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MARE ISLAND NAVAL SHIPYARD. Mare Island Sites Time Critical Removal Action Presented By: David Godsey, Navy Dwight Gemar, Weston. RAB Meeting April 26, 2007. Time Critical Removal Action. Objectives/Scope
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MARE ISLAND NAVAL SHIPYARD Mare Island Sites Time Critical Removal Action Presented By: David Godsey, Navy Dwight Gemar, Weston RAB Meeting April 26, 2007
Time Critical Removal Action • Objectives/Scope • Excavate soil with contaminant concentrations exceeding established target cleanup goals for five sites • Transport soil to Investigation Area H1 (IA-H1) for placement within the IA-H1 Containment Area as subgrade fill • Perform confirmation sampling of excavations • Restore sites • Timing • Coordinate with completion of IA-H1 Containment Area cap (in progress) 2
Time Critical Removal Action (Scope) • TCRA sites • Installation Restoration Site 04 (IR04) • Paint Waste Area (PWA) • Defense Reutilization and Marketing Office Fenced Scrapyard Area (DRMO) • Horse Stable Area (HSA) • Installation Restoration Site 05 (IR05) • Soil Consolidation at IA-H1 • Consistent with approved Remedial Action Plan for IA-H1 (August 2006) 3
Site IR04 Background • Formerly used for the disposal of expended abrasive blasting material (ABM) • ABM contaminants include copper, chromium, nickel, and zinc • Soil, sediment, and groundwater extensively characterized 1983-2006 • No munitions history (surveyed/investigated with no items encountered) • 2006 Remedial Investigation concluded that metals in soil and sediment pose unacceptable risks to the environment • Estimated TCRA soil removal volume is 20,000 cubic yards 4
Site IR04 Photos Submarine Hull Sandblasting 1980 Photo of IR04 Site 5
Paint Waste Area Background • Located in northern end of MI in an upland area adjacent to wetlands near Building 505 • Area containing exposed paint waste debris identified by U.S. Fish & Wildlife Service in 2002 • ~520 cubic yards of contaminated soil removed in 2003 removal action • Results of additional 2003 sampling indicate additional contaminated soil remains in/around the original site • Contaminants of concern are metals and organics • Estimated TCRA soil removal volume is 8,500 cubic yards 6
Paint Waste Area Photos 2003 SMHM Protection Measures PWA Site During 2003 Removal Action 7
DRMO Background • Located in central Mare Island near intersection of Azuar Drive and “A” Street • Former Defense Reutilization and Marketing Office scrapyard serving MINS and other activities (1942-2005) • Surveys completed between 1985 and 2002 identified lead oxide (submarine batteries) and PCBs (oil-filled transformers) as likely site contaminants • History of munitions and low-level radiological items • Addressed by 1996 and 2005-2006 removal actions • No longer realistic concerns • Contaminated areas under asphalt and outside DRMO fence remains • Estimated TCRA soil removal volume is 20,000 cubic yards 8
DRMO Site Map and Step-Out Grids 1980 Photo 1967 Photo 9
Horse Stable Area Background • 1.5 acre site located in the center of the Western Magazine Area • Expended ABM used as grading for stable facilities • 342 cubic yards of contaminated soil removed in 2003 based on visual survey • 2004 analysis of site soil and groundwater samples: • Chromium, arsenic, and lead exceeded human health comparison criteria at one or more location locations • Chromium, nickel, lead, and zinc exceeded conservative ecological benchmarks for soil • Estimated TCRA soil removal volume is 1,500 cubic yards 10
Site IR05 Background • Located on southern end of MI along Carquinez Strait • Munitions disposal area (burning and open detonation) from 1947 and 1975 • Also used for the open storage of munitions items • Contamination of the site by munitions documented by a series of investigations conducted 1982-1994 • Two munitions investigation/removal actions completed (1995-1997 MINS/SSPORTS and WESTON 2007) • Sampling data indicates metals and organics in soil pose a potential hazard to ecological receptors • Estimated TCRA soil removal volume is 40,000 cubic yards 12
Site IR05 Photos 1950’s Munitions Disposal IR05 Site in 2006 13
Target Cleanup Goals (TCGs) Development • Reuse considerations • Industrial (IR04, DRMO) • Open Space (PWA, HSA, IR05) • Ecological risk • Ecological Receptors (uplands vs wetlands) • Hazard Quotient = 1 using High Threshold Reference Values (TRVs) • Human health risk • < 10-5 cancer risk or Hazard Quotient = 1 for noncancer risk • Ecological risk generally drives cleanup goals lower than human health risk • Mare Island ambient/background values • Used if higher than calculated ecological or human health risk values 14
Project Schedule • Preparation and review of project documents – May and June 2007 • Public review – July 2007 • Fieldwork (excavation, confirmation sampling, backfill) – August through October 2007 • Demobilization and site restoration – November 2007 • Preparation of project summary report – January 2008 18
TCRA Benefits • Allows for economical and timely disposal • May accelerate site closures by using conservative cleanup criteria • Provides needed fill material for IA-H1 engineered cap • Reduces truck traffic on public streets • Contaminated soil transport on non-public roads only 19
Summary • Contaminated soil from five MI sites is proposed to be excavated and transported to the IA-H1 Containment Area for placement under the engineered cap • Confirmation sampling of excavations will be completed and results accepted prior to backfilling with clean soil • Accelerated timing needed to support the schedule for completion of IA-H1 Containment Area engineered cap 20