GEOSPATIAL ASSESSMENT OF GROUNDWATER QUALITY IN THE SAVELUGU-NANTON MUNICIPALITY, NORTHERN GHANA.

Abstract

Water from beneath the earth’s surface has been exploited for domestic use, livestock, irrigation and even in some areas for commercial and industrial use. Water quality is affected by a combination of natural processes, most of which relates to chemical compositions underground and human activities. The quality of some sources of groundwater had been found to be unacceptable for domestic use, with negative health implications due to either natural and/or anthropogenic factors that have the potential to adversely affect the health of consumers. There is therefore the need for groundwater quality assessment from groundwater sample results in areas where boreholes exist using geostatistics in order to be able to predict the concentrations of areas where there are no boreholes. The study aimed at using groundwater sample results from areas where boreholes exist in the Savelugu-Nanton Municipality to assess groundwater quality by producing maps of chemical parameters for groundwater quality of the entire municipality using geostatistics. The secondary data used for the study had one hundred and sixty-eight (168) borehole sample results in the SaveluguNanton Municipality, Ghana and were obtained from the Community Water and Sanitation Agency (C.W.S.A.). Chemical parameters (sodium, calcium, potassium, fluoride, chloride, nitrates and Sulphates) were mapped using indicator kriging in Geographic Information Systems (GIS). The standards by the World Health Organisation the Ghana Standards Authority were the primary thresholds for the indicator kriging geostatistical analysis. The study showed that Sodium and Fluoride concentration values were mostly above the drinking water standards, with a few values falling below the standard limits. Calcium, Chloride, Fluoride and Sodium concentration values were highest in the southeastern parts of the Municipality, with their concentrations decreasing towards the central and western portions of the study area.