Total (N=72) Groundwater (N=12) Surface water (N=60) Type Frequency(%) Frequency(%) Median (ngL-1) Maximum (ngL-1) Frequency (%) Median (ngL-1) Maximum (ngL-1) Boscalid F 72 58 16.0 2120 75 22.6 109 Metolachlor H 57 33 68.3 120 62 37.0 1750 Atrazine H 55 67 8.0 33.5 53 14.7 132 Azoxystrobin F 51 17 (0.8) (0.9) 58 30.6 59.8 Chlorothalonil F 40 50 (0.5) 8.7 35 (1.1) 228 Pyraclostrobin F 40 33 3.1 4.8 42 15.2 239 Pyrimethanil F 28 8 na 6.0 32 (1.2) (4.0) Chlorpyrifos I 21 0 nd nd 25 3.3 65.0 Pendimethalin H 17 0 nd nd 20 32.7 57.4 Trifluralin H 13 0 nd nd 13 (0.8) 2.1 Ethalfluralin H 10 0 nd nd 12 4.0 34.4 Methylparathion I 10 0 nd nd 12 41.6 65.4 pp’-DDE D 8 0 nd nd 10 (1.4) (3.2) bifenthrin I 8 0 nd nd 19 4.8 7.0 S-ethyl dipropylthiocarbamate (EPTC) H 6 0 nd nd 7 45.0 56.3 Cyprodinil F 6 0 nd nd 7 (4.0) 180 Zoxamide F 4 0 nd nd 5 23.8 493 Dacthal H 3 0 nd nd 3 6.1 6.5 Fludioxinil F 3 0 nd nd 3 (3.3) (3.3) Carbofuran I 1 0 nd nd 2 na 94.0 Simazine H 1 8 na 140 0 nd nd Diazinon I 1 0 nd nd 2 na 1.7 Fipronil I 1 8 na (2.2) 0 nd nd Fenhexamide F 1 8 na 116 0 nd nd Malathion I 1 0 nd nd 2 na 249 Triticonazole F 1 0 nd nd 2 na 66.8 Dimethomorph F 1 8 na 33.3 0 nd nd na: median not calculated when the compound was only detected once during sampling. nd: not detected.

Table 3: Summary of the pesticides detected, pesticide type, detection frequency, and median and maximum observed concentrations in surface water and groundwater samples. Resultsin parentheses are less than the method detection limit and are estimated. (F: fungicide; H: herbicide; I: insecticide; D: degradate). (Adopted from Reilly et al. [149]).