Human excreta are evolutionarily wired to feed plants. Our sanitation engineering  legacy has rid our cities of pestilence but divorced us from our intrinsic regenerative potential. Ecological sanitation reunites us with this plant-animal relationship, in a hygienic manner.

While living in Mexico I had the opportunity to work with agronomist Francisco Arroyo. Francisco had dedicated his life to the reuse of human urine in agriculture. Through him I met and was exposed to the work of some of the leading practitioners of eco-san, Peter Morgan, Cesar Añorve and Ron Sawyer. 

My work in Eco-san has focused on prototyping simple to operate, ergonomic and automated nutrient cycling systems. 

I never thought I could love a fly, but the rarely seen purple and blue iridescent wing flutter of the black soldier fly is a joy to behold. The fact that they dislike being around humans and the fondness of their larvae for organic waste, including feces, make them an excellent candidate for eco-san systems.  The larvae are mostly fat and protein so they are great as a feed for fish or chickens. The biopod, the black digester bin, features a ramp that the larvae climb when ready to emerge from their pupal state. The outlet to this ramp can drop directly into an aquaponics fishtank, as this installation exhibits, or can drop into a chicken run. In this system I can go "omelette to omelette" in four days. Funded by City of Oakland Arts Commision and sponsored by California College of Art, Festival of Water organized by Lauren Elder and Christina Bertea.

Peepeeponics - Waterless urinal, carbon loaded digestor with mustard greens, self-watering. Berkeley, California

Urine, a.k.a. yellow gold, is a blessing to plants nutritional requirements. Chock full of nitrogen, potassium, phosphorous, water and trace minerals, one would be hard pressed to manufacture a better plant food. I have been developing ergonomic systems for optimizing this wonderful cycle. I call this peepeeponics, named after my teacher Francisco Arroyo's spanish moniker pipiponico. 

Biobog with urine greywater fertigation - Swedish urine diverting dual flush toilet flushes fecal material to vermicomposter, which discharges solubilized worm castings to zero discharge biobog. Urine is mixed with greywater from bath in dosing siphon which fertigates branched drain bamboo hedge. Oakland, California.

I have always admired the Swedes daring in pioneering modern ecological sanitation. So when the Swedish blooded doctor of public health, Heather Kuiper contracted me to design a whole house sanitation system for her family I was honored. I specified and installed what I believe was the first urine diverting flush composting toilet in California. The urine was diverted into a dipper box where it mixed with greywater and was delivered to a branched drain bamboo irrigation system. The fecal flush is deposited into a worm bin. Worms eat their weight in food a day, so we created enough habitat to process all their excreta daily. Research has shown that a worms gut has a tremendous capacity for disabling fecal pathogens.  Leachate, which at this point carried mostly solubilized  worm castings, is pumped to a zero discharge lined wetland garden, a.k.a. "the biobog." We installed a three way diverter valve on the whole system so in the event of a massive rainstorm or maintenance we could send flushwater back into the sewer. 

Treatment wetland with integrated primary digester. High Prairie, Washington

Wetlands are natures liver. They are unparalleled in their efficacy in purifying water. Vigorous aquatic plant roots pump atmospheric oxygen into the rhizosphere and promote complex microbial ecosystems that perform the bulk of the purification work. Industrial sewage treatment relies heavily on chemical and mechanical means and are nowhere near as beautiful to be near. This subsurface flow constructed wetland features an internal digester for processing solids. It is built at an artists retreat in Klickitat County, Washington. 

Agronutrifier - Flush toilet discharges to Watson Wick style tropical food forest. Banana, sugarcane, papaya, etc. Kona, Hawaii

Humans acting as keystone species for complex forest ecosystems is a fascinating and ancient process. Agroforestry, popularly known as food forestry, is experiencing a hearty revival and Craig Elevitch has been researching and publishing about tropical agroforestry for decades. I was honored when he invited me to design a system for his research institute in Kona, Hawaii. Most septic leach down into the volcanic soils, a good way to get it out of sight, but really a nutrient pollution time bomb if you think about it. We challenged ourselves by building a "gley" liner through the anaerobic fermentation of banana leaves. We then installed a digestor into the gleyed basin backfilled with compost rich soil and planted sugarcane, jackfruit, papaya, bananas, mango and other fruit trees. We call it the agronutrifier.

Flush toilet to Wetland biofilter. Cityslicker Farms, Oakland, California

There is a liquor store on every other corner, but try and find some healthy vegetables and you have to drive somewhere else. Welcome to West Oakland. These "food deserts" gave rise to a movement of urban farmers. Cityslicker Farms was one such oasis that I lived and gardened. During my stay I built this flush composting toilet-wetland to address some of the sanitation issues we were facing. 

Organoponic Dry Compost Toilet - Urine separating toilet diverts urine to lined carbon wicking garden and 30 gallon fly-proof chamber is swapped out and allowed to mature before reuse.

Merritt College's Permaculture gardens is a feast for the senses. I co-taught the natural building class with Marisha Farnsworth and Kevin Rowell and we focused on building out sustainable infrastructure for this visionary program. Above is the split bamboo and urbanite compost toilet system we built on the hillside above the kitchen garden.