Finding chemical compounds in the air
Army monitoring team proves Cape Ray decontamination with sample analysis
By ECBC Public Affairs
ABERDEEN PROVING GROUND, Md. (Aug. 12, 2015) — Finding target agents like mustard and DF in a given sample of air can sometimes be like finding a needle in a haystack. Chemical compounds litter the air waves, making it hard to distinguish hazardous agents from pollutants typically found in the air. When working on an operational ship like the MV Cape Ray, the degree of difficulty becomes magnified.
Everything from grease and dirt, to cleaning products and paint were in the atmosphere due to the ship’s crew constantly performing maintenance work. Not to mention, the engine room was located directly below the main trailer deck where two Field Deployable Hydrolysis System units were performing neutralization.
“Every one of those activities is collected on the DAAMS (depot area air monitoring systems) tubes,” said Brandon Bruey, U.S. Army Edgewood Chemical Biological Center chemist. “That has the ability to mask the signal of mustard and impact what gets picks by our monitoring equipment.”
Hundreds of air and wipe samples had been collected during the 24/7 real-time monitoring of the operation.
It’s a tedious process that ECBC environmental monitoring personnel have mastered over the decades, and with new technology, they have improved the time, accuracy and safety of chemical demilitarization missions. Two near real-time systems — miniature continuous air monitors (MINICAMS) and a total phosphorous analyzer (TPA) — were used during the mission to destroy more than 600 metric tons of Syria’s declared stockpile on board the Cape Ray in the summer of 2014. In order to accurately monitor mustard and DF during operations, Bruey first had to prove the equipment could detect the desired agent in that kind of environment.
Monitoring equipment was set up at every exit of the main trailer deck and at key points along the chemical agent transport path throughout the ship. Hundreds of air and wipe samples were taken when the crew was in Rota, Spain this past spring, making final preparations, as they awaited the shipment of Syrian chemical agent.
“I don’t think we realized how dirty the environment was until it showed up analytically on our instruments,” Bruey said. “To prove we could detect agent in those conditions, we used a standard of dilute mustard to spike a clean DAAMS tube. We then pulled air from the environment through the tube and analyzed it to see if we could detect mustard. We knew it was present because we had purposefully put it on there, but could we see it?”
Not at first.
While this might have given some teams a bit of anxiety, ECBC’s CBARR team did what they do best: adapted to unanticipated conditions and rose to the challenge. The time docked in Rota, Spain allowed them to fine tune equipment to achieve more conservative monitoring requirements, and detect chemical agent at lower levels and more locations on the Cape Ray. Modifications included special filter cartridges and working with the maritime crew members to accommodate their maintenance schedules in order to limit its impact on neutralization operation hours.
“The first time we actually saw the system work and we saw what we were expecting to see, we could all exhale. By the time the operation was given the green light, we were ready,” Bruey said.
Double the Challenge
There were two different monitoring campaigns for mustard and DF during the FDHS operation, each of which required different instrumentation. According to Bruey, DAAMS and MINICAMS were used for mustard but since MINICAMS cannot detect DF, the TPA was used to clear the ship for the toxic agent precursor. TPA was used at Pine Bluff Arsenal in Arkansas at the binary destruction facility and had been successful in monitoring DF. An ECBC operator who had been involved in that operation was familiar with the instrument and had experience developing methods for accurate detection. That knowledge was used to calibrate the TPA and ended up detecting a pin-point leak that had occurred under engineering controls, and might not have otherwise been noticed.
By the time the Syrian stockpile was safely destroyed, hundreds of air and wipe samples had been collected during the 24/7 real-time monitoring of the operation. The next step was to decontaminate the Cape Ray to the worker population limit (WPL), so that non-chemical workers at port could work safely around the main trailer deck. Air and wipe samples were analyzed and confirmed to WPL levels, which are extremely low exposure levels that are safe and not expected to produce any adverse health effect. Once the ship returned to port in Virginia, the Cape Ray had to be cleaned to the general population limit (GPL) for sulfur mustard, which is 0.00002 mg/m3, or 20 times lower than WPL. This monitoring is extremely low for mustard and required ECBC to use exceptionally sensitive equipment to verify decontamination.
“CBARR has always been able to adapt and get done what needs to get done,” said Wyatt McNutt. “The monitoring requirements grew increasingly more conservative as the mission went on, and we’ve been able to meet all of those decontamination levels.”
One Last Sample
In December 2014, Bruey and McNutt traveled to Norfolk, Virginia, where the Cape Ray was docked, and conducted final sample collection to confirm the ship had been certified free of HD to the GPL. They also collected wipe samples for HD and methylphosphonic acid (MPA), a DF breakdown product. According to McNutt, MPA was used as a clearance indicator at roughly 25 locations on the main trailer deck and more than a dozen other high traffic areas around the ship’s engine rooms, galley, cargo and berthing areas. ECBC had the historical knowledge of working with this method and clearance level at other U.S. chemical demilitarization facilities.
This was the last step before DOD could provide certification to the U.S. Maritime Administration so the Cape Ray could be returned to Reduced Operating Status (ROS-5). The Cape Ray is one of 46 Ready Reserve Force vessels in the Department of Transportation’s fleet that are maintained to meet the nation’s sealift needs for national and homeland security.
“CBARR pulled off this seemingly impossible mission and made it look easy. From a sustainability standpoint, it puts us at the forefront if there is ever the need to complete a mission like this in the future,” Bruey said. ECBC does more than just eliminate harmful chemicals by executing demilitarization missions; it cleans up the environment and makes it safe for people to live in the wake of their destruction. From beginning to end, ECBC provides sustainable lifecycle solutions.
Editor’s note: The Edgewood Chemical Biological Center is part of the U.S. Army Research, Development and Engineering Command, which has the mission to ensure decisive overmatch for unified land operations to empower the Army, the joint warfighter and our nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.
Originally published at www.ecbc.army.mil.