The present work aimed to investigate the occurrence of 24 drugs and endocrine disruptors in the filters washing water from the Bolonha Water Treatment Plant in Belém, State of Pará, Brazil, since these residues are often released into water courses. The correlation of these microcontaminants with physicochemical and biological characteristics investigated in the studied matrix was also evaluated. For the research, six sampling campaigns were carried out during the rainy season and six in the dry season. The compounds determination was performed by solid phase extraction and chromatography coupled to mass spectrometry, gas chromatography for Ibuprofen, Paracetamol, 4-Nonylphenol, 4-Octylphenol, Bisphenol A, Gemfibrozil, Estrone, Estradiol, Ethinylestradiol, and Estriol, and in liquid phase for the other compounds. The compounds detected at higher concentrations than the others were Losartan (5.5 to 738.7 ng/L) and Bisphenol A (20.9 to 518.9 ng/L), also with the highest frequency. Multivariate analyzes showed that drugs and endocrine disruptors were more positively related to each other and to turbidity during the rainy season, with emphasis on 4-Octylphenol, Bisphenol A, Losartan and Loratadine, results that strengthen the hypothesis of precipitation’s influence on the variables studied.