PICATINNY ARSENAL, N.J. --To help ensure public safety, Picatinny engineers are collaborating with multiple government agencies in an attempt to use Unmanned Aerial Systems (UASs), or drones, to sample open-burn emissions at military facilities.

Both Radford Army Ammunition Plant (AAP) in Radford, Virginia and McAlester Army Ammunition Plant in McAlester, Oklahoma, each recently wrapped up 10-day sampling of efforts to determine emission factors open burning of propellants.

Though much of the manufacturing waste at Radford is disposed of through incinerators--during which emission smoke is processed through an air pollution control system before being released-a portion of propellant waste is still open-burned, in accordance with environmental permitting.

When conducting open-burning, engineers currently use Environmental Protection Agency (EPA)-approved emissions models and software to predict what emissions will result from the type and amount of material open-burned.

"We have been using conservative computer modeling to dictate what we burn. So if we burn 500 pounds of X - we should get this much Y in the air," said Charles Saks, Public Affairs Officer at the Radford AAP.

"We hope to prove that the years of using the conservative computer model has been adequate in protecting the health and welfare of the people in and around Radford," he said.

Radford protects the population because safety is the plant's number one priority, Saks added, noting that many factors, such as weather and wind speed, determine whether it is safe to open-burn.

"Radford is exploring technologies to replace the current permitted and effective open-burning solution. However, until those new technologies are underway, there are no closed disposal alternatives for the demilitarization of bulk propellants that have been proven to meet safety and environmental standards for the materials at Radford AAP," said Jorel Alberti, an engineer at the Armament Research, Development and Engineering Center at Picatinny.

Alberti is the ARDEC lead on developing potential new technologies to replace open-burning at Radford.

Two closed disposal technologies currently in the design phase -- an energetic waste incinerator (EWI) and a contaminated waste processor (CWP) -- will reduce emissions to nominal amounts.

The sampling of the Radford Open Burning Grounds emissions would help the facility to maintain its mission in two ways:
-- Provide data for use in discussions with the state environmental regulatory agency pertaining to the renewal of RFAAP's permit to operate the open-burning grounds while design and construction of the new EWI/CWP system progresses.
-- Share data with the public to foster good will and as a show of good faith in addressing environmental concerns.

Previously, the Army sampled emissions by placing testing equipment onto tethered aerostats, or balloons, and maneuvered the aerostats into open-burn smoke plumes. However, the aerostats are less maneuverable than UASs, so Picatinny engineers hope that UAS testing will be more efficient at getting into and staying in the plumes.

"Now they're doing the same sampling procedures but they're attaching the sampling equipment to an unmanned aerial vehicle, or a drone, which should be more efficient," said Alberti.

EPA INVOLVED IN SAMPLING
Since 2010, the EPA's Office of Research and Development (ORD) has worked with multiple DOD organizations to sample open-burn emissions at three sites in the U.S. and Canada.

The ORD has developed a suite of technologies for sampling emissions from open burning which have been applied toward understanding Open-burn and Open Detonation emission constituents from both aerial and ground-based sampling platforms.

The unmanned aerial vehicle sampling is the result of collaboration across multiple agencies.

The Department of Defense commissioned the National Aeronautics and Space Administration, or NASA, to fly their UAS into the plumes while carrying the ORD samplers. Participating scientists from the University of Dayton Research Institute oversee the sampling for the Army.

"The drone flies into the plume as soon as the burn is set. What they're monitoring from the ground is the concentration of carbon monoxide/carbon dioxide," Alberti said. "They know the recipe of each of these burns. They know what kinds of materials are being released and they use that to trace when they have enough sample to be representative.

"(The EPA) would monitor the emissions from the ground and NASA would use a GoPro (camera) that was attached to the drone itself to make sure they were in the plume," Alberti added. "After each burn, the drone would come back down, scientists would change out the sample gear, install new sample equipment and fly the drone back up for the next sample."

UAS sensors respond to gas concentrations. For example, home carbon monoxide and carbon dioxide detectors are sensors. In addition, the EPA tested particles on filters.

Brian Gullett from EPA's Office of Research and Development believes that this is an ideal application for a UAS: "…when you have open-burning propellant that may only last for 10, 20, 30 seconds, the ability to move the sampler into the plume is greatly enhanced by having the autonomous location controllable UAV or drone."

The sampling data taken are currently undergoing analysis, which is expected to conclude in December.

"Once the data comes in, we must make sure that that equation makes sense -- here's what was burned, here's how it should work when things burn and combust," Alberti said. "Here's the data we got and making sure it all adds up. Because this drone sample collection method employs such a new technology, we want to make sure this does represent what's burned there and that the data is valid before using it at other locations."

If the sampling from McAlester and Radford is validated, the technology could potentially be used at other military facilities.

"Now that we've seen this technology, we're trying to leverage it in as many places with open-burning as possible," she said, assuming the sampling from McAlester and Radford is representative.

DEMILITARIZATION:
Unlike Radford, which burned manufacturing waste, McAlester Army Ammunition Plant used drones to test emissions of open-burns from demilitarization of stockpiled conventional ammunition.

The data from the drone sampling will be used to validate and improve open-burn emissions factors, as well as validate and improve EPA approved computer-based dispersion modeling applications that are currently used throughout the Army in support of the open-burn permitting process, said Orest Hrycak, Chief Engineer, Product Director, Demilitarization at Picatinny Arsenal.

Product Director, Demilitarization, an organization within the Office of the Project Director Joint Services, oversees the demilitarization of all the Department of Defense's conventional ammunition and tactical missiles. In the U.S., demilitarization primarily takes place at seven depot facilities and four contractor facilities.

At McAlester AAP, a Joint Munitions Command (JMC) led Demil Research Development, Test and Evaluation (RDTE) project is utilizing the NASA drone to sample emissions emitted during open burning of 155 mm artillery and mortar propelling charges.

"We are executing this project to make sure that the modeling software is correct in predicting that the generation and dispersion of the emissions that are actually being released to the environment," Hrycak said. "The open burning of ammunition is a permitted activity and each demil facility reports emissions on an annual basis to the EPA in compliance with permit requirements, address worker and public safety, and for protection of the local environment."

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The U.S. Army Armament Research, Development and Engineering Center is part of the U.S. Army Research, Development and Engineering Command, whose mission is to provide innovative research, development and engineering to produce capabilities that provide decisive overmatch to the Army against the complexities of the current and future operating environments in support of the joint warfighter and the nation.