The Pervasiveness of Site Contamination Related to Mercury Cell Use

The Brownfield’s clean up at the former Ecusta Paper Mill located in Brevard, NC, is a Superfund caliber site that is being remediated under an agreement with NCDENR and USEPA Region IV. 

One of the primary tasks is the investigation, remedial design, and final remedy selection for the area under and around the Electrochem (EC) Building, where mercury cells were used to generate caustic and bleaching solutions from the 1950’s to the late 1970’s.  Wastewaters were conveyed from the building through process sewers and open drainage ditches to the adjacent river.  Based on historical sampling, mercury impacts to soil and groundwater were known to exist.  However, additional investigations revealed the mercury contamination on the site was more pervasive then originally discovered, including:

-          Large amounts of free mercury and mercury impacted sediments discovered in the abandoned wastewater trench system under the EC building floor.  This discovery necessitated the use of Level B/ Level C protection and confined space entry to remove the waste.

-          Extensive sampling/survey of the building revealed contamination of the structural components.  Porous materials such as concrete, brick and wooden roof components were found to contain mercury concentrations up to 800 ppm.    This requires an extremely controlled demolition and debris management scheme, as well as, a complex waste profiling methodology.

-          A significant portion of the concrete process sewer pipe that conveyed waste from the EC building was found to be contaminated and could not be crushed for re-use on site.