
Oceana has released a groundbreaking report on one of the world's biggest mercury polluters, mercury-based chlorine plants. A summary is provided below, or you can download the complete report, as well as special state- and country- specific appendices:
State Summaries: European Summaries: |
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As the extent of mercury contamination in our environment, our bodies and our food comes to light, concern over mercury pollution is increasing. While most media and public attention has focused on coal-burning power plants, most people remain unaware that a small subset of the chlorine industry makes a major - and completely preventable - contribution to the global mercury crisis.
Chlorine is a chemical building-block used in everything from swimming pools to plastic tents to paper towels. In 1894, a process was devised to produce chlorine by pumping a saltwater solution (brine) through a vat of mercury, or "mercury-cell," that catalyzes an electrolytic chemical reaction. Newer technologies that do not use mercury have been developed, but a number of plants around the world continue to use the outdated technology.
All mercury-cell chlorine plants are required to report their mercury releases to air, water and offsite disposal each year. In the U.S., the industry's self-reported figures are high enough to rank the chlorine plants using mercury technology 5th in mercury emissions among all industries releasing mercury into the air. It is very likely, however, that the quantity of mercury these few chlorine plants actually emit is much higher.
In fact, releases from chlorine plants may even approach those from power plants, the presumed greatest source of mercury releases to air, in the U.S. and Europe. The chlorine industry's reported figures for mercury releases to air are based in part on monitored stack emissions, but they also include the industry's estimates of the amount of mercury that evaporates during routine operations and escapes through unmonitored ventilation systems and other leaks - so-called "fugitive emissions."
According to the company reports, chlorine plants' fugitive emissions are nine times greater than monitored mercury releases. Yet this is an estimate only, and there is good reason to suspect that fugitive mercury emissions are even greater than the industry suggests.
Annually, the industry uses, or "consumes," far more mercury than it reports having released. But mercury does not get used up in the process of making chlorine. Only small amounts of it end up as impurities in the product. Since mercury is an element, it does not break down into other substances. It has to go somewhere. The lost mercury could be in the air, in the water, in the soil, or in the chlorine facility itself.
The discrepancy between what the industry reports having consumed and what it reports having released is substantial, to say the least:
The industry contends that the missing mercury seeps into factory infrastructure and equipment. However, what little evidence there is suggests that this explanation is inadequate. A recent plant closure in Maine provides one example. When the pipes and equipment were cleaned out, 33 tons (30 metric tons) of mercury were still missing. It is far more likely that much of the missing mercury escapes as unmonitored fugitive emissions.
Even if only half of the lost mercury is released to the environment in this way, the mercury-based chlorine industry would rival coal-fired power plants as the greatest source of mercury pollution in both the United States and Europe.
There are nine mercury-cell chlorine plants still operating in the United States, located in eight states: Alabama, Delaware, Georgia, Louisiana, Ohio, Tennessee, West Virginia and Wisconsin. According to the industry's own reported estimates, the average mercury-based chlorine plant released 1097 lbs (499 kg) of mercury to air in 2002. In the same year, on average, power plants in the United States released a total of 186 lbs (85 kg) of mercury to air. Of the 100 power plants with the highest mercury emissions, the average was 586 lbs (266 kg). More simply put, according to industry reported figures (which do not include any of the "lost" mercury), the average mercury-based chlorine plant released five times more mercury than the average power plant, and twice as much on average as a large power plant in 2002. Other statistics are equally startling:
Mercury pollution from chlorine plants is not limited to the United States. The chlorine industry is also a major source of mercury emissions in Europe. There are 53 mercury-cell chlorine plants currently operating in the European Union (EU) - 44 in Western Europe, seven in new (as of 2004) EU member states and two in countries joining in 2007.
Statistics from 2001 show the following:
This 19th century mercury-cell technology is antiquated, unnecessary and dangerous. Two alternative production methods exist: membrane cell and diaphragm cell. Most of the U.S. chlorine industry uses the newer technologies - in fact, 90% of U.S. chlorine is produced using mercury-free processes.
Even though sixty percent of the European industry still uses mercury-cell technology, the European Commission agreed in 1996 to take action to prevent releases of pollutants like mercury to water, air or land from industrial activities. Through the Integrated Pollution Prevention and Control Directive (IPPC), the Commission required facilities to follow what are called Best Available Techniques (BAT), a concept and term similar to one used in the United States. Because cleaner, more efficient methods of chlorine production are available, the mercury-based process is not considered to be BAT, and as a result European chlorine facilities are required to phase out the use of mercury by October, 2007.
Eliminating mercury technology does not mean that plants must be closed. Many plants around the world have successfully converted from mercury-based to cleaner, newer technologies - a conversion that can lower plants' energy and labor costs while increasing capacity. According to Euro Chlor, companies typically save 15% on their electric bills and 10% on total energy bills when they convert. Conversion of one Alabama facility also reduced hazardous waste generation by 92%.
A small portion of the chlorine industry is a major mercury source that has been almost completely ignored, yet this industry can completely eliminate its mercury pollution. Europe is moving toward an industry-wide transition to mercury-free technology; the U.S. should do the same. By bringing their production processes into the 21st century, chlorine manufacturers can greatly reduce the amount of mercury that is released and carried into our environment, our communities and our food.