Chemical, physical and microbiological analyses of different drinking water sources among diverse governorates in Lebanon

Multiple sources of drinking water are commonly used in Lebanon, including bottled water, tap water, potable water, spring, artesian wells and station filtered water. The quality of these waters is of great concern, as its contamination could lead to waterborne outbreaks. We aimed to investigate the quality of drinking water in Lebanon, considering different sources and geographic distributions, and to compare their profiles across diverse governorates. A total of 200 samples (133 potable water, 28 station filtered water, 18 tap water, 8 spring water, 7 artesian well water and 6 bottled water) from five Lebanese governorates (Nabatieh, Beqaa, Mount Lebanon, Baalbek-Hermel and South Lebanon) were analyzed for physico-chemical and bacterial properties. The results indicated elevated phosphate concentrations in all areas (> 1.35 mg/L). Additionally, all analyzed bacteria were present in all regions, highlighting the lack of contamination-free sources. While in Baalbek-Hermel, followed by Nabatieh, exhibited the highest chemical levels, microbiological contamination particularly total and fecal coliforms, was consistent across governorates, showing no significant difference (p > 0.05). However, the distribution of Streptococcus and Pseudomonas Aeruginosa varied significantly among the different zones (p < 0.001 and p < 0.01, respectively). All drinking water sources in various Lebanese governorates were found to be contaminated with multiple contaminants. Based on these findings, the sources used for drinking in Lebanon are not entirely safe and require monitoring.