indigenous system of productive urban waste water

INDIGENOUS SYSTEM OF PRODUCTIVE URBAN WASTE WATER TREATMENT IN

SMALL COMMUNITIES Asian Experience

By

Prof Santosh K GhoshPresident

Centre for Built Environment25 Sarat Bose Road, Kolkata – 700 020, India

E-mail : (sghoshcbe@rediffmail.com)

SMALLWAT ’07 CONFERENCE11 – 15 November, 2007

Sevilla, Spain

INTRODUCITON

The 21st 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.

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.

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.

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.

BENGAL DELTA IS THE LARGEST IN THE BENGAL DELTA IS THE LARGEST IN THE WORLD. THERE ARE MANY WETLANDS OF WORLD. THERE ARE MANY WETLANDS OF MANY KINDS, CREATED DUE TOMANY KINDS, CREATED DUE TO

(1) Heavy Rainfall and Low lands(1) Heavy Rainfall and Low lands

(2) Shifting of rivers(2) Shifting of rivers

(3) Water bodies left in between (3) Water bodies left in between

unsustainable unsustainable urbanisationurbanisation

KOLKATA IN INDIA IS A MEGACITY BUT MOSTLY KOLKATA IN INDIA IS A MEGACITY BUT MOSTLY OF IT WAS BUILT ON MARSHY, LOWLAND, OF IT WAS BUILT ON MARSHY, LOWLAND, WETLAND FUNCTIONSWETLAND FUNCTIONS

(a) Drainage outfall/water storage basins(a) Drainage outfall/water storage basins

(b) Aquaculture with fishery(b) Aquaculture with fishery--food, employment etc. food, employment etc.

(c) Recycling of waste water and use in agriculture(c) Recycling of waste water and use in agriculture

(d) Creating a buffer (green and blue) between (d) Creating a buffer (green and blue) between urban and rural areaurban and rural area

(e) Improvement of environment with oxygen(e) Improvement of environment with oxygen

(f) Biotic environment for flora and fauna (f) Biotic environment for flora and fauna

CONTROL AND REGULATION OF WETLAND CONTROL AND REGULATION OF WETLAND ARE REQUIREDARE REQUIRED

* Enhance, create or restore wildlife and fishes* Enhance, create or restore wildlife and fishes

* Protect water quality* Protect water quality

* Provide flood protection* Provide flood protection

* Stabilize shorelines* Stabilize shorelines

* Facilitate ground water recharge* Facilitate ground water recharge

* Maintain flow* Maintain flow

* Protect socio* Protect socio--economic value, recreation etc. economic value, recreation etc.

Resources – Water, raw materials, etc.

Solid & liquid waste

Utilization of resources

Treatment of waste

THERE ARE SEVERAL NECESSARY THERE ARE SEVERAL NECESSARY CONTROLSCONTROLS

(a) Weeds and plants (a) Weeds and plants (b) Harmful Algae (b) Harmful Algae (c) Biological control (c) Biological control (d) Wastewater treatment (d) Wastewater treatment (e) Shoreline protection, sediment control (e) Shoreline protection, sediment control (f) Vegetation control in the surrounding (f) Vegetation control in the surrounding

Wetland Restoration is a multi disciplinary Wetland Restoration is a multi disciplinary operation operation

THE OPERATION AND MAINTENANCE (O&M) THE OPERATION AND MAINTENANCE (O&M) MODULE OF INTEGRATED WETLAND PROJECTSMODULE OF INTEGRATED WETLAND PROJECTS(1) Maintenance of the levels of water in (1) Maintenance of the levels of water in

pretreatment and recycling pondspretreatment and recycling ponds(2) Wastewater pressure mains(2) Wastewater pressure mains(3) Release of system effluent(3) Release of system effluent(4) Appropriate harvesting schedule for recycling (4) Appropriate harvesting schedule for recycling

ponds ponds (5) Maintenance of structures, equipment's etc.(5) Maintenance of structures, equipment's etc.(6) Periodic (6) Periodic desilting desilting of pond bedsof pond beds(7) Maintenance of conditions of peripheral drains(7) Maintenance of conditions of peripheral drains(8) Maintenance of dykes(8) Maintenance of dykes(9) Evaluation and monitoring of ecosystem(9) Evaluation and monitoring of ecosystem(10) Reducing risk(10) Reducing risk

USAID, 1995 USAID, 1995

Drainage pumping station

Waste water ponds for growing finger linses and for irrigation

Solidwaste Agriculture

Waste water fish ponds

First user RegionWaste waterFish ponds

Second user Region

Third user Region Paddy fieldsEffluent irrigated

CASE STUDIESCASE STUDIES

(A) EAST KOLKATA WETLANDS(A) EAST KOLKATA WETLANDS

East East Kolkata Kolkata has the largest recycling has the largest recycling district 254 ponds district 254 ponds -- 2500 ha indigenous 2500 ha indigenous system of producing fish with sewage fed system of producing fish with sewage fed waste water in photosynthesis process with waste water in photosynthesis process with phytoplankton. Waste water is also used phytoplankton. Waste water is also used with natural compost to produce with natural compost to produce vegetables. vegetables.

(B) MUDIALY WETLANDS ECOSYSTEM(B) MUDIALY WETLANDS ECOSYSTEM

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

(C) (C) TITAGARH BANDIPUR RESOURCE TITAGARH BANDIPUR RESOURCE RECOVERY PROJECTRECOVERY PROJECT

Community Based Wetland Ecosystem Community Based Wetland Ecosystem (CBWE) was introduced in 1995. A (CBWE) was introduced in 1995. A participatory project with municipality, participatory project with municipality, fishermen, farmers and others. Reuse of fishermen, farmers and others. Reuse of wastewater yields 3000 tons of vegetables wastewater yields 3000 tons of vegetables and fishes 7 tons / ha / year. and fishes 7 tons / ha / year.

Recognized as one of the best practices, in Recognized as one of the best practices, in eastern India in eastern India in IntigratedIntigrated Recycling and Recycling and Management of Solid and Liquid Waste in Management of Solid and Liquid Waste in Urban Agriculture and AquacultureUrban Agriculture and Aquaculture

The Community Based Wetland Ecosystem (CBWE)

Urban Agriculture Using Municipal Solid and Liquid Waste

MARKET

WASTE-WATERSLUDGEMANURE

RESOURCERECOVERY

WASTE GENERATED

FISH ANDVEGETABLES

FISH CULTURE

FOOD PREPARATION

FOR CONSUMPTION

LAND FARMING

INTEGRATED RESOURCE RECOVERY INTEGRATED RESOURCE RECOVERY PROJECT AT TITAGARH PROJECT AT TITAGARH –– BANDIPUR BANDIPUR AREAAREA

ResourceResource--Efficient Stabilization Efficient Stabilization Pond SystemPond System

• The ASTP located adjoining the crop-land in Titagarhwith 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.

WETLANDS LIVELIHOOD OPTIONSWETLANDS LIVELIHOOD OPTIONS

The wetlands with productive ecosystem The wetlands with productive ecosystem can provide food. There are more than 380 can provide food. There are more than 380 wetlands plants and 44 species for food wetlands plants and 44 species for food and vegetables and also for craftwork. and vegetables and also for craftwork.

INTEGRATED PLANNINGINTEGRATED PLANNING

Wetland should be part of overall water Wetland should be part of overall water resource planning within regional resource planning within regional eivnronmenteivnronment plan. Wetlands are to be plan. Wetlands are to be treated in the concepts of treated in the concepts of

Conservation;Conservation; Environment;Environment; DevelopmentDevelopment

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.

Thank YouThank You