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Combined Technical Interchange Meeting Minutes
Facility Investigations, Closure Projects,
and Well Installations
Camp Stanley Storage Activity

F41689-96-D-0710/DO5068 TIM #1
F11623-94-D0024/RL83 TIM #3
F41624-94-D-8136/DO23 Tim #7

Date: 03 February 2000

Time: 9:30 A.M. - 4:30 P.M.

Place: Parsons Engineering Science, Inc. – Austin, Texas

Subject:  Technical Interchange Meeting (TIM) for RL83, DO5068, and DO23





Greg Lyssy

EPA-Region 6

(214) 665-8317

Brian K. Murphy



Jo Jean Mullen



William H. Batchelet



Chris Beal



Julie Burdey

Parsons ES-Austin


Brad Martin

Parsons ES-Austin


Karuna Mirchandani

Parsons ES-Austin


Susan Patterson

Parsons ES-Austin


Scott Pearson

Parsons ES-Austin


Rachey Peten

Parsons ES-Austin


Ken Rice

Parsons ES-Austin


Susan Roberts

Parsons ES-Austin


Minutes prepared by Susan Patterson, Julie Burdey, Scott Pearson; and contributions from Brian Murphy and Chris Beal.

Parsons ES jobs:  736625 (DO5068), 736071 (RL83), and 729973 (DO23)


The TIM was conducted in accordance with an agenda that was submitted February 1, 2000 to the attendees. The meeting was segmented into 14 agenda items covering issues for all subject contracts. In anticipation of the event, Parsons prepared a meeting package that provided relevant data for the items scheduled to be discussed. The presentation package consists of fourteen attachments that correspond to the items discussed at the TIM. Over the course of the TIM, a total of 13 persons were in attendance. All representatives from CSSA, AFCEE, WPI, and the EPA were present for the duration of the meeting. Susan Patterson recorded meeting minutes for the entire proceeding. The remainder of the Parsons staff was present only for relevant agenda items. Either Susan Roberts or Julie Burdey was present for the duration of the meeting.

Jo Jean Mullen opened the meeting with a request for additional material, including cost estimates and overruns. The reasoning for this is that all current delivery orders that require modification or additional funding must be amended before new delivery orders are issued. Once the final amendments have been made, CSSA will know how much remaining funds can be applied to future delivery orders.

Item 1: Community Relations Plan (CRP) status, mail-out results, and Future actions

Responses to the mail out and the next step in the community relations program were discussed. It was agreed that community relations activities need to be expedited in light of potential off-base contamination southwest of CSSA. An option for producing an Environmental Fact Sheet was presented, and it was mentioned that AFCEE was already discussing this option as an icebreaker for off-site monitoring programs. This document would include history, mission, and environmental programs. The suggested title was Camp Stanley Storage Activity Environmental Fact Sheet. The short time need for this memorandum was mentioned. The memorandum will need to be issued to community members with 100 extra copies made for base employees and the union who were excluded from the previous mailing. AFCEE noted that it was important that no community member feel slighted in regards to receiving a copy of the memorandum. In addition, congressional representatives need to receive a fact sheet if the document is going out to members of the area that they represent.

It was also suggested that a "town hall" meeting be held at a local elementary school. Fair Oaks Elementary and Leon Springs Elementary were suggested as possible meeting locations. The focus of the meeting would be to discuss the CSSA environmental program and in particular ground water issues. If there is contamination found offsite, government representatives, including risk assessors and all agencies capable of providing free technical services must meet with the landowner. The Agency for Toxic Substances and Disease Registry (ATSDR) needs to be involved also. Another suggestion was to develop a team that is going to hold the meeting. EPA will also need to be involved in the meetings. The public meeting needs a spokesperson to address the possible appearance of media representatives and the meeting announcement should be sent to the San Antonio papers. Coordination with the Public Affairs Officer (PAO) of the Corps of Engineers from Ft. Worth will be necessary. Finally, the meeting will need to have chemists, TNRCC representatives, and risk assessors in attendance. There was question about the type of representation the Air Force will need. The Region 6 EPA office in Dallas can assist with facilitation between the EPA and CSSA.

The status of the mailing list database was addressed, which has been prepared, but additional verification and the addition and removal of names based on the most recent responses received will need to be completed. CSSA is developing a Responsiveness Summary to address community questions and concerns generated by the CRP postcard mail-out.

A suggestion was made to draft an off-site monitoring response plan regarding plans for upcoming community relations with residents whose wells may be sampled for submission to EPA and TNRCC. The plan will cover a brief history of CSSA groundwater contamination, which off-site wells are to be sampled, sampling protocol and analytical requirements, "action levels" and proposed Army responses, and information on identifying potential off-site source areas. In addition, the Judge Advocate General (JAG) office will need to be involved because of potential contamination going off base. The JAG office will need to be contacted to address legal issues, and a representative of JAG will need to attend any "town hall" meeting. EPA representatives have already discussed the availability of staff members to attend "town hall" type meetings with the TNRCC. EPA indicated that they will not host these meetings, but plan to be present.

Regarding the memorandum, it was mentioned that currently this effort is not addressed in any delivery order. CSSA plans to develop this memorandum with input from Parsons. Parsons and AFCEE will look for examples of previous memoranda from other bases with similar PCE/TCE issues.

CSSA will gather more information on Community Relations Training held in San Antonio through USACHPPM to see if non-government personnel may attend. AFCEE will also investigate the possibility of sending additional Parsons staff to this training seminar.

EPA noted that a fact sheet would also generate comments. CSSA requested a full address list from Parsons, including those that recently responded to the last mailing. There was discussion about the radius covered in the most recent mailing, which was identified as approximately 2.5 miles surrounding Camp Stanley. The southern portion of the sweep included the Dominion. Fair Oaks contains approximately 5,000 people and Parsons did not receive response from this entire area, but did contact the Fair Oaks Homeowners Association, as well as community members located within the 2.5-mile radius. There was discussion about the need to have someone on site from PAO to handle these calls. CSSA has contacted Ft. Sam Houston regarding this issue, but staff there declined to handle the Public Affairs duties.

Item 2: Progress Reports

Parsons recommended that progress reports be left as reference materials and that the meeting move on to the next item on the agenda. Meeting attendees will review the progress reports to see if there are any questions.

CSSA asked how close Parsons was to finalizing treatability study results. Parsons is currently preparing responses to comments received in late January. CSSA asked what the status was on the compact disc (CD) version of the Environmental Encyclopedia and commented on removal of the Parsons name at the opening of the encyclopedia. AFCEE mentioned the need for a CD version of the encyclopedia as soon as possible. Julie Burdey stated that Parsons was waiting to receive comments regarding content and formatting of the CD version. Both AFCEE and CSSA stated that they have no additional comments to those provided previously, and that preparation of the CD may proceed.

Item 3: Revisions and Groundwater monitoring quarterly report

Overall, Parsons is in agreement with comments offered on the groundwater monitoring quarterly report. With respect to the response to comment 10, Parsons asked whether EPA will be able to give approval in writing to the shortened list of ground water analytes. This topic was discussed with EPA at a previous CSSA meeting as documented in the minutes included in Vol. 1-1 of the Encyclopedia. EPA said that written approval would be given.

Regarding the response to comment twelve addressing the decline in TCE concentrations since the initial sampling by the TWC (TNRCC) in 1991, rainfall and pumping of wells during this period need to be considered. CSSA commented that well 16 is now inactive and not showing the high TCE levels now. In addition, AFCEE noted that the group would need to evaluate the quality of the data offered by TNRCC in 1991. Regardless, it is important to note that the levels were above action levels even if the agency data does not meet the same data quality objectives as today’s data. CSSA suggested that the TNRCC data should be noted as "Unknown Data Quality" in the footnotes to the tables. A possible footnote mentioning that Parsons was not provided with the accompanying QA/QC information on the data may be needed to eliminate future questions about the reduction in TCE during this period. Within the report, it should be noted that there are questions concerning these issues, which it may not be possible to address at this time, but these questions have been considered.

Parsons would like to include the September 1999 Groundwater Report in the next update to the Environmental Encyclopedia. In addition, these meeting notes will be added to the encyclopedia. CSSA suggesting having meeting minutes scanned in and put on CD because of the volume of the notes. WPI (San Antonio office) is identifying all items needing to be scanned.

Chris Beal mentioned that he, Brian, and Scott recently met with personnel from Camp Bullis who indicated that their groundwater data could be made available to CSSA. These data include water level and water quality data, as well as geographic data in a GIS format. CSSA will also coordinate sharing water level data with Camp Bullis. CSSA will be responsible for acquiring and coordinating the pertinent Camp Bullis data.

Parsons formally requested approval for response to comments. All meeting members approved. Copies of the response to comments will need to be forwarded to Rene Hefner and Ed Brown at AFCEE.

Item 4: Discussion of Tabulated December Groundwater Results

Groundwater results presented on the tables presented in Attachment 2 are considered draft since AFCEE has not had the opportunity to review data yet. CSSA commented that the "U" flag needs to be identified in the table legend (U = nondetect at the Method Detection Limit [MDL]). The draft data validation report is being sent to CSSA and AFCEE today (February 3, 2000). Jo Jean Mullen stated that on other contracts the variances would normally be attached to the report so reviewers have access to agreed-upon terms. For future submittals, these variances will need to be attached, which will eliminate many comments back to Parsons. AFCEE will have responses back to Parsons today, and Parsons in turn will have the validated data available today. Parsons asked if EPA would accept summarized data tables in the report body, along with all results in the ITIR. EPA indicated that this would be acceptable. The EPA will only require a finalized tabulation of the validated data, and does not require raw data package submittals. However, the EPA does request that CSSA/AFCEE maintain the raw analytical data in their files for future EPA review. It was suggested that it be determined whether labs are capable of providing an electronic copy of data to AFCEE; however, it was noted that there are differences between the electronic and hard copies provided to AFCEE from the labs which renders the electronic versions incomplete.

It was stated that, theoretically, all EPA questions regarding data should have already been addressed by AFCEE in the packet it submits to the EPA. In addition, a CD copy of validated data needs to go into the Environmental Encyclopedia. The ITIR will also be included with the Environmental Encyclopedia. CSSA asked if the B-20 Reports and the June 1996 Groundwater Report were included on the CD. CSSA will need to coordinate with Parsons to access all documents needed for scanning and which documents are already held by Parsons on electronic format.

CSSA provided a handout containing diffusion sampler results from December 1999. The EPA’s testing has shown favorable results for VOC identification. ASTM is currently writing up a methodology for this new process. The diffusive sampler methodology is not acceptable for inorganic (metals) analyses. The EPA stated that the USGS is currently developing a new technology for metal sampling implementing downhole "socks". The EPA will provide contact names at the USGS that are developing the socks for passively sampling metal constituents. WPI will contact the USGS with regard to this developing technology for possible use at CSSA. The EPA also stated that they do not accept filtering for metals in groundwater samples as viable data.

Two maps depicting offsite wells are included in the presentation materials. Both Parsons and CSSA developed the maps from the current Parsons well research database. The map generated by CSSA included topographic and structural features (e.g. faults) while the Parsons map exemplified the newly proposed well identification scheme. Parsons proposed to establish a map ID number, which would eliminate the multiple well names that each location has developed in previous reports. This system will allow for incorporation of new wells. AFCEE and CSSA approved the system that was proposed.

Parsons reiterated that the placement of wells outside of a quarter-mile from CSSA were based on data from Banks Information Systems and may not be valid. Parsons has attempted to resolve these well locations as best as possible using other resources (e.g. Internet mapping), but the area outside a quarter mile is not included in the scope of work. Parsons has completed a windshield survey of all located wells within a quarter-mile of CSSA. It was recommended by AFCEE and CSSA that Parsons will need to develop a coversheet for the map, as well as footnotes on the map, that account for uncertainties on the location of wells. Dividing lines by regional grouping schemes will also need to be indicated on the map.

It was noted that there were boundary problems when considering the quarter-mile boundary. The scope of the map needs to be increased to include the entire Jackson Woods subdivision, and the Leon Springs Villa area immediately south. Parsons believes that this can be done with minimal additional effort, but reporting of all wells within 1-mile of CSSA would be beyond the scope of the contract. Parsons recommended that the group continue with the established format (1/4-mile survey). When it is decided to expand scope, additional wells outside of the quarter mile area can be added to this format. All attendees were in agreement.

The well identifier will need to be changed on the September and December reports. Also, source information will be included in groundwater report tab of the Environmental Encyclopedia. The private well sampled in December 1999, LS-7, is missing historical well construction information. CSSA plans to re-sample this well and Parsons will try to locate possible pump records; however, the current owner is not sure that he has pump records. When re-sampling, six vials for analysis, as well as a trip blank and a temperature blank will need to be collected for the independent EPA laboratory. Similar data is going to be generated as in the first sampling. Parsons will need to supply the materials needed for collection of EPA’s sample.

CSSA has obtained copies of the Consumer Confidence Reports (CCRs) for both the Leon Springs Villa (LSV) and Fair Oaks (FO) Ranch water systems. The water supply wells for LSV, which are all completed in the Trinity Aquifer, are provided by the Bexar Metropolitan (Bexar-Met) water system. The 1998 CCR for LSV indicated that 0.7 parts per billion (ppb) of tetrachlorethyelene (PCE) was detected in the water supply. Chris Beal stated that the detection of PCE should have triggered a quarterly sampling of the LSV water system. Bexar-Met will need to be contacted about the status of wells in the LSV water system. CSSA will also contact Bexar-Met to set up a meeting. The EPA requested an invitation to such a meeting. Bexar-Met also has control of wells at Hidden Springs Estates, located between Leon Springs Villa and the Dominion. Based on the CCR, it could not be determined if Bexar-Met considers the Hidden Springs Estates as part of the Leon Springs System, or if wells are listed by aquifer system, e.g., is there a list of Edwards Aquifer wells separate from a list of Trinity Aquifer wells. Bexar-Met will need to be contacted to get this information.

Fair Oaks CCR does not indicate the presence of any volatile organic compounds in their systems, however, both lead and copper were reported. Sampling results by the FO municipality are not indicative of any contamination resulting from past activities at CSSA. CSSA has already established a good relationship with the Fair Oaks municipality and water provider, Fairco.

Item 5 Break

Item 6: Monitoring Well Locations

The placement of wells was discussed and EPA approved proposed well locations. No major revisions to the well locations were made to those locations presented by CSSA and WPI except that CW-2 was moved southwest of its proposed location. Based on TIM discussions, the location of CW-3 was moved approximately 1,300 feet to the southwest, along the southern edge of the fault zone. The EPA also asked that a well be installed in the vicinity of Building 90. The following table was contributed by CSSA and WPI following the TIM, and has been adapted to fit the format of these minutes.

CSSA Monitoring Well Installation
Locations, Rationale, Contingencies

February 9, 2000 Revision
Adapted from CSSA


+Four clusters (three wells each) and three lower Glen Rose wells are to be drilled (15 wells total).

+Development and sampling can be accomplished on selected wells prior to drilling remaining wells.


Well Name
(Completion Zones)

General Location



CW-1 (3 wells)
Lower Glen Rose
Bexar Shale
Cow Creek

Along SWMU Highway adjacent to B-3. Location to be based on soil gas survey results. Well will be placed in area of highest soil gas contamination.

The goal of CW-1 will be to evaluate the area downgradient of SWMU B-3. Based on previous soil gas survey work, B-3 appears to have a greater volume of VOC contamination than O-1. Placing the well downgradient of the B-3 "hot spot" should achieve the "worst case" scenario role, provide valuable information regarding vertical migration of contamination, and stay close to Wells 16 and D which have the highest levels of ground water contamination. Prior geophysical surveys will be utilized to avoid drilling within a trench.


CW-2 (3 wells)
Lower Glen Rose
Bexar Shale
Cow Creek

Within the northern fault zone, southwest of Wells 2, 3, and 4, and northeast of wells 9, 10, and 11.

CW-2 will be used to evaluate the potential for the southwestward migration of contamination from Well 16 area. CW-2 will be located along the southern edge of the northern fault zone and will also act as a sentry well for two of the CSSA water supply wells (Wells 9 and 10).

Previously, CW-2 was to be located in the vicinity of Wells 2 and 3. However, the analytical history of both Wells 2 and 3 has shown minimal VOC con-tamination. Also, since no VOC contamination has been detected in three offsite wells located to the west of the CSSA boundary nor in FairCo Wells, it was felt that a cluster well to the southwest of our known source areas would fill a more important data gap.


CW-3 (3 wells)
Lower Glen Rose
Bexar Shale
Cow Creek

Northwest of wells D and 16.

Water table elevation mapping using weekly water level measurements collected by CSSA personnel suggest that at times, groundwater flow may have a west/northwest component. To evaluate this possibility, CW-3 will be located north of the fault zone, approximately 750 feet north of the Inner Cantonment fence line. The purpose of this well will be to:

a) check for contamination potentially moving northwest toward the large Fairco production wells on Ralph Fair Road, and

b) possibly use the well as background point (if the 3 zones are not contaminated).


CW-4 (3 wells)
Lower Glen Rose
Bexar Shale
Cow Creek

Adjacent old Well 6 location near the southwest corner of CSSA.

Based on available well records it appears that Well 6 was a Lower Glen Rose well (TD approximately 180 feet). Samples collected from Well 6 in May 1994 indicated 1.5 µg/L PCE. The off-site well LS-7, which was sampled in December 1999 had a PCE detection of 2.5 µg/L. CW-4 will be drilled in the vicinity of old Well 6 to evaluate 3 aquifers near the southwest corner of the base.


MW-3 (1 well)
Lower Glen Rose

Along the southern boundary of the North Pasture, approximately 2,400 ft east of Well 16.

MW-3 will be located in the fault zone, to the east of our known contamination areas. MW-3 will be drilled to the top of the Bexar Shale and completed as a Lower Glen Rose test well to help determine the eastern extent of contamination in the Lower Glen Rose.


MW-4 (1 well)
Lower Glen Rose

Along Salado Creek, approximately 4,000 ft southeast of Well 16.

MW-4 will be located south of the northern fault zone, downgradient of our known source areas and areas of greatest groundwater contamination. The well will help:

a) determine if the low levels of contamination found in CSSA Well 1 are related to the B-3/O-1 source areas,

b) evaluate the potential Salado Creek drainage as a conduit for contamination migration, and

c) add a valuable water table elevation point in area where we have no data.



MW-5 (1 well)
Lower Glen Rose

North of Building 90.

Well to be used as an upgradient background well for Building 90, which is a potential source area for groundwater contamination found along the southern boundary of the camp. Future drilling activities may include installation of Bexar Shale and Cow Creek wells to complete a cluster at this location.

Once results are obtained from these proposed wells, the next phase of work can be planned. Parsons is currently in the competitive bid phase for the drilling subcontract. Parsons intends to complete the RFI soil borings first, and is hoping to be back in the field in late February 2000. At this time, Parsons is estimating a mid-April start date for the well drilling phase. This information will be incorporated into the cluster well workplans, and eventually into the Environmental Encyclopedia. A draft work plan for the cluster wells was submitted to AFCEE and CSSA, but Parsons has not yet received comments.

CSSA inquired about the possibility of obtaining alternative drilling methods for the cluster well effort. Both Parsons and AFCEE stated that a SOW change would result in a significant schedule change, and it would be necessary to re-bid the amount of drilling required. Parsons estimated that such a delay would be approximately two to three months to finalize those costs.

Item 7: Additional Soil Gas Surveys

As part of the presentation materials, WPI and CSSA prepared a map proposing areas of additional soil gas surveys in the southwest quadrant of CSSA. Based on TIM discussions, the proposed soil gas areas were expanded to include the wastewater treatment plant which brought the estimated soil gas areas up to approximately 40 acres and will expand the survey area by about 15 acres. CSSA discussed the proposed soil gas sampling areas and rationales for the study. Dotted areas on the map included in Attachment 8 are based on old blue prints from the base where there were temporary wooden structures. The area was used to clean guns/artillery in the 1930’s and 1940’s. These dotted areas ring old buildings. There are railroad tracks along both the west side and east side of the former structures, and a centralized drainage ditch is also present. It appears that there was once a sewer pipe because of remaining tile in the area. The drainage pipe, which is associated with Building 90, looks like a possible area for contamination.

Historically, there have been two PCE vats located within Building 90. Recent interviews with CSSA personnel indicate that the area of concern regarding these operations may need to be expanded. The original vat was centrally located within Building 90. The vat operations were later re-located to the west side of the building. It was replaced with a citrus-based cleaner in 1997. The vat in the middle of the building has been removed and abandoned.

During a recent site visit with CSSA utility personnel, it was explained to both Parsons and CSSA Environmental Staff that the original drainpipes tied into a roof guttering system. The main trunk line passed beneath the road and discharged to a ditch just immediately west of Building 90. While the gutter pipe remains active, the drain lines from both systems have been removed from the gutter and abandoned.

The CSSA utility personnel said that the amount of discharge must have been low, and since 1986 they never observed appreciable runoff resulting from the drainpipe. The surface water flow would be towards the south during precipitation events. The storm water ditch is well pronounced at Building 90, but becomes less discernible and broader some distance downstream. For a thorough investigation, sampling may need to go all the way to the property line. The soil layer is expected to be thin in this area since rock outcrops at the surface in many places.

CSSA intends to conduct a soil gas survey in those areas that may have been impacted by the activities previously described. CSSA originally proposed to conduct the survey over approximately 32 acres surrounding both of the target areas. The EPA indicated that the soil gas survey needs to extend southward to the property line. The EPA stated that the sewage treatment plant should also be included in this effort. This will expand the survey area by approximately 8 to 10 acres. Parsons suggested for time and cost considerations, that the survey could be conducted initially at a large grid spacing (>200 feet), and the focus on target areas with a tighter grid. The EPA indicated that the grid spacing should be no more then 100 feet. Parsons did indicate some concerns about the thin profile of the soils in the southwest quadrant of the facility. Utilities, developed areas, and near-surface bedrock will result with a slower-paced survey than recently conducted in the north pasture.

The installation of RL83 cluster wells will not depend upon the results from the soil gas survey, and can proceed as scheduled. A new delivery order for soil gas will be created through AETC contracting. Parsons recommended that any investigative soil borings in this area should wait until the soil gas survey is complete.

Item 8 Lunch

Item 9: Preliminary Background Results

Parsons has prepared preliminary revised background numbers for February 2000.

The background numbers were revised for two reasons. 1) The Glen Rose background data set is being augmented with ten additional background samples.
2) Results from ITS Laboratory in the background data sets for soils are being replaced due to ITS’ questionable practices. There is a question concerning the statistical results for the Lower Glen Rose limestone. All analytical results from previous and recent sampling events appear to be in line except for lead and nickel. For this effort, ten additional samples were recently taken, and the lead results were between 1.5 milligram per kilogram (mg/kg) and 3.3 mg/kg. Similar results were found in new testing for nickel. The overall concern is that the previous background concentrations for these two metals are consistently greater than the recently-derived concentrations.

There was a question about QA/QC done on the pre-existing data. If correct, nothing can be done about the range of the numbers. The only thing that can be done is to keep the data sets that have the best QA/QC. More likely, the new numbers have better QA/QC. There were five "M" flags within the Glen Rose data. Parsons recommended not using the historic lead and nickel results in the evaluation.

In the June 1997 Background Evaluation, outlier tests were not performed, and a lognormal distribution was assumed for all metals. It may be necessary to look closer at the concentrations that dramatically increased to see if it is appropriate to adjust the statistical evaluation methodology. The revised data in the attached table include the old and new results, with nothing omitted from the statistical evaluation. What final approach to take regarding the statistical evaluation of this data will need to be addressed. Parsons is currently recalculating background concentrations with the replacement data. If a change to the statistical method is required, then a contract modification will need to be made. Parsons also asked EPA if they would be receptive to combining soil subtypes; EPA indicated they probably would be, but that this should also be discussed with TNRCC. If Parsons revises the data statistical procedures, then a modification will need to be made. The EPA indicated that they can provide input. Since TNRCC has approved the methodology used in the past, then they will need to approve additional actions. Whatever action taken will need to ensure that TNRCC gets what they require for closure and EPA accepts the methodology used for risk assessment. A risk assessor from WPI will be available to assist. EPA offered Maria Martinez’ input on the methodology.

Item 10: Soil Gas Survey and Geophysical results, potential revisions to soil boring locations

In December 1999, Parsons collected 146 soil gas samples from AOCs 37, 41, and 66. The survey area consisted of a contiguous area north of Well 16. The purpose of the study was to build upon results from earlier work in the south pasture area. The map in Attachment 11 shows compiled PCE results of seven soil gas surveys completed over the years. The data has been re-processed to include concentration intervals to the detection limit of the gas chromatograph (GC). The bulk of the results for the new survey indicated that concentrations did not exceed the instrument detection level of 0.01 parts per billion (ppb). For the most part, the December survey was successful in delineating the northern edge of the soil gas plume. There are a few isolated cells of PCE concentrations slightly above the GC detection limit, but are considered areally limited, and possibly a function of the near-surface fracture patterns. Location AOC 66-81 was the only occurrence of TCE. Depth profiles were two to eight feet. The field mowing personnel located some potential UXO at the west edge of AOC 41.

In terms of the entire soil gas plume, most areas to the south have been delineated by GC non-detections. A cluster well location has been proposed within the vicinity of the "hottest" portion of the soil gas plume, northwest of SWMU B-3 and southeast of Well 16. Most of the trends are part of the geologic structure and minor faulting. With respect to the 1996 Geologic Evaluation, there was good correlation between geology and soil gas trends in the same direction as the fault.

Parsons has started receiving unvalidated surface soil results from AOC 38 in the south pasture. This AOC is well within the confines of the soil gas plume. So far, the initial analytical results indicate no detectable VOCs. The Parsons ES geochemist (Mike Roddy) that prepared the map and has worked on CSSA soil gas surveys since 1995 is of the opinion that soil gas is being transmitted through fractures in the surface and subsurface. The results of the additional soil gas survey conclude that no other PCE/TCE sources are in the immediate vicinity north of Well 16.

Results of the December 1999 geophysical surveys were discussed. Both EM31 and ground penetrating radar (GPR) technologies were implemented at AOCs 35, 42, 43, and B-9. The interpreted results are as follows:

AOC 35: EM quad-phase data show an area of disturbed ground with multiple anomalies around Well 16. These disturbed areas are probably associated with the buried utilities around Well 16. The in-phase data do not show the same high-amplitude anomalous results that would confirm buried metallic objects. A rise in the quad- and in-phase data on the northern boundary can be attributed to the metal fence that separates the Inner Cantonment area from the North Pasture area. The five in-phase anomalies present can all be attributed to surface features. Those features listed from east to west are: the metal reinforced concrete culvert, the building surrounding Well 16, the cattle watering trough, the large water spigot near the road, and Well D, which had a 55-gallon metal drum on the wellpad during the survey. Two of the GPR survey results (files 47 and 45) confirmed the presence of buried objects.

AOC 42: EM data, quad- and in-phase, show the presence of six identifiable anomalies. Anomalies A, B, and C are the strongest anomalies and may indicate the presence of buried metallic objects in trenches. Anomaly D is slightly weaker then the previous anomalies but may be associated with them. It follows a linear trend with anomaly C that is parallel to the anomalies A and B trend. Anomalies E and F are individual and not associated with any trend. Both E and F are visible in GPR data as well. GPR data confirms the presence of other buried objects associated with anomalies A, B, and C.

AOC 43: EM data and GPR data show no significant anomalies. One of the GPR survey files shows the presence of dipping beds between 2 and 5 feet. The apparent dip of the beds is to the east.

SWMU B-9: EM data and GPR data show no significant anomalies. All GPR data files collected in the northwest-southeast trend show dipping beds with an apparent dip to the southeast.

Parsons recalled a discussion from the September 24, 1999 TIM regarding the EPA position with respect to suspected potential disposal areas and geophysical results. Based on the last discussion with EPA, if no subsurface anomalies are attributable to disposal activities, the EPA would accept surface sampling for site characterization.

Based on these factors, the Parsons recommendation is that AOCs 35 and 43 do not require the scoped soil borings, and that surface sampling will be sufficient for site characterization. On the other hand, the significant anomalies identified at AOC 42 will warrant additional soil borings than originally scoped. Additional site characterization work for B-9 is scoped under AMC task RL53, and was not discussed at this time.

Implications of the geophysical results and changes in scope of work based on findings were discussed. It was proposed by Parsons that the five scheduled soil borings at AOC 35 be replaced with five surface samples to be analyzed for PCE, TCE, and DCE. At AOC 43, Parsons recommended that the three scheduled soil borings be replaced by three surface samples. AOC 43 will also need to be sampled for explosives since appreciable amounts of projectiles and spent casing materials have been noted at this site.

Parsons proposed that the number of borings at AOC 42 be increased from five to nine. Per the EPA request, the depth of the borings will be from ten to fifteen feet. AOC 42 will continue to be termed an AOC, not SWMU, until analytical results determine if there is actually solid waste at this location. Parsons also recommended that three samples be collected from each boring (1 surface sample and 2 subsurface sample). Since the contents of the trenches are unknown, Parsons also urged the attendees to consider explosives (SW8330) analyses and UXO screening by qualified personnel. The EPA and CSSA supported the notion of explosives analyses.

The amount of money saved at AOCs 35 and 43 can be applied to the additional investigation at AOC 42. The EPA approves the reduction of scope, as long as the sampling is biased to areas more likely to contain contamination. The limited list of testing for VOCs was approved by the EPA for only these AOCs. The EPA made it clear that the precedent will not be set by these investigations that only PCE, TCE and DCE are only reported, and the EPA will normally require reporting for the full suite of VOCs. A UXO screening and explosive sampling modification will need to be added to the scope of work for AOC 42, in addition to the scope reductions at AOCs 35 and 43.

Parsons also presented a draft cost estimate for the recommended scope changes. These figures did not include additional items discussed during the TIM. The increase of scope at AOC 42 will not provide a surplus of funds to increase the investigative activities at AOC 65. For AOC 65, Parsons estimated $1,350 per boring to conduct additional field work only. Additional borings for AOC 65 will need to be addressed in a SOW modification, and may be provided with the change order for AOCs 35, 42, 43, and 50.

Item 12: AOC 50 and other potential UXO sites

The original scope was to remove 100 cubic yards of soil containing nickel penetrate scattered over a localized area. However, during a recent site visit, additional areas of waste were discovered over a much broader area. Most of the disposal areas are overgrown with cedar; however, CSSA cedar crews were clearing the area this week. During the survey some potential UXO was also discovered. Recently, a 100-pound practice bomb had been removed from the vicinity. Just this week the site has been cleared of overgrowth, and potential UXO has been removed by CSSA. CSSA notes that nothing of consequence was found. However, CSSA and Parsons want Parsons to have UXO clearance performed by qualified personnel during the excavation activities.

The results of the TCLP analyses of the raw nickel penetrate identified the material as Class 2 non-hazardous waste. CSSA will provide Parsons with an MSDS for the material to submit with the waste profiles. The assumption of the 25 percent Class 1 waste in the AETC DO5068 contract will likely no longer be required. However, the amount of solid nickel penetrant was significantly underestimated in the SOW. The Parsons estimate was based on disposal rates measured by weight rather than volume. If nickel has a considerably higher specific gravity than soil, the disposal of the actual penetrate may exceed what was originally planned for the removal of soils contaminated with nickel penetrate.

Sweeping for UXO will need to be added to the contract and an explosives sample will need to be taken before any digging and hauling. The EPA also requested that VOCs and explosives also be included in the sampling suite (four each). CSSA would also like Parsons to conduct a geophysical survey (EM31 and GPR) over an additional section adjacent to AOC 50. Parsons will visit the site next week to re-estimate the excavation volume from AOC 50. Based on this visit, the estimate of cubic yards and/or total weight may need to be increased.

Sites scheduled for upcoming work were reviewed. This list has been tabulated by Scott Pearson based on observations while marking sampling locations. The table lists those sites visited in January 2000, and notes where concerns may lie. In particular, Parsons is concerned with UXO at B-4 and B-24. The uncertainty of the AOC 42 contents is also a concern because of the large metallic signatures during the geophysical survey. Parsons will provide a UXO specialist when this work is re-scheduled. The jet-assisted take-off (JATO) devices at B-23 will need to be removed before drilling. B-7 should have no more UXO present, since the site has been cleared by UXB. A spring from a 20-pound practice bomb was also discovered at B-29 while locating drilling locations along the landfill edge of the SWMU. Since this site had metallic anomalies in a prior geophysical survey, Parsons now has some concern regarding potential UXO at this site.

Parsons inquired about the possibility of performing some grading/ramping work at some of the SWMUs prior to drilling. From a safety aspect, Parsons has some concerns with rig entry into trenches at B-23, B-25, and B-26. The major issue is what the EPA and TNRCC policy is regarding construction activities (e.g. grading) at a SWMU. The EPA tentatively approved limited SWMU grading to facilitate rig entry into unsafe areas. The EPA will contact the TNRCC to discuss what options are available to facilitate safe work practices while maintaining the integrity of the disposal units.

Item 13: Response to EPA comments

Discussion of this section will be delayed until EPA has had the opportunity to review; however, there was discussion about the response to comment 23. EPA indicated that the site this comment refers to will be looked into.

Item 14: Schedule

Most of the drilling work scheduled to begin on January 10, 2000 work was delayed because of explosive variance approval from the TNRCC. Without the variance approval, very few sites remain where work could continue. This included SWMU B-4, to which a rig was mobilized on January 10, 2000. However, work was immediately suspended when it was learned that the SMWU was used as an ammunition burning pit, and that there was a real possibility of encountering UXO. Since that time, Parsons has received verbal confirmation from the TNRCC approving the variance requests. Parsons expects to be back in the field by February 28, 2000.

The Interim Measures (IM) schedule has slipped for SWMU O-1. The selected laboratory, O’Brien & Gere (O’B&G), had problems with analysis of samples collected in November 1999. Nearly all of the VOC data was rejected during the validation process because their internal standards failed, and O’B&G failed to perform necessary corrective action. As a result, Parsons will need to basically start over with the investigation, resulting with approximately a four-month delay. Each location will be re-sampled, and the new samples will be sent to another lab (APPL) if O’B&G can’t prove that their operation has been corrected within the required timeframe.

EPA indicated that Parsons will need to write a letter to CSSA explaining that delays at O-1 are due to analytical problems. CSSA will in turn submit the letter to EPA documenting analytical problems. A new schedule for O-1 will need to be included in the letter to CSSA.