The Impacts of Dumpsite and Domestic Waste Leachate on Groundwater Quality within Kilifi Town in Kilifi County, Kenya

Abstract

The day today demands for water mainly for domestic uses have exceeded the supply from waterworks which has resulted into extensive exploitation of groundwater in Kilifi town and its environs. Groundwater refers to water which originates from the infiltration and percolation of fluids through the soil profile and accumulates below the earth's surface in a porous layer. While this alternative source of water is currently widely used, it is however vulnerable to pollution. Over the coastal region, the sources of groundwater mainly the wells have been shallowly dug making them highly vulnerable to pollution particularly from pit latrines, septic tanks and dumpsites. In this study, the levels of pollutants from groundwater within Kilifi town will be investigated and the results will be compared to the guidelines provided by the World Health Organization (WHO) and Kenya Bureau of Standards (KEBS). The main objective will be to determine the pollution status of groundwater existing near dump site and pit latrines within Kilifi town. To achieve this objective, the specific objectives w111establish: (1) the levels of pollutants as compared to guidelines provided by WHO and KEBS, (2) the effects of seasons on groundwater pollution and (3) the correlation between the levels of pollutants and the distances from the dumpsite and pit latrines. Measurements of Pb, Cd, Mn, Mg, Zn, T-N, Coli.forms, pH, temperature and electrical conductivities w111be used to collect the data. The study area w111be divided into: the central business district, the low population density and high population density residential areas. The area has ten wells that do not dry up during the dry season. The ten wells will be sampled during dry and wet seasons. Each well will be sampled three times and the mean values w111 used in the analyses. The wells are evenly distributed within the study area and the be results will provide a true reflection of the groundwater quality within Kilifi town. The dry and wet seasons sampling w111help to establish the effects of seasonal variation on groundwater pollution. Water samples w111be collected from each well on the same day using labeled sterilized water samplers. The samples will be kept in a cool box which will be used to transport them to the laboratory for safe custody under refrigerated conditions (+4oC) to avoid sample deterioration. Insitu measurements for temperature, electrical conductivity and pH, will be done by dipping respective meter probes into freshly collected water samples from the sampling wells. The trace metals, Pb Cd, Zn, Mg, and Mn will be analyzed using atomic absorption spectrophotometer (AAS) Buck Scientific-Zl O VGP (air-acetylene flame). The analysis of the Coli forms, Sulphates and total nitrogen, will be done in accordance with the standard methods for analysis of water and waste water. Descriptive statistics w111be used to analyze the data by comparing the mean measurements of the pollutants in each well with the WHO and KEBS guidelines while correlation analysis w111be done with the help of Matlab software and the results presented in tables and graphs for interpretation. The findings are expected to help in improving ways of waste handling and disposal to abate groundwater pollution in order to protect the future health of users.