We believe that operators in all of our target markets are under intense pressure to meet current and proposed federal, state and local emissions standards. As a result, we believe that these standards are a significant driver in our development and sales efforts and that our Duplex technology can provide a unique, cost-effective pollution control solution for operators in comparison to competing products.
Emissions standards largely emanate from the Clean Air Act, which is administered by the Environmental Protection Agency (EPA) and regulates six common criteria air pollutants, including ground-level ozone. These regulations are enforced by state and local air quality districts as part of their compliance plans. As a precursor to ground-level ozone, nitrogen oxides (NOx) are regulated emissions by local air quality districts in order to achieve the EPA limits. The 8-hour ground-level ozone regulations have been reduced from 84 parts per billion (ppb) in 1997, to 75 ppb in 2008, and 70 ppb in 2015, with the requirement of realizing these levels approximately 25 years following the year of legislation. The areas of non-attainment related to this 1997 limit of 84 ppb are depicted below in the map on the left and the projected areas of non-attainment related to the 2015 limit of 70 ppb are depicted below in the map on the right.