Work Mission Statement:
Safely and efficiently investigate and remove Munitions and Explosives of Concern (MEC); Materials Potentially Possessing an Explosive Hazard (MPPEH), Munitions Debris (MD) and explosively contaminated soil(TNT) from the Elkton Farms Firehole Site, as defined in EPA's geophysical study.
The site was remobed on January 28, 2008 with a limited crew. One UXO team was mobed. Team no longer performs magging and digging activities and instead supports both the trommel sifting activity and the firehole excavation as per SOW and AHA. Therefore during this reporting period no new grids were completed.
1. Total Grids Cleared Gov't QA: 78
2. Total MEC/MD found: 28,953 (MEC items include detonators,grenade fuze,blasting caps,tracer elements, incendiary bomblets, flares etc. etc.)
4. Total MD found: 4,709lbs.
5. Scrap metal found: 3,757
6. Total Phase II processed soils: 89,946 cuft
Trommel Sifting Activities:
On 5/2/08 the trommel mechanical sifter was mobilized to the site and commenced the mechanical sifting of stockpiled soils from the previous year's hydroaeration pile. Heavy rains throughout the month of May has severely minimized the effectiveness of the machine and has hampered soils handling. Numerous days and man hours have been lost. As of 5/22, 9,639cft of soil was processed thru the trommel. A total of 1491 MEC items were sreeened and captured by the trommel. The 1 inch screen is proving to be effective. QA of the clean soils from the trommel revealed only 5 tracer elements found.
Firehole Excavation Activities:
Excavation and coarsing of the fireholes continues. Approximately one half of the fireholes is completed. Excavation to 5-6ft depths continue. 53,655 cft. of soil has been excavated, coarsed thru the 4 inch screen and staged awaiting trommelling. A total of only 10 MEC items have been found thus far. This total includes a fuzed 40mm projectile unearthed on 5/21. This item was staged in the magazine. Suspected friable ACM is bagged as per the SOW. EPA sampled bulk material to determine ACM and sent off to lab on 5/14. Results returned on 5/21 reveal no asbestos detected.
During this reporting period the site Explosive Safety Submission (ESS) was ammended reflecting new soils processing technique (trommelling) and new USACE separation guidance. The DDESB issued an Interim Change to its Technical Paper 16, Revision 2 dated September 16,2007. The new revision allows for the use of Hazard Fragmentation Distance of worse case MEC found. Previous guidance required a minimum separation of 200ft regardless of the item having a calculated HFD less than 200ft. Therefore based on the unintentional HFD for the 20mm projectile of 61ft the OSC has determined the new separation distance to be 100ft. This also allows for easy field determination of separation since the site is divided into 100ft grids.
Sampling and monitoring for airborne asbestos fibers and particulate continued on dry days as per AMSAP. So far no site standards have been threatened for both asbestos and the particulate.
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