Renewable forms of energy are increasingly penetrating the electricity market, particularly, geothermal energy. A wide range of resource temperatures and fluid quality are converted mostly using traditional binary power plants and, recently, using Climeon modular units. Portuguese natural geothermal resources are far from precise estimations. Despite the parameter uncertainties, electric power resource estimations of two natural geothermal reservoirs are presented: a volcanic sourced heated high-enthalpy geothermal reservoir in Sete Cidades, São Miguel Island, Azores; and a low-enthalpy geothermal reservoir linked to a fractured zone in a granitic setting in Longroiva, in the northern part of the Portuguese mainland. Based on the volumetric method, we assessed the power potential of geothermal resources in Sete Cidades and Longroiva using a probabilistic methodology—Monte Carlo simulation. The average reserve estimations for Climeon module were 5.66 MWe and 0.64 MWe for Sete Cidades and Longroiva, respectively. This figure was by far higher when compared to traditional binary technology; those differences were mostly attributed to distinct conversions efficiency factors.

This paper presents some important results of a full-scale experiment with a soil reinforced with short, randomly distributed polypropylene (PP) microfibres. A trial embankment 50 m long × 10 m wide with different sections of different reinforcing characteristics was built to verify the feasibility of this type of construction, and to study the most suitable procedures on site for both embankment construction and soil–fibre mixing. The experiment also aims at the validation of laboratory studies. The construction and quality control of the embankment layers are described, with special attention given to the mixture production. The full-scale experiment showed a reinforced soil behaviour broadly in agreement with the results of the laboratory studies. Soil reinforced with thinner fibres showed higher compressibility but also a higher recovery capacity when compared with unreinforced soil or soil reinforced with thicker fibres. This composite material complies with the stiffness requirements for several construction applications, proving to be a suitable material for construction.

Geoenvironmental engineering involves defining solutions for complex problems, such as containment systems management, contaminant transport control, wastewater management, remediation of contaminated sites and valorization of geomaterials and wastes. In the last years, energy harvesting (EH)—or energy scavenging—methods and technologies have been developed to reduce the dependence on traditional energy sources, namely fossil fuels, and nuclear power, also responding to the increase in energy demands for human activities and to fulfill sustainable development goals. EH in geoenvironmental works and the surrounding soil and water environment includes a set of processes for capturing and accumulating energy from several sources considered wasted or unusable associated with soil dynamics; the stress and strain of geomaterials, hydraulic, vibrations, biochemical, light, heating and wind sources can be potential EH systems. Therefore, this work presents a review of the literature and critical analysis on the main opportunities for EH capturing, accumulating and use in geoenvironmental works, among basic electric concepts and mechanisms, analyzing these works in complex conditions involving biological-, chemical-, mechanical-, hydraulic- and thermal-coupled actions, concluding with the main investigation and challenges within geoenvironmental aspects for EH purposes.

São Pedro do Sul thermomineral aquifer system is located in the North of Portugal. Hydrogeochemistry and isotopic studies were conducted in order to improve knowledge of this groundwater system, known since ancient Roman times for their therapeutic properties. One thermomineral spring (NT) and three boreholes (AC1, SDV1 and SDV2) have a mean temperature around 68 °C. Currently, these waters are mainly used in thermal spas and for geothermal energy supply. Major cations and anions were used to identify and characterize different water types and sub-systems. Stable isotopes composition, δ¹⁸O and δ²H, have been used to determine the origin and have been used as a first approach to estimate the mean preferential recharge altitude of thermomineral water. The results suggest a single aquifer system with a relative composition of cations and anions and similar mineralization values. δ¹⁸O and δ²H values indicate a meteoric origin with no significant evaporation before infiltration. Besides, the isotopic composition points to recharge areas located at altitudes of about 1000 m a.s.l. This suggests a recharge area in the Freita/Arada mountains located NW of the thermomineral poles.

The risk of aquifer contamination is determined by the interaction between the pollutant load and the vulnerability of an aquifer. Owing to the decomposition of bodies and degradation of artefacts, cemeteries may have a negative impact on groundwater quality and suitability for use due to the leaching of organic compounds (e.g., biodegradable organics, pharmaceuticals, and formaldehyde), inorganic compounds (e.g., nitrate and heavy metals), pathogenic bacteria, and viruses. Factors such as burial and soil type, rainfall amount, and groundwater depth may increase aquifer vulnerability to pollutants generated in cemeteries. The potential for groundwater contamination was investigated in two cemeteries of the Soure region in Portugal (Samuel–UC9 and Vinha da Rainha–UC10), using the classic DRASTIC model, followed by some adjustments, depending on the particularities of the locations, resulting in a Final Classification considered as Specific DRASTIC. By combining Remote Sensing (RS), Geographic Information System (GIS), and Analytical Hierarchy Process (AHP), groundwater potential zones (GWPZs) were identified, and aquifer vulnerability was assessed, which included the elaboration of thematic maps using GIS operation tools. The maps allowed for the identification of areas with different susceptibilities to contamination: from “Low” to “Very high” for the DRASTIC index and from “Very Low” to “Very high” for the Specific DRASTIC index. Although the difference between the UC9 and UC10 cemeteries is negligible, UC10 is more vulnerable because of its proximity to the community and critically important mineral water resources (such as Bicanho Medical Spa). The Specific model seems better-suited for describing vulnerability to cemeteries. Although there is limited groundwater quality data for the area, the development of vulnerability maps can identify areas that can be sensitive spots for groundwater contamination and establish procedures for pollution prevention.