Chronic Kidney Disease of unknown aetiology (CKDu) is one of the major health issues in Northern part of Sri Lanka that recorded highest mortality and morbidity rates. The main responsible reason for the CKDu has not yet been identified and hence many scientists have suggested number of certain risk factors where the CKDu-mfo (CKDu multi-factorial origin) term derived. However it relates with certain drinking water quality parameters strongly. This study was focused on evaluating the drinking water quality of Ulagalla cascade in Anuradhapura district with admiration to CKDu. Thirty wells and twenty tanks were selected as sampling locations for groundwater (GW) and surface water (SW) respectively from the cascade. Water quality parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, Sodium (Na +), Magnesium (Mg 2+), Calcium (Ca 2+), Potassium (K +), Arsenic (As 2+), Lead (Pb 2+), Cadmium (Cd 2+), Ammonium Nitrogen (NH4 +-N), Nitrate Nitrogen (NO3-N), alkalinity, Sulphate (SO4 2-, Chloride (Cl-) and Phosphate (PO4 3-) were analysed and observed parameters were compared with drinking water quality standards. In GW turbidity, Mg, Cland Cd were not significantly different from the maximum permissible level (p>0.05) while SW has shown significant difference only for the turbidity (p>0.05). Both well and tank water samples from Thodamaduwa were polluted by Cd which exceeded the maximum permissible level standards. It was recorded as averages of 0.15, 0.13 and 0.019 ppb for 3 identified polluted wells in GW and 0.01ppb in tank water. Accordingly the study it can be suggested that cumulative levels of heavy metals (such as Cd) may be aggravating the CKDu in the Northern Central Parts in Sri Lanka.

Irrigated agriculture is the highest water user in Sri Lanka. Therefore, when there is an increasing demand of other sectors such as drinking, industries, environment etc., it is required to reallocate water from the irrigated agriculture sector to meet this increased demand. However, this needs to be done while ensuring the food security of the nation using the virtual water concept, which is defined as the embedded water in a product. Therefore, this study is conducted with the objective of assessing the, i) virtual water of agricultural production, ii) virtual water of food imports and exports, iii) virtual water trade and iv) water footprint of the nation. The data on crop water requirements, extent cultivated, imported, and exported agricultural products were collected from secondary sources and the analysis was made according to the globally accepted methodology. The annual virtual water value of domestic production is found to be 8.13 Gm 3 of which paddy contributes 54.7%. The average virtual water value of paddy in Maha season is less than that in the Yala season whilst the virtual water value of paddy in minor schemes are higher than that in the major schemes in both seasons implying that more water is required to produce 1kg of paddy in minor schemes. The net import of Virtual water is 3.8 Gm 3 per year. The water footprint of Sri Lanka is 12.0 Gm 3 per year with a per capita water footprint of 535.22 m 3 per year. The water required for domestic production is about 15.8% of the surface runoff of the country indicating the possibility of meeting the food demand with the available water resources.