Soil vapor extraction implementability

SPSH has several advantages. It is applicable to sites where contaminants are present as non-aqueous-phase liquids (NAPLs). The technology reduces volatile organic carbon (VOC) removal time to a few weeks for a typical site, whereas soil vapor extraction (SVE) alone requires years for remediation. This reduction in removal time can signrhcantly decrease costs over SVE (from 2 to 10 times). Excavation and ex situ soil treatment is typically much more expensive to implement than SPSH, especially at deep sites. 

In situ oil skimmers are commercially available for the recovery of free product [i.e., light non-aqueous-phase liquids (LNAPLs) such as oil, grease, or other hydrocarbons] floating on the water table. Oil skimmers can be used alone or in conjunction with other remediation technologies, such as (in situ) soil vapor extraction, bioventing, or bioremediation, or (ex sim) membrane filters, coalescers, or chemical processes. The technology is implemented in sim by lowering the skimmers into wells located in the zone of contamination. 

Soil Vapor Extraction System. Once the air is injected into the saturated subsurface, it wiU migrate toward the surface due to the effect of buoyancy. Eventually the contaminated injected air will enter the vadose zone. At this point, a sou vapor extraction (SVE) system may be implemented. Soil vapor extraction applies a vacuum to the vadose zone to assist in collecting vapors. The vacuum will help vapor collection as well as assist in preventing unwanted off-site migration. Equipment used in a soil vapor extraction system is similar to that used in an air sparging system, except that a vacuum pump is used instead of an air compressor. Additionally, if the vapors being collected by the soil vapor extraction system are moist, a dewatering system may be employed (Johnson et al., 1993). 

Community protection Risk to community not increased by remedy implementation, but, contaminated water may reach the residents within 1—3 yr Temporary increase in dust production through cap installation contaminated soils remain undisturbed Soil would remain uncovered during vapor extraction for 3-5 yr Temporary increase in dust production during cap installation Similar to Alternative 3 Fixation may result in dust and odor increase Soil would remain uncovered during incineration (about 1 yr) excavation and fixation would release dust and odors to the atmosphere... 

The Biocube aerobic biofilter is an ex situ off-gas filtration system that is commercially available. The technology utilizes microbes to biologically oxidize volatile organic compounds (VOCs) and complex odors. It can be used in conjunction with vapor-vacuum-extraction (VVE), a process that draws gases from subsurface soil. These gases often require further treatment before being released into the atmosphere. Biocube has been field tested and has been implemented at over 100 sites for the treatment of hydrocarbon vapors. The technology has also been successfully used for odor control at a variety of sites. In addition, the Biocube system can treat odor and VOC emissions simultaneously. The units are modular, so additional stacks can be added as needed for increased flow and/or removal rates. 

---