Avaliação da conformidade ao enquadramento de corpos hídricos superficiais na Unidade Territorial Estratégica Ribeirão Jequitibá/MG

Abstract

Within the river basin there is a diversity of interests in relation to the use of water and inappropriate use has generated conflicts and threatened the conservation of its quality. Due to its territorial delimitation, it is feasible to carry out quantitative and qualitative studies of water. Monitoring water quality is an essential tool in controlling pollution, since, without water quality data, it becomes difficult to plan and implement measures to control and combat water pollution. The study area is called Ribeirão Jequitibá Strategic Territorial Unit, and is part of the 23 Strategic Territorial Units (UTE’s) that make up the Rio das Velhas Hydrographic Basin. Located in the middle of Velhas, the UTE is made up of the municipalities of Sete Lagoas, Capim Branco, Prudente de Morais, Funilândia and Jequitibá. UTE Ribeirão Jequitibá has a very challenging context for the management of water resources, as the quality of its surface waters has been compromised by the discharge of effluents without adequate treatment. The sewage scenario in the municipalities that make up the Ribeirão Jequitibá UTE is challenging and endorses the statistics of municipalities that have a collection network, but are devoid of effluent treatment. The aim is to carry out an assessment of the framework of the bodies of water that make up the UTE Ribeirão Jequitibá, through the application of the Framework Compliance Index, in the historical series of monitoring carried out by the Instituto Mineiro de Gestão das Águas, for the period from 2011 to 2021, with the stations named SC24, SC25, SC26 and BV140. The results indicate a condition of departure from class 2 classification for stations SC24, SC25 and SC26, with a predominance of compliance with class 4 classification. The BV140 section located in the Jequitibá stream, located close to the confluence with the Velhas river, was the only one in that the values presented comply with the class 2 framework. It was found that the parameters that most demonstrated nonconformities are associated with the release of domestic effluents, such as phosphorus, ammonia nitrogen, BOD and dissolved oxygen. Data on the degradation of the water quality of the UTE reflect the low rate of effluent treatment in the municipalities, highlighting the need to improve and increase the treatment of collected sewage.