Water quality assessment of the upper Euphrates River basin using NSF and CCME indices in western Iraq

Many developing countries with river systems face persistent challenges related to water pollution, complicating efforts to meet safe drinking water standards. This study evaluates the water quality of the Euphrates River along the Anbar Governorate using two widely recognized models, including NSF Water Quality Index (NSF-WQI) and CCME Water Quality Index (CCME-WQI) developed by the Canadian Council of Ministers of the Environment. Seven monitoring sites were selected along the upper Euphrates basin, from Al-Qaim to Fallujah. Seventeen key parameters were analyzed, including physicochemical and biological indicators. Both indices produced similar classifications at upstream locations (Al-Qaim, Al-Haditha, and Al-Baghdadi), indicating marginal water quality, which reflects limited suitability for direct human use without treatment. CCME-WQI values were consistently lower than NSF-WQI results, indicating a more stringent assessment approach. The results align with documented pollution trends linked to urban and agricultural practices, particularly in highly populated regions. The study concludes that both models are effective for assessing water quality; however, the CCME-WQI provides greater flexibility and wider applicability across diverse environmental conditions due to its capacity to accommodate a broader range of parameters and site-specific considerations. In contrast, the NSFWQI demonstrates increased sensitivity to particular input parameters. These findings can enhance strategies for managing water resources and controlling pollution along the Euphrates River.