WATER QUALITY AND SUSTAINABILITY: A CASE STUDY IN THE RIO DO PEIXE SUB-BASIN

Abstract

Water is an essential element for life and for the proper functioning of human activities. However, the quality of water resources has been increasingly compromised by environmental impacts, such as sewage discharge, mining activities, and improper land use. The present study evaluated the water quality of the Rio do Peixe sub-basin, in the municipality of Itabira (MG), especially in the stretch receiving treated effluents from the Laboreaux Wastewater Treatment Plant (WWTP). Compliance with the standards of CONAMA Resolution no. 357/2005 and Joint Normative Resolution COPAM/CERH-MG no. 8/2022 for Class 2 water bodies was assessed. Samples were collected at two points in December 2024 (rainy season) and June 2025 (dry season), with physicochemical and microbiological analysis in a certified laboratory following APHA (2012). Results revealed non-conformities in fecal coliforms (>160,000 MPN/100mL in June 2025), BOD (up to 20 mg/L), COD (up to 47 mg/L), total iron, and dissolved oxygen (minimum 3.1 mg/L). It is concluded that the Rio do Peixe presents significant evidence of organic pollution and fecal contamination, incompatible with its Class 2 classification, reinforcing the need for sanitation actions, continuous monitoring, and environmental education.