Former Nansemond Ordnance Depot (FNOD)

Transcription

1 Former Nansemond Ordnance Depot (FNOD) December 3, 2015

2 Nansemond River Beachfront (NRB) (AOC-1) Remedial Investigation (RI) Work Plan Former Nansemond Ordnance Depot Formerly Used Defense Site US Army Corps of Engineers BUILDING STRONG

3 2 Presentation Outline Description and History Previous Sampling Results Proposed Sampling Program Status of RI Work Plan

4 3 AOC-1Description and History Encompasses approximately 4 acres of sparsely and heavily wooded land, grassy areas, and a bluff along the Nansemond River Listed as an AOC due to the presence of metal slag. Munitions and explosives of concern (MEC) items have historically been discovered at and removed from the NRB. Boundary of NRB expanded to encompass areas around the Former Wastewater Treatment Plant (AOC 13) as well as areas to the west along the Nansemond River due to the discovery of MEC at the NRB during intrusive investigations conducted in February and March 2014.

5 4 AOC-1Description and History, con t. A 1932 General Map documents the presence of a Minor Demolition Ground within the central portion of the NRB. Explosive items destroyed would have been restricted to small amounts due to the presence of a high explosive magazine (Building R-225) located approximately 400 feet east of the Minor Demolition Ground. Demolition Ground no longer shown on site maps by Encompasses approximately 4 acres of sparsely and heavily wooded land, grassy areas, and a bluff along the Nansemond River Southwestern corner of NRB falls within the limits of a land disturbance observed in a 1968 aerial photo.

6 5 AOC-1Description and History, con t. Bulk TNT and miscellaneous MEC/MD removed along the northern boundary of the NRB. Several munitions removals and investigations conducted at NRB from 2000 through Ten Areas of Interest (AOIs) identified within NRB using geophysics during investigation of the Shoreline MEC Munitions Response Site (MRS). Intrusive investigation of the AOIs completed in March With the exception of AOI-03 and AOI-47, subsurface findings were limited to rusted metal of a non-munitions origin.

7 Legend Site Features AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) TNT Trench Excavation (2009) AOC-3B Former High Explosives Magazine AOC-23 AOC-4 (GE Pond & Culvert) Bluff Areas of Interest Shoreline Areas of Interest FNOD Boundary Shoreline Stabilization (2009) AOC-13 Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service Limit of Land Disturbance as Depicted in 1968 Aerial Photo Ashley Capital Building (Former GE Facility) Retention Pond Stockpiled Soil and TCRA (1996) AOI-03 AOC Feet AOC-22 Figure 2-2 Site Features Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\2-2_NRB_SiteFeatures-Rev.mxd, 8/4/2015 9:36:42 AM, johna

8 6 AOC-1Description and History, con t. At AOI-03, a 6-in layer of consolidated black material (non-munitions related) observed at approximately 3 ft bgs. AOI-3 within area of land disturbance depicted in 1968 photo AOI-3 also in are potentially disturbed by expansion of Ashley Capital Building (formerly GE Facility) USACE currently holding in-house discussions regarding potential sources of black material and resulting sampling approach

9

10 AOI-03 Trench 2: Possible layer of non-md black consolidated layer.

11 7 AOC-1Description and History, con t. AOI-47 located within the stabilized shoreline. Total of 20 metal expended fuze boosters discovered from the ground surface to a depth of 5 inches bgs. Discovery consistent with historical findings of MD occasionally discovered along Nansemond River shoreline following significant weather events. Any additional investigations for AOI-47 will be conducted under the MMRP MEC Shoreline MRS investigation.

12 BLUFF2 SB42 BLUFF1 BLUFF4 SB41 SB11 &< BLUFF3 SB13 SB37 SB16 SB43 SB35 NRB-MW05S &< NRB-MW06S SB32 SB34 SB14 SB17 SB22 SB19 SB33 &< NRB-MW02S SB20 SB18 SB36 &< NRB-MW03S SB24 SB21 NRB-MW01S &< NRB-MW01D &< Legend &< &< Abandoned Monitoring Well Existing Monitoring Well Historical Soil Sample Locations Surface Soil Subsurface Soil Surface and Subsurface Soil Site Features AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary SB04 SB40 SB05 &< GE-MW21 SB06 &< NRB-MW04S SB10 SB07 SB09 Ashley Capital Building (Former GE Facility) Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service SB03 &< NRB-MW07S SB Feet SB01 &< NRB-MW08S &< AOC22-MW01 Figure 3-1 Historical Soil Sampling Locations Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\3-1_NRB_Historic_Soil_SampLocs.mxd, 8/4/2015 9:39:23 AM, johna

13 Legend AOC-23 Historical SVOC Sample Surface Soil Subsurface Soil Surface and Subsurface Soil AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) Shoreline Stabilization (2009) SB36 SB AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-3B SB SB42 BLUFF2 BLUFF2 BLUFF4 4-6 BLUFF4 BLUFF1 BLUFF1 SB43 SB43 SB43 BLUFF3 BLUFF3 4-6 SB17 SB17 SB17 SB SB32 SB33 SB33 SAMPLE ID DEPTH (FEET) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary - No analyte exceed screening criteria and background concentrations (if available). SB06 AOC-13 SB13 SB13 - One or more analytes exceed screening criteria and background concentrations (if available). Note: Soil samples within shoreline stabilization area were collected prior to shoreline stabilization SB SB39 Ashley Capital Building (Former GE Facility) Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service SB03 SB AOC-4 Feet AOC-22 Figure 3-2 Soil SVOC Screening Criteria Exceedances Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: \\fsfed02\tig\fnod\y:\fnod\mxd\nrb\ri Work Plan\3-2_NRB_Soil_SVOC_Sampling_Locs_REV.mxd, 8/3/2015 5:03:11 PM, johna

14 Legend Historical Pesticide Sample Surface Soil Subsurface Soil Site Features AOC-1 (Nansemond River Beachfront) SB36 SB AOC-23 Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) SD22 SB06 SB06 SB42 SB AOC-3B BLUFF4 4-6 BLUFF4 SB43 SB43 AOC-13 SB47 SB13 SB32 SB SB17 SB33 SB17 SB33 SB33 FNOD Boundary SAMPLE ID DEPTH (FEET) - No analyte exceed screening criteria and background concentrations (if available). - One or more analytes exceed screening criteria and background concentrations (if available). Note: Soil samples within shoreline stabilization area were collected prior to shoreline stabilization SB39 SB Ashley Capital Building (Former GE Facility) Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service SB03 SB Feet AOC-4 AOC-22 Figure 3-3 Soil Pesticide Screening Criteria Exceedances Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\3-3_NRB_Soil_Pesticide_Locs-Rev1.mxd, 8/3/2015 5:04:45 PM, johna

15 Legend Historical Explosives Sample Surface Soil Subsurface Soil Surface and Subsurface Soil Site Features AOC-3B SB40 SB SB05 SB05 SB04 SB04 SB06 SB06 SB37 SB37 SB16 SB BLUFF4 BLUFF4 SB17 SB SB41 SB41 SB11 SB11 SB42 SB BLUFF2 BLUFF2 SB39 SB BLUFF1 AOC-13 SB13 SB13 SB43 SB43 BLUFF1 SB35 SB35 BLUFF3 BLUFF3 4-6 SB32 SB43 SB SB10 SB09 SB10 SB SB07 SB07 SB14 SB SB19 SB19 SB34 SB SB33 SB33 SB SB22 SB20 SB SB18 SB SB36 SB SB SB21 SB21 Ashley Capital Building (Former GE Facility) AOC-23 AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary SAMPLE ID DEPTH (FEET) - No analyte exceed screening criteria and background concentrations (if available). - One or more analytes exceed screening criteria and background concentrations (if available). Note: Soil samples within shoreline stabilization area were collected prior to shoreline stabilization Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service SB03 SB03 AOC Feet SB02 SB AOC-22 Figure 3-4 Soil Explosives Screening Criteria Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\3-4_NRB_Soil_Explosives_Screening-Rev1.mxd, 8/3/2015 5:08:47 PM, johna

16 Legend Historical Metal Samples Surface Sample Location Subsurface Surface and Subsurface Site Features Shoreline Stabilization (2009) AOC-3B SB40 SB SB05 SB05 SB04 SB04 SB06 SB06 SB42 SB BLUFF2 BLUFF2 BLUFF4 BLUFF4 4-6 SB41 SB41 SB11 SB11 SB39 SB SB13 SB13 AOC-13 SB37 SB37 BLUFF1 BLUFF1 BLUFF3 BLUFF3 4-6 SB SB07 SB07 SB16 SB SB43 SB43 SB17 SB17 SB09 SB09 SB32 SB SB SB14 SB35 SB35 SB19 SB19 SB33 SB33 SB SB22 SB SB20 SB SB SB SB SB21 Ashley Capital Building (Former GE Facility) AOC-23 AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary SAMPLE ID DEPTH (FEET) - No analyte exceed screening criteria and background concentrations (if available). - One or more analytes exceed screening criteria and background concentrations (if available). Note: Soil samples within shoreline stabilization area were collected prior to shoreline stabilization Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service SB03 SB03 SB44 AOC Feet SB02 SB AOC-22 File: Y:\FNOD\MXD\NRB\RI Work Plan\3-5_NRB_Soil_Metals_Screening_REV.mxd, 8/3/2015 3:45:04 PM, johna Figure 3-5 Soil Metals Screening Criteria Exceedances Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia

17 BLUFF2 SB42 BLUFF1 BLUFF4 SB41 SB11 &< BLUFF3 SB13 SB37 SB16 SB43 SB47 SB35 NRB-MW05S &< NRB-MW06S SB32 SB34 SB14 SB19 SB17 SB48 SB22 SB33 &< NRB-MW02S SB20 SB49 SB18 SB36 &< NRB-MW03S SB24 SB21 NRB-MW01S &< NRB-MW01D &< Legend &< &< Abandoned Monitoring Well Existing Monitoring Well Proposed Soil Sample Historical Soil Sample Locations Surface Soil Subsurface Soil Surface and Subsurface Soil Site Features AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary SB54 SB53 SB55 SB04 SB52 &< NRB-MW07S SB40 SB50 SB51 SB05 &< GE-MW21 SB06 &< NRB-MW04S SB39 SB10 SB07 SB09 Ashley Capital Building (Former GE Facility) Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service SB Feet SB01 &< NRB-MW08S &< AOC22-MW01 Figure 3-6 Proposed Soil Sampling Locations Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\Proposed_Soil_Sampling_Locations.mxd, 8/4/ :28:04 AM, johna

18 Legend Proposed Sample Location Proposed Soil Sample AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-3B (Offshore Area (near)) SB55 SB50 SB54 SB52 SB51 SB53 AOI-03 Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service Feet Figure 3-7 AOI-03 Proposed Soil Samples Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\3-7_NRB_AOI03_SoilSample-Rev1.mxd, 8/4/2015 9:55:50 AM, johna

19 SD05 SD06 SD05 SD06 SD15 SD12 SD04 SD04 SD12 SD14 SD15 ") SD14 ") ") ") SD07 ") ") ") SD18 ") SD10 ") ") ") ") ") SD11 SD11 ") ") SD19 ") SD19 ") ") ") SD20 ") SD13 ") ") SD03 SD03 SD13 SD02 SD02 SD22 SD01 SD22 SD21 SD08 SD21 SD08 SD07 SD16 SD16 ") ") SD17 ") SD09 SD24 SD09 SD25 SD25 Shoreline Stabilization (2009) AOI-03 SD23 Ashley Capital Building (Former GE Facility) Legend ") Historical Sediment Sample Site Features AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary - No analyte exceed screening criteria and background concentrations (if available). - One or more analytes exceed screening criteria and background concentrations (if available). Note: Sediment samples within shoreline stabilization area were collected prior to shoreline stabilization. Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service Feet File: Y:\FNOD\MXD\NRB\RI Work Plan\3-6_NRB_Sediment_Metal_Screening_REV.mxd, 8/3/2015 4:03:00 PM, johna Figure 3-8 Sediment Metal Screening Exceedances Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia

20 SD29 ") Legend &< Existing Monitoring Well ") Proposed Sediment Sample Site Features AOC-1 (Nansemond River Beachfront) &< NRB-MW06S Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) SD28 ") NRB-MW02S &< AOC-23 (Renovation Plant) AOC-4 (GE Pond & Culvert) FNOD Boundary SD27 ") NRB-MW05S &< SD26 ") Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service &< GE-MW21 &< NRB-MW04S Feet &< NRB-MW07S Figure 3-9 Proposed Sediment Samples Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\Proposed_Sediment_Samples.mxd, 8/4/ :20:36 AM, johna

21 Legend &< Proposed Monitoring Well &< Abandoned Monitoring Well &< Existing Monitoring Well Site Features AOC-1 (Nansemond River Beachfront) Shoreline MRS AOC-22 (Arsenic Investigation Area) AOC-23 &< NRB-MW01D NRB-MW01S &< AOC-3B (Offshore Area (near)) AOC-13 (Former Wastewater Treatment Plant) AOC-23 (Renovation Plant) Shoreline Stabilization (2009) AOC-3B NRB-MW06S &< &< NRB-MW10S &<&< NRB-MW03SR NRB-MW03D AOC-4 (GE Pond & Culvert) &< NRB-MW02S &< NRB-MW05S GE-MW21 &< AOC-13 &< NRB-MW04S Projection: Virginia State Plane South NAD 83, U.S. Survey Feet Imagery: ESRI Mapping Service AOI-03 &< NRB-MW09S Ashley Capital Building (Former GE Facility) &< NRB-MW07S AOC Feet &< NRB-MW08S AOC-22 &< AOC22-MW01 Figure 3-10 Existing and Proposed Groundwater Monitoring Wells Nansemond River Beachfront Former Nansemond Ordnance Depot (FNOD) Suffolk, Virginia File: Y:\FNOD\MXD\NRB\RI Work Plan\3-7_NRB_Groundwater_MonitoringWell_Locs_REV.mxd, 8/3/2015 4:05:35 PM, johna

22 8 AOC-1Proposed RI Scope Surface and subsurface soil sampling to delineate areas where explosives and metals concentrations exceeded risk screening criteria and BTVs. Potential surface and subsurface soil sampling at AOI-03 for metals and PAHs due to black material. Sediment sampling for explosives and metals where historical samples exceeded risk screening criteria. Due to 2009 shoreline stabilization, the planned sampling effort will be the initial one conducted. Installation of groundwater monitoring wells and groundwater sampling to further characterize the vertical and lateral extent of explosives and metals that historically exceed risk screening criteria and BTVs in groundwater.

23 9 AOC-1 RI Work Plan Status Work Plan currently undergoing internal USACE review Discussed proposed RI scope with USEPA and VDEQ on 3 December 2015 Plan to submit RI Work Plan to USEPA and VDEQ by 30 December 2015

24 SHORELINE MEC - REMEDIAL INVESTIGATION Former Nansemond Ordnance Depot Formerly Used Defense Site December 2-3, 2015

25 REMEDIAL INVESTIGATION 2011 (RI, Weston) Geophysical investigation was initiated on 51 acres along the shoreline and bluff areas Bluff surveys: 46 AOIs; Shoreline surveys 9 AOIs At AOIs 36, 37 and 47, Mark III boosters and M7 fuses discovered during geophysical investigation Present (RI, WESTON) Intrusively investigating 24 AOIs and nine individual targets along the bluff and nine AOIs along the beach identified in the Army s Recommendation Memo- MC Sampling if MEC is found Geophysical investigation at TCC parking area, and six other vegetated portions adjacent to parking Intrusive investigation at AOI 36, AOI 37, AOI 47 and kickout areas

26 AOI 47

27 AOI 47 Work conducted 0n 2014

28 AOI 37 Intrusive Investigation on 2014

29 AOI 36 Intrusive Investigation on 2014

30 Geophysical Work Conducted on June 2015 Intrusively investigate AOIs AOI 36 AOI 37 Parking Lot Area with ground disturbance and the potential for containing munitions-related items and debris Areas with potential staining or potential land disturbance

31 Current and Future Plan Technical Memorandum (TM) is prepared for review by stakeholders. TM present current findings and proposes new work Additional RI will include analog magnetometer surveys, reacquisition and intrusive investigations of DGM anomalies, and MC sampling and analysis Upon approval of Tech Memo

32 Recommended Actions for Parking Area

33 RI-Continued AOI 36 AOI 37

34 The circular feature area of approximately 2.7 acres is associated with Area of Interest (AOI-36) and AOI-37 and is based on the anticipated fragmentation distance of 200 feet for the munitions items found at AOI-36 and AOI-37

35 Recommended Actions for Kick-out Area To characterize the nature and the extent of the anomalies detected across the Kick-Out Area, it is recommended that the 168 DGM targets proposed in Table 3-2 and the seven AOI be reacquired and intrusively investigated MC sampling will be performed at MEC/MPPEH release locations as necessary based on the intrusive investigation results

36 EM31 Survey of Dark Areas from 1957 Aerial Imagery BUILDING Building STRONG Strong

37 Recommended Actions for six smaller grids traversed in the wooded area A total of eight AOIs (05 through 12) were identified in the Potential Burial Pit areas. To characterize the nature and the extent of the AOIs, it is recommended that the AOI be further investigated by test pitting Perform the intrusive investigation and MC sampling if needed

38 FINAL RI REPORT RI Report should include the nature, location, and concentration of MEC and MC at the MRS and include a hazard assessment (MEC-HA) to quantify potential impacts to human health and the environment

39 Main Burning Ground (MBG) Supplemental Site Characterization Former Nansemond Ordnance Depot Formerly Used Defense Site December 3, 2015 Building Strong

40 FNOD Site Map

41 Potential Sources and Areas of Residual Contamination Based of MPI Revised RI

42 Summary of RI and MEC Activities RI-Weston 2000 RI Activities Completed to Date The initial RI field investigation at the MBG site was completed between November 1999 and April 2000 and the results of this investigation were documented in the Draft RI Report (Weston, 2000) SRI-Weston 2005 Supplemental RI (SRI) field investigations were completed between October and November 2002 to investigate data gaps identified in the initial RI and areas identified during the MEC removal action activities. The results of this investigation were documented in the draft final combined RI/SRI Report (for both MBG and HSP) (Weston, 2005) Revised RI-Malcolm Pirnie, 2012 Revised RI field investigations were conducted from August through November 2008 to address data gaps identified in the initial RI and SRI. The results of this investigation were documented in the Revised RI Report (Malcolm Pirnie, 2012) which was submitted to EPA in December 2012 Comments received in March of 2013 Revise the SLERA Revise the data tables SLERA revised in 2015 by USACE comments received and RTCs prepared but not yet submitted BERA discovered that was finalized in 2008 as a combined HSP/SOP BERA no risk found To be included as appendix in RI On Going- Supplemental Site Characterization- AECOM The two primary objectives of the supplemental site characterization field activities include: Complete additional MEC investigation activities in select areas of the MBG site; Complete additional COPC characterization needed to fill RI data gaps and complete the FS

43 COCs by Media All Soils Groundwater Sediment Benzo(a)pyrene Dibenzo(a,h)anthracene Indeno(1,2,3-cd)pyrene Arsenic Cobalt Iron Manganese Selenium 2,3,7,8 - TCDD Benzo(a)pyrene Aluminum Arsenic Iron These COCs are derived from Future Child Resident Receptor at least 1E-05 risk or 0.1 HQ (Total Risk of 2E-04 and HQ of 10)

44 Summary of Risks at MBG Both human health and ecological risk assessments (HHRA and ERA) were completed as part the Revised RI Report by MPI (2012) Ecological Risk The ERA concluded that ecological effects from the COPCs are anticipated to be negligible Human Health The HHRA identified future residential receptors (adult and children) as the only potential receptors with cumulative risk greater than the EPA target risk range of 10-4 to 10-6 and a noncarcinogenic hazard greater than 1.0. The carcinogenic PAHs benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene were identified as constituents of concern (COCs) in soil based on the unacceptable cancer risk to residential receptors. Potential sources of PAH COCs detected at the MBG site include historical burning practices and debris piles at the MBG site

45 Proposed MEC Investigation Areas

46 MEC Investigation and Findings Significant construction and metallic debris (potentially landfilled) was located in all three areas of munitions investigation (two grid areas and border area) during survey and vegetation removal activities In Sub-Area A, a few locations with munitions casings on the ground surface were identified following vegetation removal. These locations are outside the planned MEC

47 MEC Investigation and Findings AECOM conducted MEC investigation transects and trenching/test pits in eight 100x100 ft investigation grids. These grids included B-11, B-12, C-11, C-12, C-13, D-4, E-2, and E-3 In the first five grids investigated, B- 11, B-12, C-11, C-12, and C-13, saturated response areas were encountered caused by construction debris fill to depths of 3 to 5 ft below ground surface (bgs). Hand digging hundreds of anomalies along the investigation transects in saturated areas was replaced with mechanical excavation For all eight investigation grids, trenching or test pits were conducted to characterize anomalies/debris below 2 ft bgs and identify the depths of these materials, if feasible. No munitions related debris or MEC/MPPEH was encountered in the eight investigation grids

48 MEC Investigation and Findings MEC investigation of the border area included a 100% sweep. The border area was divided into 9 investigation grids by the UXO team (grids WB-1 through WB-9). In grids WB-1 and -2, non-mec trash/debris areas were encountered and limits approximated. Excavator test pits determined the non-mec debris/trash in this location to be approximately 1 to 2 ft deep In the remaining border area outside of the trash/debris areas, a 100% sweep was completed in each grid. All detected anomalies were identified and recovered using mag & dig techniques except for two anomalies in grid WB-8. These anomalies were determined to be below 5 feet depth and could not be dug safely due to groundwater infiltration and caving concerns.

49 MEC Investigation and Findings Significant construction and metallic debris (potentially landfilled) was identified on the surface in border area planned for investigation WB-9 which is about 50ftx100ft, 206 anomalies were flagged. Dug 69 of the 206 anomalies and all were non-munitions related cultural debris (attached photo of grid with flags and photo of debris they were finding). In WB-8, 128 anomalies were found and dug approximately 20 and found all non-munitions related cultural debris. In WB-7 28 anomalies were found and dug them all were nonmunitions related cultural debris. This pattern of lower anomaly counts continued a little further as team moved westward, but there were cultural debris/trash disposal areas in the vicinity of WB-1 and WB- 2 based on visual observations. No munitions related debris or MEC/MPPEH was encountered in the border area

50 MEC Conclusion All anomalies dug and found during the two weeks of investigations across the site were non-munitions cultural debris. In the border Area all anomalies outside of the trash pit area were resolved except two in grid WB-9. These two anomalies were greater than 5 feet bgs. AECOM stopped digging at this depth due to groundwater infiltration and safety concerns associated with the caving of sandy soils. Whatever is at depth is highly likely to be cultural debris similar to the rest of the debris found in the grid/area

51 Data Gap Field Samplings AECOM completed the data gap sampling including direct push soil/sediment sampling, and groundwater sampling Sampling included the collection of 57 soil/sediment samples from 31 boring locations utilizing a Geoprobe DPT rig. The rig was also utilized to install five temporary well points Low flow groundwater samples were collected from the 24 existing monitoring wells at the site as well as the five temporary well points The initial phase of data gap sampling has been completed. Follow-on phase sampling, if needed, will be based on initial phase results and summarized in a technical memorandum for stakeholder concurrence prior to implementation

52 Project Closeout, Funding, Contracts and Updates

53 Website Demonstration

54 Projects Closeout Decision Statements were signed J-Lake (AOC-7) Track K Magazine Line (AOC-14) Track K Magazine Line Landfill (AOC-15) Abandoned Water Treatment Plant (WTP) (AOC-20) Possible Closeout: Track J Magazine Line-Scar (AOC-12)

55 FUNDING & CONTRACT ACTION Contract was awarded for Horeseshoe Shaped Pond (HSP) for removal action and restoration of the site Contract Actions for 2016 James River Beachfront (JRB)- Remedial Design and Remedial Action MEC Shoreline - Feasibility Study, Proposed Plan and Record of Decision 2016 Funding: $3.4 M

56 Public Comment & Questions New Business/Establish Action Items Set Agenda for next RAB Meeting Next RAB Meeting Thursday, March 3, 2016