Evaluation of the Usability of Treated Urban Wastewater in Agricultural Irrigation: The Case of Çanakkale

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With the increasing demand for water over time, coupled with the effects of climate variability, the pressure on existing clean water resources is dramatically increasing. Today, creating alternative water sources has become essential to reduce the pressure on renewable but limited clean water resources. Therefore, treated wastewater stands out as an important option. The reuse of treated wastewater contributes to reducing water scarcity by providing an alternative and sustainable water resource, while also offering significant advantages in terms of environmental protection and resource efficiency. In this study, the potential for reusing treated wastewater from urban wastewater treatment plants in agricultural irrigation was evaluated using the discharge water of the Çanakkale Wastewater Treatment Plant. Within the scope of the study, physical, chemical, microbiological, and toxicological parameters were analyzed in samples taken from the inlet and outlet points of the treatment plant, and the results obtained were evaluated according to the criteria of the Wastewater Treatment Plant Technical Procedures Regulation in force in Türkiye. Considering the discharge water of the treatment plant, it was determined that it largely remained within the limits of the legislation. In addition, it was determined that there is currently no risk in terms of heavy metals and toxic elements. The study determined that treated wastewater has the potential to reduce the fertilizer needs of plants due to the nutrient elements it contains, and this can lead to a decrease in production costs, providing economic advantages in terms of irrigation water and fertilizer requirements. The irrigable areas identified as a result of the spatial analyses reveal significant potential for use, especially for orchards and field crops. Subsurface drip irrigation systems stand out as the most suitable method due to their increased water use efficiency and reduced hygiene risks. In conclusion, it is shown that treated urban wastewater can be used safely and sustainably in agricultural irrigation with appropriate treatment and management strategies, and that this approach will make significant contributions to the conservation of water resources, circular water management, and the reduction of production costs.