Friday, August 6, 2010

PS 112-150: Community based rural wastewater management using constructed wetlands

Deblina Dwivedi, National Institute of Ecology

Background/Question/Methods

In developing countries like India, wastewater collection and treatment systems are totally non-existent in the rural areas. The domestic wastewater flows in open drains to end up in ponds within the human habitation, and thereby causes health hazards and other nuisance. Besides their high costs for construction and maintenance and high energy requirement, the conventional sewage treatment facilities are also not suitable for small volumes that vary greatly diurnally and seasonally.

The natural systems for wastewater treatment offer a viable option in rural areas. They rely on the major contributions made by the soil, vegetation and microorganisms. Aquatic plant-based systems, though land-intensive, avoid in a greater part, the use of energy, materials and chemicals, and typically require very low costs for operation and maintenance. Further, they have a potential for sustaining livelihoods, poverty alleviation, improving water quality, and enhancing the aesthetics of rural landscape.

Results/Conclusions

Such a sustainable wastewater treatment system has been set up for domestic wastewater in a village near Kurukshetra (northwest semi-arid India). The system is comprised of a septic tank for pretreatment and a subsurface vertical upflow Typha angustata-based wetland. The system is highly effective in removing pollutants such as suspended particulates, ammonia-nitrogen, BOD, COD and pathogens. The treatment plant has the capacity to treat 4m3 of wastewater per day. The system has been developed with active interest and participation of the local community in its construction and O&M.  

The paper presents some initial results of the wetland-based treatment system and shows that the local community’s participation can contribute to solving the problems of wastewater and help improve water quality and aesthetics at a low-cost in the rural areas.