A Guide for Best Management Practice (BMP) Selection in Urban Developed Areas

Book excerpt: This guide examines permanent structural techniques, or Best Management Practices (BMPs), which can be used for retrofitting the stormwater management systems in existing developed areas. The advantages and disadvantages of each technique are explained to help engineering professionals select the BMP (or series of BMPs) best suited for removing pollutants from stormwater runoff at a particular location. The design factors considered include land availability, type of pollutant to be removed, groundwater levels, soil types, BMP costs, maintenance costs, and desired pollutant removal efficiency. The BMPs evaluated are ponds, alum treatment systems, constructed wetlands, sand filters, baffle boxes, inlet devices, vegetated swales, buffer strips, and infiltration/exfiltration trenches. A BMP Selection Guide, in an easy-to-use matrix format, aids in the decision-making process for BMP selections. Five design factors and five pollutant types (total suspended solids, total phosphorus, total nitrogen, heavy metals, and floating trash) are evaluated for each BMP in the matrix. BMPs presented in this guide were chosen based upon common availability, ease of maintenance, and an established track record.