Major Modifications must be approved by S.C. DHEC or permitting entity (MS4, Delegated Program) prior to being implemented in the field. The majoritiy of alterations that affect the volume of stormwater discharges and/or any of the site drainage patterns will be required to be submitted for review before implementation.
Minor Modifications are simple design changes that are required to address unforeseen drainage issues that may have been overlooked in the design phase. An example of this type of modification would be the addition of riprap check dams or sediment tubes in a swale to help maintain non-erosive velocities within the channel. All Minor Modifications may be implemented without approval, however all minor changes should be recorded on the on-site construction plans.
Below is a list of items that S.C. DHEC considers as Major or Minor Modifications to the Stormwater Pollution Prevention Plan (SWPPP). These are not all inclusive lists.
Please submit all Major Modifications to S.C. DHEC or Affliated Permitting Entity (MS4)
Where To Submit Modifications
If you have any questions as to whether a Modification would be considered major or minor, please contact the permitting entity before proceeding with the modification.