SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

EPA COMMENTS ON DDRW-TRACY MEETING OF JUNE 15-16, 1992 DRAFT FINAL RI/BRA REPORT FOR OD 1 Areas of Disagreement 1. It is both Region IX and national risk assessment guidance policy to use unfiltered (total) metals data in the BRA. EPA has seen no convincing quantitative evidence to discount total metals due to turbidity. 2. EPA is not in favor of excluding metals contamination from the definition of OU-1. The draft RI data indicate a potential threat to human health and the environment from metals. There is no compelling reason to delay addressing metals in ground water. The FS needs to address metal contamination. 2 . Many issues regarding the BRA for OU 1 have been deferred to a meeting of the risk assessment personnel to be held as soon possible. 3. EPA maintains that aluminum and cobalt need to be included in the risk assessment. Following the meeting the Corps and WCC were to hold private discussions and attempt to resolve this issue. Areas of Agreement 1. EPA agrees with DDRW-Tracy' s suggestion to prohibit fishing from the storm water drainage pond (SWMU #4) . When this is done the pathway will no longer be considered complete. However, this pathway must be acknowledged and the rationale for its elimination be presented in the BRA for OU 1. 2 . Additional sources for the OU 1 groundwater plume will be addressed in the Comprehensive RI/FS Work. 3 . Characterization of sources of nitrate, boron, and pesticides will be continued in the Comprehensive RI/FS Work. DRAFT FINAL COMPREHENSIVE RI/FS WORKPLAN Areas of Disagreement 1. EPA feels that the Detailed Risk Assessment Workplan, to be developed later by DLA's new contractor, must be handled as a primary document as (1) all workplans under the Federal Facility Agreement (FFA) are primary documents, and (2) this will be consistent with the agreement to consider the phase 2 and phase 3 work plans primary documents (as addenda to the Comprehensive Work Plan) . 1