Physico-chemical quality of drinking water of Mpohor, Mpohor-Fiase District of the Western Region, Ghana

Physico-chemical quality of drinking water from Mpohor was conducted between January 2012 to September 2012. The study was to ascertain the concentration of the water quality parameters were within the WHO specification. The drinking water sources were analysed to assess the differences that existed between them, storage tank water and its supply lines and to assure of the quality of the water for drinking. Ten (10) sampling sites made up of four (4) boreholes, four (4) hand dug wells and two (2) points on the town distribution network were selected for the study. The parameters included physical (pH, Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Electrical Coductivity (E.C.), Colour and Turbidity) , chemical ( Total Alkalinity, Total Hardness, Nitrate, Nitrite, Phosphate, Sulphate, Fluoride, Calcium, Magnesium and Chloride) and trace metals Manganese (Mn), Iron (Fe), Arsenic (As) and Lead (Pb). A total of 50 samples were collected during the study duration made of one (1) sample from every site per sampling cycle. Significant statistical differences were found between concentration values for borehole and hand dug well sources for calcium, iron, sulphate, chloride, nitrate, total alkalinity, hardness, pH, total dissolved solids and electrical conductivity. Results showed hand dug well (HDW) sources (pH range 5.38 to 5.65) were slightly acidic compared to borehole water sources (pH range 6.45 to 6.67). Iron concentration values for borehole water (Fe range 0.17 to 0.58 mg/L) were relatively high compared to HDW sources (Fe range 0.05 to 0.18 mg/L). The iron values reflected in the high turbidity (ranging from 2.8 to 9.5 mg/L) and colour (1.25 to 25 mg/L) values for borehole water whereas HDW sources recorded minimal values for the two parameters with results ranging from 1.8 to 4.4 mg/L and 0 to 8.75 mg/L respectively. Borehole water also showed to be fresher than well water sources indicated by low conductivity (range 235 to 289 μS/cm) and TDS (range 128 to 154 mg/L) concentrations whereas HDW sources recorded 276 to 339 μS/cm and 151 to 175 mg/L respectively. Results for total hardness and alkalinity iv for borehole ranged from 87 to 103 mg/L and 90 to 105 mg/L respectively whereas that for HDW ranged between 59 to 68 mg/L and 24 to 40 mg/L respectively. Hand dug well sources were relatively softer suggesting lower buffering characteristics exhibited by their low alkalinity. Variations between the means of concentration values for magnesium, manganese, fluoride, phosphates, nitrite, total suspended solids, turbidity and colour for the borehole and HDW sources were found to be statistically insignificant. Results for fluorine ranged from 0 to 0.24 mg/L for HDW sources whilst that for borehole ranged from 0 to 0.12 mg/L. Results recorded for manganese for borehole sources ranged from 0.03 to 0.14 mg/L and HDW sources ranged from 0.02 to 0.08 mg/L for the parameter. Analytical results showed distribution water had improved concentration values chiefly low iron and several other parameters due to settling of the particles in the overhead storage tanks. The overhead tank thus needs to be washed on regular schedule, at least every 3 months. Based on the research findings, the drinking water sources in the Mpohor township have safe levels of physic-chemical water quality parameters and are thus safe for human consumption.

Source: KNUST