(a) For purposes of removal for disposal of a pipe segment that has been sampled, the sample results for that segment determines its PCB surface concentration. Determine the PCB surface concentration of a segment which was not sampled as follows:

(1) If the unsampled pipe segment is between two pipe segments which have been sampled, assume that the unsampled segment has the same PCB surface concentration as the nearest sampled pipe segment.

(2) If an unsampled pipe segment is equidistant between two pipe segments which have been sampled, assume the PCB surface concentration of the unsampled segment to be the arithmetic mean of the PCB surface concentrations measured in the two equidistant, sampled, pipe segments.

(b) For purposes of abandonment of a pipeline section, assume that the PCB surface concentration for an entire pipeline section is the arithmetic mean of the PCB surface concentrations measured at the ends of the pipeline section. If additional representative samples were taken in a pipeline section, assume that the PCB surface concentration for the entire pipeline section is the arithmetic mean of the concentrations measured in all representative samples taken.

(c) For purposes of removal for disposal under §761.60(b)(5)(ii)(A)(1) or abandonment under §761.60(b)(5)(i)(B), if the surface PCB concentration of a pipe segment, determined by direct measurement or in accordance with paragraph (a) of this section, or of a pipeline section as determined in accordance with paragraph (b) of this section, is >10 µg/100 cm2, but <100 µg/100 cm2, then that segment or section is PCB-Contaminated.