Quality Assessment of Underground Water before and afterTreatment: A Case Study of Tobruk City, Libya

The present study was carried out to assess the quality of various wells for drinking purposes and with regard to their current state of repair. Ten wells (W1, W2, W3, W4, W5, W6, W7, W8, W9 and W10) were selected in the study area. This study was designed to determine the physico-chemical and bacteriological quality of wells water before and after water treatment in east Libya, specifically in Tobruk. The bacterial load (E. Coli) of the water samples was determined using standard microbiological methods. Physicochemical properties including pH, total dissolved solids (TDS), electrical conductivity, and Na⁺, K⁺, Ca²⁺, Cl⁻, NaCl concentrations and total alkalinity were determined. The values obtained were compared with the World Health Organization (WHO) standards for drinking water. The results showed that E. Coli bacteria were present in some wells prior to treatment, but were E. Coli-free post-treatment. Furthermore, the physico-chemical parameters of the water samples were generally greater the limits recommended by the WHO with particularly high values seen in well W10, prior to treatment. However, only a few of the bacteriological and physicochemical parameters of the water samples remained above the tolerable limits recommended by the WHO (WHO, 2011) post-treatment. This suggests that regular monitoring and purification of boreholes to ensure good water quality is vital to maintaining the required health standards.