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Description of Current Conditions Report
Solid Waste Management Units
During an Environmental Assessment, conducted in 1992 and 1993, a total of 37 SWMUs were identified at CSSA. All of these sites were solid waste disposal areas, with the exception of four burn areas (B-1, B-2, B-4, and B-22), two ordnance demolition areas (B-20 and Bldg. 43), one incinerator (I-1), one oxidation pond (O-1), and one less than 90-day waste materials storage area (F-14). A short description of the current conditions of each site is provided in the following paragraphs. A summary of the analytical program which has been conducted at each site is provided in Table 1.
SWMU B-1 is a medium priority site which was reportedly an area where powder and incendiary materials were burned in 1954. The site is located in the north pasture, and has an area of approximately 3 acres. An EM geophysical survey was conducted at the site in February 1995, during which no geophysical anomalies were identified. Three soil borings were drilled to a depth of 30 feet below ground level in February 1995; samples were analyzed for VOCs, SVOCs, and metals. None of the analyte concentrations exceeded RRS2 criteria. The only contaminants exceeding RRS1 criteria were phthalate compounds, which were detected at various depths in each of the three borings. However, these SVOC results were rejected due to inadequate quality control. No contaminants of concern were found above RRS2 criteria in a groundwater sample collected from one of the borings at a depth of approximately 20 feet. Groundwater was not observed in the other borings. In June 1995, one soil boring was redrilled and resampled due to laboratory QA/QC problems from the sampling effort in February. Contaminants of concern were not found in the soil samples collected from this boring. In August and September 1996, three additional soil borings were drilled to depths of 22.5 to 38 feet below ground level; samples were analyzed for SVOCs only to address the rejected SVOC results from the previous investigation. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-1 links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-1, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-2 is a medium priority site which was reportedly used to burn small arms ammunition in 1954. The site is located outside the security fence line in the northeastern section of CSSA, and has an area of approximately 2.6 acres. An EM geophysical survey was conducted at the site in February 1995, during which five geophysical anomalies potentially related to past waste management activities were identified. Soil and ground water samples were collected from five soil borings drilled to a depth of 30 feet below ground level in March 1995. The only contaminants exceeding site background levels were chromium (in 5 of 13 Glen Rose limestone samples), toluene (in 3 of 13 limestone samples), and phthalates (in 2 of 4 surface soil samples). Contaminants of concern found above RRS2 criteria in one of two groundwater samples were cadmium and lead. In June 1995, one soil boring was redrilled due to laboratory QA/QC problems associated with the groundwater sample collected from the soil boring drilled in March. However, insufficient water for sampling was present in the redrilled boring. A soil gas survey was conducted in June 1995, during which PCE was found in samples at concentrations less than 1 u g/L. In September 1997, two trenches (north and south) were excavated to determine if any buried debris included UXO. The trenches contained buried metal debris and ordnance-related materiel.
Future activities planned for SWMU B-2 include sifting soil from the north trench to remove metal debris only, and sifting soil from the south trench to remove potential UXO and metal debris. Specific data regarding all site activities may be found in SWMU B-2 Links.
SWMU B-3 is a high priority site which was reportedly a landfill area that was thought to have been primarily used for garbage disposal and burning trash. The trench areas were reportedly filled in 1990-1991. SWMU B-3 is located in the inner cantonment area northeast of the main compound, and southeast of well 16, and has an area of approximately 2.9 acres. Several investigations have been conducted to assess groundwater contamination detected in well 16 located north of SWMU B-3. These investigations have focused on identifying possible source areas that have contributed to the contamination of the groundwater. The presence of chlorinated hydrocarbons in soil and soil gas samples collected from this site in 1995 and 1996 have implicated SWMU B-3 as a potential source area for the contamination detected in well 16.
Geophysical test methods indicated that the site consists of at least two large anomalous areas, or trenches. This finding was confirmed by drilling soil borings to investigate the portions of each area exhibiting apparent geophysical anomalies, and the presence of high volatile organic concentrations in soil gas. Additional borings were drilled to install vapor extraction wells and multi-depth vapor monitoring points. Analytical data from soil samples collected during drilling at the site also confirmed the presence of TCE, PCE, and cis-1,2- DCE.
The trenches were reportedly created by taking advantage of the natural slope to the west and cutting into the weathered limestone to provide greater disposal volume. The approximate thickness of the fill material appears to extend to almost 20 ft bgl. The west trench (hereafter referred to as the main trench) appears to be the deeper trench based on the apparent grade of the limestone surface. In 1996, an SVE pilot test was performed using six vapor extraction wells and four multi-depth vapor monitoring points installed in and near the main trench to evaluate the use of SVE as a removal mechanism. The main trench was selected as the focus of this test because of its apparent depth and because the soil gas survey indicated that the main trench contained the highest potential levels of volatile organic compound contamination.
The initial SVE pilot test demonstrated that an SVE system operated at the site could significantly reduce VOC concentrations present in the vicinity of the trench areas. VOC removal was observed primarily in deeper soils in the main trench, but the results indicated that the subsurface soils at the site were complex, and that it would be difficult to extrapolate the pilot test results across the entire site without the collection of additional data. Based on the success of contaminant removal observed in the pilot test, the SVE system was expanded in December 1996 by adding an additional 12 vapor extraction wells. Additional treatability testing was performed on the system to further evaluate the site, and to determine optimal operating parameters for long-term operational requirements for VOC remediation at the site. Additional characterization data was collected during the system expansion to provide a more complete characterization of subsurface contamination within the main trench.
The lateral extent of VOC soil contamination in the main trench appears to have been defined with the exception for a small portion on the south side of the trench. VOC contamination appears to have migrated into the underlying and bordering fractured limestone surrounding the main trench, but the areal extent and potential mass of contaminants remaining in limestone fractures is unknown. The treatment area determined by those portions of the main trench that exceed cleanup criteria for detected VOCs is estimated at 9,000 square feet, and the total volume of contaminated material in the target cleanup zone is estimated at 5,000 cubic yards.
The treatability study evaluated four different extraction configurations to determine which extraction wells were capable of removing the greatest volumes of VOCs (high VOC concentration and high emission flow rate), but was limited by the standard air exemption registered with the TNRCC which allowed up to six extraction wells per configuration. The standard air exemption was modified in January 1999 to permit expansion of the extraction configuration to include all eighteen wells currently installed at the site (primarily in the main trench and surrounding limestone). Further treatability testing is planned for the near future, with full-scale remedial design to follow. Links to specific data regarding all site activities can be found at SWMU B-3 Links.
SWMU B-4 is a high priority site which was reportedly an area used to burn classified documents, trash, and ordnance-related materiel. The site is located in the inner cantonment area northeast of the main compound near well 16. The site is a large unvegetated area of approximately 3.8 acres. The exact dates of usage are unknown. An EM geophysical survey was conducted at the site in February 1995, during which three geophysical anomalies potentially related to past waste management activities were identified. A GPR geophysical survey conducted later in February 1995 identified three separate trenches. Six soil borings were drilled to a depth of 9 to 34 feet below ground level in March 1995. Concentrations of cadmium, chromium, copper, lead, and nickel exceeded background concentrations in at least one sample. The only contaminants exceeding RRS2 criteria were copper and lead, which were found at a depth of 6.0 to 9.0 feet below ground level in a boring that was drilled into a waste trench. No contaminants of concern were detected above RRS2 criteria in a groundwater sample collected from one of the borings. Soil gas surveys were conducted in July and November 1995, during which PCE was found at concentrations between 0.04 and 3.8 u g/L. The November 1995 survey was done on a tighter grid spacing within the B-4 area. The survey results indicated that the distribution of PCE shows a trend of decreasing concentrations away from SWMU O-1 located at the northeast corner of the site. Specific data regarding all site activities may be found in SWMU B-4 Links.
An investigation of the site is planned under the RL83 contract with Parsons ES. Future work planned at the site includes drilling and sampling of twelve soil borings (three at each of the four trenches). If groundwater is encountered, up to three monitoring wells will be installed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-5 is a low priority site which was reportedly used as a disposal area for fired small arms ammunition brass. The site is located in the southern portion of the north pasture near Gate 6, and has an area of approximately 3,300 square feet (0.08 acre). The exact dates of usage are unknown. In 1993, the site could not be located during the field survey, even through vegetation had been cleared from the vicinity of the site. In 1996, the site was located and a geophysical survey was conducted. Two geophysical anomalies were found, both associated with non-waste management activities. During the same field effort, three surface soil samples were collected. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-5 Links.
Due to the laboratory’s QA/QC problems on the most recent sampling and analytical effort at B-5, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-6 is a low priority site which was reportedly used as a disposal area for miscellaneous solid waste. The site is located in the north pasture south of Well G, and has an area of approximately 7,200 square feet (0.17 acre). The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which no geophysical anomalies were found. Also in 1996, three surface soil samples were collected. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-6 Links.
Due to the laboratory’s QA/QC problems on the most recent sampling and analytical effort at B-6, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-7 is a low priority site which was reportedly used as a fired small arms ammunition brass disposal area. It was reported, but not documented, that CSSA personnel found live rounds at this site. The site is located in the north pasture, and has an area of approximately 1.2 acre. The exact dates of usage are unknown. A 1993 field investigation revealed weapon crates and packing material near the road, and numerous types of small caliber ammunition brass scattered throughout. A geophysical survey was conducted at the site in 1995, during which no geophysical anomalies were identified. In 1996, three surface soil samples were collected. Analytical data provided by ITS Laboratory are currently in question. In 1997, vegetation was cleared and a UXO sweep was completed. Only small amounts of surface debris were observed. Specific data regarding all site activities may be found in SWMU B-7 Links.
Due to the laboratory’s QA/QC problems on the most recent sampling and analytical effort at B-7, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-8 is a high priority site which was reportedly an area where fire bricks and ammunition shells were disposed of. The site is located in the north pasture, and has an area of approximately one acre. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1995, during which one geophysical anomaly potentially related to past waste management activities was identified. In 1996, three borings were drilled around the anomaly to a depth of 9.5 to 13.9 feet below ground level. Soil analytical data provided by ITS Laboratory are currently in question. In 1997, the anomaly was excavated to determine if any buried debris included UXO. During excavation, it was found that the anomaly was caused by pieces of concrete which contained steel rebar. No other waste was encountered during the excavation, and no magnetic anomalies were found under the concrete. Specific data regarding all site activities may be found in SWMU B-8 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-8, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-9 is a medium priority site which was reportedly an area where miscellaneous solid waste, including metal debris, were disposed. The site is located in the southern portion of the east pasture, and has an area of approximately ¼ of an acre. B-9 is adjacent to an archeological site consisting of World War I foxhole-type trenches. The exact dates of usage are unknown. In 1996, the site location was confirmed from an aerial photograph. Mortar mounds, thought to have been fired but not detonated, were found along with various metal debris, barbed wire, and rubble. A geophysical survey was conducted at the site in 1996, during which one geophysical anomaly potentially related to past waste management activities was identified. Specific data regarding SWMU B-9 may be found in SWMU B-9 Links.
Future plans are to map SWMU B-9, complete a geophysical survey at the site, and collect surface samples from three pre-identified locations (biased toward any anomalies observed during geophysical activities). Parsons ES will prepare and submit a work plan before the sampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-10 is a high priority site which was reportedly utilized as an ammunition disposal area. The site is located in the northern portion of the inner cantonment, and has an area of approximately 3,700 square feet (0.09 acre). The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which one geophysical anomaly related to non-waste management activities was identified. Afterward, an additional geophysical survey was performed for verification of site features. In 1997, a UXO surface sweep of the site was conducted. Results indicated that there are either two small trenches or one large one. The waste consists of banding material and ammo cans, but does appear to contain any UXO. Specific data regarding all site activities may be found in SWMU B-10 Links.
An investigation of the site is planned under the RL53 contract with Parsons ES. Future work planned at the site includes drilling and sampling of three soil borings; excavating, characterizing, and recycling or disposal of contents of B-10 trenches; and sampling of trench bottom. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-11 is a high priority site which was reportedly utilized as an ammunition, scrap metal, and construction debris disposal area. The site is located in the inner cantonment, and has an area of approximately ¾ acre. The exact dates of usage are unknown. A 1993 field survey indicated that miscellaneous ammunition boxes, arms packing crates, and construction debris were located at the site, adjacent to Salado Creek. A geophysical survey was conducted at the site in 1995, during which no anomalies were identified. Specific data regarding all site activities may be found in SWMU B-11 Links.
An investigation of the site is planned under the RL53 contract with Parsons ES. Future work planned at the site includes drilling and sampling of five soil borings. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-12 is a high priority site which reportedly served as a landfill area for large pieces of scrap metal and weapons. The site is located in the southeastern portion of the inner cantonment in F section, and has an area of approximately 0.4 acre. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1995, during which no geophysical anomalies were identified. In 1996, four borings were drilled to a depth of 10.5 feet. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-12 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-12, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-13 is a high priority site which was reportedly an area where engineering trash was dumped. The site is located in the southern portion of the inner cantonment, and has an area of approximately 0.8 acre. The exact dates of usage are unknown. A field survey conducted in 1993 indicated an area where miscellaneous solid waste was disposed of. This area has been covered and semi-compacted, but there are several areas where the cover has eroded, revealing the trash. A geophysical survey was conducted at the site in 1996, during which five geophysical anomalies were identified. Three of these anomalies are potentially related to past waste management activities, while two are associated with construction debris piles on bedrock. An additional geophysical survey was performed to verify data. Site boundaries were surveyed. Also in 1996, four borings were drilled to a depth of 12 feet. In 1997, two additional soil boring samples were collected. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-13 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-13, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-14 is a low priority site, which was reportedly an area where fired brass was disposed of. The site is considered to be an area of concern, is located in the southwestern portion of the east pasture, and has an area of approximately 30,000 square feet. The exact dates of usage are unknown. In 1993, the site could not be located during the field survey even with the area upturned from fence repair operations. Letter requesting that this site be delisted was sent to TNRCC in September 1996. Specific data regarding all site activities may be found in SWMU B-14 Links.
SWMU B-15/16 is a high priority site which reportedly served as a landfill area for target vehicles and weapons mounts. The site is located in the southern portion of the outer cantonment, and has an area of approximately 5.8 acres. The exact dates of usage are unknown. In 1993, B-15 was observed to be two large rectangular areas of settled soil and stressed vegetation. Also during this year, a field survey of B-16 indicated two trenches in which metal objects were visible on the surface partly covered by soil that had settled into the trenches. A geophysical survey was conducted at the site in 1995, during which three geophysical anomalies potentially related to past waste management activities were identified. In 1996, a controlled burn of vegetation at the site was conducted. In March of 1996, geophysical grid points were surveyed. Specific data regarding all site activities may be found in SWMU B-15/16 Links.
An investigation of the site is planned under the RL83 contract with Parsons ES. Future work planned at the site includes drilling and sampling of nine soil borings (three at each of the three trenches). If groundwater is encountered, up to three monitoring wells will be installed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
Sites originally identified as B-17 and B-18 are now part of RMU-1, and therefore, are not included as separate SWMUs.
Miscellaneous solid waste, metal, and weapons were identified on CSSA’s original list for SWMU B-19, a medium priority site. The site is located west of the oxidation pond, and has an area of approximately 0.1 acre. The exact dates of usage are unknown. An EM geophysical survey was conducted at the site in February 1995, during which no geophysical anomalies were identified. Three soil borings were drilled to a depth of 30 feet below ground level in February 1995. No contaminants of concern were found above RRS2 criteria in soil and groundwater samples collected from the borings. The chromium concentration in one limestone sample slightly exceeded background. In June 1995, three soil borings were redrilled and resampled due to laboratory QA/QC problems from the sampling effort in February. The only contaminant of concern exceeding RRS2 criteria was PCE, which was found in one groundwater sample. No contaminants of concern were found above RRS2 criteria in soil samples collected from the borings. In August and September 1996, three additional soil borings were drilled to depths of 34.2 to 35.8 feet below ground level. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-19 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-19, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-20 is a high priority site which was used periodically as an open burn/open detonation area between 1946 and 1987. The site is located on approximately 35 acres in the north pasture. SWMU B-21 is located in the southeast corner of SWMU B-20 and consists of an aboveground disposal area for sand and projectiles from the Building 90 test range. Due to its small size and close proximity to SWMU B-20, it has been combined with B-20. SWMU B-20 included fifteen craters where ordnance was detonated. Six of these craters located in the northern portion of the site were presumably used during the early history of the site. In June 1993, EPA issued a Compliance Order for the B-20 site for unpermitted treatment of hazardous waste and for failure to have a closure plan.
Investigations of the site were initiated in 1994 after a work plan for closure/investigation was submitted in March. The first phase of the investigation was conducted in November and December 1994. The surface of the site was swept for UXO, and 193 UXO items were identified. In addition, a large amount of metal debris was found on the ground surface. Samples of surface soil, subsurface soil, sediment, and surface water were collected. A grab groundwater sample was also collected from one boring. A wet interval was observed at a depth of 10.5 feet bgl. The results of these sampling efforts indicated that mercury, cadmium, barium, and lead levels in surface soil exceed background levels. The explosives analyses were conducted by ITS; therefore, results are in question. Contaminant concentrations were below background levels in the subsurface soil and rock samples, with the exception of mercury in one sample (SB2), and arsenic in four samples (SB9 and SB10). No analyses exceeded MCLs in groundwater. Based on the contamination and amount of UXO items found at the site, additional investigation was recommended in the Remedial Investigation Report (Parsons ES, June 1995).
In September 1995, the second phase of the B-20 investigation was conducted. Additional surface soil and subsurface soil and rock samples were collected to better define the limits of contamination. Surface soil in approximately one-third of the site exceed background levels. After receiving concurrence from the USFWS in October 1995 for planned vegetation clearing activities at the site, UXO identification activities continued. Vegetation was cleared so that UXO could be safely identified and removed. In December 1995, subsurface magnetic anomalies in craters and in the northern portion of the site were excavated and removed. While the craters in the southern portion of the site contained very little buried debris, the northern portion of the site was found to contain a significant amount of buried debris, some of it UXO. These items were identified, flagged for later excavation, and removed during a "mag and flag" effort that lasted until March 1996. By the end of this investigation, an additional 447 UXO items had been identified at SWMU B-20. The Remedial Investigation Report Addendum (Parsons ES, June 1996) recommended additional UXO clearance in the northern portion of the site and around the outskirts of the site, as well as a treatability study to identify an appropriate remediation technology for the contaminated surface soil at the site.
Between January and September 1997, additional UXO clearance activities were conducted at the site. These activities included vegetation clearing and surface sweeping of areas adjacent to SWMU B-20, and sifting of soils in the approximately five acre northern portion of the site to remove UXO and metallic debris. Approximately 2,000 cubic yards of soil were sifted and sampled. In addition, the surface of the B-20 site was swept again to remove metallic debris, to the extent possible, and any remaining UXO. A total of 1,624 UXO items have been removed. In March and April, benchscale treatability studies of phytoremediation, soil washing, and stabilization technologies were initiated; however, results are currently pending resolution of the ITS Laboratory data issues.
In June and July 1999, approximately 80 cubic yards of sand containing shot material were disposed of as hazardous waste (due to elevated lead levels). This material had been generated at the Building 90 firing range and had been disposed of at an unknown date in the northern portion of the B-20 site. Prior to disposal, the material was carefully inspected for any possible UXO by USA Environmental, Inc. No UXO was found. Specific data regarding all site activities may be found in B-20/21 Links.
SWMU B-22 is a low priority site which was reportedly an area used to burn artillery shells. The site is located in the north pasture, and has an area of approximately 5.3 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1995, during which no geophysical anomalies were identified. In 1996, five surface samples were collected and analyzed for VOCs, explosives and metals. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-22 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-22, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-23 is a high priority site which is an area where a trench was observed in a 1966 aerial photograph. In addition, half-buried green canisters were observed at the site. The exact dates of usage are unknown. The site covers approximately 0.6 acre in the north pasture. A geophysical survey was conducted at the site in 1995, during which no geophysical anomalies were found. In 1996, a soil gas survey was performed at the site. No VOCs were detected in any of the soil gas samples collected at the site. Specific data regarding all site activities may be found in SWMU B-23 Links.
An investigation of the site is planned under the RL83 contract with Parsons ES. Future work planned at the site includes drilling and sampling of three soil borings. If groundwater is encountered, up to three monitoring wells will be installed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-23A is a high priority site which is an area where a trench was observed in a 1966 aerial photograph. In addition, several glass ampoules containing different color liquids are located on the ground surface at the site. The exact dates of usage are unknown. The site covers approximately 0.3 acres in the north pasture. A geophysical survey was conducted at the site in 1995, during which two geophysical anomalies were found. In 1996, a soil gas survey was performed at the site. Toluene was detected in one of the soil gas samples collected at the site. No other VOCs were detected in the samples. Specific data regarding all site activities may be found in SWMU B-23A Links.
An investigation of the site is planned under the RL83 contract with Parsons ES. However, prior to any sampling, the Army will verify that the ampoules do not contain chemical warfare agent. After this verification has been completed, ampoule liquid and three surface soil samples will be collected and analyzed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-24 is a high priority site which was reportedly an area of four trenches used to dispose of spent ammunition, small spent rockets, and other metal scrap. The site is located in the north pasture, and has an area of approximately 3.4 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1995, during which three geophysical anomalies potentially related to past waste management activities were identified. A fourth trench was identified from a 1966 aerial photograph. In 1997, the anomalies were excavated to determine if any buried debris included UXO. Approximately 5,500 cubic yards of soil was sifted and stockpiled onsite. A preliminary soil sample was collected during UXO removal activities to identify contaminants at the site. The only contaminants exceeding RRS1 criteria in the soil for this sample were copper, lead, zinc, 2,4-DNT and 2,6-DNT.Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-24 Links.
An investigation of the site is planned under the RL33 contract with Parsons ES. Future work planned at the site includes drilling and sampling of five soil borings and sampling of sifted soil. Results of these sampling efforts will be used to identify appropriate treatment technologies for the site.
SWMU B-25 is a low priority site which was reportedly an area where a trench was observed in a 1966 aerial photograph. No other documentation regarding this area was found. The site is located in the upper portion of the east pasture, and has an area of approximately 0.4 acre. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which one geophysical anomaly potentially related to past waste management activities was identified. In March 1996, three surface soil samples were collected and analyzed for VOCs, SVOCs and metals. In September 1996, three borings were drilled around the anomaly to a depth of 8 to 15 feet below ground level. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-25 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-25, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-26 is a low priority site which was reportedly an area where a trench was observed in a 1966 aerial photograph. No other documentation regarding this area was found. The site is located in the upper portion of the east pasture, and has an area of approximately 0.4 acre. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which two geophysical anomalies potentially related to past waste management activities were identified. In March 1996, three surface soil samples were collected and analyzed for VOCs, SVOCs and metals. In September 1996, three borings were drilled around the anomalies to a depth of 10 to 13 feet below ground level. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-26 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-26, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-27 is a high priority site which was reportedly an area used as a sanitary landfill. The site is located on the west side of the inner cantonment, and has an area of approximately 5.8 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which one large geophysical anomaly potentially related to past waste management activities was identified. In March 1996, three surface soil samples were collected and analyzed for VOCs, SVOCs and metals. In August 1996, three borings were drilled around the anomaly to depths of 10.2 to 13.7 feet below ground level. In 1997, one soil boring was completed for further data clarification. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-27 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-27, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-28 is a medium priority site which was reportedly an area where small arms ammunition, metal ammunition parts, aerial flares, and molten metal were disposed of in two trenches. The site is located west of the oxidation pond, and has an area of approximately 0.1 acre. The exact dates of usage are unknown. An EM geophysical survey was conducted at the site in February 1995, during which two geophysical anomalies potentially related to past waste management activities were identified. An additional EM geophysical survey was conducted in May 1995 to verify previous data. Six soil borings were drilled to a depth of 30 feet below ground level in February and March 1995. None of the analyte concentrations exceeded RRS2 standards; however chromium, copper, and phthalate concentrations exceeded background. No contaminants of concern were found above RRS2 criteria in a groundwater sample collected from one of the borings. In June 1995, two soil borings were redrilled and resampled due to laboratory QA/QC problems from the sampling effort in February and March. No contaminants of concern were found above RRS2 criteria in soil and groundwater samples collected from the borings. A soil gas survey was conducted in June and July 1995, during which PCE was found in samples at concentrations less than 1 ug/L. Between March and July 1997, two trenches were excavated to determine if any buried debris included UXO. The trenches contained buried metal debris and small amounts of UXO. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-28 Links.
Presently, approximately 600 cubic yards of sifted soil remain on the site. The most appropriate method for remediating or disposing of sifted soils must be evaluated for the B-28 site. The RFI Work Plan recommends additional characterization of the sifted soils and evaluation of potential treatment technologies.
SWMU B-29 is a high priority site which was reportedly an old quarry area used for disposal of miscellaneous solid waste, munitions, and construction debris. The site is located southeast of the munitions maintenance area, and has an area of approximately 2.8 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which three geophysical anomalies potentially related to past waste management activities were identified. In March 1996, three surface soil samples were collected and analyzed for VOCs, SVOCs, explosives and metals. Six borings were drilled around the anomalies to a depth of 6.5 to 14 feet below ground level. In 1997, soil boring SB1 was resampled for VOCs only. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-29 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-29, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-30 is a medium priority site which was reportedly an area used for disposal of miscellaneous construction debris. A field survey indicated scrap concrete, roofing shingles, and construction trash. The site is located southeast of the active facility, behind the quarry, and has an area of approximately 0.7 acre. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which one geophysical anomaly potentially related to past waste management activities were identified. Three surface soil samples were collected and analyzed for VOCs, SVOCs, explosives and metals. In the surface soil samples, PAH concentrations exceeded both background and RRS2 standards. Three borings were drilled around the anomaly to a depth of 8 to 13 feet below ground level. The only surface soil contaminants to exceed RRS1 criteria were PAHs. Contaminants exceeding RRS1 criteria in the limestone for these borings were chromium and PAHs. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-30 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-30, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-31 is a medium priority site which was reportedly used for disposal of sand and projectiles from the Building 90 test range. The disposed materials were used as pipe bedding. The SWMU consists of the bedding material only. The site is located northeast of Building 92, and has an area of approximately 1.1 acre. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which no geophysical anomalies potentially related to past waste management activities were identified. Three surface soil samples were collected and analyzed for explosives and metals. In the surface soil samples, the contaminant that exceeded RRS1 criteria was HMX. Three borings were drilled around the area to a depth of 10 to 11 feet below ground level. The contaminants that exceeded RRS1 criteria in the limestone for these borings were copper and zinc. In 1997, sand and shot investigation activities were conducted. Seven test pits were dug along the line to identify lead and shot contamination. No shot material or other evidence of waste was found. Seven confirmatory soil samples were collected, the data for which are currently in question. Specific data regarding all site activities may be found in SWMU B-31 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-31, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-32 is a medium priority site where sand and projectiles from the Building 90 test range were reportedly used as pipe bedding. The SWMU consists of the bedding material only. The site is located on the north side of Building 34, and has an area of approximately 0.2 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which no geophysical anomalies potentially related to past waste management activities were identified. Three surface soil samples were collected and analyzed for explosives and metals. In the surface soil samples, the contaminants that exceeded RRS1 criteria were copper, lead, mercury, zinc, and 2,6-DNT, and lead and 2,6-DNT levels exceeded RRS2 criteria. Three borings were drilled around the area to a depth of 9.5 to 12.5 feet below ground level. The contaminants that exceeded RRS1 criteria in the limestone for these borings were copper and zinc. Approximately 36 cubic yards of soils were excavated. The trench was backfilled with clean sand. Four confirmatory soil samples were collected from the trench bottom before it was backfilled. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-32 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-32, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. In addition, the 36 cubic yards of soil excavated from the trench will be stabilized, if necessary, and disposed of. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-33 is a medium priority site where sand and projectiles from the Building 90 test range were reportedly used as pipe bedding. The SWMU consists of the bedding material only. The site is located on the south side of Building 45, and has an area of approximately 0.5 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which no geophysical anomalies potentially related to past waste management activities were identified. Three surface soil samples were collected and analyzed for explosives and metals. In the surface soil samples, the contaminants that exceeded RRS1 criteria were copper, lead, mercury, zinc, 2,6-DNT, and HMX. In 1997, three borings were drilled around the area to a depth of 9.1 to 12.5 feet below ground level. Only zinc exceeded RRS1 criteria in the limestone for these borings. Sand and shot excavation activities were conducted in July 1997. Approximately 100 cubic yards of soils were excavated. The trench was backfilled with clean sand. Four confirmatory soil samples were collected from the pit. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-33 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-33, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. In addition, the 100 cubic yards of soil excavated from the trench will be stabilized, if necessary, and disposed of. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU B-34 is a medium priority site which was reportedly pipe and pipe bedding for a 230-foot section of pipe leading from a locomotive maintenance pit. The pipe extended southwest from the building and continued underneath an open field to an outfall opening near a culvert at McElroy Road. The site is located near Building 28 (the locomotive maintenance building), and has an area of approximately 0.5 acres. The exact dates of usage are unknown. A geophysical survey was conducted at the site in 1996, during which one geophysical anomaly potentially related to past waste management activities associated with Building 28 was identified. Three surface soil samples were collected and analyzed for VOCs, SVOCs, explosives and metals. Three borings were drilled around the area to a depth of 10.2 to 13.8 feet below ground level. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU B-34 Links.
Due to the laboratory’s QA/QC problems during the most recent sampling and analytical effort at B-34, future plans are to resample. Parsons ES will prepare and submit a work plan before the resampling is completed. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
Building 43, a high priority site, was reportedly an inactive makeshift ammunition facility used to burn miscellaneous solid waste and ammunition. The site is located northeast of the oxidation pond, and has an approximate area of 500 square feet (0.01 acres). The exact dates of usage are unknown. In 1995, soil gas survey samples were collected between SWMUs 3 and 4, which includes the area surrounding Building 43. However, the soil gas survey grid was spaced at every 100 feet, and Building 43 is only approximately 20 by 25 feet, so the soil gas survey interval was not adequate to characterize SWMU Building 43. TCE was detected in one soil gas sample collected at the site. A geophysical survey was conducted at the site in 1996, during which no geophysical anomalies potentially related to past waste management activities were identified. In 1997, UXB swept the surface for UXO. Only surface debris was observed (no UXO was found). Specific data regarding all site activities may be found in SWMU BLDG 43 Links.
An investigation of the site is planned under the RL53 contract with Parsons ES. Future work planned at the site includes drilling and sampling of six soil borings. In addition, soil surrounding the building will be excavated if analytical results indicate that soil containment levels exceed TNRCC standards. If necessary soil beneath the building will be removed after coordination with the State Historical Preservation Office for potential demolition Building 43. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
The DD Area is high priority site which was reportedly used for disposal of dud ammunition. The site is located east of the active facility areas and has an approximate area of 1.7 acres. The exact dates of usage are unknown. In 1997, UXB completed UXO removal activities. Approximately 600 cubic yards of soils were sifted and excavated. Three soil samples were collected from the sifted soils. Analytical data provided by ITS Laboratory are currently in question. Specific data regarding all site activities may be found in SWMU Demolition Dud Area Links.
An investigation of the site is planned under the RL33 contract with Parsons ES. Future work planned at the site includes drilling and sampling of three soil borings and re-sampling of sifted soil. Results of these sampling efforts will be used to characterize the extent of contamination and to identify appropriate treatment technologies for the site.
I-1, a high priority site, is an incinerator in Building 294 used to burn paper trash from 1943 to the late 1960s. In the late 1980s, the building was used to store transformers. The building is adjacent to the wastewater treatment facility. A geophysical survey was conducted at the site in 1996, during which no geophysical anomalies potentially related to past waste management activities were identified. Specific data regarding all site activities may be found in SWMU I-1 Links.
An investigation of the site is planned under the RL53 contract with Parsons ES. Future work planned at the site includes wipe sampling inside the incinerator building for PCBs and dioxins and sampling of surface soil surrounding the building. In addition, three soil borings will be drilled and sampled. If the site is found to meet RRS1 criteria after this work has been completed, a closure report will be prepared in accordance with TNRCC closure requirements.
SWMU O-1, also referred to as the oxidation pond, is a high priority site reportedly constructed in 1975. The pond was lined with a vinyl plastic, which had a life expectancy of 10 years. Waste liquids and sludges were tank-collected from CSSA’s bluing operation, pumped out, and trucked to the pond. The site is located in the inner cantonment northeast of the main compound, and has an area of approximately 0.34 acre.
In April 1984, the Texas Department of Health collected a liquid and sludge sample from the surface of the pond and delivered the sample to Brooks AFB for metals analysis. The results of analyses indicated that the material was non-hazardous for metals concentrations. In 1985, RRAD prepared a recommended procedure for closure of the pond. The pond was excavated and filled with surrounding soil in the fall of 1985. The pond liner was reportedly destroyed during excavation.
EM and GPR geophysical surveys were conducted at the site in February 1995, during which one geophysical anomaly potentially related to past waste management activities was identified. Surface water samples were collected from the pond on two separate occasions in March 1995. In addition, four soil borings were drilled to a depth of 16 to 30 feet below ground level in March 1995. The only contaminant of concern exceeding CSSA background levels and RRS2 GWP criteria was cadmium, which was found in surface soil samples collected from one of the borings (0-2 feet). Surface soil samples collected in November 1995 indicated that PCE, chromium, and cadmium exceeded RRS2 levels.
Two soil gas surveys conducted in the summer and fall of 1995 identified PCE in the soil gas samples associated with the geophysical anomaly. PCE was found in soil gas samples at concentrations as high as 80,000 parts per billion volume. The presence of PCE at concentrations much higher than other areas around well 16 has implicated this site as one of two likely source areas for groundwater contamination.
A liner investigation was initiated in January 1996, in which approximately 80 cubic yards of soil material was excavated from the pond. Nineteen cubic yards of soil were placed into a plastic-lined bermed laydown area on site, and 61 cubic yards of excavated soil were placed near the excavation area. Analytical results of soil samples collected from the bermed laydown area over a 3-month period indicated that significant amounts of PCE volatilized from the contaminated soils.
An electrokinetic treatability study was conducted between April 1997 and January 1998 to remove chromium contamination. Three trenches were excavated and soil samples were collected in April to find a suitable location for a field test unit. A laboratory benchscale test was conducted in May and construction of the field pilot scale test unit began in July. Soil samples collected during the treatability study indicated that the efficiency of the electrokinetic removal of chromium observed during the benchscale test was extremely high and the field test results demonstrated much lower efficiency in chromium removal. In April 1999, Parsons ES submitted a final report for the electrokinetics treatability study, which included a description of study methods, general conclusions and significant findings of the study, and recommendations for future operation of the treatment system. Specific data regarding all site activities may be found in SWMU O-1 Links.
Interim measures at the O-1 site are planned under the RL74 contract with Parsons ES. Contaminated soil at the site will be excavated and disposed, and soil borings will be drilled to verify that all contaminated soil has been and to characterize contamination, if any, in the underlying bedrock.
F-14 was a fenced, diked materials storage area for drummed halogenated solvents used in degreasing operations, pesticides, herbicides, used oil, spent chemicals from fingerprint removing operations, and transformers containing PCBs. It is located on 0.15 acres in the southeast portion of the inner cantonment in F section. The area was used from at least 1984 to 1992. An investigation was conducted at the site in 1992, and a site assessment report was submitted to TNRCC in February 1993. The TNRCC approved closure of this site on November 2, 1995. Specific data regarding all site activities may be found in SWMU F-14 Links.