EPA Puzzled By Tons Of 'Missing Mercury' At Plants

WASHINGTON — More than two years after the Environmental Protection Agency admitted it does not know what happens to tons of toxic mercury used in chemical plants in Georgia, Ohio and four other states, the agency says it is still "reviewing" the matter.

The plants, which use mercury in a century-old process to produce chlorine and lye, appear to be purchasing tons of the metal for which neither they nor EPA can account.

"This represents somewhat of an enigma," EPA declared in 2004 when it approved a rule change that, as of this month, removed limits on the amount of mercury that so-called "chlor-alkali" plants are allowed to release.

In their place, the agency imposed "housekeeping" requirements designed to ensure that the toxic metal is contained.

Environmentalists, medical associations and others say the chlor-alkali plants' missing mercury represents a severe danger, especially to unborn children, whose developing brains can be damaged if they are exposed to micrograms of the metal in their mothers' wombs.

Fetuses are exposed to the metal when their mothers consume contaminated fish, and most states have advised against eating fish from mercury-contaminated streams.

The American Medical Association in November noted that "there is a huge discrepancy between what the industry reports having consumed and what it reports having released."

The physicians' group noted that 53 chlor-alkali plants have switched to technologies that do not use mercury, and said it "encourages reduction in mercury use in manufacturing wherever possible."

Owners of the remaining six mercury plants reported releasing 6.7 tons of mercury into the air and water in 2005, according to the Chlorine Institute, a trade association that represents them.

The association said another three tons could not be accounted for. In 2004, the association reported to EPA that seven tons were unaccounted for, and in 2003 it said 30 tons were unaccounted for.

Even without the "missing mercury" in 2005, reported emissions from the six plants represent nearly one-seventh as much mercury pollution as the 48 annual tons attributed to approximately 450 coal-burning power plants in the country.

Yet, mercury from the chlor-alkali industry has received much less attention than mercury from power plants.

The Savannah Riverkeeper, an Augusta, Ga.-based environmental group, has launched a petition campaign to pressure the Olin Corp. of Clayton, Mo. to either close the chlor-alkali plant it operates near Augusta or convert it to a process that does not use mercury.

"They use tons of mercury, and it is too hard to control for them to keep it out of our air and water," said Frank Carl, executive director of Savannah Riverkeeper.

"Ninety percent of the chlor-alkali plants in America have shifted to non-mercury technology, and they are saving money in the process, because it takes less energy to operate the new plants," he added.

The other five chlor-alkali plants that still use mercury are a Pioneer-Americas plant in St. Gabriel, La.; an Olin plant in Charleston, Tenn.; an ASHTA Chemicals plant in Ashtabula, Ohio; a Vulcan Chemicals plant at Port Edwards, Wis., and a PPG Industries plant in New Martinsburg, W.Va.

An Olin spokeswoman said the Augusta plant accounts for all of the mercury it uses and that the company does not plan to change or close the facility, which employs about 300 people.

"We have reduced our mercury emissions by 87 percent in the past 20 years," Elaine Patterson said. She said the company carefully accounts for all of the mercury it uses and sees "no reason to convert."

In an effort to resolve the dispute, Richmond County Commissioner Andy Cheek has arranged a meeting of company representatives and Savannah Riverkeeper members this week.

Since 1894, chlorine and lye have been produced at chlor-alkali plants in a process by which an electric current is passed through huge vats containing salt water.

The current first passes through a layer of liquid mercury that slides along the bottom of the vats, known as "mercury cells."

An individual cell may contain as much 8,000 pounds of mercury, and plants have an average of 56 cells, according to a report on the "missing mercury" issue last year by the Natural Resources Defense Council.

Since the chemical reactions involved generate heat and mercury evaporates easily, environmentalists suspect the missing mercury is escaping from the plants and not being measured.

Lenny Scott, director of technology for Olin, said in a telephone interview that the Augusta plant has been installing larger cells, which result in less pollution, and has had to purchase additional mercury for them.

"The differences between what we purchase and what we report is potentially explained by adding larger, more efficient pieces of equipment, which require us to use more mercury," he said.

He said that "over the last five to eight years, we've been on a program to continuously upgrade our equipment."

However, in data provided at EPA's request in 1998, Olin reported that from 1993 to 1997, it purchased 100,000 pounds more mercury than the approximately 7,400 pounds it reported releasing into the environment during those years.

Asked how this difference could be accounted for, Scott repeated that the company had been working to improve its operations.

In fact, he said that in recent years, the Augusta plant has emitted less than one-third as much mercury as EPA regulations permitted.

Measurements by scientists from EPA, Oak Ridge National Laboratory and other agencies at the Augusta plant have failed to find large enough quantities of "fugitive emissions" to account for missing mercury.

However, reports of two studies contained the caveat that measurements may not have been accurate, and further investigation was needed.

On the Web:

Savannah Riverkeeper: www.savannahriverkeeper.org