[Code of Federal Regulations]
[Title 40, Volume 30]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR761.247]

[Page 708-709]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 761_POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, 
DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS--Table of Contents
 
Subpart M_Determining a PCB Concentration for Purposes of Abandonment or 
  Disposal of Natural Gas Pipeline: Selecting Sample Sites, Collecting 
        Surface Samples, and Analyzing Standard PCB Wipe Samples
 
Sec.  761.247  Sample site selection for pipe segment removal.

    (a) General. (1) Select the pipe segments to be sampled by following 
the directions in paragraph (b) of this section.
    (2) Locate the proper position along the length of the pipe segment 
that you have selected for sampling, by following the directions in 
paragraph (c) of this section.
    (3) Select the proper sampling position around the circumference of 
the pipe segment that you have selected for sampling, by following the 
directions in paragraph (d) of this section.
    (4) Prior to removing pipe from the ground or lifting the pipe from 
its location during former operations, mark the top side of the pipe.
    (5) Do not sample if there are free-flowing liquids in the pipe 
segment. Free-flowing liquids must be removed prior to sampling.
    (b) Selecting pipe segments to sample. Select the pipe segment(s) 
that you will sample from a length of pipe or group of pipe segments, as 
follows:
    (1) Do not sample a pipe segment that is longer than 12.2 meters (40 
feet). If a segment is longer than 12.2 meters in length, cut the 
segment so that all resulting segments are 12.2 meters or less in 
length.
    (2) Determine which pipe segments to sample as follows:
    (i) When a length of pipe having seven or fewer segments is removed 
for

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purposes of disposal, sample each pipe segment.
    (ii) When removing a length of pipe having multiple contiguous 
segments less than 3 miles in total length, take samples from a total of 
seven segments.
    (A) Sample the first and last segments removed.
    (B) Select the five additional segments according to one of the two 
following procedures:
    (1) Assign all segments a unique sequential number. Then select five 
numbers using a random number table or random number generator. If the 
random number generator or random number table produces either the first 
pipe segment, the last pipe segment, or any previously selected segment, 
select another random number until there are seven different numbers, 
each corresponding to a different pipe segment.
    (2) Divide the total number of segments by six. Round the resulting 
quotient off to the nearest whole number. The resulting number is the 
interval between the segments you will sample. For example, cut a 2.9 
mile length of pipeline into 383 segments of approximately 40 feet each. 
Sample the first (number 1) and last (number 383) segments. To determine 
which additional five segments to sample, divide the total number of 
segments, 383, by 6. Round up the resulting number in this example, 
63.8, to the next whole number, 64. Add 64 to the number of each 
preceding pipe segment five separate times to select five additional 
pipe segments for sampling. In this example, the first pipe segment has 
the number 1, add 64 to 1 to select segment 65. Next, add 64 to 65 to 
select segment 129. Continue in this fashion to select all seven 
segments: 1, 65, 129, 193, 257, 321, and 383.
    (iii) When removing a length of pipe having multiple contiguous 
segments more than 3 miles in total length for purposes of disposal, 
take samples of each segment that is \1/2\ mile distant from the segment 
previously sampled. Sample a minimum of seven segments.
    (c) Selecting the sampling position--length. Select the sampling 
position along the length of the pipe segment, as follows:
    (1) Take samples at the end upstream of the former gas flow of each 
segment removed.
    (2) If the pipe segment is cut with a torch or other high 
temperature heat source, take the sample at least 15 cm (6 inches) 
inside the cut end of the pipe segment.
    (3) If the pipe segment is cut with a saw or other mechanical 
device, take the sample at least 2 cm (1 inch) inside the end of the 
pipe segment.
    (4) If the sample site location selected in the procedure at 
paragraph (c)(2) or (c)(3) of this section is a porous surface (for 
example, there is significant corrosion so that the wipe material will 
be shredded), then move the sample site further inside the pipe segment 
(away from the end of the pipe or pipe segment) until there is no such 
porous surface. For purposes of this subpart, natural gas pipe with a 
thin porous corrosion preventive coating is a non-porous surface.
    (5) If there is not a non-porous surface accessible by paragraphs 
(c)(2) and (c)(3) of this section, use one of the following three 
options:
    (i) Sample the downstream end of the pipe segment using the same 
sample site location procedure as for the upstream end.
    (ii) Select another pipe segment using the random selection 
procedure described in paragraph (b) of this section.
    (iii) If there is no other pipe segment in the population to be 
sampled and both ends of a pipe segment have porous surfaces at all 
possible sample collection sites, then assume that the pipe segment 
contains =50 ppm PCB but <500 ppm PCB.
    (d) Selecting the sample position--circumference. Based on the mark 
on the top of the pipe segment made prior to removing pipe from the 
ground or lifting the pipe from its location during former operations, 
sample the inside center of the bottom of the pipe being sampled. Make 
sure the sample is centered on the bottom of the pipe segment; that is, 
sample an equal area on both sides of the middle of the bottom of the 
pipe segment for the entire length of the sample.

[63 FR 35462, June 29, 1998, as amended at 64 FR 33762, June 24, 1999]

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