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TIM #7 Meeting Minutes
Treatability study for Area of Concern (AOC)-65
Camp Stanley Storage Activity
F41624-00-D-8024/Task Order 0058
Parsons 740999.02020

Date: July 30, 2003

Time: 8:30 A.M - 5:00 P.M.

Place: Camp Stanley Storage Activity (CSSA)

Subject: TIM #7 to discuss current status of Area of Concern (AOC)-65 soil vapor extraction (SVE) treatability test; to discuss preliminary data related to recharge study; to review innovative technical methods for evaluating recharge and obtaining more data on the dynamics of the EpiKarst underlying AOC-65; and to review future restoration activities that should be considered at AOC-65. 

Attendees:

 ^*Minutes prepared by Brian Vanderglas, Parsons.

These meeting minutes are organized in the order discussed.

Current Status of SVE Treatability at Building 90/AOC-65

The meeting was opened with a discussion of the current status of the tasks:

Under work breakdown schedule (WBS) 01000, the period of performance for the project was extended through September 30, 2004, which will hopefully allow for 6 months of operation and maintenance (O&M) of the SVE systems and provide ample time for sufficient rainfall events to sample and test groundwater recharge flows through the intervals monitored by the piezometers installed under this TO.  Fourteen more months remain, so an additional 14 monthly status reports will be prepared. 

Under WBS 02000, three Technical Interchange/Progress Meetings (TIMs) remain in the scope of work, two Karst support meetings are still planned (with George Veni), and one fact sheet remains.  The topic of the final TO 0058 fact sheet will be progress of cleanup at AOC-65.

WBS 03000 is almost complete.  Some minor repairs to the gutter spouts installed on the west side of Building 90 and updates to the Permit by Rule submittals to the Texas Commission on Environmental Quality (TCEQ) are two of the activities that remain.  The Interim Measures Report for the removal actions completed at AOC-65 will be finalized upon resolution of Air Force Center for Environmental Excellence (AFCEE) comments.  O&M of the SVE subslab system installed inside Building 90 will be conducted in coordination with the O&M activities of the exterior SVE system planned under WBS 04000.

Under WBS 04000, the standard operating procedures (SOPs) prepared for the recharge study were reviewed, and sampling triggers were discussed.  Preliminary SVE testing was completed, and the results are currently being evaluated.  The initial testing cycles were completed in July, and full-scale operation of the system was initiated, although routine monitoring and maintenance is not planned until the O&M plan for the two systems is approved.  The possibility of any miscellaneous testing was also discussed, such as tracer testing or other University of Texas at San Antonio (UTSA) proposals, and it was determined none of these tests will be conducted under this TO to enable collection of more groundwater data.

Two of the key deliverables under WBS 05000 were completed, including the technology evaluation, which was prepared by Scott Pearson for presentation at this meeting.  The draft Geophysical Test Report was complete, but Parsons needed to respond to both CSSA and AFCEE comments.  The draft interim SVE Test Report is tentatively scheduled to be completed by the end of October 2003, whereas the Technology Evaluation Report (which is supposed to incorporate the recharge study results) is not due until after 6 months of O&M activities are complete (or June-July 2004).

The remaining budget was presented.  Approximately $227,000 remained in the TO budget to complete the remaining activities.

Soil Vapor Extraction Results

The preliminary results from the initial system startup tests for the exterior SVE system at AOC-65 were discussed.  Most of the discussion focused on the changes in soil gas concentrations measured at vapor monitoring points when the system was operating either from the entire subslab system (first test event), or when extracting only from VEW-17 during the second test event.  Radius of influence was inferred for intervals where oxygen and carbon dioxide level trends diverged in the same sample points over a four-week period.  Basically, influences were noted over relatively large distances, but appeared to be somewhat hampered by inability of the installed blower units to increase extraction flow rates.  The most influenced depth intervals appeared to be near the surface and in the zone where the largest voids were observed during drilling and borehole geophysical testing (28-32 feet below ground surface [bgs]).

To obtain additional data on the radius of influence to complement the soil gas changes, Ross Miller suggested getting more sensitive magnehelics to measure pressure responses at each vapor monitoring interval.  He also suggested conducting some additional testing on the subslab system to determine if volatile organic compound (VOC) removal can be improved or optimized.  He suggested that we consider composite sampling of multiple subslab lines, isolating some lines, and using averages to assess which extraction points are the most critical for optimizing contaminant removal.

Groundwater Sample Results

Groundwater results from both the initial groundwater recharge sampling efforts and packer tests performed during installation of the TO 0042 Westbay wells sampling efforts near AOC-65 were presented and discussed.  Because of the construction of the piezometers into bedrock material, it could not be positively determined that the groundwater being sampled was representative of recharge water moving through the formation or whether the groundwater encountered in the wells is the result of accumulation into the casing sump, or the low permeable nature of bedrock where the screen is set.  It was determined that during dry periods between significant rainfall events, it would be prudent to purge and develop the piezometers to assess whether the groundwater obtained from the screened interval is representative of formation water, or could be more stagnant water associated with a “sump” effect.  Also, the shallow monitoring wells at AOC-65 (AOC-65 MW-1, -2A, -2B, -3, and –4) would be included in future evaluations of shallow groundwater in the area under a separate delivery order.

The results from the piezometer testing indicated low to moderate levels of tetrachloroethene (PCE) and cis-1,2-dichloroethene (DCE) whereas the greatest contaminant levels were encountered in the Westbay groundwater packer samples collected from the borehole west of Building 90 from depths below 200 feet below grade.  Results from this testing were discussed in Scott Pearson’s presentation of technical methods for evaluating recharge.  A copy of this presentation is attached to these minutes.  These findings suggest that there are intervals deeper than the currently installed SVE system where significant levels of VOCs continue to persist.  Installation of a deeper, more flexible SVE system  that could operate  when the water levels drop below critical depths (more than 150 feet below grade) will be considered.

Applicability of Results to CSSA Restoration Program

The results of the site investigations, SVE treatability tests and groundwater sampling under TO 0058 were discussed with respect to the applicability to CSSA’s post-wide restoration program.  The purpose of this assessment was to identify areas where additional efforts may prove beneficial to CSSA’s program. 

Biological activity appears to be occurring in the vicinity of SWMU B-3 and AOC-65.  Remediation of source zones should prove helpful in stabilizing the dissolved groundwater plumes, it was therefore suggested that CSSA conduct push-pull tests by injecting a lactate into a specific interval, and then pulling samples over a period of time after the injection to assess its effect on bioremediation within the injected interval. 

Given the findings of high levels of chlorinated VOCs detected at below 200 feet west of Building 90, and the absence of a monitoring well upgradient of AOC-65 that can distinguish the southern plume from the northern plume, it appears that another monitoring well to the northeast of Building 90 should be installed to verify that the source of the contaminants detected in the Westbay groundwater packer data is Building 90 and the surrounding ditches which comprise AOC-65. 

SWMU B-3 was identified as an additional potential source area for VOCs in the groundwater associated with the plume in the central portion of the post.  During TIM#6, it was decided that additional remedial efforts utilizing SVE on the fill material and fractured bedrock may result in significant reductions in the levels of VOCs entering the groundwater regime and could also help render contaminated soil scheduled for removal nonhazardous.  Plans for this SVE study were discussed, with focus on utilizing some of the ideas presented by Scott Pearson in his presentation on innovative investigative techniques for the hydrogeologic and contaminant characterization of the SWMU B-3 site.    

Action items

	Parsons will evaluate indoor air sampling inside Building 90 to retest exposure, and consider isolation and averaging techniques of individual extraction wells to optimize contaminant removal from beneath Building 90.
	Parsons will evaluate the radius of influence of the AOC-65 SVE system utilizing more sensitive pressure meters or instruments.
	Parsons will develop and purge the piezometers at AOC-65 to assess the nature of the water encountered in the screened intervals.
	Parsons will incorporate techniques discussed during this presentation during the upcoming RL83 SVE pilot testing at SWMU B-3 to obtain as much data as possible from the initial SVE well.  This well was originally intended to be drilled only to 150 feet below grade, but was extended to 250 feet to obtain more detailed geologic information from this one boring.

Attachment 1:  Meeting Agenda

Attachment 2: Meeting Presentation

Attachment 1

Agenda for Technical Interchange/Progress Meeting #7
CSSA Treatability Study and Removal Action
Area of Concern 65 (Building 90)

Time:  Wednesday, July 30, 2003;  8:30 pm to 5:00 pm

Place:  Camp Stanley Storage Activity, Boerne, Texas,  Environmental Office

OBJECTIVES:

1.    Discuss status of TO 0058 Scope of Work.

2.    Discuss results from SVE testing at AOC-65, and DQOs for SVE O&M at AOC-65.

3.    Discuss results from shallow ground water at AOC-65 recharge study and Westbay packer testing under TO 0042.

4.    Discuss other technical methods for evaluating recharge and obtaining more data on the dynamics of the EpiKarst and fractured LGR underlying AOC65.

5.    Review future restoration activities that should be considered at AOC-65 and how it relates to other restoration activities at CSSA, such as SVE pilot study from fractured rock planned at SWMU B-3.

Proposed Order of Discussion