| Title: | A systematic approach to derive natural background levels in groundwater: Application to an aquifer in North Lebanon perturbed by various pollution sources |
| Author(s): | Khadra WM; Elias AR; Majdalani MA; |
| Address: | "American University of Beirut, Department of Geology, P.O. Box 11-0236, 1107 2020 Riad El-Solh, Beirut, Lebanon; Bureau Technique pour le Developpement, 70492 Antelias, Jal El Dib, Lebanon. Electronic address: wk20@aub.edu.lb. Lebanese University, Faculty of Engineering, Branch 1, Ras Maska, Tripoli, Lebanon; Bureau Technique pour le Developpement, 70492 Antelias, Jal El Dib, Lebanon. Bureau Technique pour le Developpement, 70492 Antelias, Jal El Dib, Lebanon" |
| DOI: | 10.1016/j.scitotenv.2022.157586 |
| ISSN/ISBN: | 1879-1026 (Electronic) 0048-9697 (Linking) |
| Abstract: | "Several efforts have recently emerged to develop methods capable of determining groundwater natural background levels (NBLs) due to their utmost importance in assessing water quality. A recently developed systematic approach to derive NBLs is the Khadra-Stuyfzand (KS) scheme. It has a clear and standardized flow with multi-steps to eliminate biased or contaminated samples, and hence it is capable of dealing with different pollution sources as well as saltwater intrusion. This method was applied to the Koura-Tripoli-Zgharta (KTZ) Miocene aquifer of coastal North Lebanon. It derived baseline conditions for 2 physical, 16 chemical, and 3 bacteriological parameters in addition to 8 trace elements, and 83 pesticides, polynuclear aromatic hydrocarbons, and volatile organic compounds. The results revealed the extent of anthropogenic shift from background levels, and delineated the main contaminated spots. In fact, the established groundwater baseline composition is typical of limestone aquifers with oligohaline-fresh, moderate alkalinity, calcium bicarbonate water, under freshening conditions. Nonetheless, this quality is locally degraded by microbial contamination due to wastewater disposal sites, saltwater intrusion, and minor nutrient loading from agricultural activities and/or urban development. The measured concentrations of major water ions and a variety of drinking water contaminants (e.g. nutrients, pesticides, hydrocarbons, and heavy metals) are below human health benchmarks, but the microbiological content at several spots has exceeded the permissible limits which renders the water unsuitable for domestic use, and calls for prompt mitigation measures" |
| Keywords: | "Calcium Carbonate *Drinking Water Environmental Monitoring *Groundwater/chemistry Humans Lebanon *Metals, Heavy/analysis *Pesticides *Polycyclic Aromatic Hydrocarbons *Trace Elements *Volatile Organic Compounds Wastewater *Water Pollutants, Chemical/analy;" |
| Notes: | "MedlineKhadra, Wisam M Elias, Ata R Majdalani, Michel A eng Netherlands 2022/07/27 Sci Total Environ. 2022 Nov 15; 847:157586. doi: 10.1016/j.scitotenv.2022.157586. Epub 2022 Jul 24" |
