In December of 2008, an approximately 5-foot deep sump or shallow well with an organic (similar to diesel fuel or gasoline) odor was encountered in the excavation area (Area O). The area of the sump was secured for the winter months and on May 1, 2009, the contractor resumed excavations in that area.

Once the sump itself was removed, it was determined that the soils in the vicinity of the sump were stained and had an organic odor. Excavations of these soils encompassed an area of about 140’ by 75’ and extended to a depth of 30’ in one area. The soils were right next to and below the location of the former office and maintenance building. The excavated soils were placed in stockpiles within the Containment Area where the soils will be further tested to determine whether the material can be placed permanently in the Containment Area. Two stockpiles are present: one containing soils with detectable levels of volatile organics and lead levels above the performance standard (500 ppm) and the second pile containing soils only with detectable levels of volatile organics and no lead contamination.

A sampling instrument called a geoprobe was brought in to try to delineate the vertical and horizontal extent of the volatile organics in the soil.  Geoprobes combined with screening of the soils with a PID to detect the presence of volatile organic compounds found that the residual contamination is likely present within the weathered rock zone. Further excavation or characterization was determined to be impractical without significantly impeding the lead clean-up, and the excavation was backfilled with the approval of the EPA and DEP so that restoration activities can could proceed in this area. Throop Borough was also informed of the plans to backfill the excavation by both EPA and Gould prior to the work taking place. A low permeability layer was placed within the backfill to minimize the infiltration of rain water into the former excavation. Gould has committed to submit a summary report presenting the analytical results and information on the excavation and the geoprobes to the agencies along with a proposal for follow-up activities to be conducted and a schedule for those activities.  An agency decision has not been made yet regarding what additional characterization and/or remediation of the volatile organics, if any, may be required.

 

As of October 23, 2009, Gould estimates that implementation of the Final Remedy at the Marjol Battery Site is approximately 85% complete. 

EXCAVATION NEARLY COMPLETE - The excavation of contaminated material is expected to be completed by October 23, 2009 except for sediment in Area B that was affected by stormwater management (stormwater from the Containment Area or cap area was pumped into Area B to prevent additional overflows of water from the Containment Area).  Testing of sediment in the basin has shown that some sediment  from the basin will also need  to be handled as contaminated material before solidification is complete in the CA.  These areas should be complete by October 30, 2009.

STATUS OF SOLIDIFICATION – The bottom layer of the CA is a solidified layer comprised of three separate 9-inch lifts of solidified material.  As of October 23, 2009, solidification is about 70% complete.  Off-site sources of clean fill will be used for solidification for the third lift across the entire CA and on the steep slopes because there was an insufficient volume of contaminated soil in Area H for all three lifts of solidified material.   Mixing of the clean fill with lime kiln dust is occurring off-site so that the mixed material can be placed and compacted as it is brought on-site.   

Solidification will be ongoing into November 2009 using both a machine on-site (called a Stehr) to solidify the lifts of contaminated soils that have been placed in the CA, and by bringing clean fill that is already mixed with lime kiln dust to the site and placing it.  The compaction requirements and the performance standards for the solidified material are the same for both solidification methods.

OFF-SITE VERIFICATION SAMPLING - Once the excavation of contaminated materials is completed, the second phase of the off-site verification sampling will take place.  Off-site verification sampling was performed prior to and will be performed following remedial activities to confirm that remedial activities did not cause off-site contamination.  Five locations were sampled in areas that were previously remediated.

A total of 20 samples were collected from each location during the pre-construction sampling.  Ten samples from each location were sent to a lab and analyzed and the remaining ten samples were archived for future analysis if required.  The same procedures will be followed for the second phase of testing.        

INSTALLATION OF GEOSYNTHETICS (PLASTIC LAYERS OF THE CAP) – Once the solidified layer on the cap is completed, the next step is installation of the geosynthetic layers.  A decision on whether to proceed with at least part of the installation of the geosynthetics this fall will be made in November  2009.  If the geosynthetic installation is postponed until spring, all exposed, loose soils will be seeded and protected with either straw, jute matting or temporary erosion control mat depending on the slopes.  Within the CA, all contaminated materials will be covered with at least one 9-inch lift of uncontaminated, solidified material, so there will not be any contaminated material at the surface of the Site. 

 

The construction work began on May 12, 2008 and is currently projected to be completed by the end of November 2009.  However, the construction schedule depends on many factors, including the amount of contaminated material in each excavation area (if it is greater/less than what is expected based on testing) and of course, the weather.  At this time, we do not know yet whether we will need to go into a third construction season in spring 2010.  Our priority is to make sure the work gets done carefully and completely, more so than keeping to the original schedule.  We will continue to provide construction information on this page as the 2009 season proceeds.