INDIGENOUS SYSTEM OF PRODUCTIVE URBAN WASTE WATER TREATMENT IN SMALL COMMUNITIES Asian Experience. Prof Santosh K Ghosh

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1 INDIGENOUS SYSTEM OF PRODUCTIVE URBAN WASTE WATER TREATMENT IN SMALL COMMUNITIES Asian Experience By Prof Santosh K Ghosh President Centre for Built Environment 25 Sarat Bose Road, Kolkata , India (sghoshcbe@rediffmail.com) SMALLWAT 07 CONFERENCE November, 2007 Sevilla, Spain

2 INTRODUCITON The 21 st Century will be an urban century Asia will be a continent of megacities Rapid urbanisation, economic boom and changing life styles Unsustainable pattern of development with globalisation Ecological doom depletion of water resources, receding aquifer level, loss of waterbodies, forests and agricultural land. Increasing consumption of resources producing more solid and liquid waste and disposal is a problem. Wastewater treatment plants are expensive, and smaller municipalities do not have fund to construct or operate these. Waste must be regarded as a resource for sustainable development. Urban system is to become an ecological system in which waste and resource are the same in the same system.

3 The World Health Organisation and later the World Bank suggested reuse of wastewater for aqua-agriculture and guidelines are given. Many mechanised system has failed. Both construction and maintenance are costly. In many countries India, China, Vietnam, Bangladesh and others recycled waste water is in use for longtime in irrigation in vegetable production and for fish culture. Small municipalities and communities are adopting non-mechanised natural and indigenous treatment for waste water.

4 METHODS There are several methods of waste water treatment and reclamation : (1) Solid and liquid separation (Sedimentation, filtration) (2) Biological treatment (Aerobic treatment, Oxidation pond etc.) (3) Disinfection (Removal of pathogens) (4) Advanced treatment (Activated carbon, Ion exchange, chemical treatment, Membrane filtration) Advanced and Chemical treatment are expensive. Traditional indigenous system has been developed for a long time. Small communities of fishermen and farmers have considered waste water (sewage fed) as a resource for urban food production. They utilise wetland in the periphery of cities, and effluent from wastewater treatment plants, or sewage fed drainage systems.

5 The restoration process is by phytoremediation for use of plants removing pollutants and photosynthesis where sunlight is utilised for phytoplankton for algael growth and photosynthetic oxygen. Water Hyacinth (Eichhharia erassipes) and duckweed (sp. Lamnacea) are used to remove metals, pollutants etc. Both natural wetlands and constructed wetland are developed for recycling of waste water for aquaculture producing fish. United States Agency for International Development prepared a basic manual for poor countries. Kolkata has the largest recycling operation in indigenous system. Kolkata (Previously Calcutta) is a megacity located in Bengal delta.

6 BENGAL DELTA IS THE LARGEST IN THE WORLD. THERE ARE MANY WETLANDS OF MANY KINDS, CREATED DUE TO (1) Heavy Rainfall and Low lands (2) Shifting of rivers (3) Water bodies left in between unsustainable urbanisation

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8 KOLKATA IN INDIA IS A MEGACITY BUT MOSTLY OF IT WAS BUILT ON MARSHY, LOWLAND, WETLAND FUNCTIONS (a) Drainage outfall/water storage basins (b) Aquaculture with fishery-food, food, employment etc. (c) Recycling of waste water and use in agriculture (d) Creating a buffer (green and blue) between urban and rural area (e) Improvement of environment with oxygen (f) Biotic environment for flora and fauna

9 CONTROL AND REGULATION OF WETLAND ARE REQUIRED * Enhance, create or restore wildlife and fishes * Protect water quality * Provide flood protection * Stabilize shorelines * Facilitate ground water recharge * Maintain flow * Protect socio-economic value, recreation etc.

10 Utilization of resources Solid & liquid waste Resources Water, raw materials, etc. Treatment of waste

11 THERE ARE SEVERAL NECESSARY CONTROLS (a) Weeds and plants (b) Harmful Algae (c) Biological control (d) Wastewater treatment (e) Shoreline protection, sediment control (f) Vegetation control in the surrounding Wetland Restoration is a multi disciplinary operation

12 THE OPERATION AND MAINTENANCE (O&M) MODULE OF INTEGRATED WETLAND PROJECTS (1) Maintenance of the levels of water in pretreatment and recycling ponds (2) Wastewater pressure mains (3) Release of system effluent (4) Appropriate harvesting schedule for recycling ponds (5) Maintenance of structures, equipment's etc. (6) Periodic desilting of pond beds (7) Maintenance of conditions of peripheral drains (8) Maintenance of dykes (9) Evaluation and monitoring of ecosystem (10) Reducing risk USAID, 1995

13 Drainage pumping station First user Region Waste water Fish ponds Waste water ponds for growing finger linses and for irrigation Solidwaste Agriculture Waste water fish ponds Second user Region Third user Region Paddy fields Effluent irrigated

14 CASE STUDIES (A) EAST KOLKATA WETLANDS East Kolkata has the largest recycling district 254 ponds ha indigenous system of producing fish with sewage fed waste water in photosynthesis process with phytoplankton. Waste water is also used with natural compost to produce vegetables.

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17 (B) MUDIALY WETLANDS ECOSYSTEM A fishermen s cooperative society with 15 ponds and 50 ha area, 25 million litres of sewage fed waste water is treated. Now a nature park - an indigenous system of wetland management with multiple benefits to fishermen.

18 (C) TITAGARH BANDIPUR RESOURCE RECOVERY PROJECT Community Based Wetland Ecosystem (CBWE) was introduced in A participatory project with municipality, fishermen, farmers and others. Reuse of wastewater yields 3000 tons of vegetables and fishes 7 tons / ha / year.

19 The Community Based Wetland Ecosystem (CBWE) Recognized as one of the best practices, in eastern India in Intigrated Recycling and Management of Solid and Liquid Waste in Urban Agriculture and Aquaculture

20 Urban Agriculture Using Municipal Solid and Liquid Waste

21 INTEGRATED RESOURCE RECOVERY PROJECT AT TITAGARH BANDIPUR AREA FISH AND VEGETABLES LAND FARMING FISH CULTURE WASTE- WATER SLUDGE MANURE RESOURCE RECOVERY MARKET FOOD PREPARATION FOR CONSUMPTION WASTE GENERATED

22 Resource-Efficient Stabilization Pond System The ASTP located adjoining the crop-land in Titagarh with well-laid-out drainage system to individual plots. The pond-system is located in Bandipur comprises a number of natural ponds treating domestic and commercial waste-water.

23 WETLANDS LIVELIHOOD OPTIONS The wetlands with productive ecosystem can provide food. There are more than 380 wetlands plants and 44 species for food and vegetables and also for craftwork. INTEGRATED PLANNING Wetland should be part of overall water resource planning within regional eivnronment plan. Wetlands are to be treated in the concepts of Conservation; Environment; Development

24 CONCLUSION Recycling of wastewater for aquaculture by small communities has many benefits It provides employment to the poor It provides nutrition with fish and vegetables It enhances environment as more oxygen is produced It provides green and blue and a buffer between urban and rural areas. It creates biotic environment for flora and fauna. It is less expensive with participatory management. Urban and periurban agri-aquaculture is helping green cities for sustainable development. Many cities have incorporated this in future landuse planning. However there are health related aspects and environmental risks and widescale acceptance should be in the framework of regional environmental plan.

25 Thank You