On a planet where water demand will exceed availability by 40% by 2030, continuing to use primary sources as if they were infinite is a direct threat to industrial, social, and environmental sustainability. The region of Natal, in Rio Grande do Norte, reflects this tension with stark clarity: aquifer overexploitation has reduced available flows, competition among water‑intensive sectors generates constant friction, and wastewater discharges deteriorate the quality of the Potengi River, one of the region’s main water sources. This project emerges as a turning point in this crossroads, transforming sanitary effluents into high‑quality reclaimed water and replacing 25% of groundwater consumption. The impact translates into more than 21,600 m³ of avoided monthly extraction—equivalent to the annual consumption of nearly 2,000 Brazilian households—demonstrating that water circularity can become a driver of regional resilience.
The strategic objective is clear and ambitious: to guarantee water resilience for one of Brazil’s largest textile industries, minimize pressure on the Potengi River basin, and demonstrate that the circular water economy is not an aspirational concept but a concrete, viable, and profitable practice. This project is a direct response to the urgent need to preserve strategic aquifers and comply with increasingly strict environmental regulations, while ensuring operational continuity of a historically water‑intensive industrial sector of high economic relevance for the country.
The initiative is developed under an investment, operation, and maintenance model that ensures financial and technical sustainability, with supervision and support from local and regional environmental authorities, guaranteeing regulatory alignment and public trust. Its design is aligned with the Water Positive roadmap, meeting the principles of intentionality, additionality, and traceability defined by VWBA 2.0 and WQBA. Each cubic meter saved and each pollutant removed is monitored with online sensors, digitally reported, and validated by external verifiers, ensuring transparency and credibility. This effort is not only a technical solution: it represents a paradigm shift in the way water is produced, consumed, and managed, projecting the Brazilian textile industry as a reference for water transformation in Latin America.
The main challenge facing the operation in Natal is its historic dependence on groundwater, with extraction levels reaching 120 m³/h (86,400 m³ per month). This model has generated structural risks: declining water tables, user conflicts, impacts on water quality, and increasing regulatory restrictions that threaten the sector’s continuity. At the same time, the plant’s sanitary effluents, without advanced treatment, represent an environmental liability that increases Potengi River pollution, deteriorates associated ecosystems, and limits the industry’s competitiveness against increasingly strict international demands.
The opportunity arises from reversing this linear logic through the construction of a Reclaimed Water Production Plant (EPAR) based on MBR (Membrane Biological Reactor) technology, designed to operate continuously with a capacity of 30 m³/h. This system, which combines biological processes with ultrafiltration membranes, produces high‑quality reclaimed water that meets national and international standards. Thus, more than 21,600 m³/month of effluents are transformed into a safe, useful resource suitable for critical industrial processes such as dyeing, laundry, washing, and facility cleaning. With this intervention, groundwater consumption will be reduced to 90 m³/h (64,800 m³/month), ensuring an immediate 25% saving and significantly reducing pressure on local aquifers.
Direct and immediate benefits appear across several dimensions: quantifiable water savings, reduction of contaminant discharges, mitigation of regulatory risks, and strengthened operational resilience to recurring droughts. Indirect benefits also stand out, such as reducing the carbon footprint associated with water pumping and treatment, improving public perception of the textile industry, and increasing competitiveness in international markets that demand sustainability. Process traceability through flow meters, online sensors, digital reports, and external audits builds trust among authorities and investors, providing verifiable evidence of the change delivered.
In the short term, the impact is reflected in operational efficiency and reduced water and treatment costs; in the medium term, in reputation, regulatory compliance, and a strengthened social license to operate; and in the long term, in the creation of a replicable model for other water‑intensive industries in Brazil and Latin America. Textile, food, and beverage sectors can see in this experience a benchmark for how to transform environmental liabilities into strategic assets.
Implementation follows a BOT scheme integrating investment, operation, and maintenance, ensuring technical and financial sustainability. This project positions the textile industry not only as a responsible user of the resource but also as a pioneer in water innovation within a sector historically associated with a high water footprint. In an increasingly regulated market, monitored by ESG‑oriented investors, leading a water reuse project is not just an operational improvement: it is a strategic move that secures social license to operate, strengthens reputation, and provides competitive differentiation. The time to act is not the future, it is now, and every cubic meter recovered represents a decisive step toward a regenerative and Water Positive industry.
The technical solution is based on the implementation of a tertiary treatment plant using MBR technology, capable of continuously processing 30 m³/h of sanitary effluents. The MBR combines a biological reactor with ultrafiltration membranes, ensuring efficient removal of suspended solids, organic matter, and pathogens, producing consistently high‑quality reclaimed water. This technology was selected over alternatives such as conventional activated sludge or sand filters due to its compactness, operational reliability, and ability to guarantee water quality for demanding industrial uses.
The main quantifiable benefits include the production of 21,600 m³/month of reclaimed water, a 25% reduction in aquifer extraction, decreased contaminant loads discharged into the Potengi River, and savings in water supply and treatment costs. Additionally, digitalization of the system through SCADA ensures complete process traceability, with real‑time monitoring of critical parameters such as turbidity, BOD, TSS, conductivity, and residual chlorine, generating verifiable reports for regulators and external auditors.
Identified operational risks include potential membrane failures, variability in influent contaminant load, and social acceptance of reuse. To mitigate these, the design includes redundancy of critical equipment, preventive and predictive maintenance protocols, treated water storage to balance flow variations, and awareness campaigns for employees and communities. Climate resilience is reinforced by reducing dependence on primary sources vulnerable to drought, while shared governance between the company, operator, and authorities supports long‑term sustainability.
In terms of replicability, the solution can be applied in other water‑intensive sectors such as food, beverage, or automotive in regions facing similar water stress. Selection criteria, efficiency, competitive cost per cubic meter reclaimed, regulatory compliance, and operational simplicity, make the model highly scalable. Moreover, integration with VWBA 2.0 principles ensures that water quantity and quality benefits are measurable, additional, and intentional, making it a project that is both verifiable and exportable to other industrial markets committed to transitioning toward a regenerative water economy.
The project is implemented under a phased and adaptive approach, with clearly defined stages that ensure technical quality and long‑term sustainability. The first phase was diagnosis and baseline, assessing current extraction flows (120 m³/h), effluent quality, and aquifer overexploitation risks. This stage included monitoring campaigns, water characterization, and technical audits.
The second phase, design and planning, included selecting MBR technology after comparing treatment alternatives, prioritizing efficiency, cost per cubic meter treated, compactness, and final water quality. In parallel, control and traceability instruments were defined: ultrasonic flow meters, online multiparameter probes, IoT sensors, and an integrated SCADA system capable of recording and reporting in real time.
The third phase involved installation and commissioning of the EPAR, with equipment designed for 24/7 operation, ensuring constant performance of 30 m³/h. Commissioning included validation of critical parameters, load testing, and calibration of digital systems. The fourth phase is continuous operation, supported by preventive and predictive maintenance protocols and a contingency plan that incorporates storage tanks and redundant systems to avoid interruptions.
In terms of timelines, diagnosis and design took six months, installation and commissioning eight months, and continuous operation is projected for 20 years with periodic technology reviews.
Key performance indicators (KPIs) include reclaimed water volume, reduction in groundwater extraction, quality parameters (BOD, TSS, coliforms), energy efficiency, and operating costs. These are constantly compared between with‑project and without‑project scenarios, providing verifiable evidence of the benefits.
Physical traceability is ensured through flow meters and separate storage tanks, while digital traceability is secured with SCADA, blockchain for immutable reporting, and annual external audits. The system issues automatic alarms for deviations in quality or flow and generates monthly reports for environmental authorities.
Governance includes the user industry as the main beneficiary, a specialized operator as technical manager, environmental authorities as regulators, and external verifiers for VWBA/WQBA validation. Roles are clearly defined in operation and maintenance contracts.
Finally, the project incorporates a continuous improvement plan based on data feedback, technological updates of membranes and sensors, and process reviews every five years. This approach ensures the permanence of benefits, replicability in other industrial plants, and direct contribution to global Water Positive commitments and the SDGs.
The project implements a Reclaimed Water Production Plant (EPAR) with MBR technology in Natal (Rio Grande do Norte) to transform sanitary effluents into safe, stable process water. Technically, it integrates pretreatment (fine screening and grit removal), aerated biological reactor, submerged ultrafiltration membranes (0.04 µm), UV disinfection, residual adjustment with hypochlorite, and buffered storage with a segregated distribution loop. The nominal capacity is 30 m³/h (24/7), equivalent to 21,600 m³/month or 259,200 m³/year. Operation is controlled via SCADA with online instrumentation (flow, turbidity, indirect BOD/COD, TSS, conductivity, ORP, residual chlorine) and automatic logging. The system complies with CONAMA 357/2004 and 430/2011 for discharge, and internal specifications for industrial reuse (typically BOD < 10 mg/L, TSS < 5 mg/L, turbidity < 1 NTU, E. coli < 200 CFU/100 mL and residual chlorine 0.2–0.5 mg/L), with verification by accredited laboratories.
This solution is relevant because it addresses the dual bottleneck of the Potengi basin: aquifer overexploitation and pollutant load. Compared to the baseline (extraction of 120 m³/h and limited effluent treatment), the project changes the logic: it replaces 25% of groundwater with reclaimed water (21,600 m³/month), reduces discharges, and stabilizes industrial supply quality. It is the most adequate option in a context of water stress and regulatory pressure, providing operational security, environmental compliance, and social legitimacy to a water‑intensive industry.
Expected results are concrete and measurable: (i) 259,200 m³/year of primary water substituted (equivalent to the annual consumption of ~2,000 households), (ii) effluent quality improvements with typical reductions >95% in TSS and BOD compared to influent, (iii) deferred CAPEX savings in new abstractions and OPEX reduction in treatment through volume optimization, and (iv) risk reduction from droughts and regulatory restrictions. Environmentally, the project contributes to a smaller carbon footprint from reduced pumping and treatment and relieves pressure on the coastal aquifer (lower risk of saline intrusion). Socially, it indirectly supports public health improvement by lowering pollutant loads in the receiving body and freeing water for priority uses in the city.
The strategic and commercial value is multiple. Within the Water Positive roadmap, the intervention generates volumetric benefits (A‑2: avoided consumption; A‑6: safe onsite reuse) traceable under VWBA 2.0, and quality benefits auditable under WQBA. This strengthens ESG/ESRS reporting, facilitates eligibility for standards such as AWS, and supports the social license to operate. At a branding level, water circularity in the textile chain becomes a differentiated value proposition for clients and regulators, with digital evidence and third‑party verification.
Replicability and scalability are high: the EPAR–MBR–UV with segregated distribution can be adapted to other textile, food, beverage, and automotive plants in Brazil and Latin America, particularly in industrial hubs with overexploited aquifers (NE Brazil: RN, CE, PE). Enabling conditions include: availability of technical area, water/discharge costs that valorize reuse, regulatory frameworks that recognize the benefit, and operator–technology–authority partnerships. The project fosters public‑private partnerships (industry–operator–authorities–verifier–universities) that accelerate expansion.
The final expected impact on the water system is twofold: quantity balance (sustained substitution of abstractions by >250,000 m³/year) and quality improvement (controlled discharges with lower organic and microbiological load). In climate resilience, the plant reduces exposure to water supply variability, ensuring production continuity and contributing to basin adaptation. Socially, it delivers skilled employment, health and safety protocols, and a regenerative industry narrative that aligns investment, compliance, and purpose. For investors and clients, this project demonstrates how a treatment asset can become strategic infrastructure creating operational, environmental, and reputational value that is measurable, verifiable, and scalable.
