I confess, my husband and I both pee in our backyard garden, waiting until nightfall so as not to surprise neighbors.
We’ve always been comfortable relieving ourselves alongside lonely highways, even in daylight when waiting for the next bathroom seems unreasonable. But peeing in our own garden started as something of a lark, a combo of enjoying feeling a little naughty while also stealing a moment to take in the stillness of the night.
However, after a little research into the contents of urine and the ecological footprint of toilet flushing, I’m approaching my nightly garden visitations with a renewed sense of purpose, armed with sound reasons to continue the habit.
#1. Urine is a good fertilizer, organic and free
Contrary to popular belief, urine is usually germ-free unless contaminated with feces. It’s also about 95 percent water. The chief dissolved nutrient is urea, a nitrogen (N)-rich waste metabolite of the liver. Consequently, urine is high in N. Synthesized urea, identical to urea in urine, is also the number one ingredient of manufactured urea fertilizers which now dominate farming industry. Furthermore, urine contains lower amounts of the other two main macronutrients needed for healthy plant growth, phosphorous (P) and potassium (K).
Poor soil conditions and the prohibitive cost of manufactured fertilizers in third world countries have inspired rigorous study of urine fertilizer as a sustainable strategy to reduce poverty and malnutrition and promote worldwide food security. As example, in an in-depth 2010 practical guide for using urine as crop fertilizer, an international research institute (Stockholm Research Institute) writes that, “Nitrogen, phosphorus, potassium and sulphur as well as micronutrients are all found in urine in plant available forms. Urine is a well balanced nitrogen rich fertilizer which can replace and normally gives the same yields as chemical fertilizer in crop production.”
Depending on water intake, humans produce roughly 1-2 liters of urine a day. With proper planning, the urine from person during one year could suffice to fertilize “300-400 m2 of crop,” according to the Stockholm Environment Institute.
Urine as crop fertilizer is not just a theoretical concept, but has been put into practice successfully all over the world, including Africa, northern Europe, India, Central America, and even the United States. In fact, if you live near Brattleboro, Vermont, you can contact the Rich Earth Institute to participate as a “urine donor” in the first field studies of urine as fertilizer in the United States.
Obviously, there are important guidelines and safety procedures for farms and entire communities that rely on urine fertilizer for crop production – like special two-compartment toilets designed to collect urine free of fecal contamination – which are unnecessary for someone like me who pees directly in the garden and with more casual purpose in mind. Guidelines that do apply to everyone, however, include applying the urine to soil rather than foliage and mixing the urine in right away.
#2. Combat drought
Regions in all five continents are in the grip of sustained droughts. One-third of the contiguous United States was experiencing moderate to exceptional drought as of the end of August, according to the U.S. Drought Monitor. My home state of California is suffering record-breaking drought with no end in sight. Governor Brown recently called on Californians to reduce their water consumption by 20 percent, and peeing in the garden gives me a good head-start to meeting that goal.
On average, Americans each use 80-100 gallons of water per day, according to the U.S.Environmental Protection Agency. Seventy percent of a household’s water consumption is typically for indoor uses, with toilet flushing the biggest water hog.
Although newer toilets generally use 1.6 gallons per flush, older ones use at least three gallons. So someone flushing urine 6 to 8 times per day could easily save 10 to 24 gallons of water daily by diverting all their urine to the yard. But, even if collecting urine in the daytime is out of the question – say, if you work outside the home or simply consider peeing into a receptacle and ferrying it to the yard a deal-breaker – the water savings by just peeing in the yard twice a night could easily amount to an annual water savings of between 1000 and 2000 gallons per person.
#3. Slow groundwater depletion
Based on satellite data, NASA recently released an alarming report describing dramatic groundwater depletion in the Colorado River Basin in under a decade. The Colorado River Basin is considered the water lifeline of the western United States. NASA calculated the water loss at 53 million acre feet, nearly twice the volume of freshwater in Nevada’s Lake Mead. The real shocker is that groundwater loss accounted for three-fourths of the depletion, and no one knows how much groundwater is left or when it could run out.
In California, a third of the state’s water supply comes from regional groundwater. Rapidly dwindling groundwater levels, due to unregulated well drilling and extraction, is threatening the availability of water for agriculture and even human consumption, finally prompting California to enact a package of critical groundwater protections in Sept.
Individuals can do their part too, by peeing in the yard or, at least, adhering to the adage I grew up with, “If it’s yellow, it’s mellow, if it’s brown, flush it down.” If each of California’s 12.5 million households flushed just four fewer times daily, the drain on the state’s groundwater would be lessened by 25-50 million gallons annually.
#4. Bypass sewage treatment plants
Though the pathogens (germs) in household wastewater come primarily from feces, many pharmaceuticals and chemicals in personal care products (PPCPs) areexcreted in the urine, producing global pollution of natural bodies of water and even drinking water because sewage treatment systems are not designed to eliminate such substances.
Everything flushed down the toilet is piped to either onsite septic tanks or more often to municipal treatment plants where the liquid undergoes a two-step process, first separation from the bulk solids through settling and then incubation with bacteria to digest disease-causing pathogens and produce an effluent safer for return to the natural environment. The treated effluent from septic tanks is allowed to seep on-site into the ground, whereas treatment plants typically release directly into rivers, lakes and oceans.
Depending on regional policies, the effluent might also undergo so-called tertiarytreatment involving chemical purification and/or microfiltration before release. Water shortages are increasingly driving reuse of tertiary-treated wastewater for landscaping, recharging groundwater aquifers and even for crop irrigation, prompting closer scrutiny of the water’s purity. However, even tertiary treatment is not generally designed to remove PPCPs.
Happily, soil generally does a good job of trapping and eliminating many pollutants, offering an alternative to conventional wastewater treatment of urine. When a liquid is doused onto soil, pollutants adhere to soil particles then undergo biodegradation by the abundant fungal and bacterial flora in soil. Sunlight and the rich oxygen content of soil also foster degradation. In fact, the filtration and incubation steps in conventional wastewater treatment mimic these naturally occurring processes in soil.
In the last decade, researchers have been measuring how fast common PPCPS biodegrade in soils and typically find half-lives on the order of days or weeks.
So letting soil decontaminate your urine seems a sound idea. A word of caution is in order, however, for those of us in more developed countries where our urine is more likely contaminated with PPCPs. A recent study reported solid evidence that irrigating the soil of common field vegetables with tertiary-treated water produced low levels of PPCPs in the edible portion of the vegetables. Until we know whether such residues represent any health risk, it seems wise to deposit urine outside the home vegetable garden.
#5. Reconnect with nature
The simple act of returning my urine directly to the soil, whilst attending to the sights, sounds and smells of the night, has heightened my awareness of my place in nature. It’s also confronted me with a glaring reality, that every man-made environmental ill threatening all life forms, everything from global climate change to the buildup of PPCPs and plastic waste in bodies of water and industrial chemicals in human and animal tissues, stems from an ill-conceived notion that humans are somehow exempt from the laws of nature.
Obviously, spotty progress can be made here and there applying new technologies or policies to address focused environmental issues. For example, California just became the first to institute a state-wide ban on single-use plastic bags. Though I’ve welcomed this legislation, I also see how limited the impact will be on the global environment: Since the dawn of the “age of plastics” in the 1950s, non-biodegradable plastics have come to pervade nearly every aspect of daily life in westernized societies, and the steep rise globally in the production of consumer plastics is projected to continue unabated into the future.
Peeing in my garden has instilled in me a sobering certitude that solving the planet’s looming environmental crises will require something far more fundamental and all-encompassing than regional policy changes. A global paradigm shift is needed, both away from believing we can unthinkingly manipulate and destroy natural resources and toward humbling seeking and embracing our natural and sustainable place within this unspeakably beautiful garden that is planet earth.
Though peeing in the garden is now a habit with me, it still feels a little risqué, and I like that.