The results are presented considering two different seasonal periods: rainy season (January and March of 2018); and dry season: (May and July of 2018). These tables also show: (i) different concentrations tested (expressed as μL/plate); (ii) results of lineages of Salmonella typhimurium (TA98 and TA100) performed by in the absence (−S9) and presence (+S9) of the metabolic activation mixture (S9) (result of mutagenic activity expressed as positive or negative); (iii) results of mutagenicity index (MI) and (iv) toxicity classification for the mutagenic tests (i.e. non-toxic, signalled in green. For more details, see item 2. Materials and Method. Note: *Tombo channel could not be sampled in the July campaign (dry season) because the rainwater course was dry.