Which regulatory agency must approve major modifications to the On-Site SWPPP?

The South Carolina Department of Health and Environmental Control (DHEC) is the agency responsible for approving major modifications to the On-Site Storm Water Pollution Prevention Plan (SWPPP) in South Carolina. This is because DHEC is tasked with implementing state and federal environmental regulations within South Carolina, focusing on protecting water quality and managing stormwater runoff.

In this context, the SWPPP is a critical framework that outlines the measures and practices that must be implemented to prevent pollution from construction activities. When significant changes to this plan occur—such as modifications that could impact the site's water discharge or overall environmental compliance—DHEC must review and approve these changes to ensure they align with state regulations.

Other agencies, such as the Environmental Protection Agency (EPA), provide overarching federal regulatory frameworks but typically do not handle individual project modifications at the state level. The Department of Transportation (DOT) may be involved if transportation-specific regulations apply, but they do not directly manage stormwater plans. Similarly, local city councils may have a say in development projects but are not the approving authority for the environmental aspects directly governed by DHEC in this specific context. Therefore, understanding the local regulatory framework helps clarify DHEC's critical role in ensuring compliance with state environmental laws.