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Environmental Restoration, Former MCAS Tustin, CA

Accord Engineering, Inc.  was awarded this $2.84M firm-fixed-price contract by NAVFAC Southwest to remove soil contamination located at two former hanger buildings in the former Marine Corps Air Station (MCAS) at Tustin.  MCAS Tustin was slated for closure in 1997, one of the first major military installations in Southern California to be closed for redevelopment and reuse.   Due to past operations at the site, the soil was contaminated and required a removal action under the Federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as the “Superfund Act,” for the cleanup of environmental legacy resulting from past contamination.

This CERCLA remediation project was implemented under the supervision of a Base Closure Team consisting of the Department of the Navy,  California Department of Toxic Substances Control,  U.S. EPA Region IX,  and Santa Ana Regional Water Quality Control Board.  In accordance with CERCLA compliance, the work scopes included preparation of remedial design/removal action work plans, participation in CERCLA procedural review and approval, implementation of remedial action plan, confirmation sampling and analysis, and preparation of a site closure report meeting CERLCA protocols.

The work had to be performed in accordance with a tight schedule dictated by the Base Closure Plan. Accord prepared the remedial design/removal action, which included a project quality assurance plan, site contingency plan, waste management plan, environmental control plan, stormwater pollution prevention plan, project health and safety plan, and transportation/traffic control plan to meet various environmental compliance requirements identified in the Applicable or Relevant and Appropriate Requirements per CERCLA. The plans were subsequently reviewed and approved by the Base Closure Team through the public review/comment process. The Accord Team also participated in public meetings presenting the cleanup plan to concerned community members in the City of Tustin.

Between September 2004 and February 2005, Accord conducted the field remediation in accordance with the approved work plan. The field work consisted of demolition of heavily reinforced concrete slabs, pile foundations, and substructures of former hangar buildings. Approximately 3,700 cubic yards of concrete slab was demolished. The rebar and concrete in the debris were segregated and recycled. An estimated 7,000 cubic yards of arsenic-contaminated soil was then excavated and transported to an off-site hazardous waste landfill for final disposal. The excavated sites were then backfilled with imported clean soil and restored to the original grade. The removal action involved over 4,700 man-hours and 2,300 loads of imported/exported of soil. Over 20,000 cubic yards of earthwork were performed through the remediation process. Although the fieldwork was impacted by one of the wettest winters ever recorded in Orange County, the fieldwork was still completed on schedule, below budget, and without a safety incident.

Accord conducted post-excavation environmental sampling to verify that the contamination was removed to meet the site-specific cleanup goals. The extent of the residual contamination was delineated and assessed for exposure risk through a simplified human health risk assessment. The site met the risk criteria and was approved for no further action. As such, over 4 acres of once-contaminated properties were approved for postclosure development with no deed restriction. The success of project performance was commended by the Navy for meeting the schedule  and  goals  for  property  transfer  in  the  Base  Closure  Plan.

More pictures from this very important project