ARCHIVED REPORTS_REMEDIAL INVESTIGATION REPORT 2000

Home Browse Search

7kN3dwe11&R0110 comments on the 3 December 1999 report and recommendations for additional soil and • groundwater investigation. A Field Investigation Workplan was prepared by Treadwell & Rollo to address the recommendations presented in the 2 February 2000 memorandum and in subsequent meetings and conversations with DTSC personnel (Treadwell & Rollo, 1999). The DTSC recommendations for additional work dealt predominantly with determining the extent of contaminants identified at specific sampling points during previous investigations. The Workplan was submitted to DTSC on 24 March 2000. Field work was completed by Treadwell & Rollo personnel at Areas 10, 11, 20, and 21 during the week of 17-21 April 2000. Field work was performed by Advanced GeoEnvironmental (AGE)at Areas 15 and 16 on 2 May 2000. 1.1 Purpose of Report The purpose of this report is to summarize environmental investigations that have been conducted at the sites in order to provide site characterization information suitable to perform a • feasibility study and risk assessment. 1.2 Definition of Operable Units The six land parcels have had different development and use histories and they have different environmental issues. For the purposes of this project,the parcels have been placed into two operable units (OUs) which contain three parcels each. Operable Unit 1 (UO-1) contains the parcels identified by the SDHR as Areas 10, 11 and 20. Operable Unit 2 (UO-2) contains the parcels identified by the SDHR as Areas 15, 16 and 21. The two operable units are shown on Figure 1. Generally, OU-1 parcels have contamination in shallow soil resulting from historic industrial uses such as shipbuilding and steel fabrication, but do not have significant groundwater contamination. OU-2 parcels have contamination in vadose zone soil and groundwater from leaking underground storage tanks. Additionally, each of the parcels in OU-2 is currently being • 2 25970309.DGD 24 August 2000