Upset over Cemex plant

Facility ranks No. 6 for production " upsets " that violate emissions standards

On Nov. 1, a cloud of dust and exhaust billowed into the air above Cemex Inc.'s cement plant near Lyons. Kiln maintenance was the cause, company officials said.

On Aug. 25, a motor jam gave rise to a similar cloud. The jam cut power to the plant's kiln and other systems, including a massive fan that keeps air circulating through the kiln and pollution-control systems.

Cemex aerial
The Cemex Inc. plant near Lyons reported 99 production “upsets” between 1999 and October 2005, more than all but five industrial
plants in Colorado. The top spot was held by another cement plant, Holcim Inc.’s plant in Florence. Sammy Dallal/Daily Camera

The kiln's coal, boiling crushed limestone and other ingredients of the 2-century-old recipe for Portland cement at 3,300 degrees didn't much care what the issue was. It burned on, pumping forth a plume of particulate matter and coal exhaust visible for miles. It was obeying physical and, as it turns out, state and federal law in the process.

Such production hiccups - known as " upset conditions" - are a part of doing heavy-industrial business, and they're recognized by state and federal regulators as an unfortunate part of complicated, high-volume production processes that create the refined petroleum, steel, electricity and other commodities upon which a modern economy depends.

Pollutants emitted in such upsets are noted on forms submitted to state regulators, but not counted against permitted emissions of particulate matter, sulfur dioxide, dioxins, heavy metals or various toxic compounds that cement-making can send into the environment.

A Daily Camera study of Mexican-owned Cemex Inc.'s upsets since 1999 shows the plant to have sent state regulators more upset reports than all but five industrial facilities in the state. Cemex reported 99 upsets between January 1999 and Oct. 13 at its Lyons plant . Yet in light of data from selected cement plants in Colorado and Texas, Cemex's rate of production upsets appears to be typical.

Of the 130 Colorado facilities reporting upsets during that period, 99 had 10 or fewer, and 51 reported just one upset . Xcel Energy's Valmont Station east of Boulder, with 35 upsets , was the 15th worst.

The state's most prolific reporter of upsets was Swiss-owned Holcim Inc.'s cement plant in Florence, which reported 375 upsets during the same period. Holcim and Cemex are the only two cement plants in Colorado.

It turns out that cement manufacturing is hard on hardware.

The business of cement

Cement is the glue in concrete. It makes up 10 percent to 15 percent of the manmade rock we drive and live on.

Making cement is a violent endeavor. At the Cemex plant near Lyons, crushed limestone rides in on a 2-mile conveyor belt from the company's Dowe Flats quarry. The rock is again crushed, mixed with sand or clay, iron ore and other materials, crushed yet again, and preheated to roughly 1,800 degrees, or about triple the melting point of lead.

It lands in the cement kiln, one of industry's most massive pieces of hardware. Wide enough to drive a sport utility vehicle through, more than half the length of a football field and sloping gently downward as it rotates, the kiln's temperatures peak at about 3,300 degrees.

The inputs melt into marble-sized globs called clinker. Clinker is mixed with a small amount of gypsum and other trace additives, ground finer than talcum powder, and shipped as cement.

This is truly a bulk process: Cemex Lyons' 100 employees produce 630,000 tons of cement a year, or 1,725 tons a day, company spokesman Rick Shapiro said. The company sells it as fast as they can make it, primarily to the Denver metro-area market.

Cemex plant in Lyons, Colo.
Concrete pours soft, wet and cold, but it takes a combination of tons of crushed rock and 3,300-degree heat to produce the Portland cement that makes concrete work. The Cemex plant in Lyons produces 630,000 tons of cement a year. The Portland Cement Association says the massive kilns require the energy equivalent of 1,240 kilowatt hours to produce a ton of cement, or as much electricity as an average household uses in about 42 days. Cliff Grassmick/Daily Camera

Cement plants across the country are operating at full-tilt to keep up with demand driven by a combination of booming construction and the political hurdles associated with opening new cement plants . Shapiro said the Lyons plant runs between 89 percent and 95 percent of the hours in a year.

To produce a ton of cement, the kilns require the energy equivalent of 1,240 kilowatt hours, or as much as an average household uses in about 42 days, according to the cement industry group Portland Cement Association.

The association says there are 118 U.S. cement plants in 38 states, producing about $8.6 billion worth of cement annually. Cement prices have risen about 21 percent since October 2003, U.S. Bureau of Labor Statistics' producer price index data shows.

Portland Cement Association economist Tom Carter said the industry is projected to boost current annual U.S. capacity from 83 million tons to 103 million tons by 2010. Cement imports have climbed to 27 percent of U.S. consumption and show no sign of slowing.

Combine an aggressive production schedule with a mechanically brutal process and you have a recipe for breakdowns, which are evident across the cement industry.

Apples to apples

Combining Colorado cement- plant upset data with a sample of that posted online by the Texas Commission on Environmental Quality offers a means for comparison across the cement industry. Although state air-pollution laws vary, they tend to stick to federal guidelines for opacity, the pollutant mentioned in the vast majority of cement- plant upset reports in both Colorado and Texas.

The Holcim plant in Florence reported nearly three times as many upsets as Cemex in the 34 months from February 2003 to November 2005. But Holcim also produces three times as much cement. Pound for pound, the Cemex plant had slightly more upsets per ton than Holcim in Florence.

Adjusted for volume, Cemex's plant in Odessa, Texas, had about four times as many upsets as either of the Colorado plants , and its New Braunfels, Texas, plant had 50 percent more upsets.

Cemex's Shapiro said the company could not comment on the variability in the number of upsets among its plants . In a statement, Cemex officials said, "The three cement manufacturing plants that you have requested information on ... are each operated in an environmentally compliant and sensitive manner. In addition, each of the plants you have referenced are plants that have historically operated well from an operational perspective, and continue to do so."

Raw upset numbers aren't everything. The duration of each of Cemex's reported upsets since 1999 was brief - almost all less than an hour, and often less than 15 minutes. In contrast, upsets at Holcim in Florence sometimes last for days. That was the case with an upset that began Nov. 23.

The event, caused by a clinker transport pan falling off its rails, led to an unknown degree of excess opacity for 90 hours, according to the report filed with the state.

Holcim spokesman Tom Chizmadia said the upset numbers in Florence reflect the breaking-in of a new plant , built in 2002 on the site of a predecessor half its size. He said the upsets represent 0.2 percent of total operating time.

Colorado upset data shows that in 2005, Holcim's upsets actually accounted for 2 percent of its operating time through November; Cemex's amounted to 0.1 percent. In terms of upset count, Holcim has had fewer this year, with 18 reports filed through Dec. 1. Cemex had 21.

Cemex Lyons versus other Cemex plants in the United States

Eric Schaeffer, former head of enforcement at the U.S. Environmental Protection Agency and now director of the Washington, D.C.-based Environmental Integrity Project, said the number of upsets at Cemex's Lyons plant didn't strike him as extreme.

"A typical power plant will run opacity exceedances 3 or 4 percent of the time," many times longer than what Cemex has reported, Schaeffer said.

But upsets sometimes offer hints of a deeper problem.

Upsets as warning signs

Jana Milford, senior scientist with Environmental Defense in Boulder, said upsets represent a compromise within the Clean Air Act.

In exchange for more stringent pollution limits during normal operations, plants are given leeway for unplanned problems.

"But when there are a lot of ( upsets ), you've got to start worrying about whether there is something significant going on, and about whether peoples' health is being affected," Milford said.

It is a state health department inspector's job to decide whether reported upsets are indeed unpredictable, and "not due to poor maintenance, improper or careless operations, or ... otherwise preventable through the exercise of reasonable care," as the department's Air Pollution Control Division's policy states.

Paul Carr, the state inspector assigned to Cemex's Lyons plant , takes note of upsets such as the one Cemex filed May 24. The event began at 12:29 p.m. May 23 and lasted 17 minutes. The reason for the upset , as Cemex officials stated on a faxed-in upset form: "Exceeded temperature on main baghouse when primary pump to spray tower failed. Backup pump was activated immediately."

Rather than "opacity," which describes the clouds of particulates often reported by the plant's neighbors, this one's pollution description box contained the letters "DF."

DF stands for dioxins and furans, carcinogens that cement kilns can emit in certain circumstances. In Cemex's case, so-called stack tests, which test emissions at varying temperatures, have shown that dioxins form if temperatures at pollution-control equipment intakes are above 517 degrees.

Even at 522 degrees, Cemex's load of dioxins and furans is more than 10,000 times below U.S. Environmental Protection Agency thresholds, said Pamela Milmoe, air and waste coordinator for Boulder County Public Health.

The state's subsequent investigation using Cemex's own data found that the Lyons plant violated the 517-degree temperature limit 72,067 times in 2004 alone, amounting to about 15 percent of its total operating time. Cemex could face civil penalties of up to $15,000 per day.

Cemex told state and county regulators Oct. 20 that the computer system monitoring dioxins and furans had malfunctioned, but other production data showed temperatures to have been below 517 degrees. The investigation is ongoing.

"It's not the individual upsets . It's when they indicate a larger problem," Milmoe said. "It's the morass we're unable to get out of with Cemex ."

Colorado Upsets

Environmental watchdogs say industrial companies sometimes exploit upset regulations to avoid shutdowns and make more money. Neil Carman, a former cement- plant inspector for the state of Texas and now clean-air program director for the Lone Star Chapter of the Sierra Club, contends that many upsets are "not legitimate."

"They are preventable if they do their proper maintenance and prevention work, but they don't want to shut the plant down because they're not making money when they shut down," Carman said. "Companies gamble like this all the time."

David Ouimette, manager of the stationary sources program for Colorado's Air Pollution Control Division, said state inspectors watch for such behavior.

"We look for patterns (in upsets), then we seriously question whether it's an unforeseeable breakdown of equipment," Ouimette said.

What's in the air?

Cemex's production upsets comprise a tiny fraction of its operating time. But the combination of the unknown nature of what is billowing into the air during an upset and Cemex's plans to resume tire burning has some residents concerned.

Ouimette said the specific toxins released in an upset are often unknown, particularly when the problem is reported simply as "opacity."

"Opacity is an indicator of a problem," he said. "The problem isn't opacity. It's whatever (the opacity) is made of, and we don't know what that is, generally."

Upsets can blow particulate matter, nitrogen oxides, sulfur dioxides and carbon monoxide out of the kiln without necessarily passing through pollution-control equipment, said Boulder County's Milmoe.

The Sierra Club contends that upsets generally bring higher pollution rates, and that agencies have not monitored the health effects of such emissions, according to Carman, the former inspector with the environmental group's Texas chapter.

"They just take a leap of faith," he said. "It's an issue all across the country and especially in Colorado."

Cemex's plans to burn tires for the first time since 1993 has some locals concerned about air quality. Two federal reports concluded that burned chipped tires posed "no public health hazard" at Cemex . But the agency did not consider emissions during upset conditions.

Burning tires as a supplement to coal is a widespread practice, and is already done at Holcim's Florence plant . But tires can produce more heavy metals and other toxins than coal.

Richard Cargill, who lives two miles east of the Lyons plant and leads the St. Vrain Valley Community Watchdogs, a group long critical of Cemex's operating record, opposes tire burning at the plant . He says the federal reports brush off the potential health impacts of upsets while burning tires because upsets are so infrequent.

"But I'm still very curious about what could be released out there if there's an upset when they're burning tires," Cargill said.