percent reduction of total nitrogen, the design of the site shall include green infrastructure in accordance with the BMP Manual and shall optimize nutrient removal. The minimum 65 percent total nitrogen reduction may be achieved by using a singular stormwater management measure or multiple stormwater management measures in series.

The runoff from the site will be treated to a minimum of 65 percent reduction of the post-construction total nitrogen load. The runoff from the area is designed to be routed through bioretention basins or porous pavement and then to infiltration basins. The bioretention basins will reduce the nitrogen load by 30%, and the infiltration basins will reduce the remaining nitrogen load by 50%, for a total reduction of 65%, which meets the required reduction. The porous pavement will reduce the nitrogen load by 50%, and the infiltration basins will reduce the remaining nitrogen load by 50%, for a total reduction of 75%, which meets the required reduction. Runoff from roof areas will be piped directly into subsurface infiltration basins.

In accordance with N.J.A.C. 7:8-5.5(b) stormwater management measures shall be designed to reduce the post-construction load of total suspended solids (TSS) in stormwater runoff generated from the water quality design storm by eighty percent TSS removal of the anticipated load, expressed as an annual average for the stormwater runoff from the net increase of motor vehicle surface.

The site has a total proposed motor vehicle surface of 0.79 acres. The roads, driveways, and lawn area drain into bioretention basins or porous pavement (80% TSS removal) and then subsurface infiltration basins (80% TSS removal), which will act in series and provide a combined 96% TSS removal.

• v.Stormwater management measure design, siting and construction standards:
• Stormwater management measures designed to infiltrate stormwater shall be designed, constructed, and maintained to provide a minimum separation of at least two feet between the elevation of the lowest point of infiltration and the seasonal high water table;
• The stormwater management measures will provide a minimum separation of at least two feet between the elevation of the lowest point of infiltration and the seasonal high-water table. All the proposed stormwater management infiltration basins have been designed by setting the basin bottom at a minimum of two feet above the seasonal high-water table. The basin bottom and seasonal high-water table elevations for each basin or porous pavement area are included in the Green Infrastructure section below.
• Stormwater management measures shall be sited in suitable soils verified by testing to have permeability rates between one and 20 inches per hour. A factor of safety of two shall be applied to the soil's permeability rate in determining the measure's design permeability rate. If such soils do not exist on the parcel proposed for development or if it is demonstrated that it is not practical for engineering, environmental, or safety reasons to site the stormwater infiltration measure(s) in such soils, the stormwater infiltration measure(s) may be sited in soils verified by testing to have permeability rates in excess of 20 inches per hour, provided that stormwater is routed through a bioretention system prior to infiltration. Said bioretention system shall be designed, installed and maintained in accordance with the New Jersey Stormwater Best Management Practices Manual;

18 | Page