The technology of managed aquifer recharge (MAR), which has been proven in Germany, was introduced in Peru as a nature-based solution. Its potential for the cost-effective supply of high-quality industrial and drinking water in densely populated water-deficit regions were demonstrated.
Lima is among the driest metropolitan regions in the world, making the water supply for its 10 million inhabitants, as well as for industry and commerce, a significant challenge. This challenge is expected to require substantial investments in the coming years. The local rivers carry water only for a few months per year during the rainy season in the Andes, and groundwater resources are limited. The research project NEWA-LIMA, funded by the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) aimed to demonstrate managed aquifer recharge (MAR) as a nature-based and cost-effective approach for the sustainable use of groundwater resources, thereby contributing to solving Lima’s water-related challenges.
Following extensive preliminary investigations, a MAR pilot plant was constructed on the premises of a wastewater treatment plant in the Lurín Valley. This pilot plant comprised three infiltration basins for treated wastewater, as well as several monitoring wells, and was operated in collaboration with Lima’s water supply and wastewater utility (SEDAPAL) for a duration of 17 months. The removal efficiency of the soil passage was assessed through comprehensive microbiological and chemical water analyses, including anthropogenic trace substances and the novel “effect-directed analysis” (EDA). Additionally, accompanying small-scale studies on activated carbon adsorption and reverse osmosis evaluated the applicability of these advanced treatment technologies. Furthermore, the project included an assessment of the legal framework and social implications of MAR initiatives in Peru. The development of a local groundwater model and a concept for the use of trickling filters in wastewater treatment served as a basis for deriving specific recommendations for large-scale MAR implementation in the Lurín Valley.
A key finding of the study is the high permeability of the soil in the Lurín Valley, which allows for the infiltration of large volumes of water on relatively small infiltration area. Potential water sources for MAR include "excess water" from the Río Lurín during the rainy season (approx. 50 million m³ per year) and treated wastewater from treatment plants available year-round (approx. 40 million m³ per year). Regarding water quality, analyses demonstrated that, despite the high flow velocity and short subsurface flow path, the pilot plant’s infiltration process effectively retained turbidity and particles, resulting in efficient hygienic and microbiological purification of the treated wastewater effluent. Chlorine-resistant pathogens, such as parasitic cysts (e.g., Giardia and Cryptosporidium), were completely removed. Through EDA, it was further demonstrated that the minor endocrine and neurotoxic effects detected in the wastewater effluent were significantly reduced by soil passage. As expected, the degradation of anthropogenic trace substances was limited due to the short soil passage; however, no relevant concentrations of the analyzed "emerging contaminants" were detected in the infiltrate (treated wastewater effluent).
The MAR approach, which has been successfully implemented in Germany and other regions worldwide, thus presents significant potential for securing groundwater resources in Lima. Consequently, within the framework of NEWA-LIMA, preliminary designs for MAR facilities at two sites in the Lurín Valley were developed. Furthermore, recommendations were formulated to enhance social acceptance among the local population, and general guidelines for the implementation of MAR projects were derived.
Publications:
Fesch, K., Hügler, M., León, C. D., Perez, H., Stauder, S., Xanke, J.: Kontrollierte Grundwasseranreicherung (MAR): Ein Beitrag zur Lösung der Wasserprobleme in Lima, Peru (2025) Abschlussbericht des Projekts NEWA-LIMA. Universität Stuttgart & TZW: DVGW-Technologiezentrum Wasser. Stuttgart und Karlsruhe, März 2025 (in German)
León, C. D.; Brauer, F.; Hügler, M.; Keller, S.; Kosow, H.; Krauss, M.; Wasielewski, S.; Wienhöfer, J. (Eds.): Integrated Water Management Solutions in the Lurín Catchment, Lima, Peru – Supporting United Nations’ Sustainable Development Goal 6. Final report of the joint project TRUST. University of Stuttgart, ISBN 978-3-00-068498-2 (2021)
http://dx.doi.org/10.18419/opus-11390
Minn, F.; Hügler, M.; Kosow, H.; Kramer, H.; Krauß, M.; León, C. D.; Stauder, S.; Wasielewski, S.: Leitfaden für Konzeption, Aufbau und Betrieb von Schulungs- und Pilotanlagen zur Aufbereitung von Trinkwasser und Reinigung von Abwasser aus einer sozio-technischen Perspektive. Hrsg.: Universität Stuttgart und TZW Karlsruhe (2021)
http://dx.doi.org/10.18419/opus-11793
