2.5.1 Data Collection
The samples were extracted from the watercourse, at a station located downstream from the areas where the watershed has the highest density of cultivated areas, and they were collected by the São Paulo Environmental Company (CETESB, 2020), once a month, in the months of February, October, and December. Sampling followed the 1060 and 9060 methods of the Standard Methods for the Examination of Water and Wastewater (SMWW d), at the collection point with code 00SP21438PEIX02100 / UGRHI 21 (coordinates: S22°18’13.62” - W50°2’53.62”).