(B.) OTC NOx - Regional Ozone Program in Place
As the federal SO2 program demonstrates, acid rain presents a complex set of problems for policy makers, regulators, environmentalists, and American industry. When compared to NOx controls, however, the SO2 program seems relatively straightforward.
NOx contributes to the acid rain problem nationwide and it contributes to the ground level ozone problems in the East and in certain densely populated areas in the rest of the country. In relation to acid rain, the concern about NOx is the issue of accumulation. The pollutant's effects build up over time and can have a lasting effect on the environment. In relation to ozone, the concern is about acute loading in which the build up of NOx emissions at any given time during the summer season is when the environmental and health impact is most great.
It is these temporal and spatial concerns that have influenced the design of NOx trading programs. Power plants in the Northeast increase generation in the summer months to meet their customers' needs for more electricity to run their air conditioners. These power plants are also emitting nitrogen oxides (NOx) that, combined with summer sunshine and other pollutants known as volatile organic compounds (VOCs), create ground-level ozone across the northeast region. Northeastern states have adopted a multi-state approach to address these concerns.