Research carried out by Prof. Sarath Bandara, Professor of Agriculture at the University of Peradeniya, has revealed that the waters of River Mahaweli is contaminated with Cadmium from upstream down. Cadmium is a heavy metal that has been incriminated in the development of Renal Failure in humans and animals. It is also strongly suspected as the causative agent of the Chronic Kidney Disease (CKD) epidemic that has affected various parts of the North-Central Province. Already hundreds have died and thousands more have been diseased from this illness.

Prof. Bandara’s team has collected water samples from over twenty tributaries that feed into the River Mahaweli from Talawakele up to Welimanda and Bandarawela, along its course. These include Watahena oya, Maldeniya oya, Pundalu oya, Huna oya, Pinga oya, Hulu ganga, Gal mal oya, Makandura oya, Talathu oya, Ma oya, Uma oya, Bandulu oya, Belihul oya and Mala oya. Further samples were obtained from Rantambe, Randenigala and Polgolla reservoirs and from the River Mahaweli adjacent to the townships of Peradeniya, Gampola, Kandy, Bandarawela, Welimada and Nuwara Eliya.

Graphite Furnace Atomic Absorption Spectrophotometry (AAS) facility at the Kelaniya University has been used for the analysis of water samples. Further confirmations of the results have been obtained from Adelaide University Australia and Kasetgrat University in Bangkok.

According to Prof. Bandara, in areas where the land use is predominately rice and vegetables, the Cadmium content of water ranged from 12.25 to 20.30 parts per billion (ppb). However, in areas where there were tea estates this was 3.7-9.0 ppb. While the paddy and vegetable cultivators used the imported chemical fertilizer rich in Triple Super Phosphate (TSP), tea plantations used Eppawala Rock Phosphate, which has less phosphate content, thus accounting for the differences in contamination levels. The permissible level of Cadmium in drinking water stands at 5 ppb.