Community-managed sewage treatment systems in rural Gujarat do a good job

Published on: 26/07/2011

Community-managed sewage treatment systems do a good job and have as added bonus that they also encourage local people in rural areas to build their own toilets. What is more, local farmers can re-use the treated effluent which brings them money as well as promotes sustainable agriculture, preserves scarce water resources, and maintains environmental quality.

The Decentralized Wastewater Treatment System (DEWATS) usually functions without technical energy inputs, requires few operation and maintenance skills, can be constructed from locally available materials and installed by the local workforce. Appropriate combinations of treatment modules such as anaerobic baffled reactor, anaerobic filter, planted gravel filter and polishing tank can be selected depending on the required treatment efficiency, costs, land availability, and so on.

Five treatment systems studied

An evaluation of DEWATS installed with the support of the Water and Sanitation Management Organization, a facilitating organization established by the Government of Gujarat, in three villages in Kutch and two in Surendranagar in Gujarat, India was conducted from February to May 2011. The study analyzed performance of five treatment systems. It also examined community perceptions of the benefits of the waste water treatment system and of the impacts of the sewerage system on people’s health, the local environment, and social well being.

The study included assessment of significant parameters like pH, Total Suspended Solids, Chemical Oxygen Demand, Biological Oxygen Demand, Ammonium and fecal coli-form in laboratory. For social survey 54 households were interviewed using semi-structured questionnaire. Further, focus group discussion with water supply committee and women groups, key informant interviews with public health workers and medical officers and other resource persons associated with the functioning of the system was conducted in respective villages.

Key findings from the study

Key findings from the study include:

•  Assessment of the pH, Total Suspended Solids, Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Ammonium and fecal coli-form show that the five DEWATS studied are functioning well and meeting the discharge limit set by the Central Pollution Control Board for Irrigation. However, the BOD value for one village did not meet the discharge to inland surface water limit.
• DEWATS with an average daily flow of 100,000 litres a day leads to a 69% reduction in total suspended solids, a 90% reduction in biological oxygen demand, and a 45% reduction in chemical oxygen demand per year.
• The medical costs of 1,000-3,000 rupees per incidence of a disease can be saved with access to safe drinking water and adequate sanitation with waste water treatment system
• Re-using treated waste water for irrigation is economically attractive because it boosts agricultural production in water-scarce areas. In Anandpar village, the treated water is used to produce castor, cotton, and maize on ten acres of land. In 2010, one farmer earned 250,000 rupees selling his cotton and castor and in Pantiya village a farmer earned 200,000 rupees selling groundnuts. 
• Installing sewerage systems and DEWATS has encouraged households to construct toilets: in Jepar 50 households (or 60%) built a toilet and in Nanamatra 100 (or 30%) built toilets in their homes.
• Pani Samiti – the local water supply committee and villagers were empowered to plan, approve, implement, operate and maintain the scheme themselves. This capacity enables rural communities to manage their facilities themselves.

Lessons learnt

Lessons from the study include:

• A decentralized approach is effective in serving peri-urban and rural areas without a centralized wastewater collection system.
• Only when people perceive the need for and want a wastewater re-use system at the community/user level, will implementation be successfully executed.
• The selected technology must be cost-effective, simple to operate, and must use local labour. It is also important that it has minimal energy input and can be maintained by the local community to reduce the risk of malfunction.
• DEWATS technologies are the best choice available where skilled and responsible operation and maintenance cannot be guaranteed.

Recommendations to Pani Samiti water committee

 A few recommendations emerged also for the Pani Samiti, the local water committee including:

•  Regular cleaning and monitoring of different components of DEWATS will sustain the system and keep it in working order.

• Assess significant parameters such as BOD and COD of treated waste water to ensure that discharge standards are met.

Bimala Khana (IDS Nepal, member of RCN Nepal), story written from a study she did at WASMO, India, as part of a nine-month PSO/IRC Youth Zone young professionals exchange programme.