Water Reuse Plant . Alicante, Spain

Co-investment

Compensation

Catalytic activities

Restoration of Aquatic Ecosystems

Water Recycling and Reuse

Overview

This project aims to increase the operational efficiency of the reverse osmosis (RO) system of the WATER REUSE PLANT, located in Alicante, Spain, improving its current recovery rate from an estimated 70–75% to an enhanced range of 75–80%. The plant treats approximately 10,000 m³/day of urban wastewater which, after primary, secondary, and tertiary treatment, is subjected to ultrafiltration and reverse osmosis processes to obtain high-quality water suitable for agricultural irrigation. The current efficiency is limited by fouling phenomena and the accumulation of salts (scaling), which affects membrane productivity and lifespan.

The proposed intervention focuses on the implementation of advanced chemical products (broad-spectrum antiscalants and biofilm-specific biodispersants), the optimization of in situ cleaning protocols (CIP) through precise adjustment of operational parameters (pH, sequence, temperature, and frequency), and the design of adaptive purge strategies to stabilize the system’s hydraulic conditions. These actions will increase the volume of regenerated water, significantly reduce the volume of reject, and decrease operational pressure on the membranes, thereby extending their lifespan and reducing the system’s energy consumption.

The proposed efficiency improvement aims to generate additional Volumetric Water Benefits (VWBs), in accordance with the VWBA 2.0 framework. This involves quantifying the incremental volume of regenerated water resulting from the technological optimization, comparing the with-project scenario against the baseline. These benefits are considered additional since they would not have been achieved through standard operation and represent a net increase in the availability of safe water for agricultural reuse in a water-stressed basin. The applied formula allows for calculating the VWB as the difference between the regenerated volume after the intervention and the baseline volume, ensuring traceability and technical robustness of the reported benefit.

Problem and Causes

The plant shows moderate efficiency in RO (~72%), mainly due to the accumulation of mineral scaling, the development of biofilm on membrane surfaces (biological fouling), and suboptimal purge strategies that affect the hydraulic balance of the system.

Additionally, the currently implemented CIP protocols are not precisely adapted to the specific operating conditions or the prevalent type of fouling, reducing their effectiveness and increasing intervention frequency. These conditions result in high volumes of reject water (unrecovered water), increased specific energy consumption per cubic meter produced, and accelerated membrane deterioration, consequently raising operational and environmental costs.

Health Effects

Mitigation Measures and Solutions

To reverse these inefficiencies, the project proposes an integrated package of solutions, including:

Application of next-generation antiscalants and specific biodispersants, selected based on feedwater characterization and membrane compatibility testing, aimed at reducing mineral deposits and biofouling without compromising system integrity.

Automation and redesign of CIP protocols, introducing differential pressure, conductivity, and pH sensors to execute cleanings based on real conditions rather than fixed intervals. Additionally, chemical sequence and temperature will be optimized to improve contaminant removal efficiency.

Implementation of intelligent purges regulated by key operational variables such as SDI (Silt Density Index), reject water conductivity, and differential pressure. This will enable more controlled and efficient discharges, minimizing loss of useful water.

Continuous monitoring via SCADA system, integrating all relevant operational variables, facilitating traceability of hydraulic behavior, daily recovery tracking, and real-time deviation response, generating a predictive control environment aimed at maximizing volumetric performance.

Sustainable Development Goals (SDGs)

SDG 1 – No Poverty: Access to treated water for industrial and agricultural use reduces operational costs and promotes employment opportunities, strengthening local livelihoods. Lower dependence on potable water reduces pressure on urban supply, indirectly benefiting vulnerable communities.

SDG 2 – Zero Hunger: Reuse of treated water supports sustainable irrigation, increasing food production without the need for additional freshwater extraction.

SDG 6 – Clean Water and Sanitation: Central goal of the project. Improved treatment, reuse, distribution, and real-time water quality monitoring directly impact the availability of water resources.

SDG 8 – Decent Work and Economic Growth: The project creates jobs in operation, maintenance, infrastructure, monitoring, and water management. It also sustainably supports industrial and agricultural sectors that depend on water.

SDG 9 – Industry, Innovation and Infrastructure: Promotes technological modernization through ultrafiltration, advanced disinfection, and intelligent control systems, fostering resilient and sustainable industrial innovation.

SDG 11 – Sustainable Cities and Communities: Reduces pressure on urban water systems, alleviating demand on potable water sources and contributing to greater urban water resilience.

SDG 12 – Responsible Consumption and Production: Promotes efficient water use and circular economy by reducing discharges and recirculating treated water.

SDG 13 – Climate Action: Reduces carbon footprint by lowering pumping from conventional sources and enhances climate resilience of critical sectors.

SDG 14 – Life Below Water: Minimizes effluent discharge into receiving water bodies and nutrient load, reducing impact on coastal aquatic ecosystems.

SDG 15 – Life on Land: Reduces groundwater extraction, improves soil health, and preserves biodiversity associated with terrestrial systems.

SDG 17 – Partnerships for the Goals: Strengthens collaboration among public, private, and civil society actors through external validation processes (AWS, Act4Water) and co-financing, creating replicable synergies.

Project Information

Country:

Spain

Implementation

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

Automatic dosing of chemical products.
CIP automation with continuous monitoring.
Intelligent purge valves and inline sensors.

Monitoring Plan

SDI, Transmembrane Pressure (TMP), reject flow, and CIP logged in SCADA.
Traceability of each cleaning and dosing cycle.
Pre/post comparison with external auditor validation.

Understanding the Project

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:

Hazard and risk assessment: The project includes monitoring of key indicators (SDI, TMP, coliforms, conductivity), enabling microbiological and physicochemical hazard analysis per the plan’s requirements.
Control measures: The proposed system includes CIP automation, purges, and disinfection, allowing corrective actions in case of quality deviations.
Health surveillance and self-monitoring: The plant’s SCADA sensors enable continuous surveillance. This should be complemented with sampling plans and coordination with health authorities and irrigation users.
Risk communication and institutional coordination: The project fosters coordination among companies, EPSAR, and irrigators, facilitating roles for control, emergency response, and oversight.
Documentation and traceability: SCADA data and external validation protocols (e.g. SCS) provide an adequate basis for the required traceability under the risk management plan.

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.

Estimated price:

1,10 €