DETECTION OF SUBSURFACE CONTAMINATION VAPOR PHASE
COLLECTION
	- Variable depth collection at depths of 4, 7, or 12 feet with manual hand probe - Deeper depth collection up to 100 feet with geoprobe
ANALYSES
	- Light gases (C1-C4) - Gasoline Range Gases - Carbon Dioxide - Chlorinated Hydrocarbons
INTERPRETATION
KEY CONCEPTS
- of the four phases of petroleum contamination, vapor phase contamination generally has the largest volumetric distribution, is close to the surface, is a recognized exposure pathway, and is the most cost-effective stage of environmental assessments. - environmental site assessments should initially start with soil vapor surveys - presence of methane and carbon dioxide gases confirm the process of anaerobic and aerobic biodegradation of the petroleum fuels in the subsurface - locations for continuous soil borings should be selected from areas of maximum soil vapor concentrations