ENVIRONMENTAL CHARACTERIZATION OF THE GUARANI AQUIFER SYSTEM (SAG) IN MATO GROSSO DO SUL (MS) AND GROUNDWATER QUALITY

Abstract

The study analyzed environmental changes and groundwater quality in the Guarani Aquifer System (GAS) in Mato Grosso do Sul (MS), Brazil, between 2002 and 2022, using MapBiomas data and IMASUL monitoring. Results showed a decline in natural formations, including forests (-1.3%) and savannas (-2.4%), while agricultural crops (soybeans: +2.22%) and planted forests (+0.9%) expanded. Pasturelands remained dominant (52.1% in 2022) but decreased slightly (-2.7%), and urbanization grew modestly (+0.3%), raising concerns over soil sealing in recharge zones .  Water quality analysis (2018–2022) identified nitrate contamination exceeding CONAMA 396/2008 limits (10 mg/L) in wells like ALC-005 (14.8 mg/L), linked to agricultural fertilizers. Microbiological pollution (total coliforms and E. coli) was detected in wells such as DOU-036, indicating sewage or animal waste infiltration. Physical-chemical parameters (pH: 5.0–8.3; conductivity: 17.3–285 μS/cm) generally met standards, while turbidity (<0.5–3.3 NTU) remained below the WHO limit (5 NTU) .  Key risks include intensive agriculture (agrochemicals and irrigation), deforestation (reducing infiltration and increasing erosion), and inadequate sanitation (worsening contamination). Sustainable management requires integrated policies: recharge area zoning, well monitoring, agrochemical regulation, and investments in sanitation and sustainable farming .  The aquifer’s preservation depends on collaboration among public and private sectors and local communities, aligned with legal frameworks like CONAMA 396/2008 and PERH-MS. Overexploitation and pollution demand urgent action to prevent water crises, especially under climate change and growing demand . 

DOI: 10.56238/edimpacto2025.058-002