ASSESSMENT OF POTENTIALLY TOXIC ELEMENTS IN HAND DUG WELLS AND BOREHOLE WATER IN IKOLE-EKITI AND ITS ENVIRONS, EKITI STATE, NIGERIA.

ABSTRACT

Water is an important resource for almost all human activities like agriculture, industry, transportation, domestic uses and the proper functioning of the human body, The study examined the physiochemical properties and potentially toxic metals in hand-dug wells and boreholes in Ikole Ekiti and its Environs. Six functional hand-dug wells and six boreholes in the area were sampled and analyzed using standard procedures. Potential toxic metals were determined using Atomic Absorption Spectrometer. From the result. it was deduced that the odour, colour and turbidity of the samples were all within the WHO (2008) acceptable permissible limit.

All the other chemical parameters were within the WHO permissible limit in most of the locations except fur Total hardness (TDS) that ranged from 530-680 mg/L in three hand-dug wells and boreholes which exceeded limits. Similarly. Total Hardness in three of the hand-dug and borehole wells exceeded WHO limits including Calcium concentration in the water.

Some of the potentially heavy metals analysed (Cr. Mn, Cd and Fe) in well and borehole water were below the WHO standard Iimits in some locations and but Manganese concentrations in two borehole samples and three hand-dug well samples exceeded the WHO limit. Chromium in Udo-Oro borehole at 0.24 mg/L Using hand-dug well at 0.462 mg/L greatly exceeded WHO0limit of 0.05 mg/L

The generally low level of heavy metal content in the water samples in both hand-dug wells/boreholes showed they me less polluted and as such suitable for human consumption. In order to maintain the present quality status of wells and boreholes in the area, routine monitoring and assessment of boreholes by well owner or authorized agencies is recommended. Also, proper education on environmental requirements of citing well is essential for private well diggers for the purpose of preventing contamination from dung hill, underground tanks etc.