- water
- stormwater
Erosion and sediment control is the set of temporary practices — silt fence, sediment basins, stabilized entrances, cover on bare ground — that a construction site uses to keep loosened soil from washing into storm drains and streams. Sediment is itself a regulated pollutant, and it carries phosphorus and other contaminants with it, so controlling it protects downstream water quality during the build.
ESC is the operative content of a site's stormwater plan under its construction general permit. Its demands scale with the site: erodible soils, the lower-infiltration HSG classes (C and D), and steeper slopes raise the curve number and shed more sediment-laden runoff, so they need more control. On a multi-hundred-acre data-center clearing, the adequacy and upkeep of erosion and sediment control is a recurring compliance question — and a lapse in it is a common early violation in the construction record.