You Can Compost Human Waste!

More and more people are discovering the water- and money-saving benefits of fertilizing their gardens with human waste. It’s not just for homesteaders anymore!

Human Waste

Nance Klehm demonstrates that human waste can be composted and used to safely fertilize soil. 


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Oceans of sewage. Tapped-out water sources. Ever-costlier fertilizers. A flurry of recent studies warn of resource scarcity for the world’s cities. Fortunately, a growing legion of urban dwellers think the nutrients and water in their toilets are too valuable to flush away. From Boston to San Francisco, city dwellers are taking the “waste” out of wastewater, and showing that recycling at the toilet isn’t just for homesteaders anymore.

Don’t Waste Your ‘Waste’

Although his Boston apartment has a comfortable modern bathroom, Patrick Keaney usually trudges down two flights of stairs to use a waterless, urine-diverting composting toilet.

Keaney and his housemate, David Staunton, constructed the simple toilet system after learning that most of the nutrients in human excrement — as much as 90 percent of the nitrogen and half of the phosphorus — are in urine alone. The two saw an opportunity to capture free fertilizer and cut their water bill.

Knowing their landlord wouldn’t allow plumbing changes, Keaney and Staunton installed their toilet in the basement next to the warmth of the water heater. The toilet consists of a wooden bench with an opening to which a plastic diverter is affixed (you can also use a trimmed funnel) to drain urine into a 3-gallon pail. Solids (feces, toilet paper and any wood shavings or mulch added) drop to an 18-gallon plastic bin. When the bin fills up, they cap it with a perforated lid, let it season for a year, then shovel its contents into a composter. “We use it to build up the soil around fruit trees and flower beds,” Keaney says. As for the urine, it’s composted with woody material or poured onto well-mulched and well-watered garden beds.

Is using urine this way safe? Most pathogens we excrete are in feces. Urine is almost always pathogen free. Any trace pathogens get deactivated as the urine ages. Some experts say one month of aging is sufficient for a household’s urine used on its own garden, while six months is advised for urine from combined sources. If applying directly to plants, you must dilute it with eight parts water to one part urine to avoid burning plant roots (some sources recommend 20 parts to one).

The Great Giveback

Chicago landscaper, ecologist and urban poo-pioneer Nance Klehm took waste recycling to the community scale with her “Humble Pile” project: For three months, 22 participants pooped into 5-gallon buckets instead of their toilets and brought them to Klehm to be emptied into aerated 32-gallon garbage cans in an undisclosed location. After 11 months, the 50 garbage cans were dumped into one large pile. After another year of composting with only comfrey and some old straw, Klehm delivered a fluffy compost — that tested negative for fecal bacteria — in 2-pound bags printed with “The Great Giveback.”

“It got people thinking more consciously about their personal connection to land, the cycle of food, water use, municipal water treatment and human health,” Klehm says.

It Pays to Pee-Cycle

In Oakland, Calif., Heather Kuiper and Lauren Rauch look out over a verdant backyard fertilized with urine combined with graywater from laundry and bathing. Their “EcoFlush” Swedish urine-diverting toilet features a urine drain in the front of the bowl, through which urine and flush water drain to a graywater system that irrigates their landscape. Everything else flushes to the city’s treatment plant. A switch allows Kuiper and Rauch to divert the graywater-urine mix to the city sewer on rainy days.

And near San Francisco, Anna Zander collects her urine in discarded plastic bottles. One bottle, cut in half, acts as a funnel that fits into the mouth of a larger bottle. A wine cork serves as a stopper to contain odor. She pours her urine into her composter, which is full of brown leaves that need moisture and nitrogen to break down quickly. Other days, she pours it directly onto her vegetable garden, usually followed by a bucket of water collected from her tub.

To learn more about recycling human excrement, check out The Humanure Handbook and Liquid Gold: The Lore & Logic of Using Urine to Grow Plants.

11/23/2016 5:12:18 PM

I have not used or flushed my WC for over six years. That is since making a very simple compost toilet that I use for all my solid waste (shit). The toilet is idiotically simple, just a 5 gallon lidded bucket set in a commode like box in my shower room. I also keep a small bucket of sawdust in this commode too that I to cover the faeces with when I've deposited them. This stops smells and dries them out and adds extra carbon for the compost. when the bucket is more or less full I spread the contents on my compost heap and cover them with a thick layer of vegetable waste and let the whole lot decompose for at least a year. The compost I produce and the crops I get from my vegetable plot are sufficient testimony for me .l I also collect all my urine and use this diluted 20 to 1 to feed most of my fruit and veg. This is easy to collect (for a man), I use one litre yoghurt tubs. These are like small buckets with seal-able lids, so are perfect as they are easy to pee into, easy to transport and contain any odours. Urine is a wonder fertiliser and I can't produce enough in the growing season. Slightly different in the winter, but I still collect it all and add it to my compost heaps. I am also experimenting with adding it to the ash from my wood burner. I understand this makes a good fertiliser. Be glad to know if anyone knows more about the chemistry of this.

10/19/2015 10:45:10 PM

hallo from australia--i am making a compost toilet using farm pods --i have 3 acres in tropics any suggestions ? i like the simplicity of containment of the poo and composting the shit out of pathogens

craig hassler
3/12/2013 8:47:21 PM

Bravo, Mother Earth News for this article! I've been using compost from my 5 gallon composting toilet for the last year to condition raised, square-foot beds that I'm developing around my house. Also used compost from my simple composting toilet last summer to crreate flower beds while I was occupying a city-owned warehouse in Harrisburg. I had bicycled from Morehead City, NC to Harrisburg, PA on a one-speed bicycle starting at the beginning of "Bicycle to Work Week" and took two weeks, camping in random places along the way, to get there. Then worked for Harrisburg Bike Taxi and helped out at various gardens there including Joshua's Farm a CSA, the Catholic Workers' gardens, gardens being developed at the former William Penn High School (my Mom graduated from there in 1939), Reservoir Park, and Harrisburg Boys and Girls Club with Rafiqya Muhammed and some wonderful folks from Harrisburg Unitarian Church. They all thought I was crazy, like so many others, when I talked about how safe and easy it is to use human compost. I simply add leaves or pine needles to the "toilet" after using it. Then, when the bucket gets filled (about 7 days for one person) I take it out to a developing raised bed. Dig down about 6 to 8 inches and then dump the contents in. Usually within 2 weeks, when I dig up the bed, wonderful earth worms are happily wriggling about. Regarding the comment about concern due to toxins in foods and prescription drugs, I don't use prescription drugs. Thankfully, I don't have health insurance. Likewise I'm eating low on the food chain lots of beans, rice, and wonderful veggies growing around the house in raised beds, watered with grey water from sinks and tubs. I just plug em up and then scoop the grey water into buckets and then water. Now I use rainwater caught in the cistern to make my home-brewed beers. I also have rainbarrels that I use to soak bottles in to remove labels to use for my home-brewed beers and aluminum cans before I cut and flatten them to make them into shingles that I'm using to shingle a shed in the backyard with. I shingled the inside of a bathroom with aluminum shingles. It's fun! Also taking over all the yard with a mulch created by putting down card or paper board and junk mail, minus tape and plastic labels, then covered with a layers of grass clippings, pine needles, and oak leaves whenever I find them out on the street.

maxie coale
4/20/2011 8:38:13 AM

Great example of recycling. It makes sense, we use animal poop to fertilize soil so why shouldn't our waste be able to do so. If this become large scale though, I wonder where the facility will be placed and whether there will be people opposed to living near it. I imagine the smell coming from the facility will be unpleasant. Here's another cool use of poop:

3/22/2011 11:33:45 PM

I have a major concern with the using of human waste as fertilizer; the problem is that, as humans, we eat so much processed food that our waste often contains large amounts of toxins and heavy metals. Also, any medications we take which aren't fully utilized by the body, are passed through and end up in our waste. Simply "seasoning" the waste for a year or so won't get rid of the dangerous substances in it; that's why there are water treatment facilities. Ask yourself sometime why many people won't use genetically modified grains as feed for cattle or chickens; perhaps it's because they don't want the contamination in the animal waste to be spread on their gardens. Now look at the food labels from the grocery store; what's on the label will end up in your poo, and potentially in your garden.

3/15/2011 7:45:30 PM

Two corrections about The Great Giveback project: the participants were given back roughly 20# of composted human waste in handsewn bads, not 2#. the photo of the bags in the gallery reflects this. As well, Klehm actually did all the pick up of waste and delivery of toilets, sawdust and new containers throughout the project. If participants had to do it themselves, they might not have been motivated.