Air clearing after Asarco demolition kicks up fine dust particles

By Diana Washington Valdez \ El Paso Times

Fine dust particles in El Paso’s airshed rose from good to moderate levels for two days following the demolitions of Asarco’s two smokestacks, according to Texas Commission for Environmental Quality air monitoring data.

On April 12, the day before the demolitions, El Paso experienced a “good” range of PM-2.5 fine dust particles, which averaged 38 on the U.S. Environmental and Protection Agency Air Quality Index. The indicator remained in the good range, at 40, on Saturday before jumping to a moderate range of 68 on Sunday. The dust particles level reached 58 on Monday, according to the state’s unofficial data on the TCEQ’s website.

The AQI is used let the public know when air pollutants reach unhealthful levels. The color-coded index includes six ranges: good (0-50), moderate (51-100), unhealthy for very sensitive groups (101-150), unhealthy (151-200), very unhealthy (201-300) and hazardous (301-500).

“There was a short-lived spike of elevated levels of PM10 and PM2.5 on Saturday morning,” TCEQ spokesman Terry Clawson said Monday. “There were elevated levels of PM-10 and PM-2.5 Sunday morning and lasting until early Sunday afternoon. These particulate matter concentrations remained below a level of health concern all weekend.”

PM-10 dust particles are coarser than PM-2.5 particles; both are measured in micrometers.

“TCEQ reviewed the preliminary data from our ambient monitoring network in the El Paso area,” said Clawson, adding that “preliminary data has not been validated and therefore subject to change. Concentrations remained in the good range for carbon monoxide, nitrogen oxides, ozone, and sulfur dioxide all weekend.”

Higher levels of PM-2.5 — considered the region’s main air pollutant — can affect people who are sensitive to dust particles, such as asthmatics and others with respiratory illnesses.

Robert Puga, trustee for the $52 million Asarco site cleanup in West El Paso, said it may take another week to learn the results from his dust-monitoring analysis from the demolitions.

For decades, El Paso’s Asarco’s smelter refined lead and copper, and for several years it also incinerated unpermitted hazardous wastes from a military depot.

Asarco shuttered its refining operation in 1999.

Puga said that initial tests of nine core samples from the concrete smokestacks did not turn up anything that would harm people or the environment.

Although water cannons were used to keep the dust down, a large cloud of smoky dust spread quickly and was visible to everyone who watched the stacks come down.

Because of an air inversion in the region, dust and other possible pollutants from the massive demolitions also lingered despite some light winds.

An inversion occurs whenever a layer of cool air is trapped near the ground by a layer of warmer air above it. Smog is the most visible sign of this meteorological event.

State Sen. JosĂ© RodrĂ­guez, D-El Paso, said Saturday that he was concerned about the thick clouds of dust reported on both sides of the border, and called for a “thorough review” of the event.

“Despite reassurances from the trustee, TCEQ and EPA, thousands of people in El Paso and Juárez were exposed to a cloud of Asarco dust,” RodrĂ­guez said.

Sito Negron, spokesman for the senator, said, “We’ve been in contact with the TCEQ since Saturday and are asking that we be apprised of the results.”

In response to RodrĂ­guez’s request, Clawson said the TCEQ plans to review the monitoring data, “but all indications are it was a successful demolition and no long-term health effects are anticipated.”

An official with the EPA-Region 6 in Dallas was unavailable for comment late Monday.

Environmental advocate Heather McMurray said she is worried that fugitive dust containing dangerous contaminants escaped during the demolition into the air and or remained in the ground at the Asarco site.

Fugitive dust can get into the air from work at construction sites, unpaved roads, or demolitions.

John Walton, civil engineering professor at the University of Texas at El Paso, said he took note of the air inversion and the path that the cloud of dust followed.

He is an expert on environmental remediation and fugitive dust.

“It looked like a weak low-level inversion Saturday morning but I haven’t actually seen any data on it,” Walton said. “The plume went slowly down valley and the effects can be seen on the TCEQ UTEP and Chamizal sites. I was watching from just above the freeway (Interstate 10).

“The real question is not ‘was there dust?’ — dust was expected,” Walton said. “The question is was the dust, particularly from Asarco, contaminated with heavy metals? To know that one must chemically analyze the dust samples. I have not seen any analysis.”

Walton has conducted research on fugitive dust.

“Based on observation and first principles I suspect the Asarco dust was only slightly contaminated,” Walton said. “This is because it appeared to be mostly (a) resuspension of dirt laid down for the fall zone. Hopefully we will see some hard data to confirm or deny this from Mr. Puga. One should maintain perspective, (because) contaminated dust left the Asarco site every time the wind blew for the past 100-plus years.”

The city of El Paso also conducted a demolition on Sunday of the former City Hall building in Downtown El Paso, and hired a company to do an air-monitoring analysis. That report will be ready in a week to 10 days.

Diana Washington Valdez may be reached at; 546-6140.