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Lozano, Sacha

Rubenstein School of Environment and Natural Resources

2007

MS

Global water depletion and unsustainable food production systems represent two iconic crises of our time. These two crises have important themes in common, referring to basic human needs and the way we interact with landscapes in order to satisfy them. But they are also closely related to the way we produce and dispose wastes in our current societal organization. Insufficient, or inadequate, sanitation and waste management practices continue to undermine not only human well-being, but the entire planet's ecological integrity, on which humans depend. An ecological design approach to manage human waste invites to learn how to participate more harmoniously within the planet's recycling of matter, using renewable energy sources and mimicking nature's low entropic states to maintain the life-support systems that we and our economies are part of. This thesis is an in-depth exploration of such an approach, and an attempt to integrate several elements from ecology, engineering, economics, and community development, around issues of water quality, sanitation and waste management in Latin America. As a whole, the thesis explores how can this transdisciplinary approach translate into coherent, feasible, and concrete action, providing appropriate solutions for sanitation, in ways that are effective and viable on a long term, for Latin American rural communities.
Three different papers address different dimensions of the problem, focusing on domestic wastewater and human excreta, as a type of waste of major importance to ecological integrity, public health and economic development. Two of the papers are case studies, carried out at two different rural communities in South West Colombia; one of them focuses on technological and ecological aspects, and the other focuses on social and economic considerations, for a multifunctional-ecological waste management. In the first paper I present an overview of the sanitation problem in Latin America, and the opportunities and challenges of managing waste with an ecological and multifunctional perspective. More specifically, this papers attempts to provide a sound conceptual framework for managing wastewater (sewage) as a valuable resource, in a way that: 1) is affordable -or even profitable- by small communities in developing countries; 2) is safe to the environment and to public health; and 3) provides opportunities for recycling nutrients and organic matter (available in wastewaters), to restore and protect water and soil resources, while enhancing rural livelihoods in tropical agroecosystems.
The second paper evaluates the performance and feasibility of an experimental, solar-energy-based, wetland mesocosm, as a complementary aerobic unit to enhance anaerobic wastewater treatment, in a rural locality of the Cauca Valley in Colombia. In the third paper I explore the integration between ecological design and community-based solutions to sanitation, and discuss opportunities and challenges of implementing ecological waste management in the particular bioregional and socioeconomic context of a proposed ecological-low-income co-housing project, in another rural community of Colombia. In doing this, several arguments are presented to support the idea that assuming the responsibility of managing its own waste can be a powerful and transformative experience for a community to fundamentally change its perspective and understanding of its place within the planet. Furthermore, managing waste can be an integrative force linking economic, social and environmental considerations, and favoring human-scale development, genuine progress, and self-reliance in a community. In its broadest level my research aims at reviewing and questioning the very notion of "waste" and the articulation between humans, nature, and technology within that context.