Former Industrial Warehouse – Tacoma, WA

CRETE prepared a cleanup plan, construction drawings and specifications, and provided construction oversight for the demolition of an 117,000-square foot warehouse located near the head of the Sitcum Waterway in Tacoma, Washington. The site has had a variety of manufacturing uses which resulted in volatile organic compound (VOC) contamination in the soil and groundwater beneath the building. The building materials include interior and exterior PCB-containing paint and caulk. PCBs leached from the paint and caulk into the adjoining building material (concrete) and also migrated into the shallow soil adjacent to the building. CRETE worked with the Port of Tacoma to develop a strategy to segregate PCB-impacted materials from other building materials during building demolition to reduce disposal cost and avoid generating PCB Remediation Waste. PCBs in the building materials and surrounding soil trigger EPA TSCA and Washington State Dangerous Waste Regulations.

A fully-contained pilot abrasive blasting test was performed to evaluate the removal of paint with TSCA-level PCBs from building material surfaces. The results of the pilot testing determined that abrasive blasting technologies could not adequately remove TSCA-level PCB contaminated paint from building materials. As a result, the cleanup action used existing data to delineate TSCA level soil which eliminated the need to sampling during construction. In addition, the cleanup action utilized the 2013 TSCA reinterpretation to profile demolition wastes as PCB Bulk Product Waste, regardless of PCB concentrations. This pre-characterization of the demolition waste as suitable for Subtitle D landfill disposal eliminated the need for Subtitle C disposal and sampling during construction.

Building demolition and PCB soil cleanup were performed in late 2014 and early 2015 and the Port is currently using the site for truck queueing.

CRETE is continuing to support the Port through oversight of remedial investigation and feasibility study work being performed by a previous site operator under the MTCA VCP program. Soil and groundwater contamination with solvents and metals resulted from previous electroplating operations. This contamination has triggered an evaluation of indoor air quality and potential discharge of groundwater contamination to the Sitcum Waterway. In addition to the MTCA RI/FS support, CRETE is also supporting insurance and PLP cost recovery.

Work Performed

• Regulatory negotiations – MTCA, TSCA
• Cost Recovery
• Upland cleanup design
• PCB abatement pilot test
• Permitting – construction stormwater
• Construction plans and specifications
• Construction oversight

Value Added

• Used 2013 TSCA reinterpretation to save client significant demolition and disposal costs
• Used pilot test to demonstrate most cost-effective abatement and demolition approach
• Triggered additional investigations that demonstrated further soil and groundwater impacts caused by previous site operations

Former Naval Shipyard – Tacoma, WA

CRETE completed the MTCA RI/FS in March 2016 under an Agreed Order. Investigation data was collected to allow future cost recovery from PLPs that performed shipbuilding and dismantling. The site is located at the end of the Blair-Hylebos peninsula in the Tacoma tide flats and is an aggregation of multiple smaller sites that are primarily driven by TPH impacts.

In reviewing work by previous consultants, CRETE was able to identify and correct several errors. CRETE was able to identify USTs that were previously mislocated. Work included execution of a tidal study to evaluate attenuation as groundwater migrates to a tidally-influenced water body, a detailed evaluation of TPH chromatograms to help identify likely sources, and a review of indoor air sampling data. Review of chromatograms identified sources of contamination for which cost recovery will be pursued. A review of air data determined that Port contamination was not responsible for any indoor air exceedances.

CRETE also prepared a UST Decommissioning Interim Action Work Plan. CRETE supported the Port in overseeing this work in Fall 2015 and incorporated the results of this work into the RI/FS report. CRETE is continuing to work on the Cleanup Action Plan and will support Consent Decree negotiations and perform the remedial design. Cleanup work is expected to be performed in 2018.

Work Performed

• Regulatory negotiations – MTCA
• Upland RI/FS
• Permitting – UST decommissioning
• UST interim action
• Indoor air evaluation
• TPH fingerprinting

Value Added

• Accurately mapped and located abandoned USTs that could not be located previously
• Performed TPH fingerprinting to identify contaminant sources for cost recovery
• Evaluated sub-slab, indoor, and ambient air quality to demonstrated client impacts were not a source of indoor air impacts
• Negotiated use of groundwater sample preparation and analytical techniques to address sample interference and potential false positive results