Phoenix Pays the Price In Air Quality

Dec. 21, 2012

War is being waged over Phoenix.

It’s the brown cloud that hovers over the city versus clean air, and the stakes are high. On one side is the economic vigor of the region. On the other is the personal vigor of its inhabitants.

The clean-air forces seized the advantage in the 1980s and 1990s, thanks to stiff regulations and technological advances. They beat back three evil pollutants – carbon monoxide, sulfur dioxide and, to a lesser degree, nitrogen dioxide.

Thinking Arizona illustration by Tony Bustos

The assault caused Phoenix’s bad-air days to nose-dive from 265 in 1981 to less than 80 in 1996. The brown cloud didn’t disappear, but it was retreating.

Unfortunately, however, the siege is far, far from over. This war is not going to end in a day or a year or even a decade.

While three pollutants have been vanquished, Phoenix is beset with three other stubborn nemeses. Ground-level ozone, small and large particulate matter are continually reinforced by the booming growth of Phoenix, its location on an unforgiving landscape, and the vagaries of the weather. None of those conditions are going to go away.

Given the circumstances, it’s a tribute to the air-quality effort that the brown cloud hasn’t swallowed the valley. Sooner or later, though, it catches up with you. Clean-air officials say they are running out of weapons to meet standards that the EPA is gradually tightening as the health consequences of bad air become more deeply understood.

The American Lung Association ranks Phoenix 19th worst in the nation for ozone pollution and 7th worst for the microscopic particles found up there in the haze. The latter is actually an improvement. Phoenix used to be the worst.

Not every county in the country is monitored for air quality, but the ALA grades all those that are. And it doesn’t grade on the curve. Under its tough standards, Maricopa County – along with many other counties that are home to major cities – gets an “F” for ozone.

Thinking Arizona took the ALA’s grades for ozone and particle pollution a step further by then factoring in the population of each of the monitored counties to create weighted air-quality averages for each of the 50 states. This in an attempt to determine the degree to which each state’s population is affected by air pollution.

By this analysis, Vermont, which is lightly populated and lightly monitored, has the cleanest skies in the nation. No town there gets worse than a “B.”

California, which is heavily populated and heavily monitored, has the dirtiest. Other than San Francisco and areas directly north of it, “F” is the norm in California.

Arizona comes in nine places better than California at 41st.

That’s because so much of the state’s population is centered in Phoenix. A bad-air day in Maricopa County affects 60 percent of Arizonans. The population of few other metro areas across the country dominates their respective states to the degree Phoenix dominates Arizona.

Of course, air pollution is not limited to urban centers. Janice Nolen, the ALA’s assistant vice president for national policy, points out for instance that there are hot spots at oil and gas fields, near coal-fired power plants such as the Navajo Generating Station in Page, and around busy highway interchanges.

But she says that, with budgets running tight, states and the EPA tend to locate monitoring stations where the most people live. That means urban centers are mostly what get graded.

The prominence of Phoenix overshadows some pretty impressive results coming from elsewhere in Arizona. In fact, Prescott, Tucson and Flagstaff are cited by the ALA as being among the 15 cleanest cities in the country on a combination of two measures of particulate pollution.

Thinking Arizona illustration by Tony Bustos

The story down in Tucson is particularly good. Thirty years ago, believe it or not, Tucson was worse off than Phoenix in what the EPA’s Air Quality Index termed “good” days. Tucson had just nine of them in 1981. Phoenix had 33.

On this score, Tucson was soon to move past its bigger neighbor to the north. It now boasts about 230 good days per year. Phoenix, which briefly elevated itself to 100 good days in the 1990s, has fallen back to the 30 it had 30 years ago.

That’s partly because standards have been toughened.

Jumping through all the hoops required by the EPA is a huge job onto itself. And it gets even more challenging as the hoops are narrowed. Eric Massey, director of the air quality division of the state Department of Environmental Quality, points out that air-quality readings the EPA once regarded as “healthy” would be out of compliance today.

Beyond that, however, two very big issues cast a shadow over Phoenix.

The first is that the rapid growth in vehicles traveling the roads of Maricopa County is far outstripping the progress in curtailing their emissions.

Three decades ago, the introduction of the catalytic converter and other improvements bought time for cities by cleaning up the exhaust coming out of all those tailpipes.

Since then, the EPA credits the state of Arizona and Maricopa County for having required cleaner burning gasoline and vehicle emission testing, along with taking other pollution reduction measures. It has removed Maricopa from EPA purgatory – which in bureaucratic parlance is called “non-attainment” – for the old standard of measuring ozone levels.

But the jury remains out on what will happen with a different ozone measure, for which the standard has been tightened, and on the standard for small particulates. Phoenix falls short of both of those standards.

Thinking Arizona graph by Tony Bustos

The mushrooming armada of vehicles on Maricopa roads has increased by nearly 70 percent since 1998. That’s an additional 1.5 million vehicles, most of which cruise the asphalt of Phoenix. During that same time period, EPA figures show, automakers have managed to reduce the emissions coming out of new vehicles by just 12 percent.

Even if every vehicle on the street was a new one, which they are not, and even if they were being driven the same number of miles, which is unlikely as the megalopolis expands ever outward, the figures behind the percentages above suggest that vehicles are spewing 50 percent more pollutants into the Phoenix air than they did in 1998.

Keep that up and Maricopa won’t be able to escape the bad graces of the feds. More importantly, it doesn’t bode well for the health of Phoenix residents or for the sky above.

That’s one of the two big issues for Phoenix. The other is the uneasy relationship the city has with the ground on which it sits.

What does the ground have to do with the air? In air-quality speak, the connection is called large particulate matter. Most of which is what we know as dust. The dratted dust.

It’s a problem peculiar to the arid West. And Phoenix is particularly dry, particularly big, and particularly vulnerable.

Dust shows up on monitors both as one of the components of small (under 2.5 microns) particulate matter and the primary contributor of large (under 10 microns) particulate matter. Maricopa struggles with both, but particularly the larger version. The county has been in EPA purgatory for large particulates since 1996. Try as it might, it can’t escape.

Thinking Arizona graphs by Tony Bustos

Large particulates are unlike the other two members of the unholy trinity of pollution. Ozone and small particulates get produced in fairly predictable patterns. But the levels of large particulates shift with the winds.

The number of days that Phoenix’s air is judged to be unhealthy fluctuates wildly from year to year. Unhealthy days were as high as 255 as recently as 2006, and as low as 44 in 2010. Last year there were 122 of them.

The ups and downs are attributable to drastic swings in large particulates. The mean readings over 24-hour periods bounced around from 232 micrograms per cubic meter in 2006 down to 82 micrograms in 2010 and back up to 139 micrograms last year. On the very worst days, the readings can exceed 2,000.

The wild card is the meteorological pattern. State air official Massey blames the fluctuations on the vicissitudes of the weather.

In 2010, for instance, Maricopa County didn’t have a single dust “exceedance.” Massey attributes that to good rainfall during the year.

In 2011, the opposite occurred. There was little rain and therefore many dust storms, including the infamous “haboob” on July 5 that Massey calls the worst in 30 years. The reading for large particulates that day exceeded 2,200 micrograms.

The connection between wind and what’s blowing around is easy to see, but the correlation is spelled out in painstaking detail in a report done by an Arizona State University graduate student on the four Maricopa monitoring stations with the highest readings.

The study by Heloise Cook for her master’s thesis in 2011 showed that spikes in large particulates are driven by heavy winds, particularly it seems when gusts get up in the range of 20 miles per hour.

That, however, is only the half of it. Cook also showed that the dust primarily originates where the earth has been disturbed. Where, one might say, settlement has unsettled the setting.

Maricopa officials blame part of their woes on a monitoring station not even located in Maricopa County, but near feedlots and an ethanol plant in Pinal County. They argue that the off-the-chart readings from this station shouldn’t color Phoenix results. The ALA’s Nolen responds that even if the station is technically located in Pinal, it still affects those living within the Greater Phoenix standard metropolitan statistical area.

Sources Are Foreign — And Local

Air, of course, knows no boundaries. Arizona’s monitoring stations pick up pollutants originating not only in neighboring Mexico, but from as far away as the port of Los Angeles and even from China.

Cook, however, found plenty of local sources as well. The worst days at the four Maricopa stations she studied came when the wind was blowing from the direction of agriculture operations, sand and gravel companies, and other stationary sources near the monitoring stations.

Massey and his fellow air-quality officials are trying to contend with these conditions by placing a growing emphasis on forecasting when weather conditions are likely to kick up bad-air days.

As one of those periods approach, they call on government agencies and businesses with air-quality permits to curtail or postpone dust-causing activities.

Beyond that, however, environmental officials are running out of tricks. “There’s just not much left this area can do,” Massey said.

Just as Arizona’s prosperity is centered in Phoenix, so are the consequences. Ozone alerts, haze hanging over the city, dust that sometimes clouds the skies are a part of life. They’re the price people pay for living in a booming metropolis in the middle of a desert.

Phoenix may have no alternative but to forever do penance for the dust it kicks up. But the mix overhead will become even more volatile if the city keeps growing without new breakthroughs in vehicle emissions.

The war over Phoenix hangs in the balance.

– Richard Gilman

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