The American Creosote site is an NPL site currently in the feasibilty study phase of RI/FS stage. Following the emergency response in August of 2005, the On-Scene Coordinator noted that the removal program has the authority to respond to the presence of creosote waste on the Site. The remedial program enlisted the support of the ERRB in order to address the ongoing threat to which they are unable to respond.
Please see Initial Pollution Report for additional information.
Operations continue with efforts concentrated on completing the PVC sheet pile wall. The cycle time for each installation has not been reduced as was the previous goal, rather certain hindrances have prevented an increase in production. Please see key issues for more details. The initial concern addressed during this reporting period was the depth to which the piles were being driven. In order to resolve the issue additional time was taken to drive the piles through a confining layer at approximately 15 feet. The OSC felt that it was necessary to utilize the time and effort due to the fact that free product was visual confirmed at depths below 15 feet during the investigation period. In order to prevent this material from entering the creek from below, the sheet piles will have to be driven to depths below the presence of free phase product.
A total of 120 sheets or 240 linear feet were installed during this period, for a total of 360 linear feet installed. The depths for panels installed during this period range from 14 to 27 feet, with an average of 17 feet.
The containment of the source at the former lagoon area will consist of installation of a barrier system, PVC sheet piling, between the creek and the source area in order to mitigate the ongoing release into the creek. The total length of the sheet pile wall is approximately 1000 linear feet. It begins approximately 200 feet east of Hughes Creek, parallel to Baremore Street, and then will extend 800 feet along the banks of Hughes Creek and the unnamed tributary to the north and northeast.
Once the seepage from the source is controlled; removal, treatment and disposal of creosote contaminated soils and sediments in the wood chip pile area and Hughes Creek may be addressed.
Operations will continue in order to complete the PVC sheet pile wall. There are approximately 550 linear feet remaining which is projected to take 20 work days. In order to complete the wall, the road must be extended to the north along the unnamed tributary. The road construction was delayed due to pending written access authorization with the adjacent property owner. Following completion of the wall there are several site mainenance issues that will be addressed, including:
- cutting the panels down to grade
- placing copper wire on top of wall for future locating purposes
- covering the wall with fill material and seeding
- managing site drainage with PVC piping and geofabric in existing drainage ditch
- backfilling disturbed areas with clean fill
- mitigating the migration of creosote from contaminated sediments in Hughes Creek
The written access authorization for the adjacent property was obtained during this period. Verbal access had been granted at the onset of the removal action, but the property owner had not had the opportunity to sign the agreement until this period. A portion of the wall further to the north along the unnamed tributary will be placed on the adjacent property. It is necessary to place the wall on this property in order to ascertain the greatest effectiveness for the prevention of contaminant subsurface migration into the creek.
The resistance of the clay layer continues to pose a problem for consistent installation depths. Time was taken to drive the panels to sufficient depth in the area of greatest concern beginning at the intersection of Hughes Creek and Baremore Street and continuing to the north along the Creek. At approximately 80 feet from the intersection an obstruction was encountered at 10 feet below land surface which prohibited any further penetration. Sheet pile operations were halted while the contractor took the time to remove the buried material with the excavator. Wood and concrete were removed from the area and placed within the containment zone. It is not known where the materials came from or how they were placed at this location. The time utilized compounded with the issues penetrating the confining layer yielded a succession of days with decreased productivity.
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