Qualidade da água subterrânea de soluções alternativas de abastecimento na sub-bacia do Rio Taperoá

Abstract

Due to the long periods of drought in Paraíba, characterizing a true drought situation, the use of groundwater through wells has been an alternative supply solution for the population. In view of the exponential growth in the use of groundwater, there is a risk of contamination for human consumption, since these waters are susceptible to contamination by sewage or agropastoral activities. This work aims to evaluate the groundwater quality of alternative supply solutions in the Taperoá River sub-basin. In order to carry out this research, nine wells were chosen in this sub-basin, located in three municipalities (Cabaceiras, Juazeirinho and Soledade), where approximately 30% of all wells in this sub-basin are located. The minimum water quality indicators required by CONAMA Resolution 396/2008 (Total dissolved solids, nitrate, thermotolerant coliforms, pH, electrical conductivity turbidity) were selected as well as other color, temperature and iron indicators for the municipality of Soledade, since better laboratory support was made available. The sample period of the analyzes was May to October 2014 (Cabaceiras), from August to December 2016 (Juazeirinho) and from June to November 2017 (Soledade), totaling 30, 8 and 20 analyzes respectively. The raw waters of the wells were classified as brackish, according to CONAMA Resolution 357/2005. The iron, turbidity, pH, color and temperature indicators were in compliance with the Maximum Permissible Values (MPV) established in Ministry of Health Ordinance 2,914 / 2011, while the nitrate indicator exceeded its MPV in most points, and the solid indicator total samples did not conform to their standard at the points analyzed (PS8 and PS9). Anthropogenic sources of contamination were identified, evidenced by the presence of microbiological indicators, evidencing health risks for the human consumption of these waters. The waters of the wells under study were classified as class 4, according to CONAMA Resolution 396/2008, and that can only be used, without treatment, for non potable purposes.