Application of PCB Field Test Kit to Delineate Soil Contaminated by Gas Pipeline Condensate Leak

摘要

This paper presents a history of the use and effectiveness of PCB test kits to delineate the extentrnof soils contaminated by a release of condensate from a natural gas pipeline.rnDuring subsurface utility work a contractor struck and damaged the riser pipe for a natural gasrnpipeline drip pot located beneath an intersection in New Jersey. The damage resulted in a releasernof pipeline condensate containing PCBs. Subsequent conventional sampling using drillingrnequipment and a fixed-base laboratory determined that PCBs were widespread in soils beneathrnthe intersection and adjacent private property. However, after several rounds of drilling andrnsampling, the extent of affected soil had not been determined.rnSchoor DePalma designed and implemented a program that incorporated the use of PCB test kitsrnto rapidly delineate the extent of affected soil during a single mobilization. During a four-dayrnfield investigation, Schoor DePalma analyzed 90 samples in the field. Laboratory confirmationrnwas conducted on 63 of these samples. Results indicated an 85% correlation with 1 falsernnegative and 8 false positive results. Post-excavation sampling demonstrated that this methodrnsuccessfully determined the horizontal and vertical extent of contaminated soils.rnThis approach offered a number of advantages over standard delineation methods. By accuratelyrnand quickly delineating the extent of affected soil, the project team was able to:rn1. Collect and analyze a relatively large number of samples quickly and inexpensivelyrn2.Provide results within several hours of sample collectionrn3.Clearly delineate and mark the affected zones in the field for the remediation contractorsrnMinimize over-excavationrn4.Limit the duration of road opening.