What are "treatment trains" in stormwater management?

In stormwater management, "treatment trains" refer to a sequence of Best Management Practices (BMPs) designed to work together for the effective removal of pollutants from stormwater runoff. Each BMP in the treatment train addresses different types of contaminants and, when combined, they enhance the overall water quality treatment process. The idea is that as stormwater moves through these multiple interrelated practices, it undergoes various physical, biological, and chemical processes that improve the quality of the water before it is released into the environment.

This approach allows for a more comprehensive strategy to manage stormwater impacts, specifically addressing the varying pollutant loads that different storm events may bring. The effective design of treatment trains can thus lead to better compliance with regulatory standards and improved ecological outcomes. Examples of BMPs that may be included in a treatment train are sediment basins, bioretention areas, green roofs, and vegetative swales, among others.