January 17, 2003 Field Update
FIELD UPDATE 19
ACS NPL SITE RD/RA
January 17, 2003
Recent construction activities at the ACS NPL Site have included the installation of components for the on-site area In-Situ Vapor Extraction (ISVE) system.
The photo below shows the on-site area at the beginning of January 2003. Much has changed since Field Update 15 provided a photo of this area last July. An interim clay cover was placed over the area, groundwater and vapor extraction wells were installed, and a concrete foundation was poured for the blower shed that will house the ISVE blower and manifold system.
Legend for photo above
1 - HDPE Conveyance piping
2 - Concrete pad for blower shed
3 - Two of the 46 ISVE wells
High density polyethylene (HDPE) conveyance piping has been installed between each of the extraction wells and the centrally-located concrete pad. A blower shed is being constructed with an integral manifold system; when completed it will be placed on the pad and the numbered pipes in the photo will match up with the manifold in the shed.
The photo below shows the engineering crew pressure testing several of the extraction lines to confirm that the welds and fittings will not leak during operation. Groundwater extraction pumps will be installed in 21 of the wells to more aggressively dewater the on-site area and enhance the effectiveness of the ISVE system.
Geotextile fabric has been placed over much of the clay cover. It is shown below anchored in place with small piles of gravel. In the next few months, the fabric will be entirely covered with gravel. Later it will be capped with asphalt as part of the final cover. A milestone for the ACS site has been reached with the completion of the wells and interim cover: no further excavation work will be necessary to remediate the site.
When completed, the ISVE system will extract vapors from the wells and send them to the new thermal oxidizer for destruction.