will use this excrement to fertilize their fruit trees.
To most Americans, Allen’s system would seem eccentric, if not downright weird. But while feta cheese buckets are relatively new creations, humans have used shit as fertilizer since the dawn of agriculture—the nitrogen in our urine is an excellent fertilizer, and feces, itself nutrient-rich, is a great soil amendment. It wasn’t until the turn of the 20th century that water-based sewer systems became commonplace in the United States; after that, “sewer farms,” where crops were irrigated with untreated wastewater, were commonplace. Even today, the majority of the world’s population doesn’t have access to flush toilets, making us the anomaly, rather than the norm.
As public health advocates will be quick to point out, the switch to sewers helps protects us from sewage borne diseases. But it also breaks the nutrient cycle: instead of returning nutrients to the land from where they came, we now reclassify excrement as waste and use chemical fertilizers to replace it. From an agricultural standpoint, the crazy thing isn’t the idea of using our crap as fertilizer. It’s how far we’ve strayed.
With this in mind, the idea behind our current system would seem to make sense: more than half of America’s sewage sludge is applied to land. But there’s a crucial difference between humanure and modern sludge, known in the sewage industry as “biosolids.” Humanure is made from pure human excrement. It can still contain residues from pharmaceuticals that pass through our bodies, but it lacks the industrial chemicals or other contaminants that make sludge so controversial.
Biosolids, on the other hand, can count as ingredients everything that’s dumped into our sewer system, including a mixture of domestic and industrial waste that can include heavy metals, toxic chemicals, and thousands of other pollutants—and its long-term effects on soil are impossible to predict. The main ingredient of biosolids and humanure—feces—might be the same, but when it comes to their potential to contaminate soil, the two materials are fundamentally different.
Read More – The Guardian