In a world where 80% of wastewater is still discharged without adequate treatment, every cubic meter we recover makes a difference. Alicante, one of the driest regions in Europe, cannot afford to waste resources. In this context, the Rincón de León WWTP positions itself as a key node in the transition towards a regenerative water model: it doesn’t just treat water, it transforms it. With a treatment capacity of 100,000 m³/day and high-performance technology, this plant turns urban wastewater into a strategic source of reclaimed water and recoverable nutrients, building water resilience in a stressed basin and anticipating new climate and regulatory demands.
The project is located in the city of Alicante, Valencian Community (Spain), within the Vinalopó River Basin, one of the most affected by aquifer overexploitation and structural water stress. Its purpose responds to multiple urgent needs: protecting coastal receiving bodies, improving the efficiency of the urban water cycle, closing the nutrient loop, and enabling non-conventional uses with sanitary safety. In a context where every drop counts, this intervention enables water to be regenerated to meet quality criteria for agricultural, environmental, or industrial uses, reducing pressure on conventional sources.
The stakeholders involved reflect a solid and traceable governance model: Aguas de Alicante operates the plant under an advanced management framework; specialized suppliers ensure the performance of the tertiary treatment and the production of biosolids suitable for agricultural valorization; and Aqua Positive structures the project under a Water Positive approach, ensuring that quantity and quality benefits are additional, traceable, and aligned with verifiable sustainability goals.
The application of VWBA and WQBA methodologies makes it possible to quantify both the reclaimed volume and the quality improvements, enabling the declaration of net water benefits with technical backing and external auditability. The intent is clear: to anticipate, innovate, and prove that a city can be a source, not just a consumer, of useful water. This is the new role of WWTPs in the circular water economy.
The reclaimed water project at the Rincón de León WWTP builds on a key technical opportunity: transforming a conventional treatment facility into a hub for circular resource generation. Through a tertiary treatment system combining coagulation-flocculation, lamella settling, sand filtration, and sodium hypochlorite disinfection, the plant produces reclaimed water suitable for agricultural irrigation, industrial uses, or environmental applications. The plant already operates with separate internal reuse networks (filter backwash, landscape irrigation, industrial processes), reducing its operational water footprint. In the next phase, the project expands external traceability for agricultural and recharge uses.
Currently, up to 100,000 m³ of wastewater are treated daily, generating a potential reclaimed water volume of over 25 million m³ per year, equivalent to the annual consumption of more than 170,000 people. This volume represents a strategic reserve in the face of prolonged droughts, and its use can reduce groundwater extraction in nearby agricultural areas by more than 20%. Added to this is the valorization of biosolids as agricultural fertilizer, closing the nutrient cycle and avoiding emissions from the use of synthetic fertilizers.
The model is fully replicable in other urban WWTPs in the Mediterranean region, particularly those with access to tertiary systems and under high water stress. Operators, technology providers, or agricultural companies can lead this solution, integrating it into their ESG narrative. By doing so, they not only reduce their exposure to climate and regulatory risks but also position themselves as enablers of the water transition. The time to act is now: European water reuse regulations are becoming stricter, society is demanding circularity, and the market is beginning to value the traceability of reclaimed water as a strategic asset.
This project does not simply upgrade a plant, it redefines what a city can be: not an endpoint, but a starting point for the water of the future.
To reverse these inefficiencies, the project proposes an integrated package of solutions, including:
The project follows a modular and scalable approach, with defined phases for design, technical implementation, validation, and monitoring. Activities begin with an operational diagnosis of the current status of the RO train, followed by the integration of new cleaning protocols, selection of optimized chemical products, and installation of automated components for hydraulic control and purging.
In parallel, intelligent sensors will be installed to monitor key indicators such as SDI, differential pressure, conductivity, and flow, all connected to a SCADA platform for continuous performance assessment and real-time operational adjustments. The entire system will operate in adaptive mode, prioritizing the minimization of chemical and energy consumption per cubic meter of regenerated water produced.
Technical collaboration agreements will be established with certified providers of antiscalants and biodispersants, as well as automation integrators with expertise in water treatment process control.
Applied Technologies
Monitoring Plan
This project aims to optimize the performance of the reverse osmosis plant at the WATER REUSE PLANT in Alicante, increasing recovery efficiency from 70–75% to 75–80%. It is a key intervention in a facility that treats 10,000 m³ of urban wastewater daily for regeneration and subsequent agricultural use. The technical improvement is based on the incorporation of specialized chemical products (antiscalants and biodispersants), automation of cleaning and purge protocols, and the implementation of real-time monitoring via a SCADA platform.
The project addresses a real operational problem: the accumulation of biofouling and scaling on membranes, as well as the suboptimal management of purges and cleanings. These conditions reduce the amount of recovered water, increase energy consumption, and shorten membrane lifespan. The proposed solution directly improves these factors through an integrated strategy of automation, optimized chemical dosing, and adaptive process management.
Its impact targets the Segura River Basin, one of the most stressed in Europe, where reclaimed water is a strategic resource for agriculture. By increasing the volume of reusable water, the project not only enhances water availability but also reduces pressure on overexploited aquifers and minimizes potable water use for non-priority purposes.
The implementation will be led by a company in coordination with EPSAR, with technical partnerships involving certified input providers, automation integrators, and verification platforms. The system will operate in adaptive logic, adjusting cleaning and purges based on indicators such as SDI, TMP, and conductivity, ensuring both traceability and efficiency.
The project must align with current regulations of the Risk Management Plan for Reclaimed Water required by MITECO, provided that it incorporates the specific elements established by Royal Decree 1620/2007 and its updated framework under the EU Regulation 2020/741.
Key regulatory compliance aspects:
This project generates additional Volumetric Water Benefits, quantified under VWBA 2.0 methodology. It represents a model case of urban water efficiency with collateral benefits in agriculture, ecosystem health, and climate resilience.
