BMP inspections for construction sites in Charleston County, SC

Charleston County is one of the fastest-growing construction markets in the Southeast. Large residential developments in Summerville, Goose Creek, and the Johns Island corridor, commercial and logistics construction along I-26 and I-526, port-related industrial development, and mixed-use projects in North Charleston all require NPDES permit coverage once they disturb one acre or more of land. The SCDHEC Construction General Permit applies to every qualifying project in the county, with the same inspection schedule that applies statewide.

Any construction project disturbing one acre or more in South Carolina must obtain coverage under the SCDHEC Construction General Permit. The CGP sets two independent inspection clocks: at minimum once every seven calendar days during active land disturbance, and within 24 hours of a rainfall event of 0.5 inches or greater at the site. The two schedules run independently. A rain event inspection does not satisfy or reset the seven-day requirement.

SWPPP inspections in South Carolina must be conducted by a Certified Erosion Prevention and Sediment Control Inspector (CEPSCI). The inspection record must cover every installed BMP and must be kept current and available for SCDHEC review. Records stay in the SWPPP for at least three years. SCDHEC's coastal region office covers Charleston, Berkeley, and Dorchester counties and conducts field inspections throughout the Lowcountry.

Charleston County's coastal setting adds complexity to BMP inspection and documentation that inland markets don't face. Flat topography and high water tables mean sediment basins fill faster and outfall conditions change more quickly after rain events than on higher-gradient inland sites. Proximity to tidal waterways, marshes, and the ACE Basin makes discharge point documentation particularly important. SCDHEC's coastal enforcement program pays close attention to sediment discharge to protected coastal waters.

Sites near tidal waterways in the Johns Island, James Island, and Wadmalaw Island areas often have discharge points that are difficult or impossible to reach by ground inspection. The marsh fringe surrounding many Lowcountry construction sites means the perimeter BMP conditions most relevant to water quality are also the least accessible. A drone flight covers the full perimeter including discharge points, sediment basin outfalls, and marsh-adjacent silt fence runs in a single session.

Charleston County receives some of the highest annual rainfall totals in South Carolina, driven by frequent afternoon sea-breeze thunderstorms from June through September and tropical moisture events from August through October. The 0.5-inch rain event trigger fires regularly during the summer construction season. An active Lowcountry site can require eight to twelve inspections in a single month during peak season, combining weekly inspections with multiple rain event responses.

For SWPPP consultants managing sites across Charleston, Dorchester, and Berkeley counties, the geography compounds the problem. A storm that produces 0.5 inches across the Lowcountry triggers simultaneous 24-hour inspection obligations across every active site in all three counties. Sites in Goose Creek, Summerville, and the greater North Charleston area are spread across a large enough area that covering all of them within 24 hours by ground inspection alone requires significant resources.

A complete BMP inspection on a Charleston County construction site covers every installed control: silt fence along the full disturbed perimeter, sediment basins and traps with current pool levels and outlet conditions, inlet protection at each drop and curb inlet, stabilized construction entrance, slope stabilization measures, and any active erosion or BMP failure. The inspection record must note the condition at each BMP location and identify any corrective action required.

On coastal sites, the inspection should also document discharge point conditions at every outfall to an adjacent waterway or marsh. An inspection record that documents interior BMPs but omits discharge point conditions at a site adjacent to a tidal waterway does not demonstrate that the most environmentally significant conditions were assessed.

Environmental consultants managing multiple active permitted sites across Charleston, Dorchester, and Berkeley counties can use aerial documentation to expand coverage capacity on inspection days and rain event responses. We work as a drone documentation subcontractor on your existing inspection program. You remain the qualified inspector of record. We deliver GPS-tagged aerial documentation covering the full site and all BMP locations, organized by BMP type, formatted for your SWPPP log.

For Upstate SC construction sites in Greenville, Spartanburg, and Anderson counties, drone BMP inspections are handled by our Upstate partner, Upstate Drone Services.