Mountains of mercury

The whole matter of the missing mercury might have slipped by, unnoticed. But Patty Jacobs, a permit writer for the Oregon Department of Environmental Quality, decided to check the math.

In 2005, after a federal mercury-reduction rule was passed (since vacated by the U.S. Court of Appeals), Jacobs and the nation's other regulators began paying attention to coal-fired power plants, a major source of the mercury building up in the nation's waterways. The Boardman plant, a coal-fired facility 160 miles east of Portland, reported that it had put 281 pounds of it into the air that year. That ostensibly made the plant the largest mercury source in Jacobs' territory, which covered much of central and eastern Oregon.

Even small amounts of mercury can cause harm. Once the metal is deposited in a lake or river, bacteria convert it to an organic form called methylmercury. From there, it works its way upward through aquatic microorganisms and insects, intensifying in the tissue of fish and, eventually, in the animals and people that consume them. Exposure to high levels of mercury causes reproductive declines and developmental problems in wildlife. Human babies exposed in utero suffer an increased risk of neurological disorders, including attention deficit and impaired coordination. In adults, mercury consumption has been linked to memory loss, muscle tremors and impaired vision.

To learn more about other mercury sources in her territory, Jacobs dug into the Environmental Protection Agency's Toxic Release Inventory, a public repository of emissions data. She learned that in 2005, the Ash Grove cement plant, located in the town of Durkee in eastern Oregon, reported emitting 631 pounds of mercury — more than twice the amount reported by the Boardman power plant.

To Jacobs, a self-described "numbers geek," that was a red flag. Checking the T.R.I. figures against Durkee's 2005 air-quality permit, she estimated that the plant's total mercury emissions should have been closer to 1,400 pounds. 

Jacobs contacted the company to double-check her findings. Ash Grove performed its own tests and found that its actual emissions were even higher — about 2,500 pounds per year.

That firmly established the Durkee facility as the nation's dirtiest cement plant in terms of mercury, responsible for 10 percent of the mercury emitted by the 101 Portland cement plants across the country. (Twenty-four are located in Western states.) Perhaps more startling, this amount was 800 pounds greater than the amount of mercury reported by the nation's top mercury-emitting coal plant in the same year.

Mercury released from the Durkee plant over the last 30 years has been deposited both regionally and globally. Yet the attendant ecological and health impacts are just now beginning to be understood. The story of Ash Grove's vast and underreported emissions offers insight into an industry that has operated for years with little federal oversight and no accounting for several of its most toxic byproducts. It also illustrates the critical and prolonged failure of the EPA to apply the Clean Air Act to one of the nation's largest and dirtiest industrial sectors.

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