the average person flushes 2920 gallons of water per year for urine disposal. (conservatively calculated for a 1.6 gallon high efficiency toilet with five urine flushings per day)
the main ingredients of urine are: water, urea, creatinine, uric acid, salt, ammonia, plus many other trace elements and hormones. the average person produces 1.5 liters of urine per day.
urine contains large quantities of nitrogen (mostly as urea), as well as significant quantities of dissolved phosphates and potassium, the main macronutrients required by plants. in other words it is a concentrated fertilizer. the urea is also rich in hydrogen which can be economically harvested as a fuel source.
why are we flushing valuable chemicals away for waste treatment?
ancient cultures drank urine for religious and unproven medicinal benefits. modern astronauts can now recycle their urine by filtering it in a forward osmosis bag. the simple bag produces a sugary drink that is similar to gatorade®. unfortunately, gatorade® tastes far worse than urine. it may be possible to create a more palatable product by using natural yeasts to turn the sugar into alcohol. if the process is perfected, it could yield a delicious wine.
the most compelling reason for winemaking is that we must give the customer a reason to conserve. water is relatively cheap in most places. only a fraction of a cent per gallon. so the inconvenience and expense of processing urine has got to be outweighed by value added. in contrast to water, even the cheapest wine will cost $15 per gallon. if we can produce enjoyable wine then this gives us a healthy working budget to justify the inconvenience of not flushing the urine. and if the wine is not up to standards, then it can be burned as ethanol fuel, still recouping the invested cost of urine processing supplies. pricing ethanol at $3 per gallon, we can justifiably buy $36 worth of supplies per month and still break even. that at least covers the sucrose which is our only major consumable in the process at $3 per gallon in bulk. even in the worst case, the winemaker breaks even and touched a little urine to save his local fellow citizens some money in wastewater treatment costs, and of course saving 243 gallons of fresh water that month which would otherwise have been flushed.
someday when diverting urine from the municipal waste water is more common, there will be incentives given back to the customer. but meanwhile our best hope is for the customer to produce 12 gallons of free wine per month as a personal reward. like any wine it needs to be casked and aged to develop flavour. but an experienced wine master will know it is a potential award winner from doing periodic barrique tastings.
so to save 2920 gallons of water per person per year, we also need to make urine drinking more trendy and fashionable. we should invite people to urine tastings and educate them on the proper way to swirl the glass and make social conversation about colour and bouquet. for example: clear, dark straw colour, with a rush of tiny bubbles that ring the glass when poured. a refreshing prickly mouthfeel. notes of asparagus which lead into a crisp ammonia flavour that follows the nose, slight sweetness well cloaked by earthy acidity. long complex finish. pairs well with sausage or clam.
the building of the future should feature ways to store urine both for drinking and for chemical harvesting. urine is best kept in a cold environment with low light. this protects the delicate flavours and ensures maximum enjoyment. filtered remnants should be processed onsite to enrich the landscape and also provide a free local fuel source.
to summarize: each person saves 2920 gallons of water ,and creates 145 gallons of sugary electrolytic sports drink per year. the filtrates are used as fertilizer and fuel. the sports drink can be drunk or reprocessed into an alcoholic fuel or beverage. the 145 gallons of urine not sent to municipal waste treatment saves the community money. the natural production of fertilizer offsets world manufacturing of petroleum based fertilizers.