Investigation of Some Pollution Indices of Underground Water Reservoirs in Ekpoma, Esan West Local Government Area of Edo State, Nigeria

The availability of good quality water is an indispensable feature for preventing diseases, improving quality of life as well as the health of the ecosystem. The water quality index (WQI) of five underground reservoirs located in different areas of Ekpoma, was determined by measuring a number of parameters including temperature, pH, total dissolved and suspended solids, total hardness, total alkalinity, total acidity, sulphates, chlorides, dissolved oxygen and biochemical oxygen demands using standard analytical methods. The quality of water did not vary considerably in the studied areas. The temperature ranged from a minimum of 26oC to a maximum of 27oC, the pH ranged from 7.80 to 8.30, total dissolved solids ranged from 224.0mg/L to 289.3mg/L, total suspended solids, from 418mg/L to 434mg/L, hardness, from 922.5mg/L to a maximum of 1045.0mg/L. Total alkalinity ranged from 85mg/L to 90mg/L, total acidity, from 23mg/L to 28mg/L, sulphates from 29.46mg/L to 43.31mg/L, chlorides from 22.53mg/L to 40.04mg/L. The value of dissolved oxygen did not change significantly as it ranged from 7.6mg/L to 7.7mg/L and biochemical oxygen demand from 92mg/L to 100mg/L. The analytical data of the various physicochemical parameters indicated that most of the parameters were within the World Health Organization prescribed limits except for the values of total solids and hardness which possibly could have resulted from the type of roof channeling such water and the cement for making such reservoir, respectively. The overall WQI indicated that these waters are quite fit for drinking purpose. They could however be improved by filtration.