As climate change accelerates water scarcity across the Mediterranean and the Sahara, countries are compelled to rethink their approach to water management. The traditional linear model of extracting freshwater, using it once, and discharging it into the environment is no longer viable in regions where rainfall is decreasing, aquifers are overexploited, and agricultural demand continues to grow [1-2]. In Algeria, this challenge is especially acute – declining annual precipitation, high evapo-transpiration rates, rapid population growth, and urban expansion place tremendous pressure on limited freshwater resources. At the same time, industrial and agricultural demands continue to rise, further stressing conventional water supply systems. These dynamics create an urgent need to adopt innovative approaches that integrate environmental, social, and economic considerations, while ensuring long-term water security [3].
Globally, water governance is evolving toward a circular economy model, in which treated wastewater is no longer considered waste but a valuable resource. This approach emphasizes the reuse of water for multiple applications, the optimization of resource efficiency, and the protection of ecosystems. When treated wastewater is reused safely, it can support agriculture, industrial operations, urban landscaping, aquifer recharge, and even potable water supply under strict regulatory and treatment conditions. Countries such as Spain, Singapore, and Australia provide concrete examples of how circular water management, coupled with robust monitoring and public engagement, can significantly reduce pressure on freshwater sources, increase resilience to drought, and promote sustainable urban and agricultural development [4-5].
Algeria, one of the most water-stressed countries in North Africa, is increasingly embracing this approach. Facing declining precipitation, rising energy and financial costs of conventional water supply, and rapid demographic growth in urban areas, the government recognizes the strategic importance of treated wastewater as a reliable, locally available water source. Recent announcements in Algerian media indicate the launch of a national program to upgrade dozens of wastewater treatment plants (WWTPs) with tertiary treatment, beginning with major facilities in Algiers, Oran, Tlemcen, Constantine, Tipasa, and Ouargla. The objective is to produce high-quality reclaimed water suitable for irrigation, reduce pressure on overexploited groundwater, and expand the reuse perimeter, particularly in arid and semi-arid regions [6].
The principle of a circular water economy is that water can and must be used more than once. Treated wastewater, when properly processed, can serve multiple functions: supporting agriculture, industry, urban landscaping, and aquifer recharge, and under certain conditions, potable applications. Advanced technologies such as membrane filtration, ultraviolet (UV) disinfection, and AI-driven smart irrigation systems enhance the safety, efficiency, and adaptability of water reuse, even under harsh climatic conditions. International experience demonstrates that with clear standards, rigorous monitoring, and public engagement, reclaimed water can achieve high acceptance and contribute significantly to national water security [7].
Algeria’s wastewater infrastructure provides a strong foundation for circular water management. Over the past two decades, more than 200 WWTPs have been constructed, serving urban agglomerations, industrial zones, and peri-urban areas. While some plants operate below design capacity due to operational and maintenance constraints, collectively they represent a substantial national asset. Treated wastewater, particularly when upgraded with tertiary or quaternary treatment, can reduce pressure on fossil groundwater, support local agriculture, and stabilize food systems in drought-prone regions such as Biskra, Oued Souf, Adrar, and Timimoun [8].
Algeria has also established a regulatory and normative framework for water reuse. Executive Decrees 06‑141 and 07‑149 define pollutant discharge limits and conditions for wastewater reuse, while an interministerial decree issued in 2012 specifies eligible crops and water quality requirements, including microbiological and physico-chemical parameters. National standards, such as NA 17683 for treated wastewater and NA 17671 for sludge reuse, define water classes based on E. coli concentrations and other parameters, ranging from Class A (≤10 CFU/100 mL) to Class D (≤10,000 CFU/100 mL). These standards provide a technical and legal foundation for safe reuse, protecting public health, agricultural productivity, and environmental integrity. However, many WWTPs still operate below optimal treatment levels, monitoring systems remain fragmented, and public confidence in water reuse, particularly for agriculture, is limited [9].
A concrete example of water reuse in Algeria comes from the Boumerdes region. The Boumerdes WWTP, serving the coastal city of Zemmouri, supplies approximately 160 m³/day of treated wastewater to the municipality. The water is primarily used for non-potable municipal applications, such as street cleaning and urban landscaping, while plans are underway to expand agricultural reuse in nearby farmland. Long-term agricultural studies in the Corso-Boumerdes area indicate that treated wastewater, combined with sewage sludge, has been applied on farmland since 2002, demonstrating safe irrigation practices under local conditions. Farmers apply sludge annually (15–20 tons per hectare) and irrigate with treated wastewater via drip systems from May to October, compensating for water shortages while maintaining soil health.
Soil monitoring has not revealed harmful accumulation of heavy metals or contaminants, supporting the safety and sustainability of reuse in this context. This example illustrates that even relatively modest volumes of reclaimed water can provide substantial benefits for both municipal and agricultural needs while offering an opportunity for replication in other regions [10].
Pilot projects like WAWARIA in the Saharan region further demonstrate the operational and strategic potential of circular water management in Algeria. WAWARIA is designed to evaluate the safe valorization of treated wastewater for irrigation under extreme climatic conditions. The project compares crop performance and environmental safety under three irrigation regimes: groundwater, secondary-treated wastewater, and tertiary-polished water using membrane filtration. Conducted on nine greenhouse plots, the project monitors crop yields, soil quality, heavy metals, and organic compounds. Advanced infrastructure, including intelligent drip irrigation and automated monitoring, ensures precise evaluation during harsh Saharan winter conditions. Crops such as tomatoes, potatoes, beetroot, lettuce, cucumber, and beans are grown under identical conditions to rigorously measure the effects of irrigation water quality on productivity and environmental safety [11].
Early results from WAWARIA show that membrane-polished wastewater produces crop yields comparable to groundwater irrigation. Secondary-treated wastewater, when applied through controlled drip irrigation, also supports safe and productive cultivation. Soil analyses indicate no harmful accumulation of heavy metals or organic contaminants, confirming that treated wastewater, when managed according to standards and monitored systematically, can be safely integrated into agricultural systems. Intelligent irrigation minimizes water loss, optimizes nutrient distribution, and increases water-use efficiency, while the project builds confidence among farmers, agronomists, and engineers regarding the reliability of treated wastewater.
Spray irrigation has higher efficiency than traditional methods.
These projects illustrate both the technical feasibility and strategic importance of wastewater reuse in Algeria. By providing water for urban landscaping, municipal cleaning, and agriculture, reuse reduces pressure on overexploited aquifers, enhances food security, and enables the sustainable development of peri-urban and arid areas. Moreover, it contributes to socio-economic development by creating technical jobs in water quality monitoring, irrigation management, and environmental engineering. Lessons from Boumerdes, WAWARIA, and other initiatives highlight the importance of integrating regulatory standards, long-term monitoring, and stakeholder engagement to ensure safe and socially acceptable water reuse.
Law 25-02 on waste management and the circular economy, adopted in 2025, reinforces these efforts. It mandates that public utilities, municipalities, and industrial operators develop valorization plans, produce reusable water, and integrate reuse into economic and environmental strategies. Financial incentives, including subsidies for reuse infrastructure and support for climate-smart irrigation projects, encourage innovation and investment. At the same time, penalties for environmentally harmful practices help enforce compliance. By linking circular water management to local economic development, the law fosters green jobs and strengthens community participation, ensuring that the transition toward a circular water economy generates tangible socio-economic benefits [12].
Taken together, the regulatory framework, technological innovation, and operational experiences provided by projects like WAWARIA and Boumerdes position Algeria to transform treated wastewater into a cornerstone of its water strategy. Expanding reclaimed water programs, upgrading treatment plants, strengthening monitoring networks, and investing in intelligent irrigation systems can convert water scarcity from a constraint into a strategic opportunity. This approach not only secures water and food systems in arid and semi-arid regions but also promotes sustainable urban development, soil restoration, and climate adaptation.
Conclusion
Algeria’s evolving wastewater reuse initiatives demonstrate the practical and strategic benefits of circular water management. The combination of regulatory standards, advanced treatment technologies, and field-based pilot projects provides a roadmap for safe, effective, and scalable reuse of treated wastewater. The Boumerdes example shows that even modest reuse volumes can have meaningful impacts when managed properly, while WAWARIA illustrates the potential for scaling such practices to harsher environments.
By integrating reuse into national planning, monitoring, and policy frameworks, Algeria can safeguard its water resources, enhance agricultural productivity, and build resilience against the impacts of climate change, turning environmental challenges into sustainable development opportunities.
References
[1] Lindsay C. Stringer; Alisher Mirzabaev, Tor A. Benjaminsen, Rebecca M.B. Harris, Mostafa Jafari, Tabea K. Lissner,Nicola Stevens,Cristina Tirado-von der Pahlen. Climate change impacts on water security in global drylands Lindsay C. Stringer. One Earth. Volume 4, Issue 6,18 June 2021, Pages 851-864.
[2], Silvia R. Santos Da Silva, Fernando Miralles-Wilhelm, Son Kim, Page Kyle, Yaling Liu, Chris Vernon, Alison Delgado, Jae Edmonds, Leon Clarke. Impacts of water scarcity on agricultural production and electricity generation in the Middle East and North Africa Front. Environ. Sci., 27 February 2023
Sec. Interdisciplinary Climate Studies.Volume 11 – 2023 https://doi.org/10.3389/fenvs.2023.1082930
[3 ] Ali Rahmani Salah Eddine, Brahim C. Water Supply Prediction for the Next 10 Years in Algeria: Risks and Challenges. Irrigation & Drainage Systems Engineering. 2017 06(03)
[4] Khaled Oabaideen, Nabila Shehata,Enas Taha Sayed,Mohammad Ali Abdelkareem, Mohamed S.Mahmoud, A.G.Olabi. The role of wastewater treatment in achieving sustainable development goals (SDGs) and sustainability guideline. Energy Nexus Volume 7,September 2022, 100112.
[5] Farfán Chilicaus, G.C.; Cruz Salinas, L.E.; Silva León, P.M.; Lizarzaburu Aguinaga, D.A.; Vera Zelada, P.; Vera Zelada, L.A.; Luque Luque, E.O.; Licapa Redolfo, R.; Ramos Farroñán, E.V. Circular Economy and Water Sustainability: Systematic Review of Water Management Technologies and Strategies (2018–2024). Sustainability 2025, 17, 6544. https://doi.org/ 10.3390/su17146544
[6] Rezzoug Cherif, Merzougui Touhami, Abdelhadi Bouchiba. Wastewater treatment technologies and challenges in Algeria and their future prospects. Discover Sustainability August 2025; 6(1), DOI:10.1007/s43621-025-01731-7
[7] Abbaszadegan, M.; Alum, A.; Kitajima, M.; Fujioka, T.; Matsui, Y.; Sano, D.; Katayama, H. Water Reuse—Retrospective Study on Sustainable Future Prospects. Water 2025, 17, 789. https://doi.org/ 10.3390/w17060789
[8] Hanane Abdelmoumene, Faiza Lallam, Mostefa Lallam, Maamar Boumediene. Assessment of the operational status of a wastewater treatment plant using the FAHP Process: case study of the Ain El Houtz WWTP in Algeria. Vol. 5 No. 2 (2024): Studies in Engineering and Exact Sciences, Curitiba, v.5, n.2, 2024.
[9] www.joradp.dz
[10] Neggache, N. (2017). La réutilisation des eaux usées épurées de la station d’épuration de Zemmouri (Master’s thesis, Université M’Hamed Bougara, Boumerdès).
[11] https://www.wur.nl/upload_mm/a/9/f/0e8ad9c2-0e7f-4617-b341-c112258ed701_wawaria.pdf
[12] https://cntpp.dz/
