The San Juan-Taxco River system is situated in the Taxco mining district, which is a well-known international producer of silver, jewelry and precious metal handicrafts. The population and biota in the area have been affected by inappropriate disposal of anthropogenic activities that pollute the hydric resources and threaten their health and sustainability, since the inhabitants use the groundwater and river water for human consumption, domestic water supply and irrigation. This study was conducted to assess the pollution in the river system, human health implications and ecological risk in the aquatic environment (groundwater, surface water and superficial sediment). This evaluation was done on the base of hydrochemical, textural, mineralogical and geochemical analysis supported by calculation of human health risk using chronic daily intake (CDI), hazard quotient (HQ) and hazard index (HI) with environmental and geochemical indices for ecological risk evaluation. The health risk assessment indicated increasing non-health carcinogenic risk to the exposed population to the river water and dug wells (HI > 1), and thus, these resources are not recommended for human consumption, domestic activities and prolonged ingestion. The results demonstrated a high degree of pollution due to toxic elements and geochemical indices. The Pollution Load Index indicated potential risk that will cause harmful biological effects in the riverine environment.

Spring water is important for human consumption, domestic use, agricultural activities, and ecotourism in the Buenavista de Cuéllar Aquifer (ABC), southern Mexico. The objective of this research was to assess the health risk from fecal coliforms, as well as the non-carcinogenic risk to human health for different age groups, by studying the oral and dermal routes. The analysis of the cartography of high-priority springs (the result of Multicriteria Evaluation (MCE)), access routes, and knowledge of the areas with high social insecurity risk enabled the selection of 20 springs to be sampled. In situ parameters were measured, major ions, fecal coliforms, and Potentially Toxic Elements (PTE). The non-carcinogenic health risk results indicated a higher risk by the oral route in children (average Hazard index (HI) value of 0.6371) and a higher risk by the dermal route in adults (average HI value of 1.2378). The highest dermal risks are in the south-southeast of the study area. On the other hand, the assessment of health risks due to fecal coliforms resulted in a medium risk for the dry season and a high risk for the rainy season. The results of this research will serve as a key reference for the management and protection of springs in order to preserve human health.

Mexico is among the countries that are facing the greatest water stress, where factors such as climate change, contamination of surface water, groundwater sources, and inefficient management have limited the availability of water resources. Consequently, new supply sources need to be implemented. Rainwater harvesting systems (RHS) are viable and sustainable alternatives, the implementation of which primarily depends on identifying suitable sites and applying technologies that are appropriate for different users. This research used the Analytical Hierarchy Process (AHP) technique in a GIS environment to select the optimal sites for designing RHS, taking into account hydrological, biophysical, and socioeconomic criteria. After determining the ideal sites, the study presents proposals and costs for the design of an urban and rural RHS based on the characteristics of the region and the needs of the community. The findings show that implementing RHS in the study area can be a practical, economical, and efficient alternative for water resource management, since these projects are aimed at sustainability.

The Taxco mining district is a well-known international producer of silver, jewelry, and precious metal handicrafts. Inappropriate disposal wastes from anthropogenic activities have been deteriorating the hydric resources and threatening the inhabitants’ health, since they use the springwater for human consumption and domestic activities. A multi-tracer approach combining measurements of hydrochemical data, trace elements, and isotopes δ²H, δ¹⁸O, ³H, and ⁸⁷Sr/⁸⁶Sr ratios was undertaken for 18 springwater samples. δ¹⁸O and δ²H indicate that the springwater comes from the rain and had experienced some degree of isotopic fractionation by atmospheric evaporation in some samples at lower altitudes. ³H values on the springwater showed the existence of old and new water. Three groups of springwater were identified according to age: local flow in rhyolites, intermediate flow through red beds to the outcrop point in sandstone and shales, and deep flow in greenschist. The results of this study show the utility of ⁸⁷Sr/⁸⁶Sr ratios in identifying the water–rock interactions and springwater flow paths, suggesting that more widespread use of the strontium isotopic fingerprint is warranted.