Arbee Mae L. Castro, Chanelie B. Tabliga, Patricia Antonette Merecido, Anthony Vince P. Bongo · 5 authors
Wastewater disposal and treatment are critical, under-recognized components of public health and environmental protection in the Philippines. This systematic review synthesized evidence on wastewater system types, treatment technologies, assessment approaches, and population-level implications from January 1982 to 11 February 2026. Following PRISMA 2020, we searched Scopus, Web of Science, PubMed, ScienceDirect, Philippine E-Journals, and Google Scholar, plus 17 gray/institutional sources. From 717 records identified, 582 were screened and 120 full texts assessed; 57 sources (39 academic studies and 18 operational/regulatory documents) were included. Across four decades, wastewater management was constrained by fragmented governance, limited financing, weak local capacity, and low sewerage coverage, with most households relying on septic systems that often provide inadequate treatment. Evidence linked untreated or poorly treated wastewater to river and lake degradation, groundwater contamination, heavy metal bioaccumulation, eutrophication, and persistent chemical markers, while industrial case studies showed high removal efficiencies where compliant treatment was implemented. Decentralized and nature-based options (constructed wetlands, DHS, MSL, MBBR and hybrids) showed promising pollutant removal and community acceptability, and recent studies highlighted resource recovery and greenhouse-gas mitigation via sludge management. Overall, stronger coordination, investment, monitoring, septage management, and scalable decentralized solutions are essential for climate-aligned wastewater sustainability and public health protection.
Giulia Cipolletta, E. Gözde Özbayram, Anna Laura Eusebi, Çağrı Akyol · 7 authors
Water supply and reuse through non-conventional water resources can significantly decrease the stress on natural water resources. Decentralized systems can help not only to alleviate issues of water security in arid areas, but also to create a sustainable framework within a circular economy. Although these small-scale innovative technologies are able to achieve ready-to-use, high quality of recovered/treated water on-site, the loop cannot be closed in most cases due to legislative barriers. Similarly, the end-use of sewage sludge after treatment in decentralized systems still lacks specific regulations that limit its valorization. This work analyzes the current policy and legislations related to water supply, wastewater treatment, water reuse and resource valorization within the context of decentralized state-of-the-art technologies applied in rural areas. The drawbacks in the current EU legislation that set barriers to close water-related loops in European countries are highlighted. A regulatory fitness check was applied to each type of loop to identify the key factors to accomplish the legislative compliance, and financing pathways were further evaluated at the EU level. As a possible solution, further development of an innovation deal approach is recommended to address the environmental, regulatory and financial gaps in water management through an integrated framework, providing ad-hoc policies and prescriptions for sustainable reuse of all water resources.
The implementation of the EU-water framework directive (EU-WFD) demands a financeable and adaptable sewage treatment, creating a need for action especially in rural areas, where the "good ecological status" is often not reached even though the sewage works fulfill the legal minimum requirements. Therefore the construction of new, more efficient wastewater treatment plants is advisable. Due to the precarious financial situation in most rural areas, many municipalities can however not master the necessary funds for an improved waste water infrastructure. A large part of the costs would have to be shouldered by the local population in the form of additional sewage levies, leading to massive socio-economic strain. Hence, different solutions, which are tailored to the socio-economic, demographic and environmental characteristics of rural areas and fulfill the legal requirements, need to be developed. One possible approach is presented in the form of the Dirlammen case study (municipality Lautertal, Hesse, Germany). It consists of 1) biological and physicochemical analyses of the waste waters, 2) a modified eco-balance for the construction of a new sewage works and 3) socio-economic and demographic analyses of the population. It serves as a tool for the assessment of the influencing ecological, socio-economic and demographic factors on the sewage problems in rural areas. These findings can easily be transferred to other rural areas with a similar configuration and thus deliver the basis for a generally applicable approach to these problems. The results of the comprehensive analysis have shown for the municipality Dirlammen/Lautertal that the continued operation of the existing pond sewage plant is, with regards to the ecological, socio-economic and demographic points of view, preferable to the construction of a new waste water treatment plant. With regard to the sustainability principles of the sewage treatment and the objectives of the EU-WFD, existing sewage works should be operated for as long as the sewage treatment is feasible within technical and legal boundaries. With the construction of new facilities on the other hand, the expected improvement of the water quality has to be weighed against the ecological impairments caused by the construction itself. Rural waste water plans have to be developed for the long-term, taking not only the ecology into account but also the demographic change. Possible approaches in this regard could be a shift towards a decentralized waste water treatment concept and-even more important-improvements of the river morphology. But also the reduction of the diffuse pollution from agricultural sources should be considered for the development of strategies for the improvement of the ecological state. Short-term optimization measures in the existing sewage works might also improve the water quality until the long-term development plans can be implemented. In particular the challenges of the demographic change and linked with that the changing requirements for the rural waste water treatment must be addressed by any future plans. Only with the help of such a comprehensive approach the dangers of bad planning and unacceptable socio-economic burdens can be minimized.