Final Third Five-Year Review, Former Adak Naval
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FINAL 31 OCTOBER 2011 Third Five-Year Review Former Adak Naval Complex Adak, Alaska Department of the Navy Naval Facilities Engineering Command Northwest 1101 Tautog Circle Silverdale, WA 98315 THIRD FIVE-YEAR REVIEW Executive Summary Former Adak Naval Complex, Adak Island, Alaska Revision No.: 0 Naval Facilities Engineering Command Northwest Date: 10/31/11 Page i 1 EXECUTIVE SUMMARY 2 As lead agency for environmental cleanup of the former Adak Naval Complex, Adak Island, 3 Alaska, the U.S. Navy has completed this third 5-year review of the remedial actions at Operable 4 Unit A (OU A) and OU B-1 conducted pursuant to Section 121(c) of the Comprehensive 5 Environmental Response, Compensation, and Liability Act and the National Oil and Hazardous 6 Substances Pollution Contingency Plan (40 Code of Federal Regulations Part 300). Progress 7 towards remedy selection for OU B-2 sites was also reviewed. The purpose of this 5-year review 8 is to ensure that the remedial actions selected in the Records of Decision (RODs) for OU A and 9 OU B-1 at Adak remain protective of human health and the environment. This review is 10 required because contaminants have been left at Adak above levels that allow for unlimited use 11 and unrestricted exposure. This third 5-year review was prepared in accordance with the 12 Navy/Marine Corps Policy for Conducting Comprehensive Environmental Response, 13 Compensation, and Liability Act (CERCLA) Five-Year Reviews (U.S. Navy 2011h) and the U.S. 14 Environmental Protection Agency’s Comprehensive Five-Year Review Guidance (USEPA 2001). 15 This review is considered a statutory, rather than a policy, review. The triggering action for this 16 review was the execution by the U.S. Navy (Navy) of the second 5-year review on December 13, 17 2006. This review is required because contaminants have been left at Adak above levels that 18 allow for unlimited use and unrestricted exposure. In accordance with Navy guidance, this 19 review covers the entire former Adak Naval Complex, including both CERCLA and non- 20 CERCLA sites. This review also provides a summary of progress on sites and OUs without 21 RODs or state decision documents to ensure a comprehensive review. This 5-year review 22 evaluates data collected at the site during the 2006 through 2010 field seasons. 23 This 5-year review concludes that the remedy is functioning as intended by the OU A ROD and 24 the State-Adak Environmental Restoration Agreement (SAERA) decision documents for all but 25 four of the 1791 OU A and post-ROD sites on Adak. All of the remedy components required by 26 the OU A ROD have been implemented and are functioning as intended by the ROD, with the 27 exception of four sites discussed in Section 7.1 of this 5-year review and mentioned below under 28 the protectiveness discussion. The landfill caps and covers have been constructed and are 29 regularly inspected and maintained. The ponds at SWMU 17, Power Plant No. 3, have been 30 drained, dredged, and restored. Impacted sediment has been removed from South Sweeper 31 Creek, and limited soil removals have been completed at all of the petroleum sites selected for 32 this remedy component. Interim remedial action product recovery has been performed at the 14 33 free-product recovery petroleum sites. 1This includes 62 petroleum sites removed from the OU A ROD and the Tango Pad site. THIRD FIVE-YEAR REVIEW Executive Summary Former Adak Naval Complex, Adak Island, Alaska Revision No.: 0 Naval Facilities Engineering Command Northwest Date: 10/31/11 Page ii 1 An Institutional Control Management Plan (ICMP) is in place, and institutional control (IC) 2 inspections occur annually. Deficiencies are identified and corrective action is consistently 3 taken. The inspection and associated follow-up is functioning as intended. Long-term 4 monitoring has been initiated and is ongoing. The long-term monitoring goals and requirements 5 are periodically revisited to maintain focus on the endpoint goals. The Navy and U.S. 6 Geological Survey have shown that natural attenuation of petroleum compounds continues to 7 occur on Adak, and natural attenuation monitoring is part of the long-term monitoring program. 8 Where the data support a quantitative estimate, it appears that natural attenuation can be 9 reasonably expected to achieve endpoint criteria within 75 years of ROD execution. 10 The final remedy established under SAERA decision documents and the additional actions 11 required by those documents have been implemented at all of the 14 free-product sites. Limited 12 groundwater monitoring, implementation of ICs, and monitored natural attenuation have been 13 implemented where required through adjustments to the Comprehensive Monitoring Plan. 14 This 5-year review also concludes that the OU B-1 remedy is functioning as intended by the 15 OU B-1 ROD. The selected remedies have been implemented at all of the 50 action sites 16 identified in the OU B-1 ROD, although the remedy cannot be considered complete at all 50 sites 17 until all documentation is complete and concurrence from the regulatory agencies is received. 18 Complete documentation and final regulatory concurrence will be assembled as part of the 19 preparation of the remedial action completion report. Conditional closure has been achieved for 20 18 of the 50 sites. 21 Changes in the applicability or relevant and appropriate requirements (ARARs) or exposure and 22 toxicity assumptions that have occurred since the RODs and SAERA decision documents were 23 signed do not affect the protectiveness of the remedies. Concentrations of many chemicals in 24 groundwater remain above the remediation goals (RGs) within the downtown area of Adak at the 25 majority of locations where long-term monitoring is occurring. This results in the need for 26 continued ICs to prevent exposure and ongoing monitoring. Although some of the RGs might be 27 lower if selected today, the remedy components continue to protect against exposures, just as 28 they did at the time the ROD was signed. ICs preventing exposure and ongoing monitoring will 29 need to continue until concentrations of chemicals of concern in groundwater are below the RGs. 30 The protectiveness of the remedies for the OU A sites is discussed in this report by grouping the 31 sites into categories of protectiveness. Of the 1792 OU A and post-ROD sites, 175 fall into the 32 categories of either “remedy is complete and protective,” or “remedy is operating and is expected 33 to be protective. Three sites fall into the category of “not protective, unless follow-up actions are 2This includes 62 petroleum sites removed from the OU A ROD and the Tango Pad site. THIRD FIVE-YEAR REVIEW Executive Summary Former Adak Naval Complex, Adak Island, Alaska Revision No.: 0 Naval Facilities Engineering Command Northwest Date: 10/31/11 Page iii 1 taken to ensure protectiveness.”3 Sites in these three categories are listed by name in Section 9 2 of this 5-year review. 3 The OU A remedy remains protective for the 1384 sites where the remedy is complete and 4 Alaska Department of Environmental Conservation (ADEC) has concurred with a status of No 5 Further Action (NFA) or No Further Remedial Action Planned (NFRAP). At these sites, the 6 NFA status selected in the ROD, the NFA/NFRAP status achieved post-ROD, or the 7 completeness of the remedy are not called into question by new information, including changes 8 in ARARs or risk assessment assumptions. 9 The OU A remedy for 39 sites is expected to be protective when the operating OU A remedy 10 (monitored natural attenuation in many cases) is complete. In the interim, exposure pathways 11 that could result in unacceptable risks are being controlled through implementation of the ICMP. 12 The remedies for the three OU A sites listed below are concluded not to be protective, unless the 13 actions identified in Section 8 of this 5-year review are taken to ensure protectiveness. Note that 14 these sites have been removed from the OU A ROD and are now regulated under SAERA (see 15 Section 2 of this 5-year review). 16 • Former Power Plant, Building T-1451 17 • SWMU 60, Tank Farm A 18 • NMCB Building Area, T-1416 Expanded Area 19 20 At these sites, trends in product thicknesses observed in surface water protection wells, or 21 ongoing impacts to adjacent surface water call into question the protectiveness of the remedy. 22 Follow-up actions are needed at these sites for the final remedy to be protective. 23 The remedy for OU B-1 is expected to be protective of human health and the environment upon 24 completion. Although the remedy is in place at all OU B-1 sites, regulatory concurrence has not 25 been achieved for all sites. Until concurrence is achieved and the remedies can be considered 26 complete, institutional controls are in place to control exposure pathways that could result in 27 unacceptable risks. Documentation of completion of the OU B-1 remedy at all OU B-1 sites, as 3One of the three sites included in the last category (NMCB Building Area) is a combination of two previous NMCB sites within the original 178 OU A sites (adding Tango Pad to the 178 OU A ROD sites gives 178 + 1 = 179). This is the reason that the number of sites in the last two categories (3 sites) added to the number of sites in the first two categories (175 sites) appears not to add up to the total number of sites (179). 4Because some sites are considered “remedy complete and protective” under one program (e.g., CERCLA), but considered “remedy is operating and expected to be protective” under another program (e.g., SAERA), some double-counting of sites occurs in the paragraphs that follow and in Section 9.