Indoor Air Quality Testing at the Middle River Complex September 2017 Indoor Air Quality Testing at the Middle River Complex Lockheed Martin has been investigating and, more recently, cleaning up soil and groundwater at the Middle River Complex (MRC). The contaminants addressed by this effort are likely the byproduct of historical operations at the MRC. They include volatile organic compounds (VOCs), which have the potential to move from underground into buildings through cracks in foundations and basement floors, through sumps, and through utility openings by a process known as vapor intrusion. Do employees need to be concerned? No. Air and soil testing results indicate that employees do not need to be concerned about air quality resulting from vapor intrusion. A vapor intrusion safety and prevention program is also in place. It includes two basic components discussed below: an indoor air and vapor testing program, and sub-slab depressurization systems (SSDSs) in A- and C-Buildings that collect and treat VOC vapors from under the buildings and discharge the cleaned air at roof level. Employees are encouraged to ask questions and raise concerns to Lockheed Martin, and they will be addressed promptly. What indoor air and soil vapor testing has Lockheed Martin done to date? Since 2006, Lockheed Martin has conducted 23 rounds of air quality testing inside A-, B-, and C-Buildings, and has tested the vapor in soil directly beneath these buildings, to ensure that indoor air quality at the Middle River Complex is safe for workers. Sampling is conducted generally twice a year to account for differences in conditions between summer and winter. Heating, ventilation and air conditioning can affect the rate at which soil vapors may be pulled into, blocked from entering, or pushed out of a building. In addition, outside air is monitored at locations surrounding the MRC to measure chemicals that might already be present in outside air from other sources. This information helps identify whether chemicals found inside the facilities are from ongoing site operations, outside sources, or from underneath the buildings. Indoor air concentrations in the main working areas of the MRC have consistently been acceptable during the 23 rounds of indoor air testing. Trichloroethene (TCE), a degreasing solvent, has occasionally been found in indoor air samples at concentrations greater than its conservative health riskbased screening level of 8.8 micrograms per cubic meter in the southern part of the A-Building basement. SSDS Sub-slab depressurization systems draw air/vapors from beneath the building through closed piping to a treatment system which removes contaminants, releasing clean air outside. TCE trichloroethene, a solvent commonly used historically for degreasing. VOCs volatile organic compounds a group of chemicals (like TCE) that easily volatilize or evaporate into air. Employees are rarely working in the A-Building basement continuously throughout an 8-hour work day. However, testing for potential vapor intrusion is considered a best practice whenever a screening level is exceeded. Those levels are determined by the United States Environmental Protection Agency (US EPA) and/or Maryland Department of the Environment (MDE). What mitigation measures has Lockheed Martin already taken? Sub-slab depressurization systems (SSDSs) were installed beneath the former Plating Shop in A-Building and beneath the south end of C-Building basement in 2008 For More Information Tom Blackman, Project Lead, (301) 548-2209, Cell (240) 460-7508, Tom.D.Blackman@lmco.com Mékell Mikell, Communications Representative, (301) 897-6934, Mekell.T.Mikell@lmco.com
2 Sampling equipment was more complex than in previous sampling activities, and included extending tubing throughout the southern end of the basement and into the middle of the basement, and into subfloor drainage structures as proactive measures to minimize the potential for vapor intrusion. Each SSDS draws vapor from the soil beneath the foundation slab, treats it, and releases it into the outdoor air. In addition to the periodic monitoring described above, the vapor is tested monthly to assess the performance of the SSDS. Each system has since been expanded to increase the overall areas beneath the main floors where vapors are pulled into the system. What was the additional sampling that took place in the A-Basement in February and April 2017? In addition to the first round of 2017 semi-annual indoor air and sub-slab vapor sampling performed within A-, B-, and C-Buildings, another sampling activity in the A-Building basement took place from February 22 through April 21. Sampling equipment was more complex than in previous sampling activities, and included extending tubing throughout the mid- and southern areas of the room. This sampling activity allowed for (1) continuous sampling over the course of eight weeks rather than the typical 8-hour duration during the semi-annual event, and (2) additional sampling locations, including in-floor features such as sumps and drains to try to identify potential sources of TCE vapors (see figure attached for sampling locations). Planned Investigations and Studies Related to TCE Contamination: Completed: Expansion of the SSDS to add further protection to the main floor of A-Building Completed: A robotic camera survey to investigate duct work between the basement and the main floor of A-Building Completed: A camera survey to investigate floor features and sump connections in A-Building basement A feasibility study to review alternatives for safely disconnecting sumps in the basement An expanded groundwater investigation west of A-Building A vapor intrusion investigation in the maintenance building west of A-Building involving sampling soil vapor beneath the building Feasibility study to assess remedial alternatives for removing TCE in soil beneath the main floor of A-Building
3 What were the findings of the additional sampling? We learned several things from the continuous sampling. First, TCE concentrations in indoor air continually change and increase and decrease on a daily and weekly basis. The changing levels may be associated with air currents in the basement and possibly increased water levels beneath the floor after it rains. All indoor air concentrations, however, were less than an MDE-approved screening level adjusted for limited exposure in the basement. Second, TCE vapors are present in sumps and floor drains, with some source locations higher than others. If these sumps and floor drains are covered, then concentrations of TCE in indoor air decrease significantly. Therefore, extracting or removing vapors from these subsurface sources will improve air quality in the basement. water from the sumps by either treating the water or removing it for offsite disposal. In the meantime, the air filtration units will continue to operate in the basement. On the main floor of A-Building, Lockheed Martin will be conducting a follow up survey with the air sampling device to make sure that the floor vents have all been sealed up successfully. Who do I contact if I have questions? Tom Blackman, Project Lead, (301) 548-2209, Cell (240) 460-7508, Tom.D.Blackman@lmco.com Mékell Mikell, Communications Representative, (301) 897-6934, Mékell.T.Mikell@lmco.com Why not just cover up the sumps now? We have to be careful because as the vapors build up they may eventually be released somewhere. As an initial step to reduce TCE levels in the basement we conducted a test to see if the SSDS was powerful enough to remove vapors from the sump with the highest TCE levels and still allow the SSDS to be effective enough to control the vapor beneath the main floor of Building A. The test was successful and the sump is now covered and the vapors are being pulled into the SSDS. Additional sumps may be added to the SSDS as well. The recent August (Round 23) indoor air results showed that there were no indoor air exceedances in the basement so pulling vapor from the sump has improved basement indoor air quality. Additional work to reduce TCE concentrations in the sumps is ongoing. What kind of sampling was conducted on the main floor vents of A-Building in July 2017? An air testing sampling device was used to conduct a two-day survey to measure TCE concentrations in indoor air to determine if TCE detected in sumps in the basement may be present in the floor vents connected through air ducts remaining from the old heating system. TCE was detected in some vents, although the results varied during the two-day survey. Since the floor vents were part of the old heating system and are no longer in use, all of the vents on the main floor were permanently covered in September, including vents that were partially covered by walls. For those vents, holes were cut in the dry wall to cover the vent and then the drywall was repaired. What comes next? In the A-Building basement, Lockheed Martin is in the process of evaluating the best way to permanently reduce TCE concentrations in A-Building sumps. The final solution may be a combination of pulling vapor from one or more sumps into the SSDS and removing
4 AIR-075-A SV: 2.2 SV-170-A-23 SV: 6000 µg/m 3 SV-173-A-23 SV: 16,000 µg/m 3 SV-174-A-23 SV: 990 µg/m 3 SV-168-A-23 SV: 8300 µg/m 3 AIR-169-A SV: 19 AIR-172-A SV: 110 AIR-138-A IA: 2.9 SV: 170 AIR-177-A SV: 7.6 AIR-116-A SV: 9.4 AIR-018-A IA: 4.5 AIR-093-A IA: 2.7 SV: 2 AIR-176-A SV: 1.4 AIR-015-A SV: 45 SV-171-A-23 SV: 4000 µg/m 3 SV-118-A-23 SV: 690 µg/m 3 AIR-139-A SV: 12 U SV-175-A-23 SV: 21,000 µg/m 3 AIR-076-A SV: 5.3 AIR-021-A AIR-078-A SV: 4.4 AIR-117-A AIR-079-A SV: 130 AIR-097-A SV-136-A-23 SV: 790 µg/m 3 AIR-033-B AIR-101-B SV: 28 AIR-051-C SV-126-C-23 SV: 850 µg/m 3 AIR-115-C AIR-113-C SV: 190 AIR-155-C IA: 0.58 J SV: 0.38 U AIR-060-C SV: 83 SV-102-C-23 SV: 1300 µg/m 3 AIR-145-C SV-152-C-23 SV: 1400 µg/m 3 AIR-088-C SV: 46 AIR-131-C AIR-081-A SV: 0.61 J Map Document: (P:\GIS\Middle_River\MapDocs\MXD\bldg_abc_tce_tags_rnd23_1117_poster.mxd) 10/23/17 -- KM AIR-100-B SV: 80 AIR-142-C SV: 11 AIR-065-C AIR-149-C SV: 3.5 AIR-153-C SV: 2.6 AIR-150-C SV: 0.38 U AIR-144-C AIR-135-C AIR-005-C AIR-004-C SV: 150 AIR-001-C SV: 240 FIGURE 1 TRICHLOROETHENE SAMPLING RESULTS ROUND 23 BUILDINGS A, B AND C LEGEND Soil Vapor Sample Results > 10,000 µg/m 3 1000-10,000 µg/m 3 293-1000 µg/m 3 < 293 µg/m 3 SSD Treatment Unit SSD Radius of Influence Buildings A, B and C Building B and C Basement Tunnel SV symbol for locations AIR-173-A and AIR-175-A are hidden on this map for illustrative purposes. All units in µg/m 3. ND - not detected. IA - Indoor Air. NS - not sampled. SV - Soil Vapor. Screening Levels Indoor Air Soil Vapor 8.8 293 August 2017 Sub-Slab Vapor TCE Concentration 10000 ug/m3 1000 ug/m3 293 ug/m3 0.1 ug/m3 Lockheed Martin Middle River Complex Middle River, Maryland ± 0 60 120 Feet DATE MODIFIED: CREATED BY: 10/23/17 JEE
1/2 1 2 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 19A 20 21 22 23 24 25 26 27 28 29 30 31 32 3 E F D C 32 33 34 35 36 37 38 39 40 41 42 43 G B ELEVAT OR 5 PGH P:\GIS\MIDDLE_RIVER\MAPDOCS\MXD\BLDG_A_TAGS_RND23_IA_SSV.MXD 10/23/17 KM F A FIGURE 2 019-A 020-A ROUND 23 SUB-SLAB VAPOR SAMPLING RESULTS GREATER THAN SCREENING LEVELS BUILDING A 094-A 095-A 074-A 075-A 109-A SV-168-A-23 TRICHLOROETHENE 8300 SV-DUP04-A-23 TRICHLOROETHENE 7900 110-A 022-A 076-A SV-136-A-23 TRICHLOROETHENE 790 021-A Legend IAQ, 1st Floor IAQ, Basement SV Round 23 Sampling Locations SSD Radius of Influence Buildings A, B and C Building A Basement Building B and C Basement Excavation Area SSD Treatment Unit * SV symbols for locations AIR-173-A and AIR-175-A are hidden on this map for illustrative purposes. All results in microgram(s) per cubic meter (µg/m 3 ). 116-A 070-A 077-A 078-A X - moved from original location once. Screening Levels Exceeded Indoor Soil Chemical Air Vapor 1,1-Dichloroethene NA 29,333 Trichloroethene 8.8 293 NA Not applicable DUP - Duplicate Sample IAQ - Indoor Air Quality SSD - Sub-slab Depressurization SV - Soil Vapor TCE - Trichloroethene SV-170-A-23 TRICHLOROETHENE 6000 SV-173-A-23 TRICHLOROETHENE 16,000 SV-171-A-23 TRICHLOROETHENE 4000 SV-174-A-23 TRICHLOROETHENE 990 018-A 026-A 169-A PIT-A 024-AX AFG-A 172-A 138-A 093X-A 176-A 177-A 093-A 014-A 013-A 011-A 012-A 024-A 015-A 016-A 017-A 046-A 046-AX 047-A 108-A 025-A 072-A 120-A 023-A 096-A SV-118-A-23 TRICHLOROETHENE 690 071-A 119-A SV-175-A-23 TRICHLOROETHENE 21,000 139-A 117-A 117X-A 073-A 106-A 079-A 107-A 097-A August 2017 Sub-Slab Vapor TCE Concentration 10000 ug/m3 1000 ug/m3 293 ug/m3 0.1 ug/m3 ABS-A 028-A 027-A ± 0 32 64 Feet 080-A 081-A Lockheed Martin Middle River Complex Middle River, Maryland DATE MODIFIED: CREATED BY: 10/23/17 JEE
36 35 34 33 32 31 30 29 28 27 26 25 24 GK GL GM H J K L M O N P Q R S T U V W X 6 PGH P:\GIS\MIDDLE_RIVER\MAPDOCS\MXD\BLDG_C_TAGS_RND23_IA_SSV.MXD 10/23/17 KM FIGURE 3 065-C 035-C 035-CX 103-C 124-C 2 1 1/2 ROUND 23 SUB-SLAB VAPOR SAMPLING RESULTS GREATER THAN SCREENING LEVELS BUILDING C 086-C 051-C 091-C 115-C 156-C 132-C 151-C 050-C 149-C 087-C 060-C 060-CX 037-CX 036-CXX 153-C 144-C 066-C 154-C 133-C 036-CX 155-C 037-C 036-C SV-126-C-23 TRICHLOROETHENE 850 111-C 125-C 141-C 150-C 145-C 127-C 146-C 148-C 128-C SV-152-C-23 TRICHLOROETHENE 1400 129-C 147-C SV-102-C-23 TRICHLOROETHENE 1300 142-C 157-C 044-C 159-C 143-C 113-C 038-C 088-C 135-C 067-C 158-C 114-C 134-C 059-C 112-C 058-C 130-C 131-C 089-C 23 22 21 20 19A 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 Legend IAQ, 1st Floor IAQ, Basement SV All results in microgram(s) per cubic meter (µg/m 3 ). X - moved from original location once. NA Not applicable Round 23 Sampling Locations SSD Radius of Influence Buildings A, B and C Building B and C Basement Tunnel SSD Treatment Unit Screening Levels Exceeded Indoor Soil Chemical Air Vapor 1,1-Dichloroethane NA 2567 Naphthalene NA 120 Trichloroethene NA 293 Vinyl Chloride NA 933 IAQ - Indoor Air Quality J = Estimated Value SSD - Sub-slab Depressurization SV - Soil Vapor TCE - Trichloroethene August 2017 Sub-Slab Vapor TCE Concentration 10000 ug/m3 1000 ug/m3 293 ug/m3 0.1 ug/m3 010-C 009-C 007-C 042-C 008-C 090-C 005-C 003-C 002-C 004-C 001-C 039-C 006-C 041-CX 040-C 104-C 041-C ± 0 32 64 Feet Lockheed Martin Middle River Complex Middle River, Maryland DATE MODIFIED: CREATED BY: 10/23/17 JEE