U.S. ENVIRONMENTAL PROTECTION AGENCY 

OFFICE OF INSPECTOR GENERAL 

Catalyst for Improving the Environment 

 Evaluation Report 

Vapor Intrusion Health Risks at 

Bannister Federal Complex Not a 

Concern for Buildings 50 and 52, 

Unknown for Other Buildings 

 Report No. 11-P-0048 

 January 5, 2011 
 

Report Contributors:	 Hilda Canes Garduño 

 Martha Chang 

 Michael Wilson 

 Eric Lewis 

Abbreviations 

DOE U.S. Department of Energy 

EPA U.S. Environmental Protection Agency 

GSA U.S. General Services Administration 

NNSA National Nuclear Security Administration 

OIG Office of Inspector General 

TCE Trichloroethylene 

VOC Volatile organic compound 

Cover photos: from left to right: Bannister Federal Complex, GSA buildings 50 and 52. 

(EPA OIG photos) 
 

U.S. Environmental Protection Agency 11-P-0048 

January 5, 2011 Office of Inspector General 

At a Glance 

Catalyst for Improving the Environment 

Why We Did This Review 

The U.S. General Services 

Administration (GSA) Office 

of Inspector General asked for 

our assistance in responding to 

a congressional inquiry. We 

evaluated EPA Region 7’s 

actions to (1) assess and 

address the potential vapor 

intrusion risk at Bannister 

Federal Complex buildings 50 

and 52, and (2) characterize 

the public health risk at 

Bannister Federal Complex. 

Background 

Bannister Federal Complex is 

a 310-acre federal property 

located in Kansas City, 

Missouri. Several 

contaminated ground water 

plumes exist beneath the 

complex. Both GSA and the 

U.S. Department of Energy 

National Nuclear Security 

Administration control the 

site. The GSA Office of 

Inspector General is 

responding to allegations that 

employees may have become 

sick due to chemical 

exposures potentially 

occurring at the site. 

For further information, 

contact our Office of 

Congressional, Public Affairs 

and Management at 

(202) 566-2391. 

To view the full report, 

click on the following link: 

www.epa.gov/oig/reports/2011/ 

20110105-11-P-0048.pdf 

Vapor Intrusion Health Risks at Bannister Federal 

Complex Not a Concern for Buildings 50 and 52, 

Unknown for Other Buildings 

What We Found 

Testing at Bannister Federal Complex in February 2010 revealed elevated levels 

of volatile organic compounds (VOCs) in the soil vapor beneath the foundations 

of buildings 50 and 52. EPA Region 7 assisted GSA in evaluating the vapor 

intrusion risk for these buildings. Only trichloroethylene vapors were observed to 

be intruding into building 50 from the contaminated ground water. Building 50 

contains office space and building 52 has a child care facility. 

Region 7 assessed the health risk from inhaling indoor air in the two buildings in 

accordance with EPA risk assessment procedures. The indoor air chemical 

concentrations were below acceptable risk levels for both short- and long-term 

exposure for the 14 VOCs measured and, therefore, are not a health concern. As a 

precaution, Region 7 recommended and reviewed the installation of soil vapor 

removal systems in both buildings in February 2010. Subsequent testing in 

March 2010 showed that contaminant levels in the soil vapors beneath both 

buildings were reduced. Trichloroethylene levels in the indoor air of building 50 

were also reduced. 

Although Region 7 conducted its assessment in accordance with EPA-approved 

procedures, additional actions would provide a more comprehensive picture of the 

chemical hazards in the indoor air and ground. These actions include testing for 

additional VOCs and assessing total VOC exposure levels in the buildings. 

Not all of the other Bannister Federal Complex buildings with underlying or 

nearby contaminant plumes have been assessed for soil vapor intrusion. As a 

result, the public health risks in those buildings have not been determined.

 What We Recommend 

We recommend that Region 7 test for additional VOCs for all future air, soil 

vapor, soil, and ground water samples in and around buildings 50 and 52. After 

discussions with Region 7, we revised our second recommendation to continue 

oversight work by assessing the responsible parties’ efforts to evaluate inhalation 

health risks at all other Bannister buildings over or near contaminated ground 

water plumes. Region 7 staff concurred with our recommendations and committed 

to completing actions that would meet the intent of both recommendations. In its 

final response to this report, Region 7 should provide a corrective actions plan for 

both recommendations, including estimated or actual milestone completion dates. 
 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

THE INSPECTOR GENERAL 

January 5, 2011 

MEMORANDUM 

SUBJECT:	 Vapor Intrusion Health Risks at Bannister Federal Complex Not a 

Concern for Buildings 50 and 52, Unknown for Other Buildings 

 Report No. 11-P-0048 

FROM: Arthur A. Elkins, Jr. 

 Inspector General 

TO: Karl Brooks 

 Regional Administrator, EPA Region 7 

This is a report on the subject evaluation conducted by the Office of Inspector General (OIG) of 

the U.S. Environmental Protection Agency (EPA). This report contains findings that describe 

the problems the OIG has identified and corrective actions the OIG recommends. This report 

represents the opinion of the OIG and does not necessarily represent the final EPA position. 

Final determinations on matters in this report will be made by EPA managers in accordance 

with established audit resolution procedures. 

The estimated cost of this report, calculated by multiplying the project’s staff days by 

the applicable daily full cost billing rates in effect at the time plus travel costs, is 

$232,360. 

Action Required 

In accordance with EPA Manual 2750, you are required to provide a written response to this 

report within 90 calendar days. Your response will be posted on the OIG’s public website, 

along with our comments on your response. Your response should be provided in an Adobe 

PDF file that complies with the accessibility requirements of section 508 of the Rehabilitation 

Act of 1973, as amended. If your response contains data that you do not want to be released to 

the public, you should identify the data for redaction. You should include a corrective actions 

plan for your actions, including milestone dates. We have no objections to the further release of 

this report to the public. This report will be available at http://www.epa.gov/oig. 
 

If you or your staff have any questions regarding this report, please contact Wade Najjum, 

Assistant Inspector General for Program Evaluation, at 202-566-0832 or 

najjum.wade@epa.gov; or Eric Lewis, Director, Special Reviews, Office of Program 

Evaluation, at 202-566-2664 or lewis.eric@epa.gov. 
 

 

 

 

 

 

Vapor Intrusion Health Risks at Bannister Federal Complex 11-P-0048 

Not a Concern for Buildings 50 and 52, Unknown for Other Buildings 

Table of Contents 

Introduction ................................................................................................................. 1 

Purpose................................................................................................................ 1 

Background .......................................................................................................... 1 

 Noteworthy Achievements.................................................................................... 3 

Scope and Methodology ...................................................................................... 3 

Vapor Intrusion Assessed and Addressed Only at Buildings 50 and 52 of 

Bannister Federal Complex........................................................................................ 5
 

Air Sampling Performed to Assess Buildings 50 and 52 for Vapor Intrusion ....... 5 

Soil Vapor Removal Systems Installed to Address Vapor Intrusion Into 

Vapor Intrusion Not Assessed at Other Buildings With Underlying 

 Buildings 50 and 52........................................................................................ 5 

Contamination Plumes ................................................................................... 6 

Health Risks Assessed According to Guidance, but Assessment 

Could Be Improved .................................................................................................... 8
 

Indoor Air at Buildings 50 and 52 Does Not Pose Health Risks from 

Short- or Long-Term Exposure....................................................................... 8 

Reporting Additional VOC Results Provides More Comprehensive 

Assessing Cumulative VOC Exposure Levels Provides Additional 

OIG Takes Precautionary Step by Assessing Early-Life Risk to 

Assessment.................................................................................................... 9 

Public Health Assurance ................................................................................ 9 

Children’s Health............................................................................................. 10 

Conclusions and Recommendations ........................................................................ 11 

Conclusions.......................................................................................................... 11 

Recommendations ............................................................................................... 11 

EPA Region 7 Response to Draft Report and OIG Evaluation............................. 11 

Status of Recommendations and Potential Monetary Benefits.............................. 13 

Appendices 

A EPA Region 7 Response to Draft Report and OIG Evaluation ........................ 14 

B Distribution ......................................................................................................... 16 
 

Introduction 

Purpose 

In February 2010, the U.S. General Services Administration (GSA) Office of 

Inspector General (OIG) contacted the U.S. Environmental Protection Agency 

(EPA) OIG to ask for assistance in responding to a congressional request from 

Missouri Senator Christopher (Kit) Bond. The congressional request was in 

response to allegations that employees at Bannister Federal Complex may have 

fallen ill due to exposure to hazardous contaminants. Our objectives were to 

evaluate: 

	 EPA Region 7’s efforts to assess and to address the potential vapor 

intrusion risk at buildings 50 and 52 of Bannister Federal Complex. 

	 EPA Region 7’s actions to characterize the public health risk at Bannister 

Federal Complex. 

Background 

Bannister Federal Complex 

Bannister Federal Complex is a 310-acre federal property located in Kansas City, 

Missouri. The complex is controlled by both GSA and the U.S. Department of 

Energy’s (DOE’s) National Nuclear Security Administration (NNSA). Currently, 

more than 2,300 NNSA contract employees work at Bannister. Office and 

warehouse space not controlled by NNSA is owned and operated by GSA. 

Approximately 1,900 federal employees work in the nonmanufacturing space. 

NNSA plans to relocate to another facility starting in 2012. A GSA relocation is 

under discussion. 

In the past, aircraft engines were manufactured at the site. Currently, NNSA 

builds nonnuclear components for nuclear weapons and makes electrical, 

electromechanical, mechanical, and plastic components at the site. From 1942 to 

the mid-1970s, neither the chemicals used nor the solid waste disposal at 

Bannister were subject to modern standards for managing hazardous materials in 

the workplace or environment. From 1942 to 1964, the U.S. Department of 

Defense operated a landfill at Bannister to dispose of manufacturing waste. The 

wastes included solvents, metals, and petroleum, which ultimately contaminated 

the soil and ground water at the site. 

After ownership of Bannister transferred to DOE and GSA in 1976, DOE took 

action to control and clean up its portion of the property. GSA, for its part, 

conducted periodic sampling and analysis of soil, ground water, and air quality. In 

May 2008, a preliminary assessment and site inspection report was prepared for 

the GSA-managed portions of Bannister. The report recommended assessing the 

11-P-0048 1 
 

indoor air of buildings 50 and 52 for vapor intrusion and monitoring ground water 

near building 50 for any changes in contaminant concentrations. The report also 

made recommendations for other GSA-managed areas of Bannister. 

Vapor Intrusion 

Vapor intrusion is the migration of volatile chemicals from the subsurface into 

overlying buildings. Volatile chemicals in contaminated soil or ground water can 

emit vapors. The vapors may migrate through the subsurface soil as soil vapor and 

into the indoor air spaces of overlying buildings (figure 1). 

Figure 1: Pathway for subsurface vapor intrusion into indoor air 

Source: OSWER 2002 Draft Guidance for Evaluating the Vapor Intrusion to 

Indoor Air Pathway from Groundwater and Soils (Subsurface Vapor Intrusion 

Guidance). 

Note: Nonaqueous phase liquids, or NAPLs, are contaminants 

that, like oil, do not dissolve readily in water. Their vapors may
 

migrate through the soil space of the vadose zone (the 

unsaturated zone above ground water) into overlying buildings, 

contaminating the indoor air.
 

Current and former National Priorities List sites could have extensive vapor 

intrusion issues and pose a significant risk to the public. In 2002, EPA issued draft 

guidance based on its understanding at the time of vapor intrusion. The guidance 

included technical and policy recommendations for determining whether vapor 

intrusion posed a health risk at sites. In December 2009, the EPA OIG issued 

Report No. 10-P-0042, Lack of Final Guidance on Vapor Intrusion Impedes 

Efforts to Address Indoor Air Risks. We recommended that EPA issue final 

guidance to establish current Agency policy on the evaluation and mitigation of 

vapor intrusion risks. We also recommended that the Agency finalize toxicity 

values for trichloroethylene (TCE) and perchloroethylene—common 

contaminants associated with vapor intrusion. The Agency agreed with our 

recommendations and provided milestones. The Agency has committed to release 

the final vapor intrusion guidance by November 2012. 

11-P-0048 2 
 

Noteworthy Achievements 

Region 7 assisted the Missouri Department of Natural Resources and GSA in 

January 2010 by reviewing GSA’s air sampling plan and providing sampling 

oversight. The Missouri Department of Natural Resources also requested that 

Region 7 evaluate risk management at the GSA portion of Bannister. Region 7 

determined that collaborating and sharing technical expertise, equipment, and 

resources with GSA would more rapidly and cost effectively assess and address 

the health risks in buildings 50 and 52. 

Region 7 signed an interagency agreement with GSA in March 2010, with 

activities beginning beforehand, to perform the following: 

	 Conduct a site reassessment focusing on buildings 50 and 52. 

	 Complete indoor air and vapor intrusion sampling, ground water sampling, 

soil vapor and soil sampling, outdoor air sampling, and air quality 

monitoring of these buildings. 

	 Provide technical and oversight support for the installation of soil vapor 

removal systems in buildings 50 and 52 as a precautionary measure 

against vapor intrusion. 

	 Provide support to GSA in public meetings and other community relations 

activities. 

Region 7 also established an environmental work agreement with GSA in April 

2010 to address other issues identified in the 2008 preliminary assessment and site 

inspection report. 

To date, Region 7 conducted three of four rounds of sampling, recommended and 

supervised the installation of soil vapor removal and ventilation systems, and 

performed risk assessments for buildings 50 and 52. Region 7 also established a 

community advisory panel for Bannister. 

Scope and Methodology 

We conducted our review from March to October 2010 in accordance with 

generally accepted government auditing standards. Those standards require that 

we plan and perform our review to obtain sufficient, appropriate evidence to 

provide a reasonable basis for our findings and conclusions based on our 

objectives. We believe that the evidence obtained provides a reasonable basis for 

our findings and conclusions based on our objectives. 

To accomplish our objectives, we reviewed documents provided by the GSA OIG 

and EPA Region 7. We conducted interviews with relevant GSA OIG staff in 

11-P-0048 3 
 

Kansas City, Missouri, and EPA Region 7 staff in Kansas City, Kansas. We also 

reviewed federal statutes, regulations, and Agency guidance. 

We reviewed two rounds of sampling data collected by Region 7 in 2010 to assess 

the potential for vapor intrusion in buildings 50 and 52. We also identified and 

assessed the actions Region 7 took to address the risk for vapor intrusion. We 

evaluated Region 7’s health risk assessment in accordance with the EPA 

Superfund guidance document, Supplemental Guidance for Inhalation Risk 

Assessment. The assessment evaluates the amount of risk contributed from 

inhaling potential indoor air contaminants and not other routes of exposure. 

Henceforth, inhalation risk will be referred to as “health risk.” 

The primary contaminants of concern for vapor intrusion at Bannister are the 

volatile organic compounds (VOCs), particularly TCE and its byproducts, 

1,2-dichloroethylene and vinyl chloride. We conducted our evaluation for these 

primary contaminants of concern and the other VOCs tested. 

11-P-0048 4 
 

 

Vapor Intrusion Assessed and Addressed Only at 

Buildings 50 and 52 of Bannister Federal Complex 

Region 7’s 2010 test results for vapor intrusion in buildings 50 and 52 showed 

elevated levels of VOCs in the soil vapor beneath the foundations of both 

buildings. However, only TCE vapors were observed to be intruding into building 

50 from the contaminated ground water. Chemical levels in the indoor air do not 

pose a health concern for either building. Building 50 contains office space and 

building 52 is primarily occupied by a child care facility. Region 7 addressed the 

issue of vapor intrusion by having GSA install soil vapor removal systems in both 

buildings. Subsequent testing showed that the soil vapors beneath both buildings 

were reduced. TCE levels in the indoor air of building 50 were also reduced. 

Contaminant plumes lie below or near other buildings at Bannister. These 

buildings have not all been tested for vapor intrusion. Consequently, the health 

risk for these other buildings has not been determined. 

Air Sampling Performed to Assess Buildings 50 and 52 for Vapor 

Intrusion 

Region 7 assessed buildings 50 and 52 for vapor intrusion and found contaminant 

vapors beneath both buildings and entering the air of building 50. Region 7 had 

agreed to conduct four rounds of sampling to determine whether subsurface 

contaminants are impacting, or have the potential to impact, the indoor air space 

of these buildings. Region 7 has completed four rounds of indoor air, outdoor air, 

and subslab soil vapor sampling. Our review assessed data from the first two 

sampling rounds only. 

The first round of vapor intrusion sampling in February 2010 confirmed that 

subsurface contaminants are volatilizing and migrating through the soil and 

collecting beneath the buildings’ foundations at elevated levels. However, only in 

building 50 did TCE demonstrate a complete vapor intrusion pathway from 

ground water to indoor air that cannot be attributed to background chemical 

sources. Background chemical sources arise from consumer products (e.g., 

cleaning products and markers) typically found in residences. All detected 

contaminants were below levels for health concern in the indoor air. 

Soil Vapor Removal Systems Installed to Address Vapor Intrusion Into 

Buildings 50 and 52 

After test results showed elevated contaminant levels in the soil vapor, Region 7 

addressed vapor intrusion risks by having GSA install soil vapor removal systems 

in buildings 50 and 52 in February 2010. A soil vapor removal system creates 

negative pressure beneath a building and vents the contaminated vapors to the 

11-P-0048 5 
 

 

outside environment. EPA scientists and external consultants consider these 

systems reliable for controlling vapor intrusion. Soil vapor and indoor air results 

for samples taken after installation of these systems confirm that they are effective 

in decreasing contaminant levels. 

The second round of sampling in March 2010 showed a decrease in the elevated 

contaminant levels in the soil vapor beneath buildings 50 and 52. The TCE 

contaminant level in the indoor air of building 50 decreased after installing the 

soil vapor removal systems. Chemical levels in the indoor air of building 52 

remained constant after soil vapor removal system installation, confirming that 

soil vapor was not previously intruding into the building. 

Sampling results also identified one contaminant, TCE, above acceptable longterm exposure levels at a subsurface sampling location—the utility tunnel 

connecting buildings 50 and 1. Region 7 recommended installing ventilation fans 

in the unoccupied utility tunnel because vapor intrusion likely affected the area. 

The area may potentially serve as an alternate entry point for contaminants to 

migrate into the occupied building 50. GSA installed the fans in May 2010. 

Vapor Intrusion Not Assessed at Other Buildings With Underlying 

Contamination Plumes 

Vapor intrusion has not been assessed for the entire Bannister Federal Complex; 

therefore, the public health risk for the entire facility has not been determined. 

The National Priorities List assessment for Bannister occurred in 1987 and did not 

consider vapor intrusion as a potential exposure pathway. Past environmental 

investigations identified large contaminant plumes beneath or near other 

buildings. Except for DOE’s portion of building 1, the other buildings were likely 

not assessed for vapor intrusion (figure 2). For the same reason that vapor 

intrusion was a human health concern at buildings 50 and 52, vapor intrusion may 

also be a concern at other Bannister buildings. 

11-P-0048 6 
 

Figure 2: Ground water contaminant plumes at Bannister 

Source: U.S. Department of Energy Kansas City Plant, Groundwater Corrective Action Report for Calendar Year 

2009. 

11-P-0048 7 
 

Health Risks Assessed According to Guidance, 

but Assessment Could Be Improved 

Our assessment agrees with Region 7’s health risk assessment that the TCE levels 

in buildings 50 and 52 do not pose a potential health concern for children or 

adults. Our review also included a precautionary step of assessing early-life health 

risk for childhood exposure for building 52, which houses a child care facility. 

Region 7 concluded that contaminant levels in the indoor air in both buildings do 

not pose health risks from either short-term or long-term exposure. Region 7 

based this conclusion on its assessment of health risks in buildings 50 and 52 

conducted in accordance with EPA’s inhalation risk assessment guidance. Our 

review determined that Region 7 conducted its assessment in accordance with 

established risk assessment procedures. However, additional actions would 

provide a more comprehensive picture of the chemical hazards in the indoor air. 

These actions include testing and reporting the results of additional VOCs and 

assessing the cumulative exposure to multiple VOCs. 

Indoor Air at Buildings 50 and 52 Does Not Pose Health Risks from 

Short- or Long-Term Exposure 

Region 7 performed tests and concluded, according to guidance, that the indoor 

air at buildings 50 and 52 does not pose health risks from either short- or longterm exposure. Region 7 followed the 2009 EPA Superfund guidance, 

Supplemental Guidance for Inhalation Risk Assessment. The assessments were 

based on two rounds of indoor sampling results taken before and after installing 

the soil vapor removal systems. Uncertainties exist when estimating year-round 

indoor air quality conditions from two sampling events. Therefore, results from 

the remaining two sampling events this year will be needed to confirm Region 7’s 

conclusions. 

Several contaminants were detected at above-acceptable exposure levels at certain 

locations during the first round of indoor air sampling. Except for TCE in building 

50, these contaminants may be attributed to background sources within the 

buildings. Furthermore, the average contaminant levels in each building were all 

within acceptable levels and, therefore, are not health concerns. 

During the second round of sampling, only chloroform at one building 52 location 

and TCE in the subsurface air of the utility tunnel were detected at aboveacceptable long-term exposure levels. The chloroform may be from background 

sources. Its average indoor concentration was within the acceptable level and 

therefore not a health concern. The TCE level is not a health concern because the 

utility tunnel is unoccupied and inhalation exposure is intermittent and of short 

11-P-0048 8 
 

 

duration. Region 7, however, recommended the installation of ventilation fans to 

prevent potential TCE migration into the indoor air of building 50. 

Reporting Additional VOC Results Provides More Comprehensive 

Assessment 

Region 7 assessed exposure to only a subset of potential VOCs present in 

buildings 50 and 52. Region 7 requested testing for only 14 VOCs in the air 

samples, instead of utilizing the full capability of the analytical method to test for 

up to 97 chemicals. Although results for the primary contaminants of concern 

were reported, indoor air typically contains over 50 chemicals. EPA guidance 

does not dictate which chemicals should be tested for at a site to characterize the 

chemical hazard. However, requesting the results for additional chemicals would 

be reasonable in cost, require minimal additional effort on the part of the Agency, 

and provide a fuller understanding of the extent of VOC exposure in buildings 50 

and 52. 

The soil and the ground water contaminant plume around buildings 50 and 52 can 

also be better understood with additional testing. Potential contaminant sources 

around the buildings have not been well defined in the past. Testing for additional 

chemicals in all media for all future sampling events, as allowed by their 

analytical methods, may alleviate potential concerns of additional VOC exposure 

and provide a more thorough picture of the contaminants around the buildings. 

Assessing Cumulative VOC Exposure Levels Provides Additional 

Public Health Assurance 

Region 7 assessed health risks due to short-term exposure in buildings 50 and 52 

based on exposure to individual contaminants and not on cumulative exposure to 

multiple contaminants. The region’s approach focuses on the health risks resulting 

primarily from the vapor intrusion of individual contaminants, such as TCE. This 

approach does not assess the health risks of short-term cumulative exposure from 

all sources. Such an approach may provide greater protection for the public 

health. An adverse cumulative VOC exposure level may have already occurred 

before any individual contaminant in indoor air reaches an unacceptable shortterm risk level. 

Region 7 can provide additional public health assurance in the buildings by 

assessing the cumulative exposure levels for a wider range of VOCs. EPA has not 

developed criteria to evaluate health risks from short-term cumulative exposure, 

but recommends summing individual health risks to estimate the risk. Although 

this approach does not take into account potential synergistic chemical 

interactions, scientific literature suggests using total VOC exposure levels as an 

aid in limiting indoor contaminant concentrations. However, as risk levels for 

cumulative exposure have not been established, they cannot be used as a health 

risk indicator, and they do not provide definitive conclusions about indoor air 

11-P-0048 9 
 

quality. EPA should consider approaches for evaluating health risks due to 

cumulative exposure to multiple VOCs at Bannister to ensure a thorough 

assessment and commitment to a healthier indoor environment. 

OIG Takes Precautionary Step by Assessing Early-Life Risk to 

Children’s Health 

In the event that EPA determines TCE to be a carcinogen that is comparatively 

more toxic to children, we performed a precautionary early-life health risk 

assessment for childhood exposure to TCE. TCE is the primary contaminant of 

concern for vapor intrusion at Bannister. Building 52 has a child care center. We 

performed the early-life risk assessment in accordance with the 2005 EPA 

guidance document, Supplemental Guidance for Assessing Susceptibility from 

Early-Life Exposure to Carcinogens. Our results show that TCE levels in building 

52 for both rounds of indoor air sampling were within the acceptable early-life 

risk level for children. We calculated the acceptable exposure level for young 

children to be 2.5 micrograms per cubic meter. The maximum TCE level found 

for indoor air at building 52 for both rounds of sampling was 0.42 micrograms per 

cubic meter. The indoor air levels we reviewed for TCE in building 52 do not 

indicate an early-life health concern for children. This early-life health risk 

assessment is not a substitute for EPA’s risk assessments. 

11-P-0048 10 
 

Conclusions and Recommendations 

Conclusions 

Region 7 assessed the health risk from inhaling contaminated air in Bannister 

Federal Complex buildings 50 and 52 in accordance with EPA risk assessment 

procedures. Elevated levels of VOCs were detected beneath the foundations of 

both buildings. Only TCE was observed to be entering building 50 from the 

subsurface into indoor air via vapor intrusion. For the 14 VOCs measured in the 

indoor air, all were within acceptable risk levels for both short- and long-term 

exposure. Region 7 recommended that the vapor intrusion risk in both buildings 

be mitigated by the installation of soil vapor removal and ventilation systems. Not 

all of the other buildings at Bannister with underlying or nearby contaminant 

plumes have been assessed for vapor intrusion. Therefore, their public health risk 

has not been determined. 

Our review identified actions that can improve contaminant characterization. 

Testing for additional VOCs in air, soil vapor, soil, and ground water samples as 

established by EPA’s analytical methods would provide a more comprehensive 

picture of the contaminants in indoor air and the surrounding area. Furthermore, 

from a public health perspective, assessing total VOC exposure levels supports a 

commitment to a healthier work environment. Both improvements can be 

achieved and assessed with reasonable cost and minimal additional effort. Such 

efforts would provide greater assurance that the indoor contaminants at Bannister 

have been thoroughly assessed. 

Recommendations 

We recommend that the Regional Administrator, Region 7: 

1.	 Test for additional VOCs listed in the appropriate EPA-approved 

analytical methods for all future air, soil vapor, soil, and ground water 

samples in and around buildings 50 and 52. 

2.	 As part of continuing oversight work, assess the responsible agencies’ 

efforts to fully evaluate the health risks from inhaling potentially 

contaminated air for all buildings over or within close proximity of 

contaminated ground water plumes at Bannister Federal Complex. 

EPA Region 7 Response to Draft Report and OIG Evaluation 

Region 7 indicated in its response to the draft report that it has already undertaken 

efforts to address both of our recommendations. The region included additional 

VOCs in its analysis of indoor air and subslab air samples for the third round of 

11-P-0048 11 
 

sampling. The region also signed an environmental work agreement with GSA to 

provide oversight in investigating and managing environmental conditions at 

other GSA-managed facilities. 

In its official response, Region 7 did not agree or disagree with either of the 

recommendations in the report but did describe actions it had taken that partially 

address our recommendations. We recommended testing future soil and ground 

water samples for additional VOCs, not just indoor air and soil vapor samples. 

The region provided no indication that it will test for additional VOCs for ground 

water and soil samples. Ground water and soil should be tested for additional 

VOCs to better characterize the contamination around buildings 50 and 52. 

In addition, our second recommendation to evaluate inhalation health risks is not 

limited to only GSA-managed facilities at Bannister. Other buildings in the 

complex, managed by other federal entities, were not assessed for vapor intrusion. 

Region 7 should evaluate inhalation health risks at non-GSA-managed buildings 

overlying or near contamination plumes in the complex. 

In followup discussions, Region 7 concurred with both our recommendations after 

revision to one of the recommendations and committed to completing actions that 

would meet the intent of both recommendations. For our first recommendation, 

Region 7 tested for total VOCs in buildings 50 and 52 during the third round of 

indoor air and soil vapor sampling held August 6–8, 2010. Region 7 indicated that 

the fourth round of indoor air and soil vapor sampling, held November 19–21, 

also tested for total VOCs, and that the region plans to test for total VOCs in 

ground water and soil samples taken on December 6–20, 2010. Confirmation lab 

reports were not yet available for these sampling events. 

For our second recommendation, Region 7 indicated that it has requested indoor 

air monitoring results from DOE to evaluate the inhalation health risks at all nonGSA-managed buildings over or within close proximity of contaminated ground 

water plumes. 

In its final response to this report, Region 7 should provide a corrective actions 

plan for both recommendations, including estimated or actual milestone 

completion dates. 

11-P-0048 12 
 

 

 

 

 

 

 

 

 

Status of Recommendations and 

Potential Monetary Benefits 

POTENTIAL MONETARY 

RECOMMENDATIONS BENEFITS (in $000s) 

Rec. 

No. 

Page 

No. Subject Status1 Action Official 

Planned 

Completion 

Date 

Claimed 

Amount 

Agreed-To 

Amount 

1 

2 

11 

11 

Test for additional VOCs listed in the appropriate 

EPA-approved analytical methods for all future air, 

soil vapor, soil, and ground water samples in and 

around buildings 50 and 52. 

As part of continuing oversight work, assess the 

responsible agencies’ efforts to fully evaluate the 

health risks from inhaling potentially contaminated 

air for all buildings over or within close proximity of 

contaminated ground water plumes at Bannister 

Federal Complex. 

O 

O 

Regional Administrator, 

Region 7 

Regional Administrator, 

Region 7 

O = recommendation is open with agreed-to corrective actions pending 

C = recommendation is closed with all agreed-to actions completed 

U = recommendation is undecided with resolution efforts in progress 

11-P-0048 13 

1 
 

 

Appendix A 

EPA Region 7 Response to Draft Report and 

OIG Evaluation 

Elizabeth Grossman 

Deputy Assistant Inspector General for Program Evaluation 

Acting Product Line Director for Special Reviews 

United States Environmental Protection Agency 

Office of the Inspector General 

Office of Program Evaluation 

Dear Ms. Grossman: 

Thank you for your providing us with the Draft Evaluation Report, “Vapor Intrusion 

Health Risks at Bannister Federal Complex Not a Concern for Buildings 50 and 52, Unknown 

for Other Buildings,” Project No. OPE-FY10-0014. We have reviewed the report, and its two 

substantive recommendations: 

	 Test for additional VOCs listed in the appropriate EPA-approved analytical methods 

for all future air, soil vapor, soil, and ground water samples in and around buildings 

50 and 52; and 

	 Require the responsible agencies to fully evaluate the health risks from inhaling 

potentially contaminated air for all buildings over or within close proximity of 

contaminated ground water plumes at the Bannister Federal Complex. 

You will be pleased to find out that the Region has already undertaken efforts that 

address both of these recommendations. Additional VOCs were included in the analysis of 

indoor air and subslab air samples for the most recent, i.e. third round, of sampling. As noted in 

your draft report, the Region also signed an Environmental Working Agreement with the General 

Services Administration. This agreement outlines a plan to further investigate and manage 

environmental conditions at other GSA-managed facilities within the Bannister Federal 

Complex, including those affected by ground water plumes. GSA will perform site 

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investigations, removal assessments and response actions under EPA oversight with work 

scheduled to begin in the near future. 

I would also like to ask you to convey our thanks to your staff who participated in this review. 

We appreciated their professionalism and courtesy, as well as their flexibility given the 

challenging calendar constraints. 

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Appendix B 

Distribution 

Office of the Administrator 

Assistant Administrator, Office of Solid Waste and Emergency Response 

Regional Administrator, Region 7 

Director, Environmental Services Division, Region 7 

Agency Followup Official (the CFO) 

Agency Followup Coordinator 

General Counsel 

Associate Administrator for Congressional and Intergovernmental Relations 

Associate Administrator for External Affairs and Environmental Education 

Audit Followup Coordinator, Office of Solid Waste and Emergency Response 

Audit Followup Coordinator, Region 7 

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