Minutes for TIM Meeting #3
Contract No. F41624-00-d-8024, Task Order 42 Parsons 740911.02000

TIM #3 Meeting at CSSA, Boerne, TX

Technical Interchange Meeting (TIM) #3 was conducted in order to discuss a revision to the Groundwater Monitoring Program DQOs. The majority of discussions during the meeting concerned edits made directly to the DQO document, included here as Attachment 1. Other specific discussions during the meeting are set out in these meeting minutes.

Revisions to Section 1.0, History/Background

Results for metals detections on-post are suspect, possibly due to equipment installed in the wells, windmills, etc. Once prepared, the table summarizing metals detections (as well as VOCs) will help evaluate whether additional metals sampling should be performed and the frequency it should be performed. It was discussed that metals sampling frequency could be reduced to less than once per year. Or, all nine metals do not need to be sampled each year. It is possible that the summary table to be prepared will support that some of the on-post monitoring wells which have had detections for several years at the same order of magnitude do not need to be sampled every quarter, but possibly once per year. Also discussed in reference to the summary detections tables were whether or not an average of all detections should be used. Only an average which is statistically derived could be used. A background concentration may have already been determined for the Glen Rose. Ed Brown will call Julie Burdey with information on deriving the groundwater background values statistically.

PCB detections near Building 90 were discussed. The new data on PCB detections at Building 90 should be included in Section 1, in addition to using the PCB discussion and recommendations presented in the Solid Waste Management Unit (SWMU) I-1 RFI report.

A discussion of the LPST site history for CSSA needs to be added to the DQOs. Tank 4 at the motor pool will need to be addressed in the future, with one boring sampled for benzene, toluene, ethyl benzene, and xylene (BTEX), TPH and/or polycyclic aromatic hydrocarbons (PAHs). Groundwater will also need to be sampled, if present. PAHs have been detected historically at CSSA, but only in perched groundwater, not the deep drinking water wells.

Action Item: Parsons will prepare cumulative detections summaries for each well with a maximum detection and possibly including the range of detections, most recent detection, etc.

Revisions to Section 2, Identify the Decisions

Regarding data gaps in the groundwater monitoring program, additional discussions of installing a well in the Texas Department of Transportation (TXDOT) right-of-way were held. The extent of the plume, both vertically and horizontally, was discussed as a possible data gap. Westbay-equipped wells to be installed will help to identify further data gaps. Off-post data was discussed and additional data gaps regarding off-post well sampling being performed. Data gaps that may be identified as part of the Conceptual Site Model (CSM) and the Recharge Study should also be listed in section 2.1.9.

A discussion was held of the reporting limits (RLs) and method detection limits (MDLs) being used by the laboratories (APPL and STL). Discussion of whether detections above the MDL (F flagged results) or above the RL should be a “driver” for further investigations was held. Brian Vanderglas advocated continuing to compile F flagged detections for future support of arguments whether the plume is shrinking versus expanding. This data will be needed for future monitored natural attenuation (MNA) remediation efforts. At the Jackson Woods area, based on F flagged detections, the plume would be identified as expanding. On-post drinking water wells have exhibited F-flagged detections of volatile organic compounds (VOCs) for three years. Joe Fernando discussed the liability issues for deciding on the use of RLs versus MDLs as levels for action/response items. It appears that CSSA is doing more than would be required in a best practice evaluation of the groundwater monitoring program. Use of MDLs was approved by US Environmental Protection Agency (EPA) as providing helpful data when defining the plume extent.

Further discussion of the plume movement over time as it will be addressed in the CSM was held. The CSM should have figures that will represent the plume as it changed from quarter to quarter, possibly from detections in 2000 through the present.

Brian Murphy discussed the responsibility from a health perspective for off-post residents, based on F-flagged detections. Joe Fernando responded that the maximum contaminant levels (MCLs) are the cutoff for the health perspective and that question has been answered by the EPA already. Julie Burdey proposed using one-half of the RL value as the “defined” non-detect cutoff value in any possible risk assessment to be prepared. However, no risk assessment studies are scoped at this time.

Brian Murphy would like draft plume maps created based on the RLs. A well within the I-10 right-of-way was discussed based on the F-flagged detections of the past. A discussion of the detections from well CS-1 was held, but due to there being no detections in DOM-2, no additional wells seem justified at that location. Julie Burdey pointed out the necessity to locate additional off-post wells based on the expectation to find contamination in preferential transport pathways due to the fault structure.

A discussion of the September 2001 MNA parameters sampling was held. No further MNA sampling is scoped at this time. These parameters will be needed in the future in order to support the plume as shrinking vs. expanding. The type of remedy selected will affect the MNA parameters that should be sampled. A discussion of SVE systems as a remedy was held.

The possibility that the granular activated carbon (GAC) canisters are changed too frequently was discussed. Based on previous calculations they may be replaced earlier than necessary. However, Scott Pearson proposed that due to the highly calcified water at these sites the problem is the formation of carbonate that clogs the system prior to the consumption of the carbon from filtration. A discussion of the flow rates and carbon consumption versus spikes in VOC concentrations that may be missed by the quarterly monitoring was held. It is possible that a total mass/mass balance estimate could be performed by Carbonair to calculate the consumption of carbon.

A discussion of the necessary revisions to the Off-post Monitoring Response Plan was held. It will need to be modified soon, the current version was made Final June of 2002.

Action Item: Parsons to recommend a schedule for MNA parameters sampling. Also determine whether all parameters sampled in September 2001 are necessary for future MNA sampling.

Revisions to Section 3, Identify Inputs

A discussion of whether to reduce the analytes in the metals sampling list was held. Brian Murphy continues to recommend that a well be sampled for the full list of VOCs and all nine CSSA metals at the first sampling event. Recharge Study Inputs need to be added to section 3.1.6 (Brian Vanderglas).

Some discussion was held on the tables to be prepared that will justify whether the full or short list of VOCs is necessary, based on historical detections. The Texas Commission on Environmental Quality (TCEQ) and EPA have already approved the short list of VOCs, so changes to the short list may not be difficult to receive approval on.

Various paragraphs in section 3 will need the revised short list and/or the list of existing wells as of June 2003 to be updated. Instead of including a list of existing wells that will need to be updated every time a new well is installed, it was decided to reference Volume 5 of the Encyclopedia where possible, for the wells that are part of the groundwater monitoring program.

Revisions were made to section 3.6.10 regarding existing transducers and transducers to be installed. The transducers should all be Supervisory Control and Data Acquisition (SCADA) compatible.

A discussion of the frequency of sampling to be conducted following rainfall events was held. Various determining factors were discussed for sampling following significant rainfall events, including:

It was decided to leave the DQO wording as is, until further evaluation of the first Westbay samples occurs. Parsons should be prepared to collect samples from Westbay-equipped wells every 15 days at a minimum.

Action Item: Brian Vanderglas will prepare the inputs necessary for the Recharge Study, section 3.1.6.

Chris Beal commented on the Recharge Study standard operating procedure (SOP) that the AOC-65 monitoring wells (five of them) could be added to that SOP. A discussion of whether there are utility conduits acting as french drains to preferentially transport COCs at or near Building 90 was held. Gary Cobb pointed out there was some evidence for that in the geophysical data. Scott Pearson stated that a moisture-filled zone was noted by Eric Tennyson at that depth in previous boring logs. Chris Beal discussed the option of an extremely shallow well which could be checked following rain events for a water level possibly due to transitional, perched water. Additional discussions of the surface drainage near Building 90 were held.

Revisions to Section 4, Define Study Boundaries

The Annual report (currently draft) to be submitted was discussed. The Annual will cover data from 1995 through the present (June 2003). The current schedule for preparation of drinking water reports was discussed. Brian Murphy indicated he has no changes to the current schedule, the reports are being submitted in a timely manner.

Revisions to Section 5, Decision Rule

No changes.

Revisions to Section 6, Tolerable Limits for Decision Errors

The applicable Quality Assurance Program Plan (QAPP) discussion needs to be revised in Section 6, especially for the CSSA QAPP approved which will affect new TOs. Some existing TOs will still follow the AFCEE QAPP. The Data Verification Report (DVR) always references the applicable QAPP version.

Revisions to Section 7, Optimize Design

No changes.

It was discussed that Brian Murphy would like these revised DQOs to be made final by July 18, 2003. Some discussion of whether the metals results from June 2003 would be back from the laboratories in time for this deadline was held. It was proposed that the new summary tables being created by Parsons would be the most time consuming revision to be made. A new design/formatted table will need to be created for all historical data for each on-post and off-post well.

The meeting was adjourned.

Attachment 1 - Draft Groundwater DQO Document - (emailed to distribution list 7/9/03)