« Return to this article

Know the West

Mountains of mercury

The pollution costs of cement production


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.

The Durkee facility, Oregon's only cement plant, is operated by the largest U.S.-owned cement company, Ash Grove Cement. In 2008, the company reported $1.2 billion in sales. That same year, it also reached an agreement with the state of Oregon to cut its mercury emissions by installing a carbon injection system.

I visited Durkee in November, hoping to see the new $20 million mercury control system, reportedly in the initial phases of construction. But my request for a tour was denied. Jacqueline Clark, Ash Grove's head of public relations, e-mailed me that the Durkee plant was facing imminent layoffs and could not accommodate a tour. Indeed, a few months earlier, Ash Grove announced plans to halt production at its nine U.S. plants, including Durkee. (In early December, the company temporarily ceased production and laid off more than half of the plant's 115 workers.) Company officials said they might close the facility altogether if proposed federal regulations on mercury are enacted next year.

Although Ash Grove refused to allow a visit, Justin Hayes, the program director of the Boise-based Idaho Conservation League, suggested that a look at the facility's exterior might be instructive. So we made the hour-and-a-half drive from Boise on a warm afternoon. The plant itself is situated on the west side of Interstate 84, tucked into a steep-sided valley along a bend in the Burnt River.

Hayes has been key in the regional fight against mercury pollution. He has negotiated mercury reductions with large industrial players such as Monsanto, and his scientific sleuthing helped to reveal massive emissions from northern Nevada gold mines. Hayes is particularly concerned about the Durkee plant because metropolitan Boise, with its rapidly growing suburbs, sits less than 100 miles downwind. An avid fisherman, Hayes also bemoans the fact that many of the area's world-class fisheries have become mercury repositories.

On the way to Durkee, we passed the husk of the old cement plant at Lime, which operated from 1922 to 1980. Hayes commented that it would make a good set for a post-apocalyptic, Mad Max-type action film. He's right, but the site is unlikely to be used for anything anytime soon. According to the Oregon Department of Environmental Quality, its soil is heavily contaminated with PCBs, arsenic, residual petroleum and hydrocarbons –– the toxic byproducts of six decades of cement manufacturing.

A little past Lime, we pulled into a dirt parking lot outside the Durkee plant's main gate. Above us, a high-pitched metallic whine emanated from a conveyer chute: crushed limestone being transported from quarry to kiln. A layer of light gray cement dust — 4 or 5 inches deep — coated a concrete highway divider. Hayes scooped up a handful and let it pour out of his fist. "The dust control could be better here," he said. "Don't you think?"
Mixed with gravel, sand and water, cement becomes concrete, a material as ubiquitous and seemingly benign as you will find in the built landscape. It is fundamental to growth — strengthening structures, hardening highways and sidewalks, underlying our cities like synthetic bedrock. In 2008, American plants supplied a staggering 189 billion pounds of raw cement and clinker, a cement precursor. Although that figure represents a 30 percent decline from 2006, when construction was still surging, enough cement was made in the U.S. last year to spackle an area roughly the size of Delaware in pavement a quarter-inch thick.

Portland cement, the light gray powder found in everything from concrete to stucco, accounts for more than 95 percent of the cement produced in the U.S. The recipe for creating it has changed little in 150 years. It still requires mountains of calcium carbonate or limestone, which, in eastern Oregon, tends to be loaded with mercury derived from the region's history of volcanism. Volkswagen-sized chunks of the rock are blasted loose, hauled in goliath front-end loaders and fed into a series of crushers. Then the limestone fragments are powdered and mixed with metal oxides that help determine the cement's compressive strength and hardening time.

This mixture is then sent to massive kilns — some as long as football fields — which reach temperatures of at least 2,500 degrees F. During heating, the limestone is chemically transformed into "clinker," pebble-like pellets that are mixed with a little gypsum and ground into the fine flour we know as cement. The process releases large quantities of carbon dioxide and — in the case of Durkee — vast amounts of mercury vapor. Mercury is also released from the coal burned as fuel in the kiln, but the amount is minuscule compared to what's baked out of the limestone. 

The mercury leaves the stack in one of three forms — as an elemental gas, a divalent gas, or as a sort of varnish coating dust particles. Elemental mercury rises high into the atmosphere, merging with an ethereal "global pool" of mercury. It can remain aloft for a year or more before falling out of the atmosphere. The divalent and dust-bound mercury is heavier and tends to precipitate nearby. Canadian studies suggest that recently deposited divalent mercury is more "reactive" than elemental mercury and therefore more readily transformed to methylmercury. 

This heavier, more reactive mercury shows up in high concentrations in the Burnt River, which roils blue and chalky past the plant. Twenty-five miles downstream, it merges with the Snake River at Brownlee Reservoir, on the Oregon-Idaho border. Mercury advisories are listed for all species of sport fish caught there. But the undisputed hotspot along Brownlee's 58-mile length is the Burnt River inlet, where the river slows and the mercury carried from the Durkee plant settles out. Tissue samples collected from smallmouth bass and catfish here contained twice as much mercury as the next most contaminated Brownlee sample, exceeding the Food and Drug Administration's mercury "action level" of one part per million by 40 percent.

The Powder River Watershed, 20 miles to the north, has also received heavy doses of Durkee mercury. The EPA estimates that of the 231 pounds of mercury deposited annually in the watershed, a full 150 pounds comes from Durkee. Most of the rest comes from the global pool, generated largely by Asian factories. 

Since the passage of the Clean Air Act in 1970, the nation's cement plants have functioned in a regulatory blind spot. In 1990, the Clean Air Act was amended to require emitters — including cement kilns — to meet standards for a host of nearly 200 pollutants, including mercury. Rules were issued for coal-fired power plants, hazardous waste incinerators and other emitters, but the EPA failed to set rules for cement kilns by the 1997 deadline.

In 1999, the U.S. District Court for the District of Columbia found the EPA in violation of the Clean Air Act and gave the agency two years to issue new rules for cement kilns. It was a deadline the EPA failed — and would repeatedly fail — to meet. "Over the last 12 years, we sued EPA over and over, and we won over and over," says James Pew, an attorney with Earthjustice, the environmental law firm that headed the campaign for regulation. "There's a long string of court decisions saying, 'EPA, you're doing this wrong. …' They weren't terribly interested in what the courts said or what the law said."

Then, last April, the EPA reversed course, announcing its determination to make cement plants comply with the Clean Air Act. (Many attribute that decision to a pro-regulation shift at the agency after the 2008 presidential election.) The proposed new rules — expected to be finalized this year — are part of the EPA's National Emissions Standards for Hazardous Air Pollutants, or NESHAP, program and cover an array of pollutants including sulfur dioxide, particulates, hydrocarbons, hydrochloric acid and mercury. Separate EPA reports estimate that curbing emissions from cement plants nationwide, including an 81 percent cut in mercury, will prevent between 620 and 1,600 deaths a year and reduce national health costs by between $4.4 billion and $11 billion.

But it's difficult to assess the ecological and health impacts of past emissions from the nation's cement plants. Until 2000, the EPA did not even require the plants to report their hazardous emissions to its Toxics Release Inventory database. Because of the lack of reliable data, estimates of the amount of mercury vary wildly. In 2006, for example, the EPA doubled an estimate from earlier that year — from 12,000 to nearly 23,000 pounds annually — after it found evidence of widespread underreporting. As of 2007, according to the agency, 8,500 waterways in 43 states were listed as "impaired" with mercury.

Even if the laws could be tightened tomorrow — and mercury emissions could be "turned off" like water from a tap — the problems would persist for decades, says Don Essig, a water quality specialist with the Idaho Department of Environmental Quality. Like carbon dioxide in the atmosphere, mercury remains in aquatic ecosystems for a long time.

And mercury is not the only dangerous pollutant coming from the nation's cement plants. Worldwide, cement production contributes significantly to climate change, with cement plants accounting for roughly 5 percent of manmade carbon dioxide emissions. Coal and petroleum coke are the most common fuel sources, but a number of plants are permitted to burn "alternative" fuels, including slaughterhouse waste, old tires and railroad ties. (Cement kilns permitted to burn "hazardous wastes," including ink solvents and petroleum residues, have been regulated under NESHAP since 1999.) Industry representatives say that these materials would otherwise clog landfills, and the high heat within the kilns prevents the formation of potentially harmful constituents. But critics argue that plants that burn such fuels release particulates, dioxins, furans and heavy metals, and should be regulated as waste incinerators. (None of those pollutants would be controlled under the new NESHAP rules.) In addition, fly ash from coal-fired power plants and slag from iron blast furnaces are often mixed into the cement as strengtheners and can significantly increase the metal content of emissions.

The Durkee plant's new mercury-control system is supposed to be completed in July 2010, according to the company. A scaled-down prototype of the filtration system — which uses powdered carbon to trap mercury in the exhaust stream –– cut mercury by 70 to 95 percent in test runs.

The mercury reduction agreement reached between the company and state in 2008 requires an 85 percent cut in emissions. However, that will be overridden if the EPA rules go into effect next year, says Douglas Welch, an engineer with the Oregon State Department of Environmental Quality. The new federal rules would require the Durkee plant to cut mercury by about 98 percent by 2013, a goal Welch doubts is attainable. "At a certain point, you inject more and more carbon and you get diminishing returns on mercury," Welch says.

He is also unsure whether the reductions achieved in the scaled-down tests can be duplicated when applied to the entire system. "In the worst case," says Welch, "it's conceivable that they'd have to close up shop for good."

Not surprisingly, cement industry representatives fiercely oppose the new standards. Andy O'Hare of the Portland Cement Association, a Skokie, Ill.-based industry group, has even questioned their legality, saying that new emissions standards must be "demonstrable and achievable." The ability of any one facility to simultaneously reduce mercury, sulfur dioxide, particulate matter, hydrocarbons and hydrochloric acid to the levels specified under the new standards, he says, has not been demonstrated.

The potential loss of Durkee foreshadows an ominous trend, O'Hare warns: the mass outsourcing of U.S. cement production. Compounding the economic loss would be an increase in overall global emissions because cement would be made in countries with lax environmental standards, such as Venezuela, Indonesia and China. "We're working closely with EPA to ensure that whatever rules are passed next year allow us to keep these high-paying jobs in the U.S.," says O'Hare.

Ash Grove is pushing for a regulatory "subcategory" at Durkee — a special designation that would allow the plant to emit more mercury than stipulated under the new rules. "We have strong community support to create a subcategory for our Durkee plant based on the high level of naturally-occurring mercury in the limestone," Ash Grove spokeswoman Jacqueline Clark wrote in an e-mail. "We have also garnered the support of area community elected officials, state elected officials, and federal elected officials." 

Justin Hayes, however, prefers to frame the issue of mercury pollution in moral terms — as an affront to his young children as well as to future generations of anglers. "No matter what anyone says, I'm not against industry," says Hayes. "But if Ash Grove can't make their cement without putting poison into the air and into the water and into the fish, then they should absolutely go out of business."

Jeremy Miller's last feature article for the magazine, "Rebooting Urban Watersheds," appeared in the June 1 issue.