KIRTLAND AIR FORCE BASE ALBUQUERQUE, NEW MEXICO ...

APPENDIX B
Standards—Chemical compounds of known purity and concentration used for calibration of analytical
instruments. Specific chemical compounds are selected as standards if site history or previous
investigation indicates that the compounds may be present at the site.
Real-time Results—Results of soil gas analyses available within minutes or hours of sample collection.
Active Soil Gas Sampling—Collection of a soil gas sample by applying a vacuum to a probe advance
into the soil.
Passive Soil Gas Sampling—Collection of a soil gas sample by burying a soil gas sampler containing an
adsorbent material. The sampler is left in place for anywhere from several days to 2 months and then sent
for laboratory analysis.
Gas Chromatograph—Analytical instrument used for analysis of soil gas samples using the principles of
gas chromatography. For real-time results, portable GCs are used. For near real-time results, lab GCs set
up at the site are used.
Temperature Ramp—A controlled increase in temperature in the GC oven. Temperature ramps are used
in bench and laboratory GC ovens to reduce analysis time and facilitate the orderly volatilization of
compounds through the analytical column. Minimum useful ramp is 10 C per minute.
Detection Limits—The minimum concentration detectable by the GC. For the compounds of primary
interest, the GC should be capable of detection limits of 0.01 microliters of vapor per liter of air,
commonly referred to as parts per million.
Responsibilities
Soil Gas Team Leader—Coordinates the entire soil gas program with the site manager and the Field
Operations Leader (FOP). He determines appropriate sampling and analysis equipment, adjusts sampling
locations based on field conditions, and may also serve as field chemist or field sampler.
Field Chemist—Responsible for the proper setup and calibration of analytical equipment used at the site
and for analyzing samples and performing the necessary QA/QC. If necessary, he adjusts the sampling
and analysis program to ensure the collection of quality data. The field chemist should have a degree in
chemistry or chemical engineering or experience with analytical chemistry instrumentation.
Field Sampler—Responsible for the collection of soil gas samples and for carrying out other functions of
the soil gas survey at the direction of the team leader.
Guidelines
A soil gas survey is designed to detect the presence of VOCs in the interstitial spaces between soil
particles in the vadose zone. The source of these compounds can be surface soil contamination,
subsurface soil contamination, or groundwater contamination. The volatile compounds migrate from the
source through the vadose zone in a gaseous state via convection and passive diffusion. The
contaminants migrating via convection are driven by changes in atmospheric pressure or by fluctuations
in the groundwater table. The contaminants migrating via passive diffusion are driven by concentration
gradients present between the contaminant source and areas with no contamination.
Kirtland AFB
SOPs for Field Investigations B-100 April 2004