[Code of Federal Regulations] [Title 40, Volume 30] [Revised as of July 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR761.243] [Page 707] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 761_POLYCHLORINATED BI PHENYLS (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. 761.243 Standard wipe sample method and size. (a) Collect a surface sample from a natural gas pipe segment or pipeline section using a standard wipe test as defined in Sec. 761.123. Detailed guidance for the entire wipe sampling process appears in the document entitled ``Wipe Sampling and Double Wash/Rinse Cleanup as Recommended by the Environmental Protection Agency PCB Spill Cleanup Policy,'' dated June 23, 1987 and revised on April 18, 1991. This document is available from the TSCA Assistance Information Service, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. (b) Collect a surface sample from a minimum surface area of 100 cm2 at each sampling site selected. The EPA Regional Administrator may approve, in writing, requests to collect a sample from smaller surface areas, when <100 cm2 of surface eligible for sampling is present; e.g., when sampling a small diameter pipe, a small valve, or a small regulator. When smaller surfaces are sampled, convert the measurement to the equivalent measurement for 100 cm2 for purposes of comparison to standards based on 100 cm2.