As part of the ongoing efforts to remove legacy contamination from the Richmond Field Station, a small area of soil in the vicinity of the former Forest Products Laboratory Wood Treatment Laboratory (WTL) will be excavated for off-site disposal beginning on October 1, 2007. A public notice from the State of California Department of Toxic Substances Control, the regulatory agency that has approved this action. This notice describes the work that will occur in this area.
The soil being removed was contaminated by wood treatment chemicals used in research at the WTL. The primary chemical of concern is arsenic, which is a constituent of commercial pressure treated wood pre-dating the EPA’s ban of arsenic-containing wood treatment compounds in 2004. The former WTL is located in the northeast corner of the RFS near Building 476. The contaminated soil was found during final clearance inspections after the WTL equipment was removed for off-site disposal to a DTSC approved landfill in 2006. Two small areas of elevated concentrations of arsenic were found in soils near the old equipment.
The soils are being removed because the arsenic contamination poses a risk to construction workers who might dig in this soil. After the soil is removed, a new facilities maintenance storage building will be placed in this area as part of the relocation of the corporation yard.
Summary of Cleanup Activities
Following is a description of the activities that will take place during the week of October 1, 2007:
Approximately 100 cubic yards of soil will be removed using a backhoe. The soil will be placed into 20-cubic yard roll-off bins for off-site disposal at licensed off-site landfill facility. The expected excavation depth is two feet in most areas and four feet in a smaller area. The excavated areas will be backfilled with clean soil that has been approved by DTSC.
Activities will occur during weekdays, Monday through Friday, between 8 A.M and 6 P.M. Soil excavation likely will take no more than three days to complete. The following activities will occur:
- Trained workers wearing personal protective equipment will use a concrete-asphalt cutter and a concrete-breaker attachment on a backhoe to cut and break up asphalt and concrete covering soil in portions of the excavation area.
- The concrete and asphalt will be stockpiled on site for future disposal at an appropriate off-site disposal or recycling facility. The stockpile will be covered to prevent dust.
- The workers will use a backhoe to excavate soil and placed it directly into roll-off bins.
- Upon completion of excavation, environmental consultants will collect soil samples to confirm that the DTSC-approved cleanup goal has been achieved. All samples will be submitted to a state-certified analytical laboratory for analysis. DTSC will oversee the sample collection and review the analytical results
- Excavated soil, asphalt, and concrete will be sampled for off-site disposal, and then trucked to an appropriately permitted disposal facility.
- After cleanup, the area will remain fenced until construction activities are completed to protect the RFS community from construction site equipment and hazards.
The excavation procedure approved by DTSC includes dust control measures, such as spraying water during soil excavation and loading, which will reduce dust generation during the work to levels that are safe. Dust monitoring will be performed at upwind and downwind locations to monitor the effectiveness of the dust control measures. If excessive dust is detected, modifications to the dust control measures will be made or work will be stopped until adequate control measures are in place.
An estimated five roll-off bins, equivalent to five truckloads, will be removed from the site. Trucks hauling soil will exit the Richmond Field Station and travel west on Meade Street for approximately 1/3 miles and then take the Regatta on-ramp to Interstate 580.