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‘Flyer’ Improves OB/OD Air Emissions Measurement

A novel measurement technology developed with SERDP support accurately characterizes air emissions from the open burning and open detonation (OB/OD) of DoD munitions. Deployed via a helium-filled balloon, the Flyer technology has quantified emissions from a variety of OB/OD scenarios in challenging field conditions. These measurements can be used to develop emission factors that will allow DoD facilities to dispose of munitions in compliance with environmental regulations.

To operate OB/OD facilities, DoD installations are required to comply with the Resource Conservation and Recovery Act (RCRA). RCRA permits impose annual limits on the amount of energetic materials that can be disposed of at OB/OD facilities. The permit limitations are based on human health risk assessments that include airborne exposure to emissions generated from OB/OD. These emissions are very difficult to measure in the field due to rapid dispersion, short event duration, spatial and temporal heterogeneity of emission concentrations, large plume lift, soil entrainment, and safety considerations. Because of these challenges, most past OB/OD emission studies were performed in limited volume structures known as “bang boxes” that do not fully replicate open air OB/OD operations.

SERDP supported a research program to develop a field measurement technology to accurately characterize the emissions from OB/OD operations. The research was conducted by a team from the U.S. Army Engineer Research and Development Center – Construction Engineering Research Laboratory (ERDC-CERL); the U.S. Army Joint Munitions Command, Engineering and Demilitarization Technology Office; the USEPA National Risk Management Research Laboratory (NRMRL); the University of Illinois-Urbana Champaign; and several private consulting firms.

The research team conducted three- to four-week field campaigns at Tooele Army Depot, Utah, in March 2010, April 2011, and June 2012. Initially, researchers conducted feasibility studies to test both in situ and optical remote sensing (ORS) emission measurement technologies for OB of M1 propellant and OD of TNT. The feasibility tests showed promise for both an in situ sampling configuration known as the Flyer and an ORS method. Because of its all-around capability, the Flyer was selected as the measurement technology for the remaining emission measurement studies.

The Flyer is an instrument pack that is lofted with a helium-filled balloon and maneuvered by two tethers connected to all-terrain vehicles (ATVs) on the ground. It collects batch gas and particle samples from ambient air or plumes and carbon dioxide via continuous emission monitors (CEMs). It includes programmable logic control hardware that enables sampling only when CEM data indicate that the Flyer is located within a plume. Initial Flyer sampling included PM₁₀, volatile organic compounds, and semi-volatile organic compounds, and measurements of PM_2.5, hydrochloric acid, perchlorate, and chlorate were added later. The team characterized air emissions from OB for propellants and static firing of Sparrow rocket motors in 2011 and emissions from surface and soil-covered OD in 2012.

Using this innovative technology, DoD now has the capability to characterize air emissions from full-scale OB/OD operations and generate accurate munitions disposal emission factors. These emission factors will enable OB/OD facilities to calculate their mass emissions and operate at levels that comply with environmental regulations and protect human health and the environment.