text: On selection as a remedy, implementation of SVE involves the following elements:  system design, operation, optimization, performance assessment, and closure.  Several guidance documents provide information on these implementation aspects.  EPA and U.S. Army Corps of Engineers (USACE) guidance documents establish an overall framework for design, operation, optimization, and closure of a SVE system.  The Air Force Center for Engineering and the Environment (AFCEE) guidance presents actions and considerations for SVE system optimization, but has limited information related to approaches for SVE closure and meeting remediation goals.  Guidance from the Pacific Northwest National Laboratory (PNNL) supplements these documents by discussing specific actions and decisions related to SVE optimization, transition, and/or closure.
  Design and operation of a SVE system is relatively straightforward, with the major uncertainties having to do with subsurface geology/formation characteristics and the location of contamination.  As time goes on, it is typical for a SVE system to exhibit a diminishing rate of contaminant extraction due to mass transfer limitations or removal of contaminant mass.  Performance assessment is a key aspect to provide input for decisions about whether the system should be optimized, terminated, or transitioned to another technology to replace or augment SVE.  Assessment of rebound and mass flux provide approaches to evaluate system performance and obtain information on which to base decisions.