What is an NPDES permit and why do I need one?
The answer below is not all inclusive. Each site is different and other items may be required, but it does provide the highlights.
NPDES stands for National Pollutant Discharge Elimination System. There are various types of NPDES permits, but the most common type in Land Development and home building is a General NPDES permit. This permit is required by law when there is earth disturbance of one acre or more (including the removal of trees/shrubs).
The basic General Permit package includes Wetland and Stream Delineation, Erosion and Sediment Control Plans, Post Construction Stormwater Management Plans, and Infiltration Testing. All of those items have a written report associated with them.