Area of Concern 63 - Chronology of Actions/Investigations

Year	Month	Action/Results	Action Performed By	Project Number
Unknown	Unknown	Area consisting of three barrels with rocks in them. Located south of deer stand 41 in the East Pasture, and southwest of the road intersection.	CSSA	NA
2001	January- February	Two soil gas survey samples were collected and analyzed for chlorinated and aromatic volatile organics. No target VOC compounds were detected.	Parsons	DO 5084
2004	October	Excavated slit trenches across the site, found only a rock trench, suspect it may be a leachate field.	Parsons	DY01
2006	December	Reviewed aerial photographs for visual indication of site activity. An area with denuded vegetation can be seen in a 1957 photo.	Weston	NA
2007	February - March	Conducted electromagnetic geophysical survey and exploratory trenching to investigate the potential presence of buried materials. A total of 12 discrete soil samples were collected form five of the six trench locations and submitted for laboratory analysis.	Weston	NA
	May	Presented results of geophysical survey and trenching investigation at a meeting with USEPA and TCEQ representatives.	Weston	NA
	June	Re-sampled three of the trench locations investigated in March 2007, including those locations with the highest reported benzene concentrations.	Weston	NA
	July	Conducted an informal reconnaissance survey to look for potential sources of low VOC and SVOC concentrations observed at site.	Weston	NA
	September	Proposed parameters for calculating a Tier 2 soil-to-groundwater PCL for benzene were discussed during a quarterly Technical Interchange Meeting with representatives from CSSA, USEPA, and TCEQ.	Weston	NA
	December	Conducted sampling to obtain vertical delineation of benzene-impacted soil. Trenches were excavated at locations with benzene concentrations exceeding the Tier 1 PCL.	Weston	NA
2008	August	Final Affected Property Assessment Report for AOC-63 submitted.	Weston	NA
2009	February	TCEQ requested additional information in order to approve closure of AOC-63.	TCEQ	NA
2009	July	Closure of AOC-63 partially approved by TCEQ.	TCEQ	NA
2010	August	Closure of AOC-63 fully approved by TCEQ.	TCEQ	NA