The deficit regarding the coverage of collection and treatment of sewage requires systems that combine proper disposal of wastewater and low construction and operating costs. In this context the bioremediation through the green septic tank, sustainable social and low cost technology, presents itself as a viable alternative especially for rural municipalities. This objective social technology contribute to confronting the domestic sewage problem and its consequences for public health and the environment; It is alternative for allocation of domestic sewage, as well as allowing the cultivation of some fruit species. Through partnership with the project Renas-Ser engaged in the management of surface and underground water bodies, three green septic tanks were constructed and are in the initial phase of operation in arid rural communities of Alagoas, contemplating the proper conditioning of domestic sewage. The first results of reduction in organic matter are very encouraging, with a view to removing approximately 38% of COD on the first support layer. The next phase is to define the others parameters to monitor and verify the approval of users of the technology.

Population growth and negative man-made environmental impacts on nature accelerate the reduction of water availability in certain regions. In this context, the reuse of treated sewage is a potential alternative, especially for agricultural activities. The municipality of Arapiraca, located in northeastern Brazil, stands out for its agricultural production, specifically in the Bananeiras pole, in its countrifields zone. Despite being inserted in a region of sub-humid tropical climate, the municipality has a picture of water scarcity. In this sense, the reuse of treated sewage may be a way of mitigating water scarcity and promoting agriculture in this locality. With the implementation of the municipality's basic sanitation system, this study aims to suggest a sustainable disposal for the planned Sewage Treatment Plant (STP). Thus, the potential for agricultural reuse of sewage treated at the STP was evaluated as a source of irrigation for farmers around that location, verifying compliance with the OMS, USEPA and PROSAB indexes. The obtained results were positive considering that the treated effluent, theoretically analyzed and based on the state of the art, depending on the efficiency level acquired during the treatment, met the analyzed parameters and the recommendations of the regulatory agencies that guide this theme.