According to the most recent UN estimates, 2.5 billion people across the globe lack access to improved sanitation while 1.2 billion of these people still practice “open defecation.” The lack of infrastructure to collect, treat and dispose of human waste exposes billions of people to grave health and safety risks and is extremely harmful to the environment and fresh water supply in many developing nations. The UN cites access to sanitation right alongside access to safe drinking water in its Millennium Development Goals.
Closer to home, a proposed partnership between the King County Wastewater Treatment Division and The Freehold Group would establish a district energy system in the Interbay neighborhood powered by sewage heat recovery. The basic concept is that heat from the sewage pipe running under Interbay to the West Point Sewage Treatment plant will be captured and used to fuel the energy needs of the buildings connected to the district energy system. Projects in Norway, Japan and the False Creek Olympic Village in Vancouver have already proven that recovering heat from untreated sewage is a viable, renewable source of energy.
This technology provides a fantastic opportunity in the developing world for connected (to district energy systems) sewage infrastructure to leapfrog disconnected sewage infrastructure in much the same way as mobile phones became the dominant technology among millions of people who never had landlines. Infrastructure needs to be built to provide improved sanitation for billions of people living in the developing world, so why not built sewage infrastructure connected to district energy systems to provide renewable energy at the same time? Of course, finding the capital to fund these projects will remain a challenge and at the current rate the UN goals for sanitation will not be met in the desired time frame. However, wrapping greenhouse gas reductions into sanitation projects can only make such projects more attractive to international sources of development capital.