Table 3.
Herbicide | Percent of samples with detection | Detection limit (ng/L) | No. of samples with detection | Maximum concentration (ng/L) |
---|---|---|---|---|
2,4-D | 100 | 0.47 | 206 | 1,850 |
MCPA | 99 | 0.58 | 205 | 374 |
Clopyralid | 99 | 0.59 | 205 | 1,050 |
Dicamba | 86 | 0.73 | 179 | 1,040 |
Diclorprop | 82 | 0.42 | 171 | 113 |
Mecoprop | 77 | 0.50 | 160 | 83.1 |
Bromoxynil | 54 | 0.99 | 112 | 384 |
Ethametsulfuron | 35 | 0.01 | 73 | 80.4 |
Atrazine | 27 | 5.76 | 48 | 52.7 |
Tribenuron | 20 | 0.01 | 42 | 30.1 |
Desethylatrazine | 21 | 26.80 | 37 | (20.8)a |
Picloram | 13 | 0.66 | 27 | 457 |
Imazamethabenz A | 13 | 0.14 | 27 | 194 |
Desethylsimazine | 12 | 148.00 | 22 | (25.3) |
2,4,5-T | 11 | 0.39 | 23 | 4.18 |
Sulfosulfuron | 10 | 1.0 | 21 | 36.1 |
Fenoprop | 9 | 0.40 | 19 | 5.8 |
Imazamethabenz B | 7 | 0.09 | 15 | 93.5 |
2,3,6-TBA | 6 | 1.10 | 12 | 2.43 |
Imazethapyr | 6 | 1.20 | 12 | 11.0 |
Thifensulfuron | 3 | 1.0 | 7 | 12.0 |
Butylate | 3 | 55.40 | 5 | (3.12) |
Metsulfuron | 2 | 1.0 | 5 | 2.1 |
MCPB | 2 | 0.63 | 5 | 12.8 |
Diclofop | 2 | 42.30 | 4 | (4.4) |
Benzoylprop | 1 | 26.20 | 2 | (1.3) |
Simazine | 1 | 16.40 | 2 | (13.8) |
Triallate | 1 | 4.14 | 2 | (3.9) |
Trifluralin | 1 | 5.15 | 2 | (1.0) |
Metribuzin | < 1 | 20.7 | 1 | 185 |
Chlorpyrifos | 3b | 14.80 | 5 | 20.1 |
Dimethoate | 1b | 25.10 | 1 | (5.98) |
Values in parentheses are estimates of concentration below the reporting limit.
n = 30.