On a breezy day, Shell's 600-acre chemical plant in Deer Park turns into a giant wind chime.
Jan. 19On a breezy day, Shell's 600-acre chemical plant in Deer Park turns into a giant wind chime.
Hundreds of thousands of metal tags, each etched with chemical names like benzene and ethylene, dangle from nearly every pump, joint and valve, creating a metallic orchestra amid the miles-long maze of pipes.
"There are so many of these and they are so close together, even the slightest breeze can cause them to move," said Louis Brzuzy, an environmental specialist at the facility. "In some units, the tags are so dense the noise is noticeable."
Their sound belies a sober purpose. Each tag marks a place where toxic air pollution can escape.
Across Texas, these so-called fugitive emissions account for a sizable portion of the toxic air pollution released by industry each year, some of which ends up in surrounding communities. Fugitives no doubt contributed to the elevated levels of air toxics detected by the Houston Chronicle at residences along the fence lines of some plants in Houston, Baytown, Freeport and Port Neches last summer.
For nearby communities, these seemingly modest sources of pollution can be more dangerous than what comes out of an industrial plant's sky-grazing stacks, since many of the leaky parts are close to the ground, where wind speeds are lower and the chemicals don't easily disperse.
Toxics "hang around when they are released at a lower level," said Daewon Byun, director of the Institute for Multi-dimensional Air Quality Studies at the University of Houston, which is modeling air emissions in the Houston area. His research, thus far, suggests that leaks of toxic pollution are underestimated.
"Fugitives are not being counted properly," he said.
State and federal investigations over the past five years also suggest that the proportion of air toxics attributed to leaks is likely greater than reported, since numerous facilities have been caught low-balling the number of "leakers" at their facilities and the amount of pollution they emit.
Besides the accounting problems, current regulations also allow some leaks to continue for years.
One thing is certain: no chemical plant or refinery in Texas is airtight.
"There have to be leaks. If you came back with no leaks, they would say, 'Hey, what's going on?' " said Melissa Baeza, who has worked for four years as a site supervisor for ARI Environmental Inc., the contractor hired to monitor most of the 250,000 tagged components at Shell Chemical whose design or age gives them pollution-releasing potential.
Baeza's 14 technicians spend 40 hours a week divided into four 10-hour days walking along the chemical plant's pipes and measuring for leaks. Some are so tiny that a permanent marker would give off more emissions. Others leak so much that the concentration of the chemicals in the surrounding vapor is four times over state and federal limits.
Taken together, their impact can be dramatic.
In 2002, according to the federal Toxics Release Inventory, leaks made up 33.3 percent of the more than 52 million pounds of air toxics companies reported they released in Texas. The remainder came from more obvious sources, including stacks and vents.
In Harris County, which in 2002 reported 11.4 million pounds of toxic air pollution the most in the state industry estimated that fugitive emissions accounted for 42 percent of the total.
Not all fugitive emissions are of one of the 188 air toxics, known to cause cancer and other health problems. However, leaks account for more than 15 million pounds of other types of air pollution in Texas, according to 2002 data.
"These are huge facilities with very complicated plumbing, basically," said John Millett, a spokesman for the U.S. Environmental Protection Agency, which wrote many of the rules governing how leaks are detected and how fast they must be repaired.
Of the 25 to 30 environmental regulations governing refineries and chemical plants, six focus specifically on leaks. Many of those rules came into being in 1990, when Congress updated the Clean Air Act and identified the 188 hazardous air pollutants. Those rules were designed to reduce fugitive pollution by 63 percent, if followed correctly.
Yet despite the regulations, the millions of dollars companies spend monitoring each year and recent advances in leak-detection technology including an infrared camera that can actually photograph emissions coming off a pipe a series of investigations suggests that many leaks are being overlooked.
In June 2003, independent investigators working for the Houston Advanced Research Center checked six chemical plants in the Houston area. All had components that were not tagged or being checked for leaks. If they had been, the amount of pollution reported to the state would have been slightly higher.
In June 2002, the Texas Commission on Environmental Quality began unannounced inspections of 53 cooling towers, which lower the temperature of chemicals by transferring heat to water. At five of the nine industrial facilities checked, the steam coming out of the cooling towers was laced with chemical pollution, a sign of a leak. If these emissions were reported, the official quantity of pollution reported by the plants would have gone up fivefold.
In 1999, the EPA's National Enforcement Investigation Center inspected leak-detection and repair programs at 17 oil refineries nationwide, including one in Texas City. It found four times as many leaks as the refineries reported, resulting in 80 million pounds of unreported pollution. The 1,062 facilities in Texas that reported releasing air toxics in 2002 emitted a total of 124 million pounds.
The reasons cited for the missed leaks included monitors not spending enough time checking the component to get an accurate measurement and the difficulty of double-checking the complex calculations used to determine how much pollution is coming from a leaking part. Companies contend they are abiding by calculations and methods set by the EPA.
"There are emissions problems with flares, fugitives and cooling towers," said John Wilson, executive director of the Galveston-Houston Association for Smog Prevention, which released a report in October 2003 on the TCEQ's cooling tower investigation.
But, Wilson said, leaks alone can't explain the huge gap that researchers have found between the concentration of chemicals in the air over Houston and the emissions estimates reported by the companies. Scientists say the concentration suggests that actual emissions are five times greater than what is being reported.
Part of the reason is that those numbers are estimates based on complex math and computer models, not exact monitoring.
Since the smog prevention group publicized the state data, Texas has required refineries and chemical plants to keep better tabs on cooling towers. But these efforts focus exclusively on butenes, propylene, ethylene and 1,3-butadiene the four chemicals in the Houston region that help to form smog. Numerous other compounds that cause cancer and other health problems are not subject to additional rules.
While Wilson applauds the efforts, he would rather see pollution control devices put on all leaking equipment or more frequent monitoring. The contractors hired to detect leaks at most chemical plants and refineries monitor most components only four times a year. At plants where less than 2 percent of the components are leaking, the state allows checkups to be even more infrequent.
While companies like Shell have successfully built airtight plants in Europe, the technology used there won't fit with the aging infrastructure on the Texas Gulf Coast, where many plants were built in the 1940s and '50s.
Over time, aging equipment has been replaced, plants have expanded, and some of those shut down have been turned back on. But not since the late 1970s has a new refinery risen on vacant land in this country. The last major new chemical plant was built in the early 1990s.
Rising prices for natural gas to fuel the petrochemical plants have forced many companies to open new facilities overseas. In the refinery business, strict environmental regulations and increasing imports of crude oil have discouraged companies from building stateside.
"You couldn't retrofit this facility because there is no room," said Shari Keller, the staff environmental specialist at Shell Chemical. "It's almost impossible. You'd have to knock it down and start over again."
To reduce pollution at its plant, Shell goes beyond the requirements. All pipes carrying benzene, a carcinogen, are routinely checked. And although less than 2 percent of the plant's components were found to be leaking, which could qualify it for an exemption, the company still completes quarterly inspections.
"We are trying to get those emissions down, and that's how you do it better monitoring," Keller said.
At other facilities, too, environmental managers have made strides to address some of the problems highlighted by the recent investigations.
The BP plant in Texas City, one of those inspected in the 1999 study, now hires a second contractor to double-check its records. It also checks how quickly leak investigators are working to make sure enough time is being spent at each component.
When the state inspected the plant in March, not a single leak was detected in a check of 300 valves, said Watson Dupont, the environmental superintendent.
In places where there are leaks, however, detection doesn't guarantee action.
The most stringent rules, those regulating the hazardous and ozone-forming chemicals like 1,3-butadiene, require equipment leaks to be repaired within a week. Other chemicals are allowed to seep for years, because regulations allow the company to wait to fix those leaks until its next major tuneup. These happen, on average, every five years.
At Shell, 200 leaks await repair.
Baeza, on her daily rounds, doesn't even bother to stop at these.
On a recent shift, she passed one with a large orange tag indicating that it had been leaking since November 2003. When it was last measured, the concentration of chemicals at the leak was 2,225 parts per million. The allowable limit is 500 parts per million.
"In order to take it out of service, they would have to shut down the entire line," Keller explained, noting the possibility of bursts of chemical releases. "A shutdown typically creates a lot of emissions."
Farther down, Baeza paused near valve No. 92181. It's part of a line carrying propane and was last tested in July. Baeza slowly waved a wandlike metal probe over it.
The valve passed.
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