Submodule 12 C, Air Quality
Chapter 15 of your textbook has a good overview of air pollution control methods and equipment. I suggest you look through it. Here I want to talk a little about the Clean Air Act. There are three main sections to the act. The first and best known is not usually a HW matter, the second two are.
I grew up in New Jersey, where the kids said, "Never trust air you cannot see." Actually that was the generation after mine. My generation accepted that rivers sometimes caught on fire and some places smelled of chemicals. Highway 1 & 9, the Pulasky Skyway, was the "road of a thousand smells." The northern end of the highway near Manhattan is elevated over the swamps, which were used as a dump by New York City and the entire region for many years. The dump/swamp has been burning under the surface for 20 or 30 years, sometimes the fire surfaces. Patches of smoke are usually seen. As the highway goes south it passes though the chemical metropolis of Bayone and other industrial communities and the smell changes from hydrogen sulfide and sometimes acrid smoke to hydrocarbons. However it is much better today than in the past, and it continues to improve. Partly the result of the Clean Air Act and partly economics, the land close to New York is becoming very valuable and industry is giving way to residences that are much less tolerant of polluting.
The first section of the CAA involves regional air pollution by key "criteria pollutants," mostly combustion and motor vehicle related pollutants. These are controlled by region, and if a region is out of compliance, the region must take steps to get back into compliance. For example here in Fairbanks we have too much carbon monoxide in the air a few times a year. Therefore, until recently, we had to have our vehicles inspected. Other regions have been denied permits for new power plants or industries because the region's air was too polluted. This NAAQS section (The National Ambient Air Quality Standards Program) is seldom a HW issue.
The second section of the CAA deals with new sources of air pollution by certain industries. For these new industries, stringent control measures are required. These are sometimes a HW issue or at least HW-type people are involved, because the standards for the new sources are by category of control equipment ("Best Available Demonstrated Technology") and there is much variation in equipment and standards. This section applies to new sources of certain industries, such as "petroleum refineries," regardless of the region's status under the NAAQS.
The third section of the CAA controls emissions of a laundry list of almost 200 toxic chemicals. These are often HW issues and HW-type people are often involved with them. Some, like asbestos, are regulated in detail. For most others there is a threshold of 10 tons per year of the particular chemical that must be discharged before the permitting process kicks in. Once into the system, the discharge must be treated with the "maximum achievable control technology" which will be defined by the permit. This section is known as NESHAPs ("Knee Shaps", National Emission Standards for Hazardous Air Pollutants).
Here's the slide show.
Here is the text version of the quiz. Quiz