Sri Lanka: Tree roots planted to decontaminate hundreds of wells

22 Mar 2010

A girl drinking purified water in Kalpitiya.
(Photo: UNDP/CWI/SGP)

On the Kalpitiya Peninsula, located on Sri Lanka’s western coast, relatively large scale irrigated monoculture agriculture is practiced. The associated heavy use of fertilizers has led to the contamination of farm and domestic wells with nitrates, which poses the risk of methaemoglobinemia (blue baby syndrome) and other concerns.

Building on successful bioremediation of wells demonstrated by the Neo Synthesis Research Centre, which achieved significant improvement in water quality, UNDP’s Community Water Initiative extended the technology to 39 public and 13 private wells serving more than 10,000 people, including church, hospital and school wells. Furthermore, the wells at St. Anne’s Church in Talawila provide water to up to 1.5 million pilgrims and visitors who visit the ancient Christian shrine each year.

Bioremediation improves water quality through the removal of contaminants from water by plant roots and soil microorganisms. In the course of four years, water quality testing showed significant reductions in levels of nitrate, nitrites, and chloride. The improved land management techniques demonstrated around wells and in home gardens increased soil fertility, leading to increased harvests and better household nutrition. The project’s methodology has been applied in other regions, such as the tsunami-affected Kalmunai on the eastern coast of Sri Lanka, leading to the purifying of 1,000 wells.