BioCycle October 2013, Vol. 54, No. 10, p. 43
I am currently at the annual World Toilet Organization meeting in Solo, Indonesia. The opening ceremony featured lovely dancers, catchy slogans and really depressing facts. I bet you didn’t know for example that Ghandi (not clear if it was father or daughter here) said, “Sanitation is more important than freedom.” Or that squatting is healthier than sitting, or that access to indoor toilets is increasingly requested by brides before agreeing to arranged marriages. And if you are looking for an alternative investment for your retirement portfolio, each $1 invested in sanitation brings you a $5 return. Or that lack of sanitation for 2.5 billion of the world’s population costs $260 billion dollars annually and is responsible for 443 million school days lost annually.
The big challenge here is how to bring clearly needed sanitation to one-third of the world’s population. Listening to the speakers, depending on which slide and whose talk, could lead you to believe that Indonesia, home to 240 million people is well on track to meeting its sanitation needs. Close to 60 percent of the nations’ urban dwellers have access to sanitation. And the goal of establishing ODF — open defecation free — zones is on track as well with about 58 million still resorting to this practice.
But the devil is in the details. Of those 60 or 70 percent in urban areas that have access to toilets, the vast majority of those toilets (> 95%) go directly into semi leaching septic tanks that are rarely pumped. When they are pumped, the contents typically go to illegal dump sites, including open water bodies. For the small minority who are connected to sewer systems, only 10 percent of the existing wastewater treatment plants function properly. Across much of the developing world, western style treatment works are sitting idle and unused. This is a result of many factors including a lack of trained operators and the expenses associated with operating and maintaining these high tech and high-energy consuming systems.
More Cell Phones Than Toilets
How do you fix this? The traditional approach of developed nations and many multinational relief agencies has been to try to replicate centralized collection and treatment systems. That is the equivalent of meeting the communication needs of Indonesia by installing landlines. But while cell phones and solar panels are replacing the need for a grid in these nations, what alternatives are there to a grid system when you are talking about materials like solid and liquid waste rather than light waves and electrons? There are currently more cell phones in the world than toilets. And while I love my smart phone, I would clearly choose sanitation over texting.
What are the options? A recent study (Dodane et al., 2012) found the cost of traditional treatment (parallel sewer with activated sludge) to be 40 times more expensive than an alternative kind of centralized system: fecal sludge to on-site septic tanks with collection and transport to drying beds. This analysis did not consider the availability of water to transport wastes or availability of energy for pumping and digestion. That would have made the cost difference even more dramatic. This type of alternative centralized collection would save water and energy. Low tech options like drying beds rather than aeration tanks would be easier to operate. Sufficient retention time coupled with adequate drying have the potential for high pathogen destruction as well.
Clearly septic systems with decentralized collection and transport are preferable options. But if this is the route to go, how do you enforce a regulatory structure to make sure those tanks are emptied in controlled facilities rather than local streams? In addition, where does the capital come from to replace the leaky tanks with impermeable ones? And what do you do with the houses, like so many here in urban Indonesia, that have installed the tanks under tile floors with no means of access to pump?
The alternative to centralized collection is some type of on-site treatment. Many options have been proposed at the World Toilet meeting, ranging from high tech, high price tag units to traditional composting toilets. Problems with high tech systems include unrealistic costs plus a need for expertise to operate. If centralized treatment facilities are laying idle, imagine the potential for malfunction with individual units. Community facilities are also discussed as potential solutions. Not surprising as use of these facilities is a function of proximity to them. Think of how you feel when you wake up in the middle of the night and face the battle of the warm bed versus the full bladder. Tack onto that debate a distance of a quarter of a mile versus down the hall.
Composting toilets can be a good option, but here adequate retention time is a concern, as is the yuck factor. Those same smart phones that have enabled sophisticated communications networks to be established have also resulted in a cultural distaste for having to see one’s waste. My husband is a popular guy at this meeting. He has developed a composting toilet with a pseudo flush and an auger system that gives the feel of a water-based system with a built in level of treatment with every flush (the “flush” actually turns the auger). His project is funded by the Gates Foundation and will be tested in Ecuador.
It is fabulous that the Gates Foundation and other organizations are recognizing the importance of sanitation in global and environmental health. Remember here that the Gates Foundation has the funding to do this work because Bill dropped out of Harvard and brought us Microsoft. Microsoft, smart phones and the Internet are all things that were unimaginable 40 years ago. Now we need to imagine an alternative to centralized water-based collection and treatment systems to meet the sanitation needs of so many people. And while you are thinking about this, realize that the solutions you come up with may be important right here at home. Our own wastewater systems are getting old, tired and leaky and it is doubtful that we will have the funding, political will, excess water and energy to replicate them.
Sally Brown — Research Associate Professor at the University of Washington in Seattle — authors this regular column. Email Dr. Brown at firstname.lastname@example.org.
Dodane, P-H, M. Mbéguéré, O. Sow and L. Strande. 2012. Capital and operating costs of full-scale fecal sludge management and wastewater treatment systems, in Dakar, Senegal. Environ. Sci. Tech., 46:3705-3711.