See previous Polreps and Site Profile for Site Description. Analytical results from the 2007 sampling event indicated the presence of volatile organic compounds, semi-volatile compounds, antimony, arsenic, lead, vanadium, pesticides and PCBs in onsite soil, and onsite groundwater. Site contaminants were also detected in surface water and sediment offsite in Stoney Creek. Contaminant concentrations in soil have been detected at concentrations which exceed EPA’s human health risk-based screening levels, however the concentrations are below EPA removal actions levels for the industrial worker. Groundwater is not a current source of drinking water in the area; there is no current human exposure to contaminants detected in groundwater. The site is an industrial facility and access is restricted by a fence and gate. Because PCBs were detected in offsite sediment samples, in August 2008 additional sampling in the Delaware River was conducted to evaluate the impact the site contaminants may have had to the sediments in the Delaware River.
On August 18th and 19, 2008, EPA START contractors collected samples in the Delaware River, south of the Metro Container Site. The area is characterized by mudflats located northeast of where Stoney Creek discharges into the Delaware River.
Surface and subsurface 5-point composite sediment samples were collected along four transect lines in the inlet closest to the Stoney Creek discharge and from a fifth transect line in the upper inlet. Surface samples were 0-6 inches below ground surface (bgs) and subsurface samples were 6-24 inches bgs. In addition five sediment grab samples were collected within the first inlet: one from an oil-saturated layer approximately twenty feet southeast of the shoreline, one from oil-saturated sediments encountered below the clay layer along the first transect line closest the shoreline, and three grab samples from a grassy high depositional area southwest of the shoreline.
All samples were analyzed for total Polychorinated Biphenyl (PCB) congeners, Target Analyte List Metals, and semi-volatile organic compounds. PCBs were detected in both inlets. The concentration of PCBs detected in the inlet closest to the site ranged from .011 ppm to 5.6 ppm. The highest concentration of PCB congeners (40 ppm) was detected in the upper inlet subsurface composite sample.
Subsequent to the receipt of analytical data the OSC tasked the contractor to compare the concentrations of PCB congeners reported in sediment samples collected from the Delaware River during the August 2008 sampling event to the PCB congeners detected in 2007 from the onsite groundwater monitoring wells and the sediment samples collected from Stoney Creek adjacent to the Site. This comparison indicated a strong correlation between the PCB congeners in the sediment samples in the lower inlet indicating that the PCBs in the Delaware River sediment can be attributed to migration of contaminants from the Site. In the upper inlet the PCB congeners also compared well with site PCBs, however three PCBs congeners at significantly higher concentrations which were not found onsite were also detected, which indicates contribution from other unknown sources. The lack of a surface water pathway from Stoney Creek to the upper inlet combined with the depth of the contamination in the upper inlet indicates that a groundwater migration pathway from the site has likely impacted the upper inlet. The depth of of the contamination also indicates that the contribution from other potenital sources has not been recent. Under typical tide cycles and storm events, the biota are not likely to be exposed to the contamination.
The Trip Reports for 2007 and 2008 field activites and analytical results can be found in the Documents section of this website: www.epaosc.org/metrocontainer.
No removal action is planned.
In April 2009, the OSC referred the Site to the remedial Site Assessement program for further evaluation and potential listing of the site on the National Priorities Lists.
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