Table 1.

TPH (mg kg−1) for surface and subsurface sediment samples

No TreatmentPre-TreatmentDuring TreatmentPost-Treatment
Ground surface
Mean40 30049 50093 20062 600
25% percentile38 00017 70037 50013 975
50% percentile (median)38 00035 00055 000*39 500
75% percentile41 50068 00082 75087 750
Number of samples312126163
Subsurface
Mean60030 30021 70017 400
25% percentile450244819152223
50% percentile (median)690*12 25068007250*
75% percentile81039 25019 80023 700
Number of samples312224169

*The median is significantly different at a 99% confidence level (P < 0.01) from the Pre-Treatment value.