UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105 September 30, 2010 Guy Romine Army Environmental Command 19932 S.E. Foster Road Damascus, OR 97089 Re: U.S. EPA Review of MOTCO Draft Five-Year Review for Site 1 Landfill Dear Mr. Romine: The U.S. Environmental Protection Agency (U.S. EPA) appreciates the opportunity to receive and review the Department of the Army's (Army) document entitled, “Draft First Five- Year Review for Site 1 Tidal Area Landfill” (Five-Year Review) for Military Ocean Terminal Concord (MOTCO), dated September 22, 2010. The Five-Year Review was submitted pursuant to the November 20, 2009, Amended Federal Facilities Agreement for the Army portion of the Concord Naval Weapons Station Superfund Site. Based on our review of the Five-Year Review, U.S. EPA concurs with the Army on the Protectiveness determination for the Site 1 remedy. The Protectiveness Statement indicates the following: “Although the remedy is incomplete, there have been substantial improvements in protection to human health and the environment since the start of construction. The potential for direct exposure to landfill waste has been substantially reduced by the thick layer of fill which covers nearly the entire landfill. In addition, infiltration of rainwater has been reduced substantially over preconstruction conditions because the site is now sloped to drain and because it is now covered with compacted fill. The remedy at the Site 1 Landfill is expected to be protective of human health and the environment upon completion, and in the interim, exposure pathways that could result in unacceptable risks are being controlled.” Additional information and recommendations are provided to improve the overall quality of the Five-Year Review and to address some long-term protectiveness issues (see Enclosure). u.s. EPA looks forward to continued coordination with the Army on cleanup activities at MOTCO. If you have any questions concerning this matter, please contact Phillip Ramsey of my staff at (415) 972-3006. Michael Montgomery Assistant Director Federal Facilities and Site Cleanup Branch Enclosure cc: Ms Cynthia Burris, USACE Mr. Jim Pinasco, DTSC Mr. Alan Friedman, RWQCB 2 ENCLOSURE September 30, 2010 U.S. EPA Review of MOTCO Draft Five-Year Review for Site 1 Landfill Based upon the U.S. Environmental Protection Agency (U.S. EPA) review of the Department of the Army’s (Army) “Draft First Five-Year Review for Site 1 Tidal Area Landfill” (Five-Year Review) for Military Ocean Terminal Concord (MOTCO), dated September 22, 2010, the following comments apply: General Comment: 1. Issues, Recommendations, and Follow-Up Actions: The Five-Year review details issues, recommendations, and follow-up actions related to long-term protectiveness. Issues cited include: need for redesign of the Site 1 cap; development of an Explanation of Significant Difference (ESD) to document the design change; and, completion of the landfill remedy. From the three issues, the report identifies two recommendations and follow-up actions: complete the ESD; and complete the cap. While U.S. EPA does not have concerns with the specific issues, recommendations, and follow-up actions described, U.S. EPA requests that the Army expand the issues to include other aspects of the overall remedy for the Site 1 Landfill, including Groundwater and Land Use Controls (LUCs). Groundwater: U.S. EPA requests that the Army acknowledge in the Five-Year Review that groundwater is an issue that potentially impacts the long-term protectiveness of the existing remedy for Site 1. The Recommendations and Follow-Up Actions should include that the Ar m y will conduct and complete the Groundwater Remedial Investigation/Feasibility Study for Site 1, as well as develop documents associated with remedy selection (i.e., Proposed Plan and Record of Decision or ROD) and implementation (Remedial Design/ Remedial Action). The schedule for these primary deliverables that is established in the Final July 2010 Site Management Plan, should also be included in the Five-Year Review. LUCs: Similar to U.S. EPA’s concern with Site 1 Groundwater, U.S. EPA requests that the Army detail in the Five-Year Review the specific LUC requirements that exist pursuant to the 2004 ROD. The 2004 Site 1 ROD, Section 2.1, the Selected Remedy, indicates that, “[t]he Navy has selected Alternative 2 (soil cap, surface controls, institutional controls, landfill gas monitoring, and maintenance) as the preferred alternative…”. On page 52, the ROD provides the detailed description of this component of the remedy: “Institutional controls to safeguard the integrity of the soil cap and associated monitoring systems. Institutional controls would prohibit construction of any habitable structures, or other land-disturbing activity into or onto the surface of the landfill or adjacent to the landfill, planting of vegetation that could threaten the integrity of the landfill cap, removal of or tampering with posted signs, irrigation of the surface of the landfill, and extraction of groundwater from beneath the landfill. The Navy will develop a LUC-RD as part of the post-closure maintenance and monitoring plan to ensure that institutional controls are maintained in the long-term.” 3 Based upon a review of the ROD and the LUC requirements, the Army is requested to review the N a v y ’ s Site 1 LUC-RD for specific LUC requirements and to determine if the existing L U C requirements are consistent with the 2003 DoD-EPA Guidance, “Principles and Procedures for Specifying, Monitoring, and Enforcing Land Use Controls…”. If the LUC requirements are not complete or inconsistent with guidance, the Army should identify it as an “Issue” and propose recommendations and follow-up actions. Specific Comments: 1. Executive Summary, page ES-1: In the third paragraph, third sentence add, “fundamentally” to the statement “…that are considered significant but that do not fundamentally change the selected remedy.” 2. Section 1.0, Introduction: Text in the second paragraph indicates that “[i]mplementation of the remedy at the Site 1 Landfill has not been completed but is scheduled for completion in 2011.” This statement appears in conflict with the 2004 ROD remedy, which is, per the 2004 Site 1 ROD, a “soil cap, surface controls, institutional controls, landfill gas monitoring, and maintenance”. U.S. EPA recommends that the Army revise this statement to clarify what components of the remedy have not been implemented. While U.S. EPA understands that the landfill cap has not been completed, other aspects including leachate and landfill gas monitoring should now be implemented. 3. Section 1.0: Text in the third paragraph indicates, “[d]ata collected to date do not suggest that groundwater contamination is present that necessitates remedial action, although the assessment is ongoing.” As indicated in the General Comment above, U.S. EPA believes that groundwater is an ” issue” for the Site 1 Landfill that needs to be documented, along with Recommendations and Follow-Up Actions. Rather than providing generalizations regarding an ongoing RI, the Five-Year Review should document that groundwater is an issue and it will be addressed through the development of the RI/FS, Proposed Plan/ROD and RD/RA, which have been planned and scheduled in the Final 2010 SMP. This comment also applies to text in Section 3.4, History of Contamination, where the Army provides an unnecessary groundwater summary. 4. Section 4.1.2, Selected Remedy: The description of the landfill cap provided at the top of page 9 is not consistent with the 2004 Final Site 1 ROD. However, it is recommended that a detailed description of the current landfill cap (as modified by the 2008 ESD) be provided instead. The current cap design, is best presented (as a cross-section) in ESD, Drawing C-102. 5. Section 4.3, Design Changes to Reduce the Weight of the Cap: U.S. EPA found the first paragraph at the top of page 11 to be difficult to follow. Given that this proposed design change description is not an essential component of the Five-Year Review, U.S. EPA requests that that paragraph be deleted. * * * 4 Draft First Five-Year Review for Site 1 Tidal Area Landfill Military Ocean Terminal Concord Concord, California September 30, 2010 Prepared for: U.S. Army Corps of Engineers Sacramento District Sacramento, California Prepared by: Tetra Tech EM Inc. 1999 Harrison Street, Suite 500 Oakland, California 94612 Prepared under: Naval Facilities Engineering Command Tetra Tech NUS Contract Number N62467-04-D-0055 Contract Task Order 310 TABLE OF CONTENTS ACRONYMS AND ABBREVIATIONS...................................................................................... iii EXECUTIVE SUMMARY .............................................................................................................1 1.0 INTRODUCTION ...............................................................................................................1 2.0 SITE CHRONOLOGY ........................................................................................................2 3.0 BACKGROUND .................................................................................................................2 3.1 INSTALLATION HISTORY ...........................................................................................3 3.2 SITE 1 HISTORY ........................................................................................................3 3.3 PHYSICAL CHARACTERISTICS ...................................................................................3