11. Surfactant And Cosolvent Flushing

When properly implemented, surfactant and cosolvent flushing technologies can recover substantial quantities of contaminant mass from chlorinated solvent source zones in relatively short time periods. As with most in situ remediation technologies, surfactant and cosolvent flushing are most effective in relatively homogeneous subsurface systems with sufficient permeability to allow for delivery of injected fluid and subsequent recovery of the contaminant. Under ideal conditions, surfactant and cosolvent flushing field trials have consistently resulted in contaminant mass recoveries of greater than 80 to 90% of the contaminant mass, although recoveries on the order of 50 to 70% are more likely at complex sites. Nevertheless, such reductions in contaminant mass hold the potential to reduce source zone longevity and downgradient contaminant mass flux, thereby reducing potential risks to the environment and public health. Recent advances in these technologies have focused on combining aggressive, short-term surfactant flushing technologies with lower impact, long-term strategies such as bioremediation, which hold promise as a means to more effectively achieve remediation goals and reduce overall treatment costs.