Which of the following lists three permanent stormwater BMPs commonly required for post-construction sites?

• A. Silt fences, sediment basins, and inlet protections.
• B. Detention/retention basins, infiltration practices, and vegetated swales/bioretention areas.
• C. Temporary berms and tarps.
• D. Check dams, rock reduces, and noise barriers.

Answer: (B)

Permanent post-construction BMPs are features designed to manage runoff from developed areas after construction is finished, keeping them in place year after year. The best-known set includes detention/retention basins, infiltration practices, and vegetated swales or bioretention areas. Detention or retention basins help control how quickly runoff leaves the site, reducing peak flows and giving sediments a chance to settle—this is a long-term feature, not just something installed during construction. Infiltration practices allow runoff to soak into the ground, reducing the amount of runoff and promoting groundwater recharge, but they rely on appropriate soil conditions and subsurface compatibility. Vegetated swales and bioretention areas use plants, soil, and microbial processes to remove pollutants as runoff flows through them, providing ongoing treatment and conveyance.

The other options describe measures that are primarily used during construction to control erosion and sediment, or items that aren’t typically considered permanent post-construction BMPs. Silt fences, inlet protections, and sediment basins are commonly temporary during site work, and temporary berms or tarps are not permanent solutions. Check dams, rock reductions, and similar structures are not standard permanent post-construction BMPs.