However, these guidelines do not address the impact of drilling techniques on the collection of a representative VOC sample. Therefore, site/program QAPPs and SAPs should address the impact of all collection techniques on sample integrity and select those appropriate for the project data quality objectives (DQOs). Potential VOC losses due to drilling techniques include, but are not limited to: sample compression and loss of pore space; introduction of air into the sample matrix; mechanical heat introduced in the drilling process; and volatilization from prolonged periods in a non- hermetically sealed sampling apparatus. .
