Located at the confluence of America’s two great rivers, the St. Louis region is defined by its access to water and its fertile alluvial soil. A healthy environment is the key to maintaining the quality of our local natural resources. These resources include abundant supplies of clean water, clean and healthy air, and our distinctive natural landscapes.
Water is an essential element that is locally sourced, treated, and consumed, and a critical ingredient in goods that are locally produced. As a result of human activities, however, many of our lakes and streams are not safe for human contact. To improve water quality, cities and sewer districts are expanding wastewater treatment and beginning to manage stormwater runoff. The St. Louis region will spend several billion dollars to construct and improve sewer infrastructure over the next 20 years.
Clean air is a natural resource that is most often taken for granted, but is essential for survival of the regional population and local economy. The primary air pollutants of concern to human health at a regional scale are ozone and fine particulate matter (PM2.5). Ozone is created when factory emissions and car exhaust (hydrocarbons and nitrogen oxides), in the presence of strong sunlight and high temperatures, chemically react with oxygen in the lower atmosphere. Fine particulate matter can be emitted into the lower atmosphere either directly or indirectly: directly through factory smoke stacks and cars and indirectly by precursor emissions from car exhaust and factory emissions with a formation process similar to ozone. The St. Louis region is a designated non-attainment area for PM2.5 and although the region has reached compliance with the 1997 annual standard for PM2.5, it does not currently meet the newer, more restrictive 2012standard. Likewise for ozone, the region reached compliance with the older standard just as a newer standard was adopted by the U.S. Environmental Protection Agency.6
Although the region is not achieving current standards, the regional air quality shows a continuous trend toward improvement. Over time, improvements in vehicle technology, more extensive vehicle emissions testing, and reformulated gasoline have helped combat air pollution, but emissions from older factories, power plants and the large number of vehicles traveling throughout the region contribute to a significant number of days that exceed the ozone standard.
