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20th Quarter - Final Quarterly Progress Report

RCRA Facility Investigation

The RFI is being conducted to characterize the environmental setting of CSSA, define the sources of contamination, define the degree and extent of contamination, identify actual or potential receptors, and to assess whether any additional I/SM may be warranted. The RFI is estimated to represent approximately 30 percent of the required actions at CSSA. The RFI includes a Preliminary Report (5 percent of RFI), RFI WP (10 percent), Facility Investigation (45 percent), Human Health and Ecological Risk Assessment (15 percent), Investigation Analysis (10 percent), Treatability Studies (10 percent), and Progress Reports (5 percent). As of the end of Quarter 19, the RFI is approximately 45 percent complete.

Task I - Preliminary Report: Description of Current Conditions

Task Description

This task included preparation of the DCC Report. The DCC Report included information from previous investigations and other relevant data. Information related to the facility background, nature and extent of contamination and pre-investigation evaluation of corrective measure technologies was included in the DCC Report. CSSA’s Environmental Encyclopedia was used to meet the DCC Report submittal requirements. The final DCC Report was submitted to the EPA and TCEQ on August 1, 1999. No regulatory comments have been received on the report. This task makes up approximately 5 percent of the RFI phase, and is 100 percent complete.

Activities this Quarter

No activities associated with the DCC were conducted this period.

Task II - RFI Work Plan

Task Description

The Order requires that the RFI WP task include a Project Management Plan, Data Collection Quality Assurance Plan, Health and Safety Plan (HSP), and a Community Relations Plan (CRP). As previously agreed by EPA, CSSA’s Environmental Encyclopedia has been used to fulfill this requirement. The Environmental Encyclopedia includes all the information required by the Order. Completion of this task is funded for the planned RFI tasks.

Activities this Quarter

Closure activities were continued at various SWMUs and AOCs during this quarter. Various work plan addenda were finalized and added to the hard copy and electronic Environmental Encyclopedia, including the TO 0009 Environmental Cleanup Plan, Standard Operating Procedures for Soil Sifting at AOC-55, and the TO 0009 Health and Safety Plan.

1. Percent Complete

The RFI WP task makes up approximately 10 percent of the RFI phase. Estimation of percent complete is difficult due to the continuing need for plan addenda as new projects are planned. As of the end of Quarter 20, WPs currently under scope are approximately 95 percent complete. The CSSA Environmental Encyclopedia will continue to be updated as WPs are completed and made Final.

2. Summary of Findings

No new findings are associated with RFI WP preparation during this reporting period.

3. Summary of Changes

No changes other than those described above in Activities this Quarter to existing RFI WP were made during this reporting period.

4. Summary of Contacts

No contacts occurred during this reporting period.

5. Summary of Problems

No significant problems occurred during this reporting period.

6. Actions Taken to Correct Problems

No actions were taken for any problems during this reporting period.

7. Projected Work for the Next Quarter

WPs for future CSSA contracts will be prepared as needed.

8. Copies of Daily Reports, Inspection Reports, Data, etc.

No daily reports, inspection reports, or data related to the RFI WP task were generated during this reporting period.

Task III - Facility Investigation

Task Description

An investigation of the facility is being conducted to:

1. Characterize the environmental setting of the facility;

2. Define the source(s) of contamination;

3. Define the nature and extent of contamination; and

4. Identify actual or potential receptors.

In some cases, multiple investigational phases may be necessary. The investigation results will be used to develop and evaluate alternatives during the CMS. All investigation activities are being conducted in accordance with the RFI WP.

Completion of this task is partially funded for the planned RFI tasks. Attachment 2 indicates the sites for which investigations have been initiated and subsequently conducted as well as sites that have been identified, but not yet investigated.

Activities this Quarter

The majority of current ongoing environmental activities at CSSA are part of the RFI task. Work on each of these tasks is described in the following paragraphs. The main areas of work this quarter include groundwater monitoring, analytical data verification and validation, closure activities at several SWMUs and AOCs, well installations, Building 90/AOC-65 investigations, SWMU B-3 SVE system, AOC-55 remediation activities, and various miscellaneous tasks.

Groundwater Monitoring

Sampling of all on-post and selected off-post wells is conducted quarterly. Off-post wells were sampled from March 1 - 10, 2004. Thirty-two private and public off-post drinking water wells were sampled, including DOM-2, FO-8, FO-J1, HS-2, I10-2, I10-4, JW-7, JW-8, JW-9, JW-12, JW-14, JW-26, JW-28, JW-29, JW-30, LS-1, LS-2, LS-3, LS-4, LS-5, LS-6, LS-7, OFR‑1, OFR-2, OFR-3, OFR-4, RFR-3, RFR-4, RFR-5, RFR-10, RFR-11, and RFR-12. The locations of these wells are shown on Attachment 1. All samples were collected from ports located near the wellhead. Additional samples were collected at the well owners’ request from the faucet tap inside the residence. Samples were analyzed by Agriculture & Priority Pollutants Laboratories, Inc. (APPL) for the EPA-approved short list of volatile organic compounds (VOCs). The VOC short list includes 1,1-dichloroethene (1,1-DCE), bromodichloromethane, bromoform, chloroform, cis-1,2-dichloroethene (cis-1,2-DCE), dibromochloromethane, dichlorodifluoromethane, methylene chloride, naphthalene, tetrachloroethene (PCE), trichloroethene (TCE), toluene, trans-1,2-dichloroethene, and vinyl chloride. Preliminary data on these samples were received on March 31, 2004, by Parsons. Data validation and verification for these samples were initiated this quarter and Parsons’ chemists submitted these data packages to AFCEE and Portage Environmental on April 9, 2004.

Quarterly groundwater monitoring of 38 on-post monitoring and/or drinking water wells was performed from March 11 – 16, 2004. CSSA wells CS-1, CS-10, CS-11, CS-2, CS-4, CS-D, CS‑I, CS-MW1-BS, CS-MW1-CC, CS-MW1-LGR, CS-MW2-CC, CS-MW2-LGR, CS‑MW3‑LGR, CS-MW4-LGR, CS-MW5-LGR, CS-MW6-BS, CS-MW6-CC, CS-MW6-LGR, CS-MW7-CC, CS-MW7-LGR, CS-MW8-CC, CS-MW8-LGR, CS-MW9-BS, CS-MW9-CC, CS-MW9-LGR, CS-MW10-CC, CS-MW10-LGR, CS-MW11A-LGR, CS-MW12-BS, CS‑MW12-CC, CS-MW12-LGR, CS-MW16-CC, CS-MW16-LGR, CS-MW17-LGR, CS‑MW18-LGR, CS-MW19-LGR, CS-MWG-LGR, and CS-MWH-LGR were sampled. Locations of the on-post wells sampled are shown on Attachment 1. Samples were analyzed by Severn Trent Laboratories (STL) for the EPA-approved short list of VOCs. The preliminary data were received by Parsons on April 12, 2004. Data validation for VOCs and metals was performed this quarter and Parsons’ chemists submitted these data packages to AFCEE and Portage Environmental on April 19, 2004.

The Final On- and Off-post Quarterly Groundwater Monitoring Reports for December 2003 were added to Volume 5 of the Environmental Encyclopedia this quarter. Preparation of the Draft March Quarterly Groundwater Monitoring Reports was initiated this quarter.

Off-Post GAC Systems

Based on previous sampling results indicating VOC levels above or approaching the maximum contaminant level (MCL), GAC filtration systems were installed at seven off-post wells. In accordance with the CSSA Off-post Monitoring Program Response Plan dated June 2002 (the Plan), the off-post GAC wellhead treatment systems are maintained by CSSA. Monthly O&M activities for the off-post residential GAC treatment systems were performed this quarter. Work included inspection and replacement, as needed, of the pre- and post-GAC micron filters at wells LS-6, LS-7, RFR-10, RFR‑11, and OFR‑3. Confirmation post-GAC samples were collected from these wells and LS-2/LS-3 during March 2004. No post-GAC samples had concentrations above the MCL for PCE, TCE, or cis-1,2-DCE during the March event. The next post-GAC sampling event will be conducted in September 2004.

Data Validation and Verification

Laboratory results from sampling efforts and investigations are validated and verified by Parsons’ chemists to ensure results are in compliance with CSSA Quality Assurance Program Plan (QAPP) requirements. Data validation and verification continued during Quarter 19 under CSSA projects TO 0019, TO 0008, TO 0042, TO 0058, and TO 0009.

Eight data packages related to quarterly groundwater monitoring activities were received by Parsons during Quarter 20. These packages covered the March 2004 quarterly sampling event. Thirty-three other data packages were received related to Westbay^® multi-port groundwater sampling, investigation derived waste (IDW), soil gas vapor sampling, air emissions, waste characterization, and soil sampling for RFIs at various SWMUs and AOCs. All data packages were validated and verified in accordance with specific project Data Quality Objectives (DQOs). Parsons submitted data packages for TO 0008 Group G (TO08#22, #23 & #24) on April 9, 2004, to AFCEE and Portage Environmental. AFCEE chemists approved nine data package groups (TO08 #11, #12, #13, #14, #15, #16, #22, #23, and #24), this quarter.

RCRA Facility Investigations/Closures of SWMUs and AOCs

A total of 84 SWMUs, AOCs, and Rifle Management Units (RMUs) have been identified at CSSA and investigations have been conducted at 59 of those sites. A summary of the status of each site, including whether the site is recommended for closure or if closure is approved, is provided in Attachment 2. To date, closure of 20 sites has been approved by TCEQ.

During Quarter 20, soil/waste investigations and/or excavations were conducted at SWMUs B-23, B-23A, B-25, B-26, B-29, B-30, B-33, DD, AOC-50, AOC-54, AOC-56 and AOC-67. Evidence of ordnance waste was observed at SWMU B‑29 and AOC-56; therefore, further work was suspended at these sites until ordnance specialists could be mobilized to the site. A brief summary of the investigation/excavation results follows:

In addition, CSSA continued coordination with the Texas Historical Commission regarding demolition of Building 43. This historic structure is situated in the middle of a contaminated area and must be demolished to allow the site to be remediated. Level III HABS documentation is being prepared.

Well Installations

There are currently 41 drinking water, livestock, and monitoring wells at CSSA that are monitored as set out in the DQOs. In addition, there are four Westbay^® multi-port wells that are sampled on a monthly basis. There are 10 shallow wells and piezometers around Building 90 that are monitored for the AOC-65 treatability investigation and recharge study.

A draft version of the CSSA Hydrogeologic Conceptual Site Model (HCSM) was submitted to AFCEE and CSSA for internal review on January 27, 2004. CSSA is reviewing the draft report and had not provided comments during Quarter 20. A draft version of the TO42 Well Installation Report was submitted for internal review April 2, 2004. Internal comments are anticipated to be addressed during Quarter 21, followed by the issue of both reports as Final versions.

Formation pressures in each sample zone were profiled eight times during Quarter 20 (February 18, February 26, March 10, March 25, April 8, April 12, April 15, and April 30, 2004. A continuous datalogger system was temporarily installed in CS-WB01-LGR to study the effects of recharge with respect to response time and pressure head changes. Each of the 10 multi-layered zones are continuously measured to monitor the flux of precipitation recharge through the upper 300 feet of the Glen Rose Limestone. Continuous data logging will continue through mid-June 2004. Four rounds of sampling from the Westbay^® multi-level wells were conducted during the weeks of February 23, March 22, April 5, and April 27, 2004. Each well was hydraulically profiled by zone and discrete samples were collected from groundwater-bearing intervals. The samples were submitted to DHL Analytical for VOC analysis. Summary graphs of multi-level hydraulic profiling and sampling are included in Attachment 3.

Parsons conducted an upgrade to the Outfall 002 GAC system located on-post. The existing 200-pound containers of carbon were expended at the close of the TO42 drilling activities. Parsons contracted with CarbonAir of San Marcos, TX to replace the carbon canisters. TCLP samples were analyzed for VOCs to characterize the spent carbon within the canisters. TCLP results indicated no detections of VOCs. The two, 200-pound carbon vessels were exchanged for two, 900-pound vessels on January 23, 2004. The spent carbon was disposed via thermal desorption by Envirotrol, Inc. in Darlington, Pennsylvania.

Additional upgrades in January and February 2004 expanded the treatment capacity from 10 gallons per minute (gpm) to 70 gpm. The upgrade was undertaken to allow for more rapid treatment of groundwater IDW generated during well installation activities and allowing implementation of a pilot study for the pumping of CS-MW16-LGR and CS-MW16-CC, and facilitate the planned irrigation system at the TPDES-permitted application area. The system modification included permanent connection to wells CS-MW16-LGR and CS‑MW16-CC. A splash pad was also constructed at the terminus of the outfall line within the Salado Creek tributary. Testing of the system was initiated on February 23, 2004. A long-term pilot study to measure the effectiveness and capacity of well CS-MW16-CC was initiated at the end of February 2004. Discharge rate, drawdown, and contaminant concentrations will be monitored throughout the duration of the pilot study. The system is currently operating at approximately 11.5 gpm (16,000 gallons per day [gpd]) which is 50 percent of the permitted discharge limit. When the irrigation system is constructed, the system will provide 100 percent of the allowable daily discharge (30,000 god).

Parsons operated and maintained the GAC unit, and prepared a Discharge Monitoring Report (DMR) each month to comply with TPDES requirements. Through April 2004, approximately 941,759 gallons of water containing VOCs was treated by GAC and discharged from Outfall 002 during Quarter 20.

Building 90/AOC-65 Investigation

Under TO 0058, groundwater sampling was performed following each rainfall event of approximately 1-inch or more. The first recharge sampling event was performed on March 15, 2004, and the second sampling event was performed on April 6, 2004. Results from these sampling events were obtained during Quarter 20 and reviewed for quality and usability. Contaminant levels measured in the wells appear to be remaining relatively consistent following moderately intensive rainfall events.

AOC-55 Excavation

Removal actions at AOC-55 were completed during Quarter 20. Approximately 35,000 cubic yards of soil were sifted for removal of ordnance and explosive (OE) scrap material, which was demilled and sent as scrap metal for recycling. The majority of the AOC-55 waste and waste residue was disposed of as Class 2 non-hazardous waste at the Waste Management, Inc., Covel Gardens Landfill.

Approximately 699 OE scrap items have been discovered at AOC-55, many found at depths greater than two feet. The OE items include 75mm projectiles, 155mm projectiles, rocket propelled grenades and Stokes mortars. Approximately 20 of the items were suspected of possibly containing high explosive filler; however, none were found to be fused. The OE scrap items were demilled and sent off-site for scrap metal recycling after inspection and certification by the UXO specialists to confirm that none of the items contain explosives. The 20 items potentially containing high explosive fillers were removed by Fort Sam Houston EOD personnel.

Confirmation sampling of AOC-55 perimeter soils and excavated bottom was conducted in order to gain RRS1 closure. This testing identified a small area where further excavation was needed. This additional excavation of 36 yd³ and the closure report for AOC-55 was completed during Quarter 20.

Miscellaneous

Letters summarizing the results of the December 2003 off-post groundwater monitoring event were mailed to the owners of the off-post wells on February 23, 2004. Fact Sheet 17 was mailed to the recipients on the CSSA mailing list during Quarter 20. Draft letters to well owners and a draft Fact Sheet 18 summarizing the March 2004 groundwater monitoring laboratory results will be submitted to CSSA and AFCEE for review during Quarter 21.

The CSSA website was updated with documents added to the Environmental Encyclopedia through the end of December 2003. Additional updates are pending while contract negotiations continue. This website includes CSSA’s Administrative Record as required under the Order.

Parsons personnel conducted various LAN and GIS support activities during Quarter 20. Parsons personnel provided support including updates to the sample coordinate database for new sampling locations, creating metadata/layer files, and assisting with various GIS-related requests as received from CSSA.

1. Percent Complete

The Facility Investigation task makes up approximately 45 percent of the RFI phase. As of the end of Quarter 20, this task is approximately 25 percent complete.

2. Summary of Findings

Groundwater Monitoring

Quarterly groundwater monitoring for both on- and off-post wells was performed at CSSA from March 1 – 16, 2004. A map of the well locations sampled is provided on Attachment 1 of this report. Thirty-two private and public off-post drinking water wells were sampled and 38 on-post monitoring and drinking water wells were sampled. Results of the March 2004 groundwater monitoring event will be formally reported in the draft March 2004 Quarterly Groundwater Monitoring Reports to be submitted to CSSA and AFCEE for review and comments during Quarter 21.

Building 90/AOC-65 Investigation

There is no new analytical data available for review for Quarter 20. Observations from the groundwater recharge study activities will be presented in the Treatability Evaluation Report prepared under TO 0058.

3. Summary of Changes

No changes to the RFI were made during the reporting period.

4. Summary of Contacts

Results from the December 2003 quarterly groundwater monitoring event were mailed to each off-post well owner February 23, 2004. In addition, CSSA received several letters from the TCEQ during Quarter 20. The following correspondence was submitted and/or received:

	February 18, 2004 - Submittal of DQOs for the Groundwater Monitoring Program to EPA and TCEQ for review;
	February 23, 2004 - TCEQ letter requesting additional information regarding SWMU Building 40;
	March 9, 2004 - TCEQ approval of permit by rule registration for the SWMU B-3 SVE unit; and
	March 24, 2004 - TCEQ letter requesting additional information concerning the December 2003 Off-post Groundwater Monitoring Report.
	March 30, 2004 - TCEQ visited CSSA to perform a Compliance Evaluation Inspection.

Copies of all correspondence are included in Volume 1-1 of the Environmental Encyclopedia.

A meeting was held April 7, 2004, with Westbay^®, Parsons and CSSA personnel attending. Discussions included a status of the Westbay^®-equipped well sampling and review of seven months of Westbay^® profiling and laboratory results. The range of concentrations detected in the Westbay^® wells compared to discrete interval samples taken from the open boreholes was discussed. The option to add Mosdax probes and Dataloggers for continuous pressure monitoring of the LGR zones at CS-WB01-LGR was discussed. Westbay^® personnel submitted a cost estimate for this profiling to be performed, which was accepted by CSSA – the Modal probes and datalogger were installed at CS-WB01-LGR on April 22, 2004.

5. Summary of Problems

No significant problems were encountered during the reporting period.

6. Actions Taken to Correct Problems

No actions beyond those previously reported for the data package review and approval process have been taken to correct problems.

7. Projected Work for the Next Quarter

Fact Sheets

Fact Sheet 18 will be prepared and submitted to CSSA and AFCEE. After approval, the fact sheet will be distributed to area residents. Draft letters to the well owners will be submitted to CSSA and AFCEE for review during Quarter 21.

Groundwater Monitoring

The next quarterly groundwater monitoring event will be conducted in June 2004. The upcoming event will include the existing CSSA drinking water and monitoring wells and approximately 25 off-post wells. O&M at the residential GAC filtration systems (LS-6, LS-7, OFR-3, RFR-10, and RFR-11) and public water supply systems (LS-2/LS-3) will be conducted monthly during Quarter 21.

The Westbay^® wells will be profiled twice a month and sampled once per month for the foreseeable future. Monitoring frequencies may be modified based on the occurrence of significant rainfall.

Building 90/AOC-65 Investigation

Under TO 0058, groundwater sampling of the AOC-65 piezometers will be performed in accordance with the Standard Operating Procedures (SOPs) and DQOs prepared for the groundwater recharge study. Analytical data from groundwater sampling performed in January 2004 will be reviewed and compiled into tables for eventual use in the Groundwater Recharge Study Report. Additional workplans will be prepared as new contracts are funded.

AOC-55 Excavation

Closure reporting for AOC-55 was completed during Quarter 20 and submitted to the TCEQ for review.

SWMU and AOC RFI/Closure Reports and Planned Closure Projects

Closure work recommended in previous RFI Reports will be continued at several SWMUs and AOCs during Quarter 21.

8. Copies of Daily Reports, Inspection Reports, Data, etc.

Reports summarizing the most recent groundwater findings are submitted to present the results from quarterly groundwater sampling events (on- and off-post). The quarterly groundwater monitoring reports present the groundwater elevations recorded (on-post wells only) and the analytical results received for each well (on- and off-post). The groundwater elevations are presented in the On-post Quarterly Groundwater Monitoring Reports on a potentiometric surface map and in tabular format. Analytical results from the most recent sampling events are compared to levels from the previous quarters, while comprehensive historical analytical results can be found in tables which are revised quarterly and presented in the Introduction to the Quarterly Groundwater Monitoring Program, Volume 5, Groundwater. Reports for each previously conducted quarterly monitoring event are also located in Volume 5, Groundwater, behind the On-post Groundwater Monitoring and Off-post Groundwater Monitoring tabs. Copies of these reports and analytical data are presented separately to the EPA by electronic version on CD Rom, at the request of the EPA. The CD ROM is delivered to the EPA within three weeks following the submittal of each quarterly progress report.

Task IV - Human Health and Ecological Risk Assessment

Task Description

This task includes a screening risk assessment, or if necessary, a baseline risk assessment for the potential human health and environmental risks posed by the site in the absence of any remedial action. For human health risks, this effort will involve the following components:

1. Contaminant Identification;

2. Exposure Assessment;

3. Toxicity Assessment; and

4. Risk Characterization.

For ecological risks, the effort will include the following components:

1. Problem Formulation;

2. Exposure Assessment;

3. Ecological Effects Assessment; and

4. Risk characterization.

Completion of this task is partially funded. Currently planned and funded (under RL83) is preparation of a preliminary post-wide human health and ecological CSM for risk assessment. The CSM identifies potential human and ecological receptors and land use surrounding the facility. In addition, a Risk Assessment Technical Approach has been prepared.

This task makes up approximately 15 percent of the RFI phase. The amount of effort needed to accomplish this task is not yet known because analytical data have not yet been fully evaluated. The percent complete will depend on the number of sites requiring risk assessment and is currently estimated at 30 percent.

Task V - Investigation Analysis

Task Description

This task includes preparation of an Investigation Analysis to support the selection of protection standards for CSSA. For sites closing under the State of Texas RRSs, this analysis will be included as part of the RFI Report. For sites closing to a risk-based standard, the analysis will be submitted along with the Risk Assessment Report. Background levels will be used to determine the possibility of closure under RRS1. The Investigation Analysis will also include groundwater protection standards and other relevant protection standards. The relevant protection standards will be used at sites where an RRS1 closure is not applicable. Due to the promulgation (September 23, 1999) of the Texas Risk Reduction Program (TRRP) (30 Texas Administrative Code [TAC] §350) by the TCEQ, two options are being considered for the protection standards. One option is to base the protection standards on the RRS2 Media-Specific Concentrations. The other option is to use the Protective Concentration Limits developed under TRRP. Site-by-site decisions will be made as additional information becomes available. New TO 0019 seeks closure of SWMUs and AOCs under the RRS.

Activities this Quarter

No activities related to Investigation Analysis this quarter.

1. Percent Complete

The Investigation Analysis task makes up approximately 10 percent of the RFI phase, and is approximately 69 percent complete.

2. Summary of Findings

As described in Task III, 49 final RFI reports have been completed and submitted to CSSA and TCEQ. As part of the preparation of these reports, investigation results were compared to closure criteria. A summary of recommendations for each site is provided in Attachment 2. Based on the final reports submitted through Quarter 20, 20 sites were recommended for closure while the remaining sites may require future investigation and/or cleanup. Through January 2004, a total of 20 SWMUs or AOCs have been approved by TCEQ for closure.

3. Summary of Changes

No changes associated with the Investigative Analysis were made during this reporting period.

4. Summary of Contacts

No contacts related to the Investigative Analysis were made during this reporting period.

5. Summary of Problems

No problems related to the Investigative Analysis occurred during this reporting period.

6. Actions Taken to Correct Problems

No actions to correct problems were necessary during this reporting period.

7. Projected Work for the Next Quarter

Continued work on comparison of investigation results to closure criteria will be performed.

8. Copies of Daily Reports, Inspection Reports, Data, etc.

No daily reports, inspection reports, or data related to investigation analysis/risk assessment were generated during this reporting period.

Task VI - Treatability Studies

Task Description

Funded activities include bench-scale treatability studies for SWMU B-20, SVE, and other treatability studies for treatment of the subsurface soils and bedrock at AOC-65 and SWMU B-3 if further contamination exists.

Activities this Quarter

As part of the Task II I/SM, a treatability study for stabilization of the excavated soils was continued during Quarter 19. Additional soil characterization data was generated during Quarter 20 for the waste characterization at SWMU B-24. Monitoring of the field treatment efforts is expected to continue. Monitoring data are anticipated to support similar closure/remediation efforts at sites with similar contaminants of concern.

AOC-65 SVE System

Parsons continued the six-month O&M period of the AOC-65 SVE system per the O&M plan schedule. O&M consisted of twice monthly system checks to assess and document the system performance, manage water in the knock-out pot, and perform miscellaneous maintenance. Pressure measurements, flow, and contaminant flux screening levels were measured during the associated system check once per month. Data collected from the initial O&M testing performed in December 2003 was received during Quarter 20, and these data indicate that the four open VEWs at AOC-65 were recovering VOCs at an approximate rate of 15 pounds per year. Two of the vent-lines from the VEWs were blocked by the accumulation of water, and the water levels in VEW-15 were above the screened interval preventing any removal from that well. The estimated emissions were well within allow emission limits established in the Permit By Rule (PBR).

The quarterly O&M sampling event of the AOC-65 SVE system was performed on March 16, 2004, and included screening of VEWs inside Building 90. Prior to the quarterly sampling and test event, some modifications were constructed to the AOC-65 system to facilitate periodic purging of the accumulated water in the vent lines from the VEWs to the blower manifold. Specifically, additional access ports were added to the individual well lines so that a compressor could be connected to the lines to apply appropriate pressure to clear liquids from all extraction lines.

SWMU B-3 SVE System

Construction of the SVE system was completed in December 2003, including manifolding the VEW piping from B3-VEW19 and B3-VEW20 to the blower, which was installed in an enclosure built specifically to house the blower. Pilot test activities were performed in December 2003. SWMU B-3 surface geophysical survey work was also performed during the week of January 19, 2004. This work, completed under RL83, was performed to identify significant geologic features, such as fault zones in the vicinity of SWMU B-3 for assessing future VEW locations. The results from the surface geophysical work were included in the Pilot Study Summary Report for SVE at SWMU B-3 submitted to CSSA on February 27, 2004.

1. Percent Complete

The Treatability Studies task makes up approximately 10 percent of the RFI phase. The amount of effort needed to accomplish this task is not yet known because all pertinent data (e.g., analytical, physical, etc.) are not yet available. The percent complete depends on the number of sites requiring treatability studies and/or the need for a Treatability Study Program, but is currently estimated to be 38 percent complete.

2. Summary of Findings

Analytical data continue to be received from the PIMS treatability study monitoring efforts. The results will be reported in the treatability study report anticipated to be completed in March 2004.

AOC-65 SVE System

Preliminary evaluation of recently collected data from VEWs surrounding AOC-65 showed estimated rates of removal of 15 pounds per year. The measured rate of removal from the subslab system was 339 pounds per year. The preliminary evaluation does not include three VEWs which were not producing flow due to blockages. Analytical data from the quarterly O&M sampling event collected from the extraction wells and from the main emission intakes following the line clearing process indicate estimated removal rates of 10 lbs/year from the AOC‑65 SVE system and 35 lbs/year from the subslab SVE system during the quarterly sampling event. All data will be presented in the annual O&M report scheduled to be submitted after six months of operation of the system and the interim treatability evaluation report to be submitted in September 2004.

SWMU B-3 Preliminary Geologic and SVE Pilot Study Investigation

Preliminary emission calculations suggest that the two blowers would be capable of removing more than 50 pounds of chlorinated hydrocarbons over one year of operation. The data was compiled and presented in a Pilot Study Report for SWMU B-3 SVE submitted to CSSA on February 27, 2004.

Results from the surface geophysical investigation conducted in February 2004 suggest a possible anomaly related to some sort of subsurface feature (fracture, buried object, or chlorinated contaminant mass) in a portion of the SWMU B-3 limits, but did not positively confirm the presence or orientation of a fault near SWMU B-3.

3. Summary of Changes

No changes associated with the treatability studies occurred during this reporting period.

4. Summary of Contacts

Revisions to the scope of work proposed by University of Texas at San Antonio (UTSA) for characterization of contaminant migration near AOC-65 were submitted in a previous Quarter. CSSA continues to consider the studies proposed, but no plans are currently ongoing to conduct any of the proposed work during the next quarter.

5. Summary of Problems

No problems related to the PIMS treatability studies occurred during this reporting period.

6. Actions Taken to Correct Problems

No actions to correct problems were necessary during this reporting period.

7. Projected Work for the Next Quarter

O&M of the SVE systems at AOC-65 will be continued during the next quarter. Upon completion of the six months of funded O&M, an O&M performance summary report will be prepared documenting all maintenance performed, measurements collected, and recommendations for future operations of the systems.

Field scale treatability studies of PIMS for the previously sifted soil piles will continue in Quarter 21 as part of the treatability activities for the soil pile disposition assessment. Because this work is associated with the soil piles, it is included in the Interim Measures description.

8. Copies of Daily Reports, Inspection Reports, Data, etc.

No analytical data are submitted during this reporting period.

Task VII - Progress Reports

This task includes quarterly progress reports pertaining to the status of the RFI phase of work. This progress report is submitted as part of this task.

Completion of the quarterly progress report preparation task is partially funded. Five progress reports (December 2003 – January 2005) are funded under TO 0005.

1. Percent Complete

The Progress Reports task makes up approximately 5 percent of the RFI phase. The percent complete is unknown because the number of quarterly progress reports needed is currently unknown; however, it is estimated to be approximately 14 percent complete.

2. Summary of Findings

No findings associated with the progress reports were made during this reporting period.

3. Summary of Changes

No changes associated with the progress reports occurred during this reporting period.

4. Summary of Contacts

No contacts relating to progress reports were made during this reporting period.

5. Summary of Problems

No problems relating to progress reports occurred during this reporting period.

6. Actions Taken to Correct Problems

No actions to correct problems were necessary during this reporting period.

7. Projected Work for the Next Quarter

The Progress Report for Quarter 20 will be submitted.

8. Copies of Daily Reports, Inspection Reports, Data, etc.

No daily reports, inspection reports, or data related to the Progress Reports were generated during this reporting period.

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