The impacts of anthropogenic activities on groundwater contamination in Sabha City, Libya

Abstract

Groundwater is the primary source of freshwater supply in Libya. Hence a decrease in this water resource will reduce the ability to maintain quality, especially when there are multiple sources of pollution. This study aims identify the anthropogenic impacts on groundwater quality in the city of Sabha, which is in the southwestern part of Libya also to investigate and analyse factors causing groundwater contamination, impacting the quality of groundwater for human consumption, to analyse the spatial distribution of groundwater contamination and to establish the statistical relationship that exist between the water quality parameters. Thirty - six water samples were collected and analyzed in the laboratory for pH, Total dissolved solids (TDS), Magnesium (Mg++), Sodium (Na), Potassium (K), Chlorides (CI), Total hardness as Ca, CO3, (TH), Nitrate (NO3), Sulphate (SO4), Calcium (Ca++), Phosphate (Po4), Iron (Fe), Bicarbonate (HCO3) and E. coli. In addition to this, a structured questionnaire was designed and administered to respondents to collect data on their perception of groundwater pollution in the area. The results showed that the sewage overflow, waste accumulation, pesticides, and fertilizer were the major sources of groundwater pollution based on the results of the analysis, where 67 % (n=151) of the population confirmed that there was an overflow of sewage, and 87% (n = 151) have noticed waste accumulation. TDS, TH, CI, Na+, K+, NO3, SO4-, Ca++, Po, Fe, and E. coli concentrations exceeded the permissible level in several samples. GIS zoning maps of groundwater quality parameters indicated that most of the high values of parameters are concentrated in the northern, north-western, and southwest parts of the study area, where there is an increase in population density and urban development. Based on the water quality index, the study found that the areas WQI water quality index is not suitable for consumption, it does not have class A (Absolutely clean) water, might cause serious health concerns as cancer. For the relationship between the water quality parameters MLR showed that WQI was found to be inversely correlated with most of the water quality parameters. A synergy between the Libyan government and farmers is recommended to solve the groundwater pollution problem in Libya.