Modified Active Gas Sampling (MAGS) is an environmental engineering assessment technique which rapidly detects unsaturated soil source areas impacted by volatile organic compounds.
The technique was developed by HSA Engineers & Scientists in Fort Myers, Florida in 2002, led by Richard Lewis, Steven Folsom, and Brian Moore.
According to the MAGS Manual, written by HSA and adopted by the Florida Department of Environmental Protection, MAGS is performed "by utilizing a typical regenerative blower fitted to a temporary soil vapor extraction well, [such that]a large volume of soil can be assessed with a limited number of samples.
[3] HSA found particular success using the technique at solvent-impacted sites that were showing signs of rebound after initial remediation efforts.
These rebounds are commonly the result of multiple (relatively small) release areas that had not been previously discovered with discrete soil sampling.