Establishing control at an incinerator site.



At the height of the Cold War, the United States began creating and stockpiling chemical weapons in an effort to deter other countries from using chemical weapons of their own against the United States. The weapon stockpile stored at eight locations in the continental United States and at Johnston Atoll in the South Pacific Ocean dates back over 50 years. These weapons are slowly deteriorating and now present an increasing storage risk, which prompted the Army to formally establish the Chemical Stockpile Disposal Project (CSDP) to oversee the disposal of the nation’s chemical weapons stockpile while providing protection to human health and the environment. In 1985, Congress directed the U.S. Army to destroy its entire stockpile of chemical weapons. Johnston Atoll is currently going through closure, having destroyed its last chemical munition in November 2000.

In June of 1999 the Army began construction on another facility at Pine Bluff Arsenal in Pine Bluff, Ark. Located 35 miles southeast of Little Rock, Pine Bluff stores 12.3 percent of the nation’s original stockpile of chemical weapons, totaling 3,850 tons of chemical agents that are stored in either bulk containers with no explosive components or in munitions such as mines and rockets.

The Army’s goal is to operate chemical agent disposal facilities that will protect the community and environment as well as its workers and families that live on military installations. Its prototype incineration facility was built at Johnston Atoll where, according to independent scientific studies, no detectable harmful impact can be found on the fish and wildlife that live there.

Incineration currently is the only proven process for safely treating and disposing of the various types of weapons contained in the stockpile including agents, explosives and metal parts. The process has been used successfully by the Army for more than 20 years and is endorsed by the National Research Council, the Centers for Disease Control and Prevention, and the Environmental Protection Agency.

Engineering controls are the first line of defense in protecting the public when a chemical agent is being destroyed, so, in September of 2000, Pine Bluff Arsenal called on JVH Construction in Olympia, Wash., because of the company’s experience working with incinerators and construction surveying. “The core specs are extremely tight on this job,” says survey co-manager Stuart Dallas, LSIT. “We’re attempting to build a first-order job and maintain the strictest accuracy that we can.”

To further complicate matters, the incinerator is actually a series of three furnaces, each with its own filtration system, spread through a five building facility connected by a maze of piping over a 17-acre jobsite. At the front end of the job, JVH had to set up construction baselines with tolerances of 1/16" and less. This requirement was effective for anchor bolts, inbeds, penetrations, wall lines, spoolwork and the hundreds of miles of piping provided by several different suppliers.

“Building a facility like that requires knowledge and high precision equipment to ensure the smallest possible margin of error,” Dallas says. JVH Construction initially used several different types of surveying equipment, but needed a high precision, high quality one-second model. Because of this, they chose the Nikon DTM-550 Total Station (Nikon Instrument Inc., Melville, N.Y.) to achieve their tolerances. JVH set up first-order baselines through traverse and resection methods, checking with Army Corp of Engineers monumentation. “Actually, we had to adjust theirs, believe it or not,” Dallas says.

The biggest challenge, according to Dallas, was in getting the buildings to “fit together.” JVH used two main baselines, one running plant north to south, one running plant east to west, aware that the area of most concern about a state plane is where the two axes meet. From the baselines, they ran sub-baselines through each building. The interiors were broken down into a grid. From one end of the Container Handling Building at the far west to the far end of the Process and Utility Building a 1/4 of a mile down, JVH was able to achieve less than 1/16" in their control.

In addition to the strict construction guidelines and to ensure that no hazardous materials are released when the agents are incinerated, the Army will employ successive layers of specially designed containment, pollution abatement, monitoring and filtration systems in its disposal facilities. These include an explosion containment room where chemical weapons are isolated and disassembled, a pollution abatement system that cleans furnace exhaust gases of particulates, and an automatic chemical agent monitoring system that monitors the air for minute traces of chemical agent within the facility and the surrounding environment.

JVH has had to meet the challenge of consistent controls in confined spaces inside the complex. “When you get into a room that needs grid from our general controls and it’s 9 x 9 off in a corner with a 22-foot wall, it’s nice to know you don’t have to take a series of shots to come to one conclusion. We’ve had that luxury,” Dallas says.

The Pine Bluff incineration complex is now a fixed build facility, a pre-built, “fit” building. Dallas and his co-manager’s current responsibility is support rather than construction. As the piping and machinery are installed, Dallas says, “We have to be able to say ‘this routing will work,’ or ‘this is an alternative you need to use because you have conflict in this particular area.’”

In this as-built support stage, JVH will be actively involved at Pine Bluff for two more years. Despite the high standards of construction that are going into this state-of-the-art incinerator, its use is finite. There are no plans for the Army to use the facilities to destroy other materials from the Department of Defense or from the public sector. As with all other CSDP demilitarization facilities, the incinerator will be used to dispose of the stockpiled weapons present at that location. Then it will be dismantled.

JVH is justifiably proud of the work they’re doing at Pine Bluff Arsenal. “We’ve built in so many safeguards that we haven’t had any surprises. Considering the current attention being paid to chemical and germ warfare, we don’t need any more surprises,” Dallas says.