Environment & Poverty Times
07 2012
Water pollution and sanitation
Water pollution and sanitation have huge repercussions both for local ecosystems and humans. The sources of pollution are many, and the cost of cleaning contaminated water can be high and energy intensive. We feature possible solutions, opportunities and creative action.
Ecological sanitation By Ryuichi Fukuhara
Wastewater management has received increasing attention in recent years, as the global water crisis concerns not only the quantity but also the quality of available freshwater. Rising water demand for urban- ization and food production is resulting in unregulated and illegal discharge of untreat- ed wastewater to the environment, which contaminates freshwater resources. In Asia there is growing concern that inappropri- ate wastewater management will hamper sustainable socio-economic development.
Promising decentralized solutions Remarkable progress in sanitation has been made in big cities over the past decades. However, this development is still not keeping pace with the needs and impacts of an ever- increasing urban population. It is estimated that 84-89 per cent of wastewater is discharged untreated, reaching freshwater and coastal water areas. The negative economic impacts of lack of sanitation cost several percentage points of national GDP in some Asian countries.
The demonstration of ecological sanitation and other decentralized sanitation projects in the Philippines, funded by the Korean International Cooperation Agency, addresses wastewater management issues by adopting small-scale environmentally sound technolo- gies at a local community level on a pilot basis. Unlike Asian megacities, where sanitation coverage is relatively good, most peri-urban and rural areas lack appropriate wastewater management. Centralized treatment systems require a dense population to be cost-effective and are not realistic solutions for these areas. Alternative solutions are needed. Decentral- ized wastewater treatment systems (DEWATS) and ecological sanitation (Ecosan) have been identified as promising options to balance socio-economic development and provision of basic services for less privileged communities.
Integrated approaches DEWATS and Ecosan are approaches to sani- tation rather than just technical hardware package. DEWATS is based on a combina- tion of treatment options such as a biogas digester, an anaerobic baffled reactor (see figure), an anaerobic filter and a planted gravel filter. These components are selected on the basis of their reliability, longevity and tolerance of inflow fluctuations. Most importantly, these treatment principles dispense with the need for sophisticated
Fifty households from five local communities in La Union Province took part in demon- stration of an ecological sanitation system. A urine-diverting dehydration toilet was installed in each home. Ryuichi Fukuhara
control, maintenance and technical energy inputs. Ecosan is based on the systematic reuse and recycling of water and nutrients as a hygienically safe, closed-loop and ho- listic alternative to conventional sanitation solutions. Ecosan systems enable nutrients to be recovered from urine and faeces for
To promote sustainable sanitation, the project addressed urine reuse for pilot cultivation in local farms. Ryuichi Fukuhara
agriculture, thus preserving soil fertility, assuring food security, minimizing water pollution and use of synthetic fertilisers, and sometimes recovering bio-energy.
The UNEP International Environmental Technology Centre (UNEP-IETC) in Osaka, Japan implemented the project in collabora- tion with the Centre for Advanced Philip- pines Studies (CAPS). Fifty households from five local communities in La Union Province took part in a demonstration of ecological sanitation. A urine diverting dehydration toilet (UDDT, see figure) was installed in each household, and the local community mem- bers received the instructions on UDDT op- eration and maintenance as well as potential reuse of diverted urine in their gardens. The project also mobilised financial and other substantial contributions from the Bauang Municipality and other partners to install a community-based decentralized wastewater treatment system. To promote sustainable sanitation, the project also looked at the question of urine reuse for pilot cultivation projects in local farms. These components were supplemented by an awareness raising campaign among toilet users, local farmers and government officials through commu- nity meetings and training workshops.
DEWATS is based on a combination of treatment principles such as a biogas di- gester, an anaerobic baffled reactor, an anaerobic filter, and a planted gravel filter.
Success through cooperation The project owes its success to the active par- ticipation and involvement of stakeholders. Thanks to the longstanding efforts of people at the Bauang Municipality, the town is now recognized as a model for decentralized wastewater treatment systems and ecological sanitation and receives many visitors, includ- ing some from abroad. This recognition encourages users, farmers, local communi- ties and government staff to further improve the performance of existing facilities and promote their achievements. This virtuous cycle boosts the sustainability of activities. UNEP-IETC will analyse and systemize this best practice for further implementation of similar activities.
Acknowledgements: The author would like to express his sincere appreciation to Mr Danilo Lapid, Head of CAPS, and his colleagues as well as to Martin de Guzman III, Mayor of Bauang Mu- nicipality, his staff and local community members for their work in implementing this project. The author is grateful for the generous contribution by KOICA, which enabled UNEP-IETC and CAPS to implement the project.
A urine-diverting dehydration toilet.
About the author: Ryuichi Fukuhara is Pro- gramme Officer at UNEP’s International Envi- ronmental Technology Centre (IETC).
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