2918 25 STORMWATER 4825 Revised Final

recharge, stormwater runoff quantity control, and stormwater runoff quality treatment as follows: 1. The minimum standards for erosion control are those established under the Soil and Sediment Control Act, N.J.S.A. 4:24-39 et seq., and implementing rules at N.J.A.C. 2:90. 2. The minimum standards for groundwater recharge, stormwater quality, and stormwater runoff quantity shall be met by incorporating green infrastructure.

12 B. The standards in this ordinance apply to all major and minor development and are intended to minimize the impact of stormwater runoff on water quality and water quantity in receiving water bodies and maintain groundwater recharge. The standards do not apply to new major development to the extent that alternative design and performance standards are applicable under a regional stormwater management plan or Water Quality Management Plan adopted in accordance with Department rules. C. Stormwater management measures for minor development shall be designed to provide erosion control, groundwater recharge and stormwater runoff quantity control through the utilization of green infrastructure techniques as follows: 1. Stormwater management facilities shall be designated to manage 6 inches of rainfall on all new impervious surfaces and meet the standards for runoff quantity and green infrastructure. 2. Soil Testing shall be performed in accordance with the current rules at N.J.A.C. 7:8. 3. The minimum standards for erosion control established under the Soil Erosion and Sediment Control Act, N.J.S.A. 4:24-39 et seq., and implementing rules at N.J.A.C. 2:90 shall be met. 4. Regular and effective maintenance shall be performed for all stormwater management facilities and shall be protected by owner. Note: Alternative standards shall provide at least as much protection from stormwater-related loss of groundwater recharge, stormwater quantity and water quality impacts of major development projects as would be provided under the standards in N.J.A.C. 7:8-5. § 25-29.4—Stormwater Management Requirements for Major Development A. The development design shall use Low Impact Development Techniques to achieve the minimum of stormwater runoff that must be managed through green infrastructure and other stormwater management measures. Retention of natural landscape features shall be emphasized in the design. B. The development shall incorporate a maintenance plan for the stormwater management measures incorporated into the design of a major development in accordance with § 25-29.12. C. Stormwater management measures shall avoid adverse impacts of concentrated flow on habitat for threatened and endangered species as documented in the Department’s Landscape Project or Natural Heritage Database established under N.J.S.A. 13:1B-15.147 through 15.150, particularly Helonias bullata

threatened and endangered species as documented in the Department’s Landscape Project or Natural Heritage Database established under N.J.S.A. 13:1B-15.147 through 15.150, particularly Helonias bullata (swamp pink) and/or Clemmys muhlnebergi (bog turtle) D. The following linear development projects are exempt from the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity requirements of § 25-29.4 Q, R and S:

13 1. The construction of an underground utility line, for any pipe size diameter, provided that the disturbed areas are revegetated upon completion; 2. The construction of an aboveground utility line provided that the existing conditions are maintained to the maximum extent practicable; and 3. The construction of a public pedestrian access, such as a sidewalk or trail with a maximum width of 14 feet, provided that the access is made of permeable material. E. A waiver from strict compliance from the green infrastructure, groundwater recharge, stormwater runoff quality, and stormwater runoff quantity requirements of § 25- 29.4P, Q, R and S may be obtained for the enlargement of an existing public roadway or railroad; or the construction or enlargement of a public pedestrian access, provided that the following conditions are met: 1. The applicant demonstrates that there is a public need for the project that cannot be accomplished by any other means; 2. The applicant demonstrates through an alternatives analysis, that using stormwater management measures, the option selected complies with the requirements of § 25-29.4P, Q, R and S to the maximum extent practicable; 3. The applicant demonstrates that, to meet the requirements of § 25-29.4P, Q, R and S, existing structures currently in use, such as homes and buildings, would need to be condemned; and 4. The applicant demonstrates that it does not own or have other rights to areas, including the potential to obtain through condemnation lands not falling under § 25-29.4d3 above within the upstream drainage area of the receiving stream, that would provide additional opportunities to mitigate the requirements of § 25- 29.4P, Q, R and S that were not achievable onsite. F. Tables 1 through 3 below summarize the ability of stormwater best management practices identified and described in the New Jersey Stormwater Best Management Practices Manual to satisfy the green infrastructure, groundwater recharge, stormwater runoff quality and stormwater runoff quantity standards specified in § 25-29.4P, Q, R and S. When designed in accordance with the most current version of the New Jersey Stormwater Best Management Practices Manual, the stormwater management measures found at N.J.A.C. 7:8-5.2 (f) Tables 5-1, 5-2 and 5-3 and listed below in Tables 1, 2 and 3 are presumed to be capable of providing stormwater controls for the

nual, the stormwater management measures found at N.J.A.C. 7:8-5.2 (f) Tables 5-1, 5-2 and 5-3 and listed below in Tables 1, 2 and 3 are presumed to be capable of providing stormwater controls for the design and performance standards as outlined in the tables below. Upon amendments of the New Jersey Stormwater Best Management Practices to reflect additions or deletions of BMPs meeting these standards, or changes in the presumed performance of BMPs designed in accordance with the New Jersey Stormwater BMP Manual, the Department shall publish in the New Jersey Registers a notice of administrative change revising the applicable table. The most current version of the BMP Manual can be found on the Department’s website at: https://dep.nj.gov/stormwater/bmp-manual/.

14 G. Where the BMP tables in the NJ Stormwater Management Rule are different due to updates or amendments with the tables in this ordinance the BMP Tables in the Stormwater Management rule at N.J.A.C. 7:8-5.2(f) shall take precedence.

15 Table 1 Green Infrastructure BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity Best Management Practice Stormwater Runoff Quality TSS Removal Rate (percent) Stormwater Runoff Quantity Groundwater Recharge Minimum Separation from Seasonal High- Water Table (feet) Cistern 0 Yes No -- Dry Well(a) 0 No Yes 2 Grass Swale 50 or less No No 2(e) 1(f) Green Roof 0 Yes No -- Manufactured Treatment Device(a) (g) 50 or 80 No No Dependent upon the device Pervious Paving System(a) 80 Yes Yes(b) No(c) 2(b) 1(c) Small-Scale Bioretention Basin(a) 80 or 90 Yes Yes(b) No(c) 2(b) 1(c) Small-Scale Infiltration Basin(a) 80 Yes Yes 2 Small-Scale Sand Filter 80 Yes Yes 2 Vegetative Filter Strip 60-80 No No -- (Notes corresponding to annotations (a) through (g) are found after Table 3) Table 2 Green Infrastructure BMPs for Stormwater Runoff Quantity (or for Groundwater Recharge and/or Stormwater Runoff Quality with a Waiver or Variance from N.J.A.C. 7:8-5.3) Best Management Practice Stormwater Runoff Quality TSS Removal Rate (percent) Stormwater Runoff Quantity Groundwater Recharge Minimum Separation from Seasonal High Water Table (feet) Bioretention System 80 or 90 Yes Yes(b) No(c) 2(b) 1(c) Infiltration Basin 80 Yes Yes 2

16 Sand Filter(b) 80 Yes Yes 2 Standard Constructed Wetland 90 Yes No N/A Wet Pond(d) 50-90 Yes No N/A (Notes corresponding to annotations (b) through (d) are found after Table 3) Table 3 BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity only with a Waiver or Variance from N.J.A.C. 7:8-5.3 Best Management Practice Stormwater Runoff Quality TSS Removal Rate (percent) Stormwater Runoff Quantity Groundwater Recharge Minimum Separation from Seasonal High Water Table (feet) Blue Roof 0 Yes No N/A Extended Detention Basin 40-60 Yes No 1 Manufactured Treatment Device(h) 50 or 80 No No Dependent upon the device Sand Filter(c) 80 Yes No 1 Subsurface Gravel Wetland 90 No No 1 Wet Pond 50-90 Yes No N/A (Notes corresponding to annotations (b) through (d) are found after Table 3) Notes to Tables 1, 2, and 3: (a) subject to the applicable contributory drainage area limitation specified at § 25- 29.4P2; (b) designed to infiltrate into the subsoil; (c) designed with underdrains; (d) designed to maintain at least a 10-foot-wide area of native vegetation along at least 50 percent of the shoreline and to include a stormwater runoff retention component designed to capture stormwater runoff for beneficial reuse, such as irrigation; (e) designed with a slope of less than two percent; (f) designed with a slope of equal to or greater than two percent; (g) manufactured treatment devices that meet the definition of green infrastructure at§ 25-29.2 ; (h) manufactured treatment devices that do not meet the definition of green infrastructure at . § 25-29.2

17 H. An alternative stormwater management measure, alternative removal rate, and/or alternative method to calculate the removal rate may be used if the design engineer demonstrates the capability of the proposed alternative stormwater management measure and/or the validity of the alternative rate or method to the municipality. A copy of any approved alternative stormwater management measure, alternative removal rate, and/or alternative method to calculate the removal rate shall be provided to the Department in accordance with § 25-29.6b. Alternative stormwater management measures may be used to satisfy the requirements at § 25-29.4P only if the measures meet the definition of green infrastructure at § 25-29.2. Alternative stormwater management measures that function in a similar manner to a BMP listed at § 25-29.4P2 are subject to the contributory drainage area limitation specified at § 25-29.4P2 for that similarly functioning BMP. Alternative stormwater management measures approved in accordance with this subsection that do not function in a similar manner to any BMP listed at § 25-29.4P2 shall have a contributory drainage area less than or equal to 2.5 acres, except for alternative stormwater management measures that function similarly to cisterns, grass swales, green roofs, standard constructed wetlands, vegetative filter strips, and wet ponds, which are not subject to a contributory drainage area limitation. Alternative measures that function similarly to standard constructed wetlands or wet ponds shall not be used for compliance with the stormwater runoff quality standard unless a variance in accordance with N.J.A.C. 7:8-4.6 or a waiver from strict compliance in accordance with § 25-29.4E is granted from § 25-29.4P. I. Whenever the stormwater management design includes one or more BMPs that will infiltrate stormwater into subsoil, the design engineer shall assess the hydraulic impact on the groundwater table and design the site, to avoid adverse hydraulic impacts. Potential adverse hydraulic impacts include, but are not limited to, exacerbating a naturally or seasonally high-water table, to cause surficial ponding, flooding of basements, or interference with the proper operation of subsurface sewage disposal systems or other subsurface structures within the zone of influence of the groundwater mound, or interference with the proper functioning of

nce with the proper operation of subsurface sewage disposal systems or other subsurface structures within the zone of influence of the groundwater mound, or interference with the proper functioning of the stormwater management measure itself. J. Design standards for stormwater management measures are as follows: 1. Stormwater management measures shall be designed to take into account the existing site conditions, including, but not limited to, environmentally critical areas; wetlands; flood-prone areas; slopes; depth to seasonal high-water table; soil type, permeability through soil testing described in Chapter 12 of the NJ BMP manual, and texture; drainage area and drainage patterns; and the presence of solution-prone carbonate rocks (limestone); 1. 2. Stormwater management measures shall be designed and demonstrated not to negatively impact wetlands or watercourses on site or adjacent to the property. 2. 3. Stormwater management measures shall be designed to minimize maintenance, facilitate maintenance and repairs, and ensure proper functioning. Trash racks shall be installed at the intake to the outlet structure, as appropriate,