Interrelationships of construction aspects of groundwater catchment wells for human consumption and pollution by multiresidues of pesticides

Abstract

Human consumption of groundwater in catchment wells whose construction aspects are neglected in rural areas has been a growing reality, caused mainly by the deficient existence of public policies that enable the collective water supply system in these locations. However, it is also in rural areas that the most intensive use of pesticide compounds is made, which, depending on their physicochemical characteristics and the specificities of the environment where they are applied and the form of application, can pollute different environmental compartments, including groundwater. Therefore, the objective of this study was to carry out a comparative analysis between the constructive aspects of Underground Water Tubular Wells (UWTW) for human consumption purposes in a rural area of a municipality in the Missões Region of the state of Rio Grande do South (RS). and, the possible interrelationships with the presence of multiple pesticide residues. The constructive assessment considered Technical Standard N° 12.212:2017 (ABNT, 2017) and the determination of 26 pesticide compounds in 5 UWTW in the rural area of a municipality in RS. The results obtained inferred construction irregularities in all wells in the study, with emphasis on the absence of: sanitary protection slab, well identification plate, above-ground walls, sidewalks and, fencing. The presence of atrazine residues was also identified in concentrations above the LQm of UWTW-1 (0,107 µg L-1), UWTW-2 (0,019 µg L-1), UWTW-3 (0,019 µg L-1), UWTW-4 (0,066 µg L-1) and UWTW-5 (0,059 µg L-1). Finally, considering that the Serra Geral aquifer is of the fissural confined type, it is inferred that possible interrelationships between construction irregularities and the presence of the pesticide compound in the public water supply from catchment wells in rural areas may occur.