Hydrogeochemical Studies of a Groundwater with a View to its Classification as Mineral Water for a New Medical Spa in Portugal

Abstract

Natural mineral waters are a high quality underground water resource and are becoming increasingly scarce. According to Portuguese legislation this resource is organized into two main types: bottled water and thermal waters. There are some cases where the same water due to its singularities is used in both situations. It is important to stress that groundwater to be considered a natural mineral has to comply with very demanding technical requirements and only after a considerable number of studies and procedures can it be proposed superior to the state to recognize this resource as mineral water. The present work corresponds to a recently licensed natural mineral water, with application in thermal activity, in classic thermalism and wellness thermalism, and that after its licensing it was designated “Termas de São Miguel”, in the municipality of Fornos of Algodres, in the district of Guarda, in Portugal. It should also be pointed out that there was no pre-existence of thermal baths, neither from Roman times, nor from any other period. It was all done from scratch. Thus, in this paper, the main aspects that lead to the licensing of the new natural mineral water are summarized, giving greater emphasis to the hydrogeochemical studies that were absolutely central in the whole process. Thus, in a first phase the geomorphological, geological, hydrogeo-environmental and hydrogeological aspects are presented and, in the whole, led to the elaboration of the geohydraulic model of the resource. In a second phase, the elements on the stability of the quality in terms of hydrogeochemicals, the respective classifications in chemical terms, are presented in detail, and their characteristics are compared with mineral waters of other Portuguese Medial Spas. Finally, some final considerations are made on the potential applications of the water under study, and the main conclusions are presented.