September 11, 2001 : Attack on America
Environmental Protection Agency Region III : Summary of Environmental Monitoring Operations at the Pentagon; October 9, 2001

Environmental Protection Agency Region III
October 9, 2001: Summary of Environmental Monitoring Operations at the Pentagon

EPA Region III emergency responders worked with the FBI and the Defense Department from September 11 through September 29, 2001 to collect air, water, and debris samples at and around the Pentagon crash site to ensure the safety of response personnel, Pentagon employees, and nearby residents. EPA's air monitoring has not detected any pollutants from the fires and building debris that are of concern to the workers or the general public. EPA sampling also indicates that there is no threat of drinking water contamination. The following is a brief summary of the sampling and monitoring that has taken place to date:

Sampling & monitoring work/support zone air quality

Throughout the two and a half weeks following the incident, EPA sampled the air in the building work zone for asbestos, volatile organic chemicals (VOCs) and other chemicals, and found only trace amounts substantially below levels of concern. A total of 244 air samples were collected in the work zone and support zones: 136 asbestos samples, 78 silica samples, 23 lead samples and 7 VOC samples. Of these samples only two silica samples were slightly above the recommended levels for work areas. Since all of the workers in the affected area were wearing respirators, this level of exposure did not present a problem.

Sampling & monitoring off-site air quality

Beginning September 11, EPA sampled air in and around Washington D.C. and northern Virginia, and the perimeter of the Pentagon facility for smoke, particulate matter, VOCs, and other chemicals. EPA's sampling found contaminants at background levels or substantially below levels of concern. Samples were collected continuously from as many as three different locations for the period from September 12 through September 17. In addition, data from existing ambient monitoring stations near the Pentagon were evaluated for impacts from the fire. All data collected from these stations were at levels typical of urban air pollution, and no influence from the fire was detected.

Sampling & monitoring water quality

EPA collected three samples of runoff water generated while fighting the fire, and one sample of runoff from the North parking area (the debris sorting area). These samples were analyzed for volatile and semi-volatile organics, metals, and pesticides. Trace amounts of metals and other chemicals substantially were found in the runoff. The runoff from the response effort was routed to a sewage treatment facility whenever possible, but much of it entered storm sewers and was discharged into the Potomac River. Results from sampling the discharged water indicate that amounts of contaminants were below levels of concern for short term exposure for human health. The concentrations of contaminants in the runoff are not expected to have any negative impact on aquatic life in the surface waters of the area, most notably on the Potomac River.

Sampling crash site debris

EPA sampled debris from inside the building for asbestos, lead and other metals. A total of 8 ash/debris samples were taken inside the building and in the debris sorting area. A few relatively high concentrations of metals were reported in ash and soot- antimony (a metal) at up to 225 mg/kg and arsenic at up to 38 mg/kg. However short-term exposure and limited routes of contact have minimized any potential for harm. Most of this debris is being or has been disposed of in an approved construction waste landfill, where it will be covered and will not be able to migrate into the environment. In addition, workers handling this material were required to wear respirators and protective clothing.

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