Innovation of the Week: Providing an Agricultural Answer to Nature's Call

by: borderjumpers

Thu Mar 18, 2010 at 10:02:14 AM EDT

It’s hard to believe, but an estimated 2.6 billion people in the developing  world—nearly a third of the global population—still lack access to basic  sanitation services. This presents a significant hygiene risk, especially in  densely populated urban areas and slums where contaminated drinking water can  spread disease rapidly. Every year, some 1.5 million children die from diarrhea  caused by poor sanitation and hygiene.

It is in these crowded cities, too, that food security is weakened by the  lack of clean, nutrient-rich soil as well as growing space available for local  families.

But there is an inexpensive solution to both problems. A recent innovation,  called the Peepoo, is a  disposable bag that can be used once as a toilet and then buried in the ground.  Urea crystals in the bag kill off disease-producing pathogens and break down the  waste into fertilizer, simultaneously eliminating the sanitation risk and  providing a benefit for urban gardens. After successful test runs in Kenya and  India, the bags will be mass produced this summer and sold for U.S. 2–3 cents  each, making them more accessible to those who will benefit from them the  most.

In post-earthquake Haiti, where many poor and homeless residents are forced  to live in garbage heaps and to relieve themselves wherever they can find  privacy, SOIL/SOL, a  non-profit working to improve soil and convert waste into a resource, is  partnering with Oxfam GB to  build indoor dry toilets for 25 families as well as four public dry toilets. The  project will establish a waste composting site to convert dry waste into  fertilizer and nutrient-rich soil that can then be used to grow vegetables in  rooftop gardens and backyards.

In Malawi, Stacia and Kristof Nordin’s permaculture project (which Nourishing the Planet co-director  Danielle Nierenberg visited during her tour of Africa) uses a composting toilet to fertilize the crops. Although these units  can be expensive to purchase and install, one company, Rigel Technology,  manufactures a toilet that costs just US$30 and separates solid from fluid  waste, converting it into fertilizer. The Indian non-profit Sulabh  International also promotes community units that convert methane from waste into biogas  for cooking.

On a larger scale, wetlands outside of Calcutta, India, process some 600  million liters of raw sewage delivered from the city every day in 300  fish-producing ponds. These wetlands produce 13,000 tons of fish annually for  consumption by the city’s 12 million inhabitants. They also serve as an  environmentally sound waste  treatment center, with hyacinths, algal blooms, and fish disposing of the  waste, while also providing a home for migrating birds and an important source  of local food for the population of Calcutta. (See also “Fish Production Reaches a Record.”)

Aside from cost and installation, the main obstacles to using human waste to  fertilize crops are cultural and behavioral. UNICEF notes in an online case study  that a government-run program in India provided 33 families in the village of  Bahtarai with latrines near their houses. But the majority of villagers still  preferred to use the fields as toilets, as they were accustomed to doing their  whole lives. “It is not enough just to construct the toilets,” said Gaurav  Dwivedi, Collector and Bilaspur District Magistrate. “We have to change the  thinking of people so that they are amenable to using the toilets.”