"Sampling areas";"Nitrates (mg/l)";"Nitrites (mg/l)";"Ammonium (mg/l)";"Total phosphorus (mg/l)" "Suchiate river";"*0,02ª + 0.04";"0,003ab + 0.01";"0,04b + 0.01";"0,18ª + 0.02" "Nandayapa river";"0,02ª + 0.01**";"0,003ab + 0.01";"< 0,01c + 0.00";"< 0,02d + 0.00" "Huixtla river";"0,02ª + 0.02";"0,005ab + 0.02";"< 0,01c + 0.00";"0,12b + 0.01" "Spring water Cahuaré";"0,03ª + 0.04";"0,004ab +0.00";"< 0,01c + 0.00";"0,1bc + 0.01" "Novillero river";"0,02ª + 0.01";"0,005a + 0.01";"< 0,01c + 0.00";"0,1bc + 0.01" "Wastewaters ""La chacona""";"0,01ª + 0.00";"0,002b + 0,00";"< 0,01c + 0.00";" 0,08c + 0.02" "Pijijiapan river";"0,02a + 0.01";"0,002b + 0.00";"0,04b + 0.01";"0,04d + 0.02" "Santo Domingo river";"0,03a + 0.02";"0,006a + 0.00";"0,08a + 0.02";"0,03d + 0.01"