Las Vegas asphalt plant’s emissions may violate EPA’s standard, expert says

The air quality in a Spring Valley neighborhood frequently downwind of a nearby asphalt mixing plant “very likely” violates the Environmental Protection Agency’s annual standard, according to a local expert.

Area residents have complained that overwhelming emissions smelling like tar come from the Wells Cargo-owned plant, located in a once undeveloped but now residential area on West Spring Mountain Road near South Buffalo Drive.

After the company announced plans to build a second, similarly sized plant across the street, worried residents reached out to Antony Chen, an assistant professor at UNLV whose research specializes in air pollution measurement and modeling.

For 20 days in October and November, Chen monitored the air quality in the Lantern Gardens neighborhood, which lies just west of the existing asphalt mixing plant.

The findings of Chen’s short-term monitoring concerned him enough that he suggests Clark County’s Department of Air Quality conduct an in-depth study of the plant’s emissions and the air quality of the immediate area for an entire year before allowing another plant to begin operations.

“Particularly, the (fine particulate matter) concentration is consistently above the annual standard that’s specified by the EPA,” Chen said. “(The standard) is 12 micrograms per cubic meter, for example, but what we see there on average is about 20 (micrograms per cubic meter).”

Chen reports that the daily readings of fine particles exceeded the EPA’s annual standard on 14 of the 20 days he monitored. Most of the elevated readings were associated with strong winds coming from the direction of the asphalt mixing plant.

COUNTY TALKING TO CHEN

Marci Henson, director of Clark County Department of Air Quality, said her staff reached out to Chen on Thursday for a copy of his collected data and to learn more about his monitoring methods.

“We take all air quality concerns very seriously, whether they’re from a resident who is calling the dust hotline or a UNLV Ph.D. researcher,” Henson said. “We’re very interested in working with Dr. Chen, looking at the data he collected and comparing it with ours … We’ve been talking to him about the additional work he wants to do.”

Wells Cargo Vice President of Operations Phil Groff said in an email that his company “takes (EPA) standards seriously and works rigorously to be within allowable limits.”

Area residents have complained that Wells Cargo’s current operations stir up dust that pervades their neighborhoods every day. But Chen said it is what they don’t see that should be their greatest concern.

While the fine particles that Chen monitored are 20 times smaller than a human hair, in large amounts they can have devastating impacts on the human body over long periods of time. Effects include reduced lung function, lung cancer, heart attacks and strokes.

CHEMICAL COMPOUND

“We have reason to believe there could actually be a problem because the (fine particle) concentration is high and there’s an indication it comes from this facility,” Chen said. “The exposure level is critical to the health outcomes, but it’s not easy to estimate for the current monitoring networks we have run by Clark County.”

In addition to a yearlong study of the presence of fine particle pollution, Chen said a detailed study should be conducted into the chemical composition of the pollutants to determine their toxicity.

County commissioners are scheduled to consider approving Wells Cargo’s expansion plans at their Jan. 18 zoning meeting. The county’s department of air quality has not yet approved a permit for the expansion.

Chen said he believes building a second asphalt plant in what is now a residential area is a bad idea for the health of nearby residents, but it’s imperative to gather more data on what kind of impact the expansion would have.

“It’s certainly not a million dollar project,” he said of the study he wants to conduct. “If you really don’t think there’s any issues at all you want to clear the thoughts of people.”

Contact Michael Scott Davidson at sdavidson@reviewjournal.com or 702-477-3861. Follow @davidsonlvrj on Twitter.