Walter van Veen of CRA
Q & A
The cleanup of the Sydney Tar Ponds and Coke Ovens site is planned to begin soon but it's neighbour SYSCO -consisting of about 445 acres of industrial land is still in the assessment phase of it's planned remediation. Walter van Veen, project management consultant for the clean up of the Tar Ponds and Coke Ovens site, was interviewed to learn how the start of one clean up could potentially impact the future of another.
Q: Have all the inputs and outputs of contamination for the Sydney Tar Ponds and Coke Ovens been defined?
A: Yes. We have looked at all the inputs of the Tar Ponds and out puts of the Coke Ovens site. Both were done in the phase 2 and phase 3 programs of the Tar Ponds and the Coke Ovens. The reports were completed by JDAC (Jacques Whitford, Dillon, ADT and CBCL).
Q: In terms of adjacent lands, which properties are considered to be an output and which are considered to be an input?
A: Of the Tar Ponds, we learned that the SYSCO property is not providing any ground water or any other contaminant input to the site pro viding we can create a physical barrier to keep any sediments at the SYSCO property out of the Tar Ponds property. Meaning that once we do the cleanup, we have to ensure there is a physical barrier to stop the movement of mate rial, sediments, from the SYSCO property into the Tar Ponds.
Q: Is SYSCO a contributor?
A: It is a contributor but in terms of being able to manage it, it's relatively straight forward. We just need to provide physical barriers there to ensure any sediments underneath the high dump can't move from the high dump to the Tar Ponds.
Q: How would you ensure that?
A: The most straightforward way during excavation is initially to install sheet pile which are sheets of steel we drive into the ground before excavation starts right at the boundary between the two sites. So essentially, as we're excavating, we're excavating against a vertical steel wall. When we finish up the job we might place gravel, sand and riprap at that boundary to support that steel wall then remove that steel wall so that we have a natural slope there. The new natural slope is essentially holding back any sediment that might be under the high dump.
Q: How much of the contamination is coming from SYSCO?
A: At this time there is really no contamination coming because the groundwater quality we've deter mined is acceptable for discharge into a marine body of water. Given the sediments we have in the Tar Ponds are holding back any sediments that might be in the SYSCO property. Really, there is no movement of contaminants from SYSCO into the Tar Ponds. But, during remediation of the Tar Ponds, we need to ensure that condition remains that way by placing physical barriers at that boundary.
Q: Is there anything leaving the Sydney Tar Ponds and Coke Ovens and heading toward the SYSCO property?
A: We only know that right at the boundary of the Coke Ovens and SYSCO, there is coal tar at that location. When SYSCO does their own study, I assume they'll be looking at those kind of issues at that boundary. There are seams of a few feet thick at that boundary.