Groundwater quality in the Endorreic basin Tabuleiro do Martins, Maceió-al

Abstract

Water is a limited natural resource, probably the only natural resource that has to do with all aspects of human civilization, from agricultural and industrial development to cultural and religious values rooted in society. It is essential to life, whether as a biochemical component of living things, as a livelihood of various plant and animal species, as a representative element of social and cultural values, and even as a factor of production of various final and intermediate consumer goods. This research brings, as its theme, the study of the groundwater quality of the endorheic basin of Tabuleiro do Martins, Maceió / AL, located in the Coastal Tablelands of Maceió domain, in the Alagoas sedimentary basin, where these waters are intensively exploited for human consumption. industrial. It is an internal drainage systemwhere surface water accumulates in the depressions of the natural terrain, from which it evaporates or infiltrates the soil. The region has a tropical climate, dry humid, with low thermal amplitude and annual precipitation around 1480 mm. The recharge of aquifer systems is mainly due to the infiltration of surplus rainwater, estimated at 400 mm per year. From the lithostratigraphic units, the Barreiras, Marituba and Poção formations are explored, alone or together, when they form a single aquifer system. Among the potentially polluting activities identified in the region, the following stand out: sanitary sewage system, consisting of septic tanks and sinks; industrial liquid effluents in the area of the Governador Luiz Cavalcante Multisectoral Complex; gas stations; and the region's surface drainage system, consisting of flood damping lagoons that are also used as household and industrial wastewater receiving bodies. The hypothetical deductive method was adopted to evaluate the quality of local groundwater captured by tubular wells of the Alagoas Sanitation Company, initially through the statistical analysis of the physical-chemical parameters determined by CASAL in 2008 and 2018, aiming at also the comparative study of the data available in this period. The spatial variability of groundwater physicochemical parameters was evaluated in order to identify areas subject to contamination, especially in regions that have economic and environmental relevance to society. It was also identified the degree of natural vulnerability of the groundwater of the endorheic basin of Tabuleiro do Martins, through the GOD model, vulnerability index based on lithology, depth to the water table and the degree of groundwater confinement. Finally, the research identified areas in the endorheic basin of Tabuleiro do Martins where there is already evidence of groundwater pollution or degradation compared with the corresponding degree of natural vulnerability.