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�`fvCES�� Ifor the transfer of organic compounds from the dissolved phase to the vapor phase Spargmg requires two components in order to control the remediation process Air must be sparged into the groundwater to provide thorough contact of the au with the impacted groundwater A vacuum must be applied to the soils above the water table to withdraw the vapor emitted from the saturated aquifer materials This vacuum system can also serve to remove COCs in the vadose I zone Treatment of the off-gas is usually required However, the groundwater is treated in-situ Air sparging is a viable option for implementation at the site In-Situ Well Aeration In-situ well aeration is suxular to air sparging in that groundwater is treated by the transfer of organic compounds from the dissolved-phase to the vapor phase Air is mjected into a double- screened well, lifting the water in the well and forcing it out the upper screen Simultaneously, additional water is drawn into the lower screen As the air bubbles rise to the water surface, the vapors are drawn off and treated by an SVE system This vacuum system can also serve to remove CDCs in the vadose zone Treatment of the off-gas is usually required Hhowever, the groundwater is treated m-situ In-situ well aeration is a viable option for the site i Enhanced Bioremediation I • The mjection of air, oxygen, or hydrogen peroxide can be used to support aerobic biodegradation and enhance natural biological activity that degrades the CDCs These may be introduced as gases or as a reactive chemical in a liquid or solid matrix form Additional nutrients (e g , phosphorus and nitrogen) may also be required to increase the natural bioactivity to levels sufficient to degrade the COCl within a preferred zone or time frame This technology can be used for both impacted sort and groundwater Systems to deliver the required additives and .4,4v;- nutrients ;nutrients typically require high maintenance since the growth of biomass can clog the m?ection Jt systems Enhanced bioremediation is a viable option for the site ,� e tuk 4.1 Technology Screening Summary ' Three of the fourteen technologies screened were deemed feasible for remediation of both the impacted soil and groundwater at the site These technologies included In-Situ Air Spargmg, In-Situ Well Aeration, and Enhanced Bioremediation A comparison of each technology in terms of ' effectiveness, implementabihty, and long-term management requirements is presented Enhanced bioremediation, as an in-situ treatment, appears feasible to meet the remedial objectives at ' this site Enhanced bioremediation can be implemented using temporary well points (e g , Geoprobe or Hydropunch) to mject the required nutrients into the soil and groundwater The nutrients would be infected along the approximate centerline of the groundwater plume This option would be the 1 9 1