LINE 3A POND

SITE DESCRIPTION 

Line 3A Pond is assumed to be an excavated, unlined pit, measuring approximately 60 x 30 x 8 feet. The pond area is relatively flat and slopes gently to the west and south. While some sources conflict on this fact, it is generally believed that this site was excavated and backfilled circa 1959.

 

At Line 3A, casings for bombs were treated with an alkaline de- greaser and solvent paint stripper. The casings were then bathed in phosphoric acid. A diluted chromic acid rinse was then applied. Approximately 15,000 gallons of spent sulfuric and hydrochloric acid were disposed in the pond and neutralized with sodium hydroxide.

 

The PA/Sl was completed in 1991, the RI was completed in May 1996; samples found no explosives or metals above action levels in the soil.

 

USACHPPM has completed a review of the data and concurs with the recommendation that no further action is required for soils.

 

Additional soil samples were collected in 2004 and documented in the Draft Final Report for the Soil Data Collection. No analytes above the background levels as determined in the OU1 ROD were detected.

 

A draft final (rev. 1) OU-4 supplemental RI was submitted to EPA for review in July 2008 and is currently in “informal dispute”.   

 

A revised draft OU-3 RI/FS was submitted to EPA for review in April 2008.

 

CLEANUP STRATEGY 

This site is included in the PBC awarded in 2004.

 

The IRP will be responsible for groundwater and soil contamination.  The recommendation for the soils is No Further Action as documented in the draft final (rev. 1) OU-4 supplemental RI.  The recommendation for the groundwater is institutional controls, monitored natural attenuation, and long term monitoring as documented in the revised draft OU-3 RI/FS.