After Anniston's chemical weapons incinerator begins destroying nerve agent next year, it undoubtedly will emit pollutants into the atmosphere.
But what and how much will it emit?
Army officials say known emissions will be minor and will fall under the levels established by the Environmental Protection Agency and the Centers for Disease Control and Prevention.
Incineration opponents say the full breadth of emissions and their impacts cannot be known.
"Do I have emissions?" said Tim Garrett, project manager of the incinerator. "I can't deny that. It's a combustion process. But burning wood or driving a diesel truck is worse than this facility."
That is based on a number of false assumptions, says Craig Williams, head of the anti-incineration Chemical Weapons Working Group.
"They can't identify a significant portion of the emissions, they assume they are harmless, and they don't consider what is emitted already in Calhoun County and the synergistic impact of these emissions," he says.
Most of what will be emitted from the incinerator stack at the Anniston Army Depot is expected from known data to be water vapor, nitrogen, oxygen and carbon dioxide. The debate comes down to less than one percent of expected emissions, comprising substances such as benzene, TCE, dioxins and furans, as well as metals such as arsenic, lead and mercury.
The results of an upcoming trial burn at Anniston's incinerator will determine the rate at which the Army can destroy nerve agent here. It is like putting as many logs as possible in a wood stove and measuring the amount and content of the resulting chimney smoke. The final burn rate will be approximately half the rate at which the Army has demonstrated it can safely burn, officials say.
After the trial burn, the Army will have a more complete picture of how many and what kinds of emissions come from the incinerator. An engineer then will plug that data into the health-risk assessment to see what the emissions exposure is to the surrounding community.
"The health-risk assessment dictates my emissions, pure and simple," Garrett said.
The assessment includes scenarios such as the exposure of a subsistence farmer outside the incinerator's gate, a fisherman on the Coosa River and a child living near the depot.
"The worst-case scenario is the subsistence farmer, and his exposure is 50 times lower than the EPA guidance," Garrett said.
But those are only the emissions you know about, says Williams of the Chemical Weapons Working Group.
Williams believes only 20 percent of the actual emissions from chemical weapons incinerators are identified. The Army agrees that some of the compounds coming from the smokestack are unidentified, but disputes that they constitute 80 percent of the emissions.
"They can only deal with what they know," Williams said. "Under the current standards they are certain of the 20 percent that are targeted. What is the standard for the other ones?"
If the majority of the known compounds are hazardous to human health, "It is ludicrous to assume the others (the unknown compounds) don't have a negative health impact."
According to a 1998 EPA report on hazardous waste incinerators, a large number of emissions can't be identified and "the current sampling and analytical schemes for characterizing hazardous waste combustion emissions are inadequate and provide an incomplete picture of the emissions profile."
Although many chemicals are counted in percentages or parts per million, unknown compounds are often on the level of parts per trillion, said Mike Durham, chairman of the American Waste Management Association's emissions control division.
"They are very difficult to even measure," he said. On a gas chromatograph it may only register as a slight blip, often indistinguishable from background hiss.
Because the monitoring equipment can't measure it, Williams said the Army should use the "precautionary principle," which states, "If you can avoid releasing this stuff, you should avoid it."
There is no perfect guaranteed solution to disposing of chemical weapons, Garrett said, but incineration is a proven technology with no adverse impact on the environment. For proof, Garrett says, you need look no farther than Johnston Atoll in the South Pacific, site of a recently closed incinerator.
"The wildlife has gone ballistic there," he said. And unlike Johnston Atoll, the Anniston incinerator will have a carbon filtration system that may remove some compounds from the plant's emissions.
To ensure that the emissions rate stay within an acceptable range during incineration, monitors will measure carbon monoxide and oxygen. Other sensors will continually monitor for nerve agent.
Because of the variety of compounds coming from the smokestack, it would be practically impossible to do measure everything, Garrett said, but carbon monoxide serves as a good indicator as to whether the incinerator is destroying everything.
Carbon monoxide comes from incomplete combustion, much like a car engine. When carbon monoxide levels stay within range, Garrett said he is assured that he is complying with his emissions goals.
Carbon monoxide is a good indicator of complete combustion, Durham said, but it is not always the best indicator of the destruction of heavy metals.
Williams contends that within the acceptable carbon monoxide range there can be a wide spectrum of toxic emissions. He agrees that not everything can be monitored, but he believes the Army should monitor for certain compounds, such as lead, mercury and PCBs, already found in high amounts in the Anniston area.
"There's no reason that can't be done," he said. Of further concern, he said, should be how the compounds coming from the incinerator will react with emissions from the iron foundries and chemical factories already in Calhoun County.
"Theoretically you could stack 15 incinerators one next to the other, and as long as they all individually met the emissions requirements they would receive a permit," he said.
New, more stringent standards may be coming from the EPA, Williams said.
Garrett said the incinerator could adapt to those standards and operate accordingly.
The Army is not certain about the effect of a Washington D.C. federal appeals court ruling on the incinerator. The court ruled that new hazardous waste incinerators must comply with the best 12 percent in existence and have the best available technology to meet emissions guidelines.
It's an attempt to get "all the jalopies off the road," said Jane Williams, chairwoman of the Sierra Club's National Waste Committee.
Although she was unaware of the specific technology in Anniston's incinerator, Ms. Williams said it should have stopgaps to prevent the incinerator from stack bypasses and excursions, essentially periodic belches of emissions.
Because of the Army's intention to burn nerve agent as quickly as possible, Ms. Williams said she worries that such belches will occur. With the best technology, those occurrences would be minimized.
Marilyn Daughdrill, spokeswoman for the Army's incineration program, said that the ruling's impact is unknown but that the Army would meet any requirements set forth by the law and get the "maximum achievable technology."
