2918-25 STORMWATER final 4_1_25.doc.pdf

24 R = A + B – (A x B) / 100, Where R = total TSS Percent Load Removal from application of both BMPs, and A = the TSS Percent Removal Rate applicable to the first BMP B = the TSS Percent Removal Rate applicable to the second BMP. 6. Stormwater management measures shall also be designed to reduce, to the maximum extent feasible, the post-construction nutrient load of the anticipated load from the developed site in stormwater runoff generated from the water quality design storm. In achieving reduction of nutrients to the maximum extent feasible, the design of the site shall include green infrastructure BMPs that optimize nutrient removal while still achieving the performance standards in§ 25- 29.4Q, R and S. 7. In accordance with the definition of FW1 at N.J.A.C. 7:9B-1.4, stormwater management measures shall be designed to prevent any increase in stormwater runoff to waters classified as FW1. 8. The Flood Hazard Area Control Act Rules at N.J.A.C. 7:13-4.1(c)1 establish 300-foot riparian zones along Category One waters, as designated in the Surface Water Quality Standards at N.J.A.C. 7:9B, and certain upstream tributaries to Category One waters. A person shall not undertake a major development that is located within or discharges into a 300-foot riparian zone without prior authorization from the Department under N.J.A.C. 7:13. 9. Pursuant to the Flood Hazard Area Control Act Rules at N.J.A.C. 7:13-11.2(j)3.i, runoff from the water quality design storm that is discharged within a 300-foot riparian zone shall be treated in accordance with this subsection to reduce the post-construction load of total suspended solids by 95 percent of the anticipated load from the developed site, expressed as an annual average. 10. The stormwater runoff quality standards do not apply to the construction of one individual single-family dwelling, if it is not part of a larger development or subdivision that has received preliminary or final site plan approval prior to December 3, 2018, and that the motor vehicle surfaces are made of permeable material(s) such as gravel, dirt, and/or shells. S. Stormwater Runoff Quantity Standards 1. This subsection contains the minimum design and performance standards to control stormwater runoff quantity impacts of major development. 2. The site shall be designed to manage, through on-site retention, the Retention Storm, (or ½ of the projected

erformance standards to control stormwater runoff quantity impacts of major development. 2. The site shall be designed to manage, through on-site retention, the Retention Storm, (or ½ of the projected 2-year storm per square foot, as reflected in Table 6) at the site or on contiguous properties in common ownership. The management shall be using one or more green infrastructure techniques and shall apply to the total impervious on the site, both retained and proposed. 2. 3. To control stormwater runoff quantity impacts, the design engineer shall, using the assumptions and factors for stormwater runoff calculations at§ 25-29.5, complete one of the following: