Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, August 1, 1993 TAG: 9308010087
SECTION: VIRGINIA PAGE: D1 EDITION: METRO
SOURCE: CATHRYN McCUE STAFF WRITER
DATELINE: LENGTH: Long
The air around here is cleaner than it used to be.
Although you can't tell by sight or smell, there's less sulfur dioxide, less nitrous oxide and fewer dust particles floating around out there.
For the past 12 years, emissions from the region's industries and other air pollution dischargers have steadily declined, said Don Shepherd, regional director of the Department of Environmental Quality's air division.
Industries are cleaning up their act and reducing the smokestack, or point-source pollution, under federal and state mandates, as well as economic necessity.
Even so, the air isn't as clean as it could be.
"These reductions are being eaten up to a large extent by vehicle emissions and routine activities," Shepherd said.
The number of cars on our roads has increased. The number of miles we drive to work, shop and play has grown. We have more wood-burning stoves, charcoal grills, lawn mowers and weed-eaters.
Shepherd's smokestack measurements do not include these kinds of mobile, non-point sources. However, he guessed that if all that air pollution was figured in, the air over Southwest Virginia would still be a little cleaner and healthier than in 1980.
Federal law requires major industries that are new or expanding to install the "best available control technology" - or BACT, as it's known in the air business - to limit air pollution.
Virginia is one of a handful of Southern states that require all industries seeking an air-pollution permit to install BACT - when economically feasible.
Although that caveat may allow some industries to use less than the best technology, Shepherd said, the requirement seems to have paid off overall in terms of cleaner air.
In this regulatory region, which covers an "airshed" stretching from Pulaski and Floyd counties to Rockingham County:
Carbon monoxide emissions from industrial sources dropped from 18,800 tons in 1980 to about 11,500 tons last year.
Nitrogen oxides dropped from 31,500 tons to 22,000.
Sulfur dioxide dropped from 64,300 tons to 42,700.
Particulate matter dropped from 25,000 tons to 7,400.
Volatile organic compounds - such as gasoline fumes from tank storage farms and solvents from furniture factories and other manufacturing processes - dropped from 35,600 tons to 29,800.
In 1991, four of the top 10 air polluters in the state were located in this region: Hoechst Celanese Corp. in Giles County, the Radford Army Ammunition Plant in Pulaski County, and two separate sources at Westvaco Corp. in Covington.
Shepherd said that these plants are doing "a lot to bring about real changes" in their air emissions.
Hoechst has spent millions of dollars to bring its acetone emissions under control. The plant, which makes synthetic fibers for clothing and cigarette filters, now captures 99 percent of its acetone emissions. Still, Shepherd said, the 1 percent that escapes amounts to about 5,000 tons a year, landing Hoechst at the top of the list of state polluters.
At Westvaco, emissions are significantly down since the company launched a $500 million expansion a couple years ago, Shepherd said. Under stricter permit requirements, the pulp company put in a new major boiler, odor-control equipment, and an incinerator to burn off some emissions. It also changed its bleaching process to reduce air pollution.
Contrary to popular belief, one of the major threats to human health and the environment is not factory pollution. Not directly, anyway.
It's ozone.
In the stratosphere, "good" ozone protects the earth from harmful ultraviolet sun rays. But in the troposphere - down here on the planet surface - "bad" ozone is a respiratory irritant that causes shortness of breath and aggravates symptoms of lung disease.
The compound - three oxygen molecules linked together - is formed from a complex series of chemical reactions that occur in sunlight.
When nitrogen oxides meet volatile organic compounds (paint solvents, gas fumes, car emissions and so forth) on a sunny day, ozone levels can jump dramatically. These other compounds, called precursors, come from industrial emissions, as well as from our cars and other daily activities.
In 1979 and 1980, this region - from the New River Valley to the Shenandoah Valley - was classified as "non-attainment" for ozone. That meant the pollutant had gone over the federal limit three times in three years.
Since then, the levels have dropped significantly, Shepherd said, and the region has gone over the limit only twice - both in 1988, a particularly hot summer.
Last year, the Northern Virginia, Richmond and Hampton Roads areas - all known for their traffic congestion - were designated as "non-attainment" for ozone in Virginia. Northern Virginia also was given the designation for carbon monoxide.
Automobiles are responsible for 40 percent of the precursor compounds in the Roanoke area, Shepherd said.
But the ozone levels would appear to be on a sort of roller coaster ride. Years ago, new rules required better pollution control on cars, so pollution decreased.
Recently, the city's population has stabilized, so the number of cars is more or less constant. Pollution remains steady.
But people are driving more, so there are more emissions and more ozone.
Now, with a new, cleaner fleet of cars hitting the road starting in a few years - as required under the 1990 Clean Air Act - ozone levels may drop again, Shepherd said.
In Southwest Virginia, ozone has remained at acceptable levels for people to breathe. Not so for trees, crops and other vegetation.
Ozone damage has been seen from the Shenandoah National Park to the Mount Rogers National Recreation Area.
It shows up as red spots on the tops of leaves, which eventually fall off if the damage is severe. By inhibiting photosynthesis and weakening a plant's natural immune system, ozone can prove fatal.
Environmentally speaking, ozone is the most serious air pollution threat in the Southeast, said U.S. Forest Service botanist Beth Brantley. Vegetation can be damaged by concentrations as low as 0.05 parts per million for a few hours. The federal human health standard is 0.12 ppm for one hour.
For instance, a black cherry tree in full bloom in June can lose more than half its leaves to ozone in one month, she said.
Brantley was on hand to help train forest employees and staff from several state agencies to identify ozone damage. The U.S. Forest Service is doing a first-time survey this month on the extent of ozone damage on vegetation in the Jefferson and George Washington forests in Virginia and the Daniel Boone National Forest in Kentucky.
"How will the ecosystem be affected if we lose our species or one species becomes more dominant?" - that's the question that must be answered, said Cindy Huber, air resource specialist with the Jefferson National Forest.
With more reliable and comprehensive data on the extent of ozone damage in the forests, federal and state regulators will have a better lever to get industries to comply with standards, or get politicians to change the standards if need be, Huber said.
The areas that will be surveyed are the James River Face Wilderness Area, Mountain Lake in Giles County, Lewis Fork Wilderness Area and the Clinch Ranger District.
Whitetop Mountain in the Mount Rogers area will also be surveyed. Since 1988, the 5,550-foot peak has been classified as "non-attainment" for the ozone standard.
There's no industry up there and no bumper-to-bumper traffic. Clouds carrying ozone drift up from the more industrialized Tennessee and Ohio valleys, and "bump into this area, and there's nothing to absorb it or eat it up or react with it to dissipate it," Shepherd explained.
The mountain has not been monitored since 1988, so the ozone levels may have dropped. Last spring, the EPA set up an ozone monitor, but the results are not in yet.
Healthy, clean air means more than better lung power. It also means continued economic development potential, Shepherd said.
Under a federal program called Prevention of Significant Deterioration, an area with clean air is allowed to incrementally increase certain pollutants.
Industries and others must apply for a permit to do that and show that their emissions would not exceed the allowable increase.
In the Roanoke Valley, Shepherd said, the issue has not come up because no major industry has moved in that would trigger those requirements.
And routine growth here has not affected the most sensitive air quality area nearest Roanoke - the James River Face Wilderness Area, 30 miles away.
So the valley has a good deal of room to go, as far as air quality is concerned. But growth doesn't have to mean dirtier air, Shepherd said.
"You can have lots of economic development and employ a lot of people and not have a lot of emissions."
by CNB