Avaliação da qualidade da água subterrânea e de aspectos construtivos de poços de captação utilizados para o abastecimento público rural

Abstract

Currently, many are the problems caused by the use of pesticides in the world, and these compounds are increasingly being used in agricultural production in order to improve the productivity of the area. However, after use, residues of these compounds may be found in soil, air and water. In this sense, this work was the main objective to identify the presence of multiresidue of pesticides in groundwater artesian wells for the public water supply in a municipality of the Region of Missions. Five wells samples were analyzed for each season and checked the quality of the water on the following physicochemical parameters potability: absorbance (λ - 254 nm), electrical conductivity (μS cm-1), apparent color (uH), fluoride, dissolved oxygen (mg L-1), pH, sedimentable solids (mg L-1), temperature (°C) and turbidity (uT), in addition to microbiological parameters, total coliforms and Escherichia coli. It is further determined by means of high performance liquid chromatography coupled with mass spectrometry 24 agrochemicals, using the main crops in the area. The results obtained demonstrated that thes parameters physicochemical are in accordance with the PRC Nº 5/2017. However, microbiological parameters present in disagreement with said conciergeBecause it was identified at least once in the presence of total coliforms in all wells monitored and Escherichia coli (3 wells). With respect to pesticides were detected: Atrazine (4 wells); Azoxystrobin (3 wells); Fipronil (3 wells); Pirimicarb (all wells); Profenofos (1 well); and Trifloxystrobin (2 wells). Despite the finding of pesticide residues in all wells, none had value above the maximum extent permitted by PRC Nº 5/2017. Regarding the constructive characteristics and surroundings of the wells, all have at least one irregularity is considered to ABNT NBR Nº 12.212/2017, the most common being the lack of an adequate surrounded and sanitary slab, which can influence the superficial contamination wells and can not prevent the infection occurs through the infiltration process at these sites. Thus, the risk of waterborne disease outbreaks in rural areas is high, especially in water function that are captured, for the most part, old wells, improperly sealed and near sources of contamination. Like this, the results of this study will provide subsidies to local governments in respect to the use of underground spring