What is the threshold for land disturbance that triggers the need for a CGP?

The threshold for land disturbance that requires a Construction General Permit (CGP) is typically set at 1 acre or more. This requirement is significant because the permit is intended to manage the environmental impact of stormwater runoff from construction activities, which can contribute to erosion and sedimentation. When land is disturbed on a scale of 1 acre or more, the risk of sedimentation entering local waterways increases, necessitating increased regulatory oversight to protect water quality.

The CGP includes guidelines for implementing best management practices (BMPs) to control erosion and manage sediment during construction activities. By establishing this threshold, regulatory agencies aim to ensure that larger disturbances, which are likely to have a more significant impact on the environment, are monitored and managed effectively. This threshold aligns with the federal regulations under the National Pollutant Discharge Elimination System (NPDES), reinforcing the importance of addressing water quality concerns associated with larger construction sites.