This project aims to transform the management of wastewater generated at a sanitary landfill located in the municipality of Ensenada, Buenos Aires Province (Argentina). This area, characterized by a complex interaction between urban, industrial zones and wetlands along the Río de la Plata, presents sensitive hydrogeological conditions that heighten the risks posed by leachate from municipal solid waste disposal.
Leachates, with a high organic load and presence of hazardous contaminants, pose a direct threat to the Pampeano and Puelche aquifers and to watercourses such as El Gato and Rodríguez streams. To address this challenge, the project proposes a structural intervention based on principles of circular economy, climate resilience, and regenerative water resource management.
The technical solution is based on the installation of a double-stage reverse osmosis leachate treatment plant, which will convert the contaminated effluent into a secondary water source suitable for non-potable on-site uses (e.g., equipment washing, dust control, industrial irrigation). This membrane separation technology effectively removes a wide range of compounds: dissolved solids, salts, organic matter, heavy metals, pathogens, and emerging contaminants.
Methodologically, the project aligns with the Volumetric Water Benefit Accounting (VWBA) 2.0 framework, particularly under the “volume treated and reused” indicator. It aims to generate measurable, additional, and durable benefits,allowing its impact to be recorded and validated within international frameworks such as Science-Based Targets for Water, ESRS E3, or the Aqua Positive platform.
Additionally, leachate treatment in this environment may yield quantifiable improvements in surface and groundwater quality, potentially integrating indicators under the Water Quality Benefit Accounting (WQBA) framework,especially if sustained reductions in key pollutants such as nitrogen, COD, ammonium, arsenic, or persistent organic compounds are documented.
In summary, this is a local intervention delivering tangible water benefits, improving operational sustainability, and reinforcing environmental safety in a critical area of the Buenos Aires coastal region.
Leachate produced at sanitary landfills is a complex and highly polluting byproduct generated by rainwater or moisture percolating through waste in operational cells. This liquid typically contains high concentrations of degraded organic matter, heavy metals (lead, cadmium, mercury), nutrients such as nitrogen and phosphorus, pharmaceuticals, hydrocarbons, pathogenic microorganisms, and microplastics,forming a highly toxic mix that, if mismanaged, can cause severe contamination of water bodies, soils, and aquifers.
In Ensenada’s landfill, located in Greater La Plata, the risk is increased due to the high permeability of local sandy soils, which facilitate vertical infiltration into the Pampeano and Puelche aquifers. The nearby El Gato and Rodríguez streams, which discharge into the Río de la Plata estuary, could also be affected,posing a threat to environmentally and socially significant ecosystems.
Water stress in this region has worsened due to climate change-induced extreme weather. More frequent and intense rainstorms cause hydraulic overload in landfill cells and leachate lagoons, leading to uncontrolled overflows and leaks. Emergency operations,such as transport to third-party treatment plants,incur high logistical, environmental, and legal costs.
Currently, leachate is collected by gravity and stored in evaporation lagoons or storage tanks. However, this approach is increasingly unsustainable due to saturation, pumping costs, and structural risks. The absence of on-site treatment generates a growing environmental liability, limits compliance with regulations, and impacts the environmental certification and institutional reputation of operators.
The proposed solution involves deploying an advanced leachate treatment plant specifically designed for variable flow and pollutant loads, typical of Ensenada’s final disposal site. The core technology is double-stage reverse osmosis, recognized for its high efficiency in removing both organic and inorganic contaminants, producing non-potable water suitable for reuse.
Process stages include:
The infrastructure also includes a fully automated system designed for variable flow conditions, real-time monitoring of key parameters, and self-regulation to maximize recovery and minimize waste. This solution redefines landfill water management,from disposal to sustainable recovery and reuse.
Technology:
Monitoring and Control Plan:
Stakeholders:
This project represents a paradigm shift in leachate management in urban-industrial settings like Ensenada. It moves away from traditional accumulation and disposal of hazardous waste toward regenerative management,turning leachate into a resource for site operations.
Environmental benefits: every liter of treated and reused leachate reduces pressure on freshwater sources, mitigates aquifer contamination risks, and lessens surface discharge impacts.
Operational benefits: lower costs in transport, off-site treatment, and potable water use, while increasing the landfill’s resilience to heavy rain events.
Beyond meeting VWBA criteria, the project aligns with broader sustainability commitments, environmental governance, and circular economy strategies. Traceability via platforms like Aqua Positive adds reputational and commercial value to performance.
System capabilities:
• Treat 50–100 m³/day of leachate with efficiency, adjusting to seasonal flow.
• Remove over 90% of critical contaminants (COD, ammonium, heavy metals, nitrates, conductivity).
• Prevent infiltration, overflow, and accidental discharge with a closed-loop treatment and recirculation system.
• Demonstrate additionality,this high-efficiency treatment and reuse would not occur without the project.
• Guarantee traceability through digitized records and third-party verification.
• Ensure permanence via long system life, modular design, and integration into daily landfill operations.
Timeline and Permanence:
• Timeline: Benefits are calculated annually but can be averaged over three years to smooth seasonal fluctuations.
• Permanence: As long as the system operates with traceability, the benefit is considered permanent. Estimated useful life: minimum 10 years.
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