Final Alternatives Assessment: Other Contamination Sources: Interim Response Action, South Tank Farm Plume.

摘要

The South Tank Farm Plume (STFP) is located in the southern half of sections 1 and 2. It is a composite plume of C6H6, MEC6H5, XYLEN, DCPD, and BCHPD which is migrating from the area of tank 464A. Recent investigations have shown that the STFP is being biodegraded naturally and will not migrate into either Lake Ladora or Lower Derby Lake prior to implementation of the final remedy. Monitoring with the specific objectives of (1) Verifying the rate of migration and (2) Locating the leading edge of the plume over the time frame of the IRA is proposed as the preferred alternative action. Sections of this assessment provide information on: (1) Site description-history, previous investigations, hydrogeology, LNAPL plume; (2) IRA objectives and evaluation; and (3) Work plan of the IRA-well network, sampling frequency. Appendices include comments and responses.