Groundwater quality index (E-IQUAS): application to communicate the water status in two case studies - Camaçari (BA) e Verdelândia (MG)

Abstract

The Groundwater Quality Index (GQI/e-IQUAS) has the following characteristics: it is flexible for parameters selection;  applicable for multiples water uses; carry water quality standards recommended worldwide; accepts any programming language for any computational platform; being available for free and limitless use by the community through a public software portal. The index aggregates the parameters occurring in groundwater that produce the same effects, gathering them in "Alteration Group”. The minimum operator method gives the score for each alteration group, creating a subindex; and, the final index (e-IQUAS) corresponds to the smaller score among all the subindexes. The tests were performed on water well samples from potable supply systems drilled in the aquifer system São Sebastião, multilayer aquifer of Sedimentary Reconcavo Basin in the metropolitan area of Salvador, specifically the urban area of Camaçari, Bahia, and monitoring network in Verdelândia, north of Minas Gerais State, in the region of the Middle São Francisco basin, belonging to the geological context of the Bambuí Group. The results obtained for the index, compared with the water quality information, demonstrated that the index is suitable for groundwater evaluation, easy to apply, free of technical complexity and flexible for the inclusion of additional variable