Stormwater runoff from construction activities can have a significant impact on water quality by contributing sediment and other pollutants to creeks, streams, rivers and lakes. That is why contractors and developers have a responsibility to prevent erosion and sediment from leaving construction sites. Contractors and developers are required to obtain coverage under the NYS SPDES General Permit for Stormwater Discharges from Construction Activity (GP-0-20-001) if the construction activity disturbs one acre or greater of land. Disturbance includes construction, demolition, clearing, grading, filling, excavating or grubbing.
Coverage under the permit involves a two-step process. The first step is preparation of a Stormwater Pollution Prevention Plan (SWPPP) detailing structural and non-structural measures that will be implemented on site to prevent erosion and control runoff and sediment transport from the site.
Specific practices required in the plan are:
- Reduction or elimination of erosion and sediment loading to waterways during construction
- Control of the impacts of stormwater runoff on the water quality of receiving waters
- Control of the increased volume and peak rate of runoff during and after construction
- Maintenance of stormwater controls during and after completion of construction
- Basic components of a SWPPP include:
- Narrative report describing pre-development conditions and details of the planned project
- Maps illustrating site location, topography, drainage area, existing and proposed structures, erosion and sediment control and stormwater control structures
- Erosion and Sediment Control Plan
- Water Quality and Water Quantity Control Plans
- Construction Sequence Schedule
- Owner and Contractor Certification Statements
- Operations and Maintenance Schedule
- Weekly Inspection Reports
Once the SWPPP is prepared for the project, contractors and developers must then file a Notice of Intent (NOI) requesting coverage under the GP-16-01 SPDES Permit for Stormwater Discharges and Construction Activities. Applicants that have met DEC's SWPPP requirements by utilizing the NYS Standards and Specifications for Erosion Sediment Control should receive coverage in 5 days and can then begin construction.
However, if the construction project is greater than 5 acres OR if the project is in a TMDL watershed or discharging to an impaired 303(d) water body, a Full SWPPP with post-construction stormwater controls must be prepared conforming with the NYS Stormwater Management Design Manual. Then an NOI can be submitted to DEC for a sixty-day review period. Coverage occurs after 60 days and then construction can begin.
When construction is finished and final site stabilization has been completed, contractors and developers must file a Notice of Termination (NOT) with DEC.