Practical Management to Minimize the Effects of Clogging in Managed Aquifer Recharge Wells at Two Sites in the Guadiana Basin, Spain

According to the experiments performed by the Tragsa Group and in the framework of the research and development Depth Investigation of New Areas for Managed Aquifer Recharge (DINA-MAR) Project, which relates to the management of aquifer recharge in the context of sustainable development, researchers studied clogging in managed aquifer recharge (MAR) facilities in two demonstration sites within the Guadiana Basin in central Spain. The author focused on the detection and distribution of physical (including air), chemical, and biological clogging processes in 25 wells and bores. Several of these sites have been in operation since 1988. The most remarkable detected processes were algae colonies and the combination of carbonate and iron. Synergistic combinations among the different elements have been studied by means of clogging and water sampling, field and laboratory analysis, field photographs, and down-hole videos. These studies were performed at two experimental sites in a permanent development in which new designs and their infiltration capacity and evolution are being investigated. Several outcomes relating to the infiltration capacity of these wells are presented in this paper. Results from both sites were used to implement a practical methodology that improves current well designs and utilizes two devices to clean and maintain injection wells and bores. This paper also outlines several practical recommendations and protocols for the management of MAR wells. These recommendations establish parameters for MAR wells considering various processes, such as single groundwater extraction, pretreatment filters, backwashing frequency, and cleaning methods.