Friday, October 7, 2011

The Cleaning Power of Storms

by Lee Waites


Air pollution has become a major problem for the people of Birmingham. Weather events directly affect the atmosphere’s ability to process and clean the air we breathe. Knowing and understanding the effects of weather on manmade contaminants and pollution will help us better react to the needs of our environment. Knowing and understanding the needs of our environment can help us make better choices about what we do and do not allow to happen.

What is happening in the world around us is not always obvious, unless we know what to look for.
Inversion, one common weather event, which occurs often in the cooler months, is when the cold air in the upper atmosphere pushes down on the warmer air below. According to Matt Lacke, Meteorologist for the Jefferson County Department of Health, “Calm conditions overnight, not a lot of wind, cause an accumulation of particulates, especially the valley areas.” This is basically what it sounds like, a blanket of cooler air trapping in the warmer, stagnant air, which is full of pollution. “So topography plays a role as well in Birmingham, not just weather. Especially across Downtown and Northside which are kind of in the valley. The cooler air traps the particulate matter closer to the ground, mostly in the morning hours. So when the air begins to heat up a little later in the day, the particulate matter is allowed to disperse more into the atmosphere.”

These days we don’t think of calm weather as a possible emergency. We’ve had years of federally mandated environmental policies that have somewhat protected us from particulate pollution. But with the growing population beginning to overwhelm our outdated regulations, as evidenced by our constant poor ozone quality throughout the summer, we could easily see these inversion events leading to more severe situations for public health, especially if we allow the EPA to be hamstrung as many are attempting now. It’s too easy to forget why the EPA was created.

Kirsten Bryant, with the local environmental advocacy group GASP, recounts one historical weather event that heavily impacted Birmingham, “In fact it was 40 years ago in 1971. It was a weather inversion that Birmingham was experiencing that held particle pollution in place . . . And this was when Alabama was not enforcing the clean air act, and it actually created a public health emergency. Thankfully our air is a lot cleaner than it was back then. But we still have weather inversions. And we still have a pollution problem.” GASP is a rebirth of a group that started years ago, whose original members tell stories of smog so bad you could not see across the city. GASP focuses on educating the public and advocating for clean air. “One good thing is when we have a weather event it can cool down the air, which helps reduce the ozone problem. And the rain can help clear out our particle pollution problem,” says Bryant.

Rain events and thunderstorms have a very beneficial effect on the air we breathe. The falling rain actually pushes the particle pollution to the ground where it can be washed away, wind brings in fresher, cleaner air. Unfortunately there are other consequences for the environment. Heavy rains and storms, with rapid rainfall, do not give the ground time to absorb the falling water. It flows rapidly across the ground, catching debris, spilled oil, litter and other pollutants. In an urban setting this means the water is carried directly into the storm drains, bypassing the regular filtration channels where eventually it winds up depositing its contaminated load into creeks, rivers, lakes and streams.

Industry and mining are also issues in storm events. Nelson Brooke, of Black Warrior Riverkeeper points out many issues of concern. “Harder rain and more volume of rain is definitely going to cause runoff patterns to change significantly . . . since our landscape has changed significantly. These bigger storms are going to be able to push off lots more water than we’ve seen. Riverbank erosion is going to be a bigger issue. That’s going to pull sediment, rocks and shrubs and wash them downriver. “According to Brooke, there are many problems created by the increased volume of rain, and intensity of storms. River banks become overwhelmed, allowing flooding of surrounding areas. As the water washes back out, the pollutants picked up are carried into the rivers as the floodwaters recede.

Brooke is mainly concerned with the impacts of industrial waste, which he says gets carried into the watershed in different ways during severe weather. “Industries are permitted to discharge pollution in certain amounts. There are certain basic controls that are put into place through these permits …most of those designs are put into place for certain types of rain events. They’re not really set up to handle your 50, 75 or 100 year storms. I don’t even know how they calculated those things back in the day. But things are changing. Storms are happening more often, more violently. The landscape has changed alot. Clear cutting, strip mining, development, it’s all getting rid of the forest and land-cover that would slow down runoff during a big storm. There’s a definite connection there for a construction site or a coal mine that has a sediment pond that’s designed to handle your typical 24 hour rain event. When you get a much larger storm they’re not going to be able to handle that. These larger rain events are just going to overload their pollution control systems.”

Finding ways to convince or force industries to respect and further advances in clean environment technology is impossible at times. According to Nelson Brooke reducing profit margins is the argument he hears most for avoiding change. One has to wonder if that is even a successful business move given the example of the auto industry. Ford, the now dominant US auto maker owes its current success, in large part to its new, smaller, more fuel efficient cars. The Chinese are rapidly moving forward with government aided green industries, as their economy moves to overtake ours as the strongest in the world. Everywhere are examples of the profitability of going green with few exceptions. Even if it could be argued as slightly less profitable to do the right thing, isn’t doing the right thing just, well…the right thing to do?

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