[Added 2-28-2006 by Ord. No. 06-08; amended 3-10-2009 by Ord. No. 09-04; 11-23-2020 by Ord. No. 20-16]
[Amended 3-26-2024 by Ord. No. 24-05]
A. 
Policy statement; purpose.
(1) 
Flood control, groundwater recharge, and pollutant reduction shall be achieved through the use of stormwater management measures, including green infrastructure best management practices (GI BMPs) and nonstructural stormwater management strategies. GI BMPs and low-impact development (LID) should be utilized to meet the goal of maintaining natural hydrology to reduce stormwater runoff volume, reduce erosion, encourage infiltration and groundwater recharge, and reduce pollution. GI BMPs and LID should be developed based upon physical site conditions and the origin, nature and the anticipated quantity, or amount, of potential pollutants. Multiple stormwater management BMPs may be necessary to achieve the established performance standards for water quality, quantity, and groundwater recharge.
(2) 
Purpose. The purpose of this article is to establish minimum stormwater management requirements and controls for "major development," as defined below in § 215-118D. Further, the purpose of this article is to implement the requirements of the New Jersey Stormwater Rule (N.J.A.C. 7:8). In the event that any subsection of this article contradicts N.J.A.C. 7:8, the requirements of N.J.A.C. 7:8 shall govern.
B. 
Applicability.
(1) 
This article shall be applicable to all site plans and subdivisions for the following major developments that require preliminary or final site plan or subdivision review:
(a) 
Nonresidential major developments; and
(b) 
Aspects of residential major developments that are not preempted by the Residential Site Improvement Standards at N.J.A.C. 5:21.
(2) 
This article shall also be applicable to all major developments undertaken by the Township of Ewing.
(3) 
An application required by ordinance pursuant to Subsection B(1) above that has been submitted prior to February 13, 2024, shall be subject to the stormwater management requirements in effect on February 12, 2024.
(4) 
An application required by ordinance for approval pursuant to Subsection B(1) above that has been submitted on or after March 2, 2021, but prior to February 13, 2024, shall be subject to the stormwater management requirements in effect on February 12, 2024.
(5) 
Notwithstanding any rule to the contrary, a major development for any public roadway or railroad project conducted by a public transportation entity that has determined a preferred alternative or reached an equivalent milestone before July 17, 2023, shall be subject to the stormwater management requirements in effect prior to July 17, 2023.
C. 
Compatibility with other permit and ordinance requirements. Development approvals issued pursuant to this article are to be considered an integral part of development approvals and do not relieve the applicant of the responsibility to secure required permits or approvals for activities regulated by any other applicable code, rule, act, or ordinance. In their interpretation and application, the provisions of this article shall be held to be the minimum requirements for the promotion of the public health, safety, and general welfare. This article is not intended to interfere with, abrogate, or annul any other ordinances, rule or regulation, statute, or other provision of law except that, where any provision of this article imposes restrictions different from those imposed by any other ordinance, rule or regulation, or other provision of law, the more restrictive provisions or higher standards shall control.
D. 
For the purpose of this article, the following terms, phrases, words and their derivations shall have the meanings stated herein unless their use in the text of this article clearly demonstrates a different meaning. When not inconsistent with the context, words used in the present tense include the future, words used in the plural number include the singular number, and words used in the singular number include the plural number. The word "shall" is always mandatory and not merely directory. The definitions below are the same as or based on the corresponding definitions in the Stormwater Management Rules at N.J.A.C. 7:8-1.2.
CAFRA CENTERS, CORES OR NODES
Those areas with boundaries incorporated by reference or revised by the Department in accordance with N.J.A.C. 7:7-13.16.
CAFRA PLANNING MAP
The map used by the Department to identify the location of Coastal Planning Areas, CAFRA Centers, CAFRA Cores, and CAFRA Nodes. The CAFRA Planning Map is available on the Department's Geographic Information System (GIS).
COMMUNITY BASIN
An infiltration system, sand filter designed to infiltrate, standard constructed wetland, or wet pond, established in accordance with N.J.A.C. 7:8-4.2(c)14, that is designed and constructed in accordance with the New Jersey Stormwater Best Management Practices Manual, or an alternate design, approved in accordance with N.J.A.C. 7:8-5.2(g), for an infiltration system, sand filter designed to infiltrate, standard constructed wetland, or wet pond and that complies with the requirements of this chapter.
COMPACTION
The increase in soil bulk density.
CONTRIBUTORY DRAINAGE AREA
The area from which stormwater runoff drains to a stormwater management measure, not including the area of the stormwater management measure itself.
CORE
A pedestrian-oriented area of commercial and civic uses serving the surrounding municipality, generally including housing and access to public transportation.
COUNTY REVIEW AGENCY
An agency designated by the Board of County Commissioners to review municipal stormwater management plans and implementing ordinance(s). The county review agency may either be a county planning agency or a county water resource association created under N.J.S.A. 58:16A-55.5, if the ordinance or resolution delegates authority to approve, conditionally approve, or disapprove municipal stormwater management plans and implementing ordinances.
DEPARTMENT
The Department of Environmental Protection.
DESIGN ENGINEER
A person professionally qualified and duly licensed in New Jersey to perform engineering services that may include, but not necessarily be limited to, development of project requirements, creation and development of project design and preparation of drawings and specifications.
DESIGNATED CENTER
A State Development and Redevelopment Plan Center as designated by the State Planning Commission, such as urban, regional, town, village, or hamlet.
DEVELOPMENT
The division of a parcel of land into two or more parcels, the construction, reconstruction, conversion, structural alteration, relocation or enlarge-enlargement of any building or structure, any mining excavation or landfill, and any use or change in the use of any building or other structure, or land or extension of use of land, for which permission is required under the Municipal Land Use Law, N.J.S.A. 40:55D-1 et seq. In the case of development of agricultural land, "development" means any activity that requires a state permit, any activity reviewed by the County Agricultural Board (CAB) and the State Agricultural Development Committee (SADC), and municipal review of any activity not exempted by the Right to Farm Act, N.J.S.A. 4:1C-1 et seq.
DISTURBANCE
The placement or reconstruction of impervious surface or motor vehicle surface, or exposure and/or movement of soil or bedrock or clearing, cutting, or removing of vegetation. Milling and repaving is not considered disturbance for the purposes of this definition.
DRAINAGE AREA
A geographic area within which stormwater, sediments, or dissolved materials drain to a particular receiving water body or to a particular point along a receiving water body.
EMPOWERMENT NEIGHBORHOODS
A neighborhood designated by the Urban Coordinating Council "in consultation and conjunction with" the New Jersey Redevelopment Authority pursuant to N.J.S.A. 55:19-69.
ENVIRONMENTALLY CONSTRAINED AREA
The following areas where the physical alteration of the land is in some way restricted, either through regulation, easement, deed restriction or ownership, such as: wetlands, floodplains, threatened and endangered species sites or designated habitats, and parks and preserves. Habitats of endangered or threatened species are identified using the Department's Landscape Project as approved by the Department's Endangered and Nongame Species Program.
ENVIRONMENTALLY CRITICAL AREA
An area or feature which is of significant environmental value, including but not limited to stream corridors, natural heritage priority sites, habitats of endangered or threatened species, large areas of contiguous open space or upland forest, steep slopes, and wellhead protection and groundwater recharge areas. Habitats of endangered or threatened species are identified using the Department's Landscape Project as approved by the Department's Endangered and Nongame Species Program.
EROSION
The detachment and movement of soil or rock fragments by water, wind, ice, or gravity.
GREEN INFRASTRUCTURE
A stormwater management measure that manages stormwater close to its source by:
(1) 
Treating stormwater runoff through infiltration into subsoil;
(2) 
Treating stormwater runoff through filtration by vegetation or soil; or
(3) 
Storing stormwater runoff for reuse.
HUC 14 or HYDROLOGIC UNIT CODE 14
An area within which water drains to a particular receiving surface water body, also known as a "subwatershed," which is identified by a fourteen-digit hydrologic unit boundary designation, delineated within New Jersey by the United States Geological Survey.
IMPERVIOUS SURFACE
A surface that has been covered with a layer of material so that it is highly resistant to infiltration by water.
INFILTRATION
The process by which water seeps into the soil from precipitation.
LEAD PLANNING AGENCY
One or more public entities having stormwater management planning authority designated by the regional stormwater management planning committee pursuant to N.J.A.C. 7:8-3.2, that serves as the primary representative of the committee.
MAJOR DEVELOPMENT
(1) 
An individual development, as well as multiple developments that individually or collectively result in:
(a) 
The disturbance of one or more acres of land since February 2, 2004;
(b) 
The creation of 1/4 acre or more of regulated impervious surface since February 2, 2004;
(c) 
The creation of 1/4 acre or more of regulated motor vehicle surface since March 2, 2021; or
(d) 
A combination of Subsection D(1)(b) and (c) above that totals an area of 1/4 acre or more. The same surface shall not be counted twice when determining if the combination area equals 1/4 acre or more.
(2) 
Major development includes all developments that are part of a common plan of development or sale (for example, phased residential development) that collectively or individually meet any one or more of Subsection D(1)(a), (b), (c) or (d) above. Projects undertaken by any government agency that otherwise meet the definition of "major development" but which do not require approval under the Municipal Land Use Law, N.J.S.A. 40:55D-1 et seq., are also considered "major development."
MOTOR VEHICLE
Land vehicles propelled other than by muscular power, such as automobiles, motorcycles, autocycles, and low-speed vehicles. For the purposes of this definition, "motor vehicle" does not include farm equipment, snowmobiles, all-terrain vehicles, motorized wheelchairs, go-carts, gas buggies, golf carts, ski-slope grooming machines, or vehicles that run only on rails or tracks.
MOTOR VEHICLE SURFACE
Any pervious or impervious surface that is intended to be used by motor vehicles and/or aircraft, and is directly exposed to precipitation, including, but not limited to, driveways, parking areas, parking garages, roads, racetracks, and runways.
MUNICIPALITY
The Township of Ewing.
NEW JERSEY STORMWATER BEST MANAGEMENT PRACTICES (BMP) MANUAL or BMP MANUAL
The manual maintained by the Department providing, in part, design specifications, removal rates, calculation methods, and soil testing procedures approved by the Department as being capable of contributing to the achievement of the stormwater management standards specified in this chapter. The BMP Manual is periodically amended by the Department as necessary to provide design specifications on additional best management practices and new information on already included practices reflecting the best available current information regarding the particular practice and the Department's determination as to the ability of that best management practice to contribute to compliance with the standards contained in this chapter. Alternative stormwater management measures, removal rates, or calculation methods may be utilized, subject to any limitations specified in this chapter, provided the design engineer demonstrates to the municipality, in accordance with § 215-120F and N.J.A.C. 7:8-5.2(g), that the proposed measure and its design will contribute to achievement of the design and performance standards established by this chapter.
NODE
An area designated by the State Planning Commission concentrating facilities and activities which are not organized in a compact form.
NUTRIENT
A chemical element or compound, such as nitrogen or phosphorus, which is essential to and promotes the development of organisms.
PERSON
Any individual, corporation, company, partnership, firm, association, the Township of Ewing or political subdivision of this state subject to municipal jurisdiction pursuant to the Municipal Land Use Law, N.J.S.A. 40:55D-1 et seq.
POLLUTANT
Any dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, refuse, oil, grease, sewage sludge, munitions, chemical wastes, biological materials, medical wastes, radioactive substance [except those regulated under the Atomic Energy Act of 1954, as amended (42 U.S.C. § 2011 et seq.)], thermal waste, wrecked or discarded equipment, rock, sand, cellar dirt, industrial, municipal, agricultural, and construction waste or runoff, or other residue discharged directly or indirectly to the land, groundwaters or surface waters of the state, or to a domestic treatment works. "Pollutant" includes both hazardous and nonhazardous pollutants.
PUBLIC ROADWAY OR RAILROAD
A pathway for use by motor vehicles or trains that is intended for public use and is constructed by, or on behalf of, a public transportation entity. A public roadway or railroad does not include a roadway or railroad constructed as part of a private development, regardless of whether the roadway or railroad is ultimately to be dedicated to and/or maintained by a governmental entity.
PUBLIC TRANSPORTATION ENTITY
A federal, state, county, or municipal government, an independent state authority, or a statutorily authorized public-private partnership program pursuant to P.L. 2018, c. 90 (N.J.S.A. 40A:11-52 et seq.), that performs a public roadway or railroad project that includes new construction, expansion, reconstruction, or improvement of a public roadway or railroad.
RECHARGE
The amount of water from precipitation that infiltrates into the ground and is not evapotranspired.
REGULATED IMPERVIOUS SURFACE
Any of the following, alone or in combination:
(1) 
A net increase of impervious surface;
(2) 
The total area of impervious surface collected by a new stormwater conveyance system (for the purpose of this definition, a "new stormwater conveyance system" is a stormwater conveyance system that is constructed where one did not exist immediately prior to its construction or an existing system for which a new discharge location is created);
(3) 
The total area of impervious surface proposed to be newly collected by an existing stormwater conveyance system; and/or
(4) 
The total area of impervious surface collected by an existing stormwater conveyance system where the capacity of that conveyance system is increased.
REGULATED MOTOR VEHICLE SURFACE
Any of the following, alone or in combination:
(1) 
The total area of motor vehicle surface that is currently receiving water;
(2) 
A net increase in motor vehicle surface and/or quality treatment either by vegetation or soil, by an existing stormwater management measure, or by treatment at a wastewater treatment plant, where the water quality treatment will be modified or removed.
SEDIMENT
Solid material, mineral or organic, that is in suspension, is being transported, or has been moved from its site of origin by air, water or gravity as a product of erosion.
SITE
The lot or lots upon which a major development is to occur or has occurred.
SOIL
All unconsolidated mineral and organic material of any origin.
STATE DEVELOPMENT AND REDEVELOPMENT PLAN METROPOLITAN PLANNING AREA (PA1)
An area delineated on the State Plan Policy Map and adopted by the State Planning Commission that is intended to be the focus for much of the state's future redevelopment and revitalization efforts.
STATE PLAN POLICY MAP
The geographic application of the State Development and Redevelopment Plan's goals and statewide policies, and the official map of these goals and policies.
STORMWATER
Water resulting from precipitation (including rain and snow) that runs off the land's surface, is transmitted to the subsurface, or is captured by separate storm sewers or other sewage or drainage facilities, or conveyed by snow removal equipment.
STORMWATER MANAGEMENT BMP
An excavation or embankment and related areas designed to retain stormwater runoff. A stormwater management BMP may either be normally dry (that is, a detention basin or infiltration system), retain water in a permanent pool (a retention basin), or be planted mainly with wetland vegetation (most constructed stormwater wetlands).
STORMWATER MANAGEMENT MEASURE
Any practice, technology, process, program, or other method intended to control or reduce stormwater runoff and associated pollutants, or to induce or control the infiltration or groundwater recharge of stormwater or to eliminate illicit or illegal nonstormwater discharges into stormwater conveyances.
STORMWATER MANAGEMENT PLANNING AGENCY
A public body authorized by legislation to prepare stormwater management plans.
STORMWATER MANAGEMENT PLANNING AREA
The geographic area for which a stormwater management planning agency is authorized to prepare stormwater management plans, or a specific portion of that area identified in a stormwater management plan prepared by that agency.
STORMWATER RUNOFF
Water flow on the surface of the ground or in storm sewers, resulting from precipitation.
TIDAL FLOOD HAZARD AREA
A flood hazard area in which the flood elevation resulting from the two-, ten-, or 100-year storm, as applicable, is governed by tidal flooding from the Atlantic Ocean. Flooding in a tidal flood hazard area may be contributed to, or influenced by, stormwater runoff from inland areas, but the depth of flooding generated by the tidal rise and fall of the Atlantic Ocean is greater than flooding from any fluvial sources. In some situations, depending upon the extent of the storm surge from a particular storm event, a flood hazard area may be tidal in the 100-year storm, but fluvial in more frequent storm events.
URBAN COORDINATING COUNCIL EMPOWERMENT NEIGHBORHOOD
A neighborhood given priority access to state resources through the New Jersey Redevelopment Authority.
URBAN ENTERPRISE ZONES
A zone designated by the New Jersey Enterprise Zone Authority pursuant to the New Jersey Urban Enterprise Zones Act, N.J.S.A. 52:27H-60 et seq.
URBAN REDEVELOPMENT AREA
Previously developed portions of areas:
(1) 
Delineated on the State Plan Policy Map (SPPM) as the Metropolitan Planning Area (PA1), Designated Centers, Cores or Nodes;
(2) 
Designated as CAFRA Centers, Cores or Nodes;
(3) 
Designated as Urban Enterprise Zones; and
(4) 
Designated as Urban Coordinating Council Empowerment Neighborhoods.
WATER CONTROL STRUCTURE
A structure within, or adjacent to, a water, which intentionally or coincidentally alters the hydraulic capacity, the flood elevation resulting from the two-, ten-, or 100-year storm, flood hazard area limit, and/or floodway limit of the water. Examples of a water control structure may include a bridge, culvert, dam, embankment, ford (if above grade), retaining wall, and weir.
WATERS OF THE STATE
The ocean and its estuaries, all springs, streams, wetlands, and bodies of surface water or groundwater, whether natural or artificial, within the boundaries of the State of New Jersey or subject to its jurisdiction.
WETLANDS or WETLAND
An area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions, commonly known as "hydrophytic vegetation."
A. 
Design and performance standards for stormwater management measures.
(1) 
Stormwater management measures for major development shall be designed to provide erosion control, groundwater recharge, stormwater runoff quantity, and stormwater runoff quality treatment as follows:
(a) 
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.
(b) 
The minimum standards for groundwater recharge, stormwater quality, and stormwater runoff quantity shall be met by incorporating green infrastructure.
(2) 
The standards in this article shall apply only to new major 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.
[Amended 3-26-2024 by Ord. No. 24-05]
A. 
The development shall incorporate a maintenance plan for the stormwater management measures incorporated into the design of a major development in accordance with § 215-126.
B. 
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 13:1B-15.150, particularly Helonias bullata (swamp pink) and/or Clemmys muhlenbergii (bog turtle).
C. 
Linear development project exemptions. The following linear development projects are exempt from the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity requirements of § 215-120P, Q and R:
(1) 
The construction of an underground utility line, 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.
D. 
Waiver. A waiver from strict compliance from the green infrastructure, groundwater recharge, stormwater runoff quality, and stormwater runoff quantity requirements of § 215-120O, P, Q and R 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 through the use of stormwater management measures, the option selected complies with the requirements of § 215-120O, P, Q and R to the maximum extent practicable;
(3) 
The applicant demonstrates that, in order to meet the requirements of § 215-120O, P, Q and R, 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 § 215-120D(3) above within the upstream drainage area of the receiving stream, that would provide additional opportunities to mitigate the requirements of § 215-120O, P, and R that were not achievable on-site.
E. 
Stormwater best management practices.
(1) 
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 § 215-120O, P, Q and R.
(2) 
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 design and performance standards as outlined in the tables below.
(3) 
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://njstormwater.org/bmp manual2.htm.
F. 
Where the BMP tables in the NJ Stormwater Management Rule are different due to updates or amendments with the tables in this article, the BMP tables in the Stormwater Management Rule at N.J.A.C. 7:8-5.2(f) shall take precedence.
Table 1
Green Infrastructure BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or Stormwater Runoff Quantity
Best Management Practice (BMP)
Stormwater Runoff Quality TSS Removal Rate
(percent)
Stormwater Runoff Quality
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
—
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 (BMP)
Stormwater Runoff Quality TSS Removal Rate
(percent)
Stormwater Runoff Quality
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
Sand filter(b)
80%
Yes
Yes
2
Standard constructed wetland
90%
Yes
No
N/A
Wet pond(d)
50%-90%
Yes
No
N/A
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 (BMP)
Stormwater Runoff Quality TSS Removal Rate
(percent)
Stormwater Runoff Quality
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 to Tables 1, 2, and 3:
(a)
Subject to the applicable contributory drainage area limitation specified at § 215-120O(2);
(b)
Designed to infiltrate into the subsoil;
(c)
Designed with underdrains;
(d)
Designed to maintain at least a ten-foot-wide area of native vegetation along at least 50% 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 2%;
(f)
Designed with a slope of equal to or greater than 2%;
(g)
Manufactured treatment devices that meet the definition of "green infrastructure" at § 215-118D;
(h)
Manufactured treatment devices that do not meet the definition of "green infrastructure" at § 215-118D.
G. 
An alternative stormwater management measure.
(1) 
An 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.
(2) 
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 § 215-122B.
(3) 
Alternative stormwater management measures may be used to satisfy the requirements at § 215-120O only if the measures meet the definition of "green infrastructure" at § 215-118D. Alternative stormwater management measures that function in a similar manner to a BMP listed at Subsection O(2) are subject to the contributory drainage area limitation specified at Subsection O(2) for that similarly functioning BMP.
(4) 
Alternative stormwater management measures approved in accordance with this subsection that do not function in a similar manner to any BMP listed at Subsection O(2) 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.
(5) 
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 § 215-120D is granted from § 215-120O.
H. 
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, so as to avoid adverse hydraulic impacts. Potential adverse hydraulic impacts include, but are not limited to, exacerbating a naturally or seasonally high water table, so as 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 the stormwater management measure itself.
I. 
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, and texture; drainage area and drainage patterns; and the presence of solution-prone carbonate rocks (limestone);
(2) 
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, and shall have parallel bars with one-inch spacing between the bars to the elevation of the water quality design storm. For elevations higher than the water quality design storm, the parallel bars at the outlet structure shall be spaced no greater than 1/3 the width of the diameter of the orifice or 1/3 the width of the weir, with a minimum spacing between bars of one inch and a maximum spacing between bars of six inches. In addition, the design of trash racks must comply with the requirements of § 215-124B(4);
(3) 
Stormwater management measures shall be designed, constructed, and installed to be strong, durable, and corrosion-resistant. Measures that are consistent with the relevant portions of the Residential Site Improvement Standards at N.J.A.C. 5:21-7.3, 7.4, and 7.5 shall be deemed to meet this requirement;
(4) 
Stormwater management BMPs shall be designed to meet the minimum safety standards for stormwater management BMPs at § 215-124; and
(5) 
The size of the orifice at the intake to the outlet from the stormwater management BMP shall be a minimum of 2 1/2 inches in diameter.
J. 
Manufactured treatment devices may be used to meet the requirements of this article, provided the pollutant removal rates are verified by the New Jersey Corporation for Advanced Technology and certified by the Department. Manufactured treatment devices that do not meet the definition of "green infrastructure" at § 215-118D may be used only under the circumstances described at § 215-120O(4).
K. 
Any application for a new agricultural development that meets the definition of "major development" at § 215-118D shall be submitted to the Soil Conservation District for review and approval in accordance with the requirements of this section and any applicable Soil Conservation District guidelines for stormwater runoff quantity and erosion control. For purposes of this subsection, "agricultural development" means land uses normally associated with the production of food, fiber, and livestock for sale. Such uses do not include the development of land for the processing or sale of food and the manufacture of agriculturally related products.
L. 
If there is more than one drainage area, the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity standards at § 215-120P, Q and R shall be met in each drainage area, unless the runoff from the drainage areas converge on-site and no adverse environmental impact would occur as a result of compliance with any one or more of the individual standards being determined utilizing a weighted average of the results achieved for that individual standard across the affected drainage areas.
M. 
Any stormwater management measure authorized under the municipal stormwater management plan or ordinance shall be reflected in a deed notice recorded in the office of the Mercer County Clerk.
(1) 
A form of deed notice shall be submitted to Ewing Township for approval prior to filing.
(2) 
The deed notice shall contain a description of the stormwater management measure(s) used to meet the green infrastructure, groundwater recharge, stormwater runoff quality, and stormwater runoff quantity standards at § 215-120P, Q and R and shall identify the location of the stormwater management measure(s) in NAD 1983 State Plane New Jersey FIPS 2900 US feet or latitude and longitude in decimal degrees. The deed notice shall also reference the maintenance plan required to be recorded upon the deed pursuant to § 215-126B(5).
(3) 
Prior to the commencement of construction, proof that the above required deed notice has been filed shall be submitted to the Township of Ewing.
(4) 
Proof that the required information has been recorded on the deed shall be in the form of either a copy of the complete recorded document or a receipt from the Office of the Mercer County Clerk or other proof of recordation provided by the recording office. However, if the initial proof provided to Ewing Township is not a copy of the complete recorded document, a copy of the complete recorded document shall be provided to the municipality within 180 calendar days of the authorization granted by the Township.
N. 
A stormwater management measure approved under the municipal stormwater management plan or ordinance may be altered or replaced with the approval of the Township, if the Township determines that the proposed alteration or replacement meets the design and performance standards pursuant to § 215-120 of this article and provides the same level of stormwater management as the previously approved stormwater management measure that is being altered or replaced. If an alteration or replacement is approved, a revised deed notice shall be submitted to the Township for approval and subsequently recorded with the Office of the Mercer County Clerk and shall contain a description and location of the stormwater management measure, as well as reference to the maintenance plan, in accordance with Subsection M above. Prior to the commencement of construction, proof that the above required deed notice has been filed shall be submitted to the Township in accordance with Subsection M above.
O. 
Green infrastructure standards.
(1) 
This subsection specifies the types of green infrastructure BMPs that may be used to satisfy the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity standards.
(2) 
To satisfy the groundwater recharge and stormwater runoff quality standards at § 215-120P and Q, the design engineer shall utilize green infrastructure BMPs identified in Table 1 at § 215-120F and/or an alternative stormwater management measure approved in accordance with § 215-120G. The following green infrastructure BMPs are subject to the following maximum contributory drainage area limitations:
Best Management Practice
Maximum Contributory Drainage Area
Dry well
1 acre
Manufactured treatment
2.5 acres
Pervious pavement systems
Area of additional inflow cannot exceed three times the area occupied by the BMP
Small-scale bioretention
2.5 acres
Small-scale infiltration
2.5 acres
Small-scale sand filter
2.5 acres
(3) 
To satisfy the stormwater runoff quantity standards at § 215-120R, the design engineer shall utilize BMPs from Table 1 or from Table 2 and/or an alternative stormwater management measure approved in accordance with § 215-120G.
(4) 
If a variance in accordance with N.J.A.C. 7:8-4.6 or a waiver from strict compliance in accordance with § 215-120D is granted from the requirements of this subsection, then BMPs from Table 1, 2, or 3, and/or an alternative stormwater management measure approved in accordance with § 215-120G may be used to meet the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity standards at § 215-120P, Q and R.
(5) 
For separate or combined storm sewer improvement projects, such as sewer separation, undertaken by a government agency or public utility (for example, a sewerage company), the requirements of this subsection shall only apply to areas owned in fee simple by the government agency or utility, and areas within a right-of-way or easement held or controlled by the government agency or utility; the entity shall not be required to obtain additional property or property rights to fully satisfy the requirements of this subsection. Regardless of the amount of area of a separate or combined storm sewer improvement project subject to the green infrastructure requirements of this subsection, each project shall fully comply with the applicable groundwater recharge, stormwater runoff quality control, and stormwater runoff quantity standards at § 215-120P, Q and R, unless the project is granted a waiver from strict compliance in accordance with § 215-120D.
P. 
Groundwater recharge standards.
(1) 
This subsection contains the minimum design and performance standards for groundwater recharge as follows:
(2) 
The design engineer shall, using the assumptions and factors for stormwater runoff and groundwater recharge calculations at § 215-121, either:
(a) 
Demonstrate through hydrologic and hydraulic analysis that the site and its stormwater management measures maintain 100% of the average annual preconstruction groundwater recharge volume for the site; or
(b) 
Demonstrate through hydrologic and hydraulic analysis that the increase of stormwater runoff volume from preconstruction to post-construction for the two-year storm is infiltrated.
(3) 
This groundwater recharge requirement does not apply to projects within the "urban redevelopment area," or to projects subject to Subsection P(4) below.
(4) 
The following types of stormwater shall not be recharged:
(a) 
Stormwater from areas of high pollutant loading. High pollutant loading areas are areas in industrial and commercial developments where solvents and/or petroleum products are loaded/unloaded, stored, or applied; areas where pesticides are loaded/unloaded or stored; areas where hazardous materials are expected to be present in greater than "reportable quantities" as defined by the United States Environmental Protection Agency (EPA) at 40 CFR 302.4; areas where recharge would be inconsistent with Department-approved remedial action work plan or landfill closure plan and areas with high risks for spills of toxic materials, such as gas stations and vehicle maintenance facilities; and
(b) 
Industrial stormwater exposed to source material. "Source material" means any material(s) or machinery, located at an industrial facility, that is directly or indirectly related to process, manufacturing or other industrial activities, which could be a source of pollutants in any industrial stormwater discharge to groundwater. Source materials include, but are not limited to, raw materials; intermediate products; final products; waste materials; by-products; industrial machinery and fuels, and lubricants, solvents, and detergents that are related to process, manufacturing, or other industrial activities that are exposed to stormwater.
Q. 
Stormwater runoff quality standards.
(1) 
This subsection contains the minimum design and performance standards to control stormwater runoff quality impacts of major development. Stormwater runoff quality standards are applicable when the major development results in an increase of 1/4 acre or more of regulated motor vehicle surface.
(2) 
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 as follows:
(a) 
Eighty percent TSS removal of the anticipated load, expressed as an annual average, shall be achieved for the stormwater runoff from the net increase of motor vehicle surface.
(b) 
If the surface is considered regulated motor vehicle surface because the water quality treatment for an area of motor vehicle surface that is currently receiving water quality treatment either by vegetation or soil, by an existing stormwater management measure, or by treatment at a wastewater treatment plant is to be modified or removed, the project shall maintain or increase the existing TSS removal of the anticipated load expressed as an annual average.
(3) 
The requirement to reduce TSS does not apply to any stormwater runoff in a discharge regulated under a numeric effluent limitation for TSS imposed under the New Jersey Pollutant Discharge Elimination System (NJPDES) rules, N.J.A.C. 7:14A, or in a discharge specifically exempt under a NJPDES permit from this requirement. Every major development, including any that discharge into a combined sewer system, shall comply with Subsection Q(2) above, unless the major development is itself subject to a NJPDES permit with a numeric effluent limitation for TSS or the NJPDES permit to which the major development is subject exempts the development from a numeric effluent limitation for TSS.
(4) 
The water quality design storm is 1.25 inches of rainfall in two hours. Water quality calculations shall take into account the distribution of rain from the water quality design storm, as reflected in Table 4, below. The calculation of the volume of runoff may take into account the implementation of stormwater management measures.
Table 4 - Water Quality Design Storm Distribution
Time
(Minutes)
Cumulative Rainfall
(Inches)
Time
(Minutes)
Cumulative Rainfall
(Inches)
Time
(Minutes)
Cumulative Rainfall
(Inches)
1
0.00166
41
0.1728
81
1.0906
2
0.00332
42
0.1796
82
1.0972
3
0.00498
43
0.1864
83
1.1038
4
0.00664
44
0.1932
84
1.1104
5
0.00830
45
0.2000
85
1.1170
6
0.00996
46
0.2117
86
1.1236
7
0.01162
47
0.2233
87
1.1302
8
0.01328
48
0.2349
88
1.1368
9
0.01494
49
0.2466
89
1.1434
10
0.01660
50
0.2583
90
1.1500
11
0.01828
51
0.2783
91
1.1550
12
0.01996
52
0.2983
92
1.1600
13
0.02164
53
0.3183
93
1.1650
14
0.02332
54
0.3383
94
1.1700
15
0.02500
55
0.3583
95
1.1750
16
0.03000
56
0.4116
96
1.1800
17
0.03500
57
0.4650
97
1.1850
18
0.04000
58
0.5183
98
1.1900
19
0.04500
59
0.5717
99
1.1950
20
0.05000
60
0.6250
100
1.2000
21
0.05500
61
0.6783
101
1.2050
22
0.06000
62
0.7317
102
1.2100
23
0.06500
63
0.7850
103
1.2150
24
0.07000
64
0.8384
104
1.2200
25
0.07500
65
0.8917
105
1.2250
26
0.08000
66
0.9117
106
1.2267
27
0.08500
67
0.9317
107
1.2284
28
0.09000
68
0.9517
108
1.2300
29
0.09500
69
0.9717
109
1.2317
30
0.10000
70
0.9917
110
1.2334
31
0.10660
71
1.0034
111
1.2351
32
0.11320
72
1.0150
112
1.2367
33
0.11980
73
1.0267
113
1.2384
34
0.12640
74
1.0386
114
1.2400
35
0.13300
75
1.0500
115
1.2417
36
0.13960
76
1.0568
116
1.2434
37
0.14620
77
1.0636
117
1.2450
38
0.15280
78
1.0704
118
1.2467
39
0.15940
79
1.0772
119
1.2483
40
0.16600
80
1.0840
120
1.2500
(5) 
If more than one BMP in series is necessary to achieve the required 80% TSS reduction for a site, the applicant shall utilize the following formula to calculate TSS reduction:
R = A + B - (A x B)/100
Where:
R
=
Total TSS percent load removal from application of both BMPs
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 § 215-120P, Q and R.
(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% of the anticipated load from the developed site, expressed as an annual average.
(10) 
Section 215-120G(8) does not apply to the construction of one individual single-family dwelling, provided that 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.
R. 
Stormwater runoff quantity standards.
(1) 
This subsection contains the minimum design and performance standards to control stormwater runoff quantity impacts of major development.
(2) 
In order to control stormwater runoff quantity impacts, the design engineer shall, using the assumptions and factors for stormwater runoff calculations at § 215-121, complete one of the following:
(a) 
Demonstrate through hydrologic and hydraulic analysis that for stormwater leaving the site, post-construction runoff hydrographs for the current and projected two-, ten- and 100-year storm events, as defined and determined in § 215-121C and D, respectively, of this article, do not exceed, at any point in time, the preconstruction runoff hydrographs for the same storm events;
(b) 
Demonstrate through hydrologic and hydraulic analysis that there is no increase, as compared to the preconstruction condition, in the peak runoff rates of stormwater leaving the site for the current and projected two-, ten- and 100-year storm events, as defined and determined in § 215-121C and D, respectively, of this article, and that the increased volume or change in timing of stormwater runoff will not increase flood damage at or downstream of the site. This analysis shall include the analysis of impacts of existing land uses and projected land uses assuming full development under existing zoning and land use ordinances in the drainage area;
(c) 
Design stormwater management measures so that the post-construction peak runoff rates for the current and projected two-, ten- and 100-year storm events, as defined and determined in § 215-121C and D, respectively, of this article, are 50%, 75% and 80%, respectively, of the preconstruction peak runoff rates. The percentages apply only to the post-construction stormwater runoff that is attributable to the portion of the site on which the proposed development or project is to be constructed; or
(d) 
In tidal flood hazard areas, stormwater runoff quantity analysis in accordance with Subsection R(2)(a), (b) and (c) above is required unless the design engineer demonstrates through hydrologic and hydraulic analysis that the increased volume, change in timing, or increased rate of the stormwater runoff, or any combination of the three, will not result in additional flood damage below the point of discharge of the major development. No analysis is required if the stormwater is discharged directly into any ocean, bay, inlet, or the reach of any watercourse between its confluence with an ocean, bay, or inlet and downstream of the first water control structure.
(3) 
The stormwater runoff quantity standards shall be applied at the site's boundary to each abutting lot, roadway, watercourse, or receiving storm sewer system.
[Amended 3-26-2024 by Ord. No. 24-05]
A. 
Stormwater runoff.
(1) 
Stormwater runoff shall be calculated in accordance with the following:
(a) 
The design engineer shall calculate runoff using the following method:
[1] 
The USDA Natural Resources Conservation Service (NRCS) methodology, including the NRCS Runoff Equation and Dimensionless Unit Hydrograph, as described in Chapters 7, 9, 10, 15 and 16, Part 630, Hydrology National Engineering Handbook, incorporated herein by reference as amended and supplemented. This methodology is additionally described in Technical Release 55 - Urban Hydrology for Small Watersheds (TR-55), dated June 1986, incorporated herein by reference as amended and supplemented. Information regarding the methodology is available from the Natural Resources Conservation Service website at https://directives.sc.egov.usda.gov/viewerFS.aspx?hid=21422; or at United States Department of Agriculture Natural Resources Conservation Service, New Jersey State Office.
(b) 
For the purpose of calculating runoff curve numbers and groundwater recharge, there is a presumption that the preconstruction condition of a site or portion thereof is a wooded land use with good hydrologic condition. The term "curve number" applies to both the NRCS methodology at § 215-121A(1)(a)[1] and the rational and modified rational methods at § 215-121A(1)(a)[2]. A runoff curve number or a groundwater recharge land cover for an existing condition may be used on all or a portion of the site if the design engineer verifies that the hydrologic condition has existed on the site or portion of the site for at least five years without interruption prior to the time of application. If more than one land cover has existed on the site during the five years immediately prior to the time of application, the land cover with the lowest runoff potential shall be used for the computations. In addition, there is the presumption that the site is in good hydrologic condition (if the land use type is pasture, lawn or park), with good cover (if the land use type is woods), or with good hydrologic condition and conservation treatment (if the land use type is cultivation).
(c) 
In computing preconstruction stormwater runoff, the design engineer shall account for all significant land features and structures, such as ponds, wetlands, depressions, hedgerows, or culverts, that may reduce preconstruction stormwater runoff rates and volumes.
(d) 
In computing stormwater runoff from all design storms, the design engineer shall consider the relative stormwater runoff rates and/or volumes of pervious and impervious surfaces separately to accurately compute the rates and volume of stormwater runoff from the site. To calculate runoff from unconnected impervious cover, urban impervious area modifications as described in the NRCS Technical Release 55 - Urban Hydrology for Small Watersheds or other methods may be employed.
(e) 
If the invert of the outlet structure of a stormwater management measure is below the flood hazard design flood elevation as defined at N.J.A.C. 7:13, the design engineer shall take into account the effects of tailwater in the design of structural stormwater management measures.
B. 
Groundwater recharge may be calculated in accordance with the following:
(1) 
The New Jersey Geological Survey Report GSR-32, A Method for Evaluating Groundwater-Recharge Areas in New Jersey, incorporated herein by reference as amended and supplemented. Information regarding the methodology is available from the New Jersey Stormwater Best Management Practices Manual; at the New Jersey Geological Survey website at https://www.nj.gov/dep/njgs/pricelst/gsreport/gsr32.pdf; or at New Jersey Geological and Water Survey, 29 Arctic Parkway, PO Box 420, Mail Code 29-01, Trenton, New Jersey 08625-0420.
C. 
The precipitation depths of the current two-, ten-, and 100-year storm events shall be determined by multiplying the values determined in accordance with Subsection C(1) and (2) below:
(1) 
The applicant shall utilize the National Oceanographic and Atmospheric Administration (NOAA), National Weather Service's Atlas 14 Point Precipitation Frequency Estimates: NJ, in accordance with the location(s) of the drainage area(s) of the site. This data is available at https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html?bkmrk=nj; and
(2) 
The applicant shall utilize Table 5: Current Precipitation Adjustment Factors, below, which sets forth the applicable multiplier for the drainage area(s) of the site, in accordance with the county or counties where the drainage area(s) of the site is located. Where the major development lies in more than one county, the precipitation values shall be adjusted according to the percentage of the drainage area in each county. Alternately, separate rainfall totals can be developed for each county using the values in the table below.
Table 5: Current Precipitation Adjustment Factors
County
Current Precipitation Adjustment Factors
Two-Year
Design Storm
Ten-Year
Design Storm
100-Year
Design Storm
Atlantic
1.01
1.02
1.03
Bergen
1.01
1.03
1.06
Burlington
0.99
1.01
1.04
Camden
1.03
1.04
1.05
Cape May
1.03
1.03
1.04
Cumberland
1.03
1.03
1.01
Essex
1.01
1.03
1.06
Mercer
1.05
1.06
1.06
Hudson
1.03
1.05
1.09
Hunterdon
1.02
1.05
1.13
Mercer
1.01
1.02
1.04
Middlesex
1.00
1.01
1.03
Monmouth
1.00
1.01
1.02
Morris
1.01
1.03
1.06
Ocean
1.00
1.01
1.03
Passaic
1.00
1.02
1.05
Salem
1.02
1.03
1.03
Somerset
1.00
1.03
1.09
Sussex
1.03
1.04
1.07
Union
1.01
1.03
1.06
Warren
1.02
1.07
1.15
D. 
Table 6: Future Precipitation Change Factors, provided below, sets forth the change factors to be used in determining the projected two-, ten-, and 100-year storm events for use in this chapter, which are organized alphabetically by county. The precipitation depth of the projected two-, ten-, and 100-year storm events of a site shall be determined by multiplying the precipitation depth of the two-, ten-, and 100-year storm events determined from the National Weather Service's Atlas 14 Point Precipitation Frequency Estimates pursuant to Subsection C(1) above by the change factor in the table below, in accordance with the county or counties where the drainage area(s) of the site is located. Where the major development and/or its drainage area lies in more than one county, the precipitation values shall be adjusted according to the percentage of the drainage area in each county. Alternately, separate rainfall totals can be developed for each county using the values in the table below.
Table 6: Future Precipitation Change Factors
County
Future Precipitation Change Factors
Two-Year
Design Storm
Ten-Year
Design Storm
100-Year
Design Storm
Atlantic
1.22
1.24
1.39
Bergen
1.20
1.23
1.37
Burlington
1.17
1.18
1.32
Camden
1.18
1.22
1.39
Cape May
1.21
1.24
1.32
Cumberland
1.20
1.21
1.39
Essex
1.19
1.22
1.33
Mercer
1.19
1.23
1.41
Hudson
1.19
1.19
1.23
Hunterdon
1.19
1.23
1.42
Mercer
1.16
1.17
1.36
Middlesex
1.19
1.21
1.33
Monmouth
1.19
1.19
1.26
Morris
1.23
1.28
1.46
Ocean
1.18
1.19
1.24
Passaic
1.21
1.27
1.50
Salem
1.20
1.23
1.32
Somerset
1.19
1.24
1.48
Sussex
1.24
1.29
1.50
Union
1.20
1.23
1.35
Warren
1.20
1.25
1.37
[Amended 3-26-2024 by Ord. No. 24-05]
A. 
Technical guidance for stormwater management measures can be found in the documents listed below, which are available to download from the Department's website at https://dep.nj.gov/stormwater/bmp-manual/.
(1) 
Guidelines for stormwater management measures are contained in the New Jersey Stormwater Best Management Practices Manual, as amended and supplemented. Information is provided on stormwater management measures such as, but not limited to, those listed in Tables 1, 2, and 3.
(2) 
Additional maintenance guidance is available on the Department's website at https://dep.nj.gov/stormwater/maintenance-guidance/.
B. 
Submissions required for review by the Department should be mailed to the Division of Watershed Protection and Restoration, New Jersey Department of Environmental Protection, Mail Code 501-02A, PO Box 420, Trenton, New Jersey 08625-0420.
A. 
Site design features identified under § 215-120F above, or alternative designs in accordance with § 215-120G above, to prevent discharge of trash and debris from drainage systems shall comply with the following standard to control passage of solid and floatable materials through storm drain inlets. For purposes of this subsection, "solid and floatable materials" means sediment, debris, trash, and other floating, suspended, or settleable solids. For exemptions to this standard, see Subsection A(3) below.
(1) 
Design engineers shall use one of the following grates whenever they use a grate in pavement or another ground surface to collect stormwater from that surface into a storm drain or surface water body under that grate;
(a) 
The New Jersey Department of Transportation (NJDOT) bicycle safe grate, which is described in Chapter 2.4 of the NJDOT Bicycle-Compatible Roadways and Bikeways Planning and Design Guidelines (April 1996); or
(b) 
A different grate, if each individual clear space in that grate has an area of no more than seven square inches or is no greater than 0.5 inch across the smallest dimension.
[1] 
Examples of grates subject to this standard include grates in grate inlets, the grate portion (non-curb-opening portion) of combination inlets, grates on storm sewer manholes, ditch grates, trench grates, and grates of spacer bars in slotted drains. Examples of ground surfaces include surfaces of roads (including bridges), driveways, parking areas, bikeways, plazas, sidewalks, lawns, fields, open channels, and stormwater system floors used to collect stormwater from the surface into a storm drain or surface water body.
(2) 
For curb-opening inlets, including curb-opening inlets in combination inlets, the clear space in that curb opening (or each individual clear space, if the curb opening has two or more clear spaces) shall have an area of no more than seven square inches, or be no greater than two inches across the smallest dimension.
(3) 
This standard does not apply:
(a) 
Where each individual clear space in the curb opening in existing curb-opening inlet does not have an area of more than nine square inches;
(b) 
Where the municipality determines that this standard would cause inadequate hydraulic performance that could not practicably be overcome by using additional or larger storm drain inlets that meet these standards;
(c) 
Where flows from the water quality design storm as specified in N.J.A.C. 7:8 are conveyed through any device (e.g., end-of-pipe netting facility, manufactured treatment device, or a catch basin hood) that is designed, at a minimum, to prevent delivery of all solid and floatable materials that could not pass through one of the following:
[1] 
A rectangular space 4 5/8 inches long and 1 1/2 inches wide (this option does not apply for outfall netting facilities); or
[2] 
A bar screen having a bar spacing of 0.5 inch.
(d) 
Where flows are conveyed through a trash rack that has parallel bars with one-inch (one inch) spacing between the bars, to the elevation of the Water Quality Design Storm as specified in N.J.A.C. 7:8; or
(e) 
Where the New Jersey Department of Environmental Protection determines, pursuant to the New Jersey Register of Historic Places Rules at N.J.A.C. 7:4-7.2(c), that action to meet this standard is an undertaking that constitutes an encroachment or will damage or destroy the New Jersey Register listed historic property.
A. 
Purpose. This section sets forth requirements to protect public safety through the proper design and operation of stormwater management BMPs. This section applies to any new stormwater management BMPs.
B. 
The provisions of this section are not intended to preempt more stringent municipal or county safety requirements for new or existing stormwater management BMPs. Municipal and county stormwater management plans and ordinances may, pursuant to their authority, require existing stormwater management BMPs to be retrofitted to meet one or more of the safety standards in § 215-124C(1), § 215-124C(2), and § 215-124C(3) for trash racks, overflow grates, and escape provisions at outlet structures.
C. 
Requirements for trash racks, overflow grates and escape provisions.
(1) 
A trash rack is a device designed to catch trash and debris and prevent the clogging of outlet structures. Trash racks shall be installed at the intake to the outlet from the stormwater management basin to ensure proper functioning of the basin outlets in accordance with the following:
(a) 
The trash rack shall have parallel bars, with no greater than six-inch spacing between the bars.
(b) 
The trash rack shall be designed so as not to adversely affect the hydraulic performance of the outlet pipe or structure.
(c) 
The average velocity of flow through a clean trash rack is not to exceed 2.5 feet per second under the full range of stage and discharge. Velocity is to be computed on the basis of the net area of opening through the rack; and
(d) 
The trash rack shall be constructed of rigid, durable and corrosion-resistant material, and designed to withstand a perpendicular live loading of 300 pounds per square foot.
(2) 
An overflow grate is designed to prevent obstruction of the overflow structure. If an outlet structure has an overflow grate, such grate shall meet the following requirements:
(a) 
The overflow grate shall be secured to the outlet structure but removable for emergencies and maintenance.
(b) 
The overflow grate spacing shall be no less than two inches across the smallest dimension.
(c) 
The overflow grate shall be constructed and installed to be rigid, durable and corrosion-resistant, and shall be designed to withstand a perpendicular live loading of 300 pounds per square foot.
(3) 
Stormwater management BMPs shall include escape provisions as follows:
(a) 
If a stormwater management basin has an outlet structure, escape provisions shall be incorporated in or on the structure. Escape provisions include the installation of permanent ladders, steps, rungs, or other features that provide easily accessible means of egress from stormwater management BMPs. With the prior approval of the municipality pursuant to § 215-124B(3), a freestanding outlet structure may be exempted from this requirement;
(b) 
Safety ledges shall be constructed on the slopes of all new stormwater management basins having a permanent pool of water deeper than 2 1/2 feet. Such safety ledges shall be comprised of two steps. Each step shall be four to six feet in width. One step shall be located approximately 2 1/2 feet below the permanent water surface, and the second step shall be located one to 1 1/2 feet above the permanent water surface. See Subsection E for an illustration of safety ledges in a stormwater management BMP; and
(c) 
In new stormwater management BMPs, the maximum interior slope for an earthen dam, embankment, or berm shall not be steeper than three horizontal to one vertical.
D. 
Variance or exemption from safety standards. A variance or exemption from the safety standards for stormwater management BMPs may be granted only upon a written finding by the appropriate reviewing agency (municipality, county or Department) that the variance or exemption will not constitute a threat to public safety.
E. 
Safety ledge illustration.
Elevation View - Basin Safety Ledge Configuration
A. 
Submission of site development stormwater plan.
(1) 
Whenever an applicant seeks municipal approval of a development subject to this article, the applicant shall submit all of the required components of the checklist for the site development stormwater plan at § 215-125C below as part of the submission of the applicant's application for subdivision or site plan approval.
(2) 
The applicant shall demonstrate that the project meets the standards set forth in this article.
(3) 
The applicant shall submit 16 copies of the materials listed in the checklist for site development stormwater plans in accordance with § 215-125C of this article.
B. 
Site development stormwater plan approval. The applicant's site development project shall be reviewed as a part of the subdivision or site plan review process by the municipal board or official from which municipal approval is sought. That municipal board or official shall consult the engineer retained by the Planning and/or Zoning Board (as appropriate) to determine if all of the checklist requirements have been satisfied and to determine if the project meets the standards set forth in this article.
C. 
Submission of site development stormwater plan. The following information shall be required:
(1) 
Topographic base map. The reviewing engineer may require upstream tributary drainage system information as necessary. It is recommended that the topographic base map of the site be submitted which extends a minimum of 200 feet beyond the limits of the proposed development, at a scale of one inch equals 200 feet or greater, showing two-foot contour intervals. The map, as appropriate, may indicate the following: existing surface water drainage, shorelines, steep slopes, soils, erodible soils, perennial or intermittent streams that drain into or upstream of the Category One waters, wetlands and floodplains along with their appropriate buffer strips, marshlands and other wetlands, pervious or vegetative surfaces, existing man-made structures, roads, bearing and distances of property lines, and significant natural and man-made features not otherwise shown.
(2) 
Environmental site analysis. A written and graphic description of the natural and man-made features of the site and its surroundings should be submitted. This description should include a discussion of soil conditions, slopes, wetlands, waterways and vegetation on the site. Particular attention should be given to unique, unusual or environmentally sensitive features and to those that provide particular opportunities or constraints for development.
(3) 
Project description and site plan(s). A map (or maps) at the scale of the topographical base map, indicating the location of existing and proposed buildings, roads, parking areas, utilities, structural facilities for stormwater management and sediment control, and other permanent structures. The map(s) shall also clearly show areas where alterations occur in the natural terrain and cover, including lawns and other landscaping, and seasonal high groundwater elevations. A written description of the site plan and justification of proposed changes in natural conditions may also be provided.
(4) 
Land use planning and source control plan. This plan shall provide a demonstration of how the goals and standards of §§ 215-119 through 215-122 are being met. The focus of this plan shall be to describe how the site is being developed to meet the objective of controlling groundwater recharge, stormwater quality and stormwater quantity problems at the source by land management and source controls whenever possible.
(5) 
Stormwater management facilities map. The following information, illustrated on a map of the same scale as the topographic base map, shall be included:
(a) 
Total area to be paved or built upon; proposed surface contours; land area to be occupied by the stormwater management facilities and the type of vegetation thereon; and details of the proposed plan to control and dispose of stormwater; and
(b) 
Details of all stormwater management facility designs, during and after construction, including discharge provisions; discharge capacity for each outlet at different levels of detention and emergency spillway provisions with maximum discharge capacity of each spillway.
(6) 
Calculations.
(a) 
Comprehensive hydrologic and hydraulic design calculations for the predevelopment and post-development conditions for the design storms specified in § 215-120 of this article.
(b) 
When the proposed stormwater management control measures (e.g., infiltration basins) depend on the hydrologic properties of soils, then a soils report shall be submitted. The soils report shall be based on on-site boring logs or soil pit profiles. The number and location of required soil borings or soil pits shall be determined based on what is needed to determine the suitability and distribution of soils present at the location of the control measure.
(7) 
Maintenance and repair plan. The design and planning of the stormwater management facility shall meet the maintenance requirements of § 215-126.
(8) 
Waiver from submission requirements. The municipal official or Board reviewing an application under this article may, in consultation with the Municipal Engineer, waive submission of any of the requirements in § 215-125C(1) through (7) of this article when it can be demonstrated that the information requested is impossible to obtain or it would create a hardship on the applicant to obtain, and its absence will not materially affect the review process.
A. 
Applicability. Projects subject to review as in § 215-118B of this article shall comply with the requirements of § 215-126B and C.
B. 
General maintenance.
(1) 
The design engineer shall prepare a maintenance plan for the stormwater management measures incorporated into the design of a major development.
(2) 
The maintenance plan shall contain specific preventative maintenance tasks and schedules; cost estimates, including estimated cost of sediment, debris or trash removal; and the name, address, and telephone number of the person or persons responsible for preventative and corrective maintenance (including replacement). The plan shall contain information on BMP location, design, ownership, maintenance tasks and frequencies, and other details as specified in Chapter 8 of the NJ BMP Manual, as well as the tasks specific to the type of BMP, as described in the applicable chapter containing design specifics.
(3) 
If the maintenance plan identifies a person other than the property owner (for example, a public agency or homeowners' association) as having the responsibility for maintenance, the plan shall include documentation of such person's agreement to assume this responsibility or of the owner's obligation to dedicate a stormwater management facility to such person under an applicable ordinance or regulation.
(4) 
Responsibility for maintenance shall not be assigned or transferred to the owner or tenant of an individual property in a residential development or project, unless such owner or tenant owns or leases the entire residential development or project. The individual property owner may be assigned incidental tasks, such as weeding of a green infrastructure BMP, provided the individual agrees to assume these tasks; however, the individual cannot be legally responsible for all of the maintenance requirement.
(5) 
If the person responsible for maintenance identified under § 215-126B(2) above is not a public agency, the maintenance plan and any future revisions based on § 215-126B(5) below shall be recorded upon the deed of record for each property on which the maintenance described in the maintenance plan must be undertaken.
(6) 
Preventative and corrective maintenance shall be performed to maintain the functional parameters (storage volume, infiltration rates, inflow/outflow capacity, etc.) of the stormwater management measure, including, but not limited to, repairs or replacement to the structure; removal of sediment, debris or trash; restoration of eroded areas; snow and ice removal; fence repair or replacement; restoration of vegetation; and repair or replacement of nonvegetated linings.
(7) 
The person responsible for maintenance identified under § 215-126B(2) above shall perform all of the following requirements:
(a) 
Maintain a detailed log of all preventative and corrective maintenance for the structural stormwater management measures incorporated into the design of the development, including a record of all inspections and copies of all maintenance-related work orders.
(b) 
Evaluate the effectiveness of the maintenance plan at least once per year and adjust the plan and the deed as needed.
(c) 
Retain and make available, upon request by any public entity with administrative, health, environmental, or safety authority over the site, the maintenance plan and the documentation required by this subsection and § 215-126B(4) above.
(8) 
The requirements of § 215-126B(3) do not apply to stormwater management facilities that are dedicated to and accepted by the municipality or another governmental agency, subject to all applicable municipal stormwater general permit conditions, as issued by the Department.
(9) 
In the event that the stormwater management facility becomes a danger to public safety or public health, or if it is in need of maintenance or repair, the municipality shall so notify the responsible person in writing. Upon receipt of that notice, the responsible person shall have 14 days to effect maintenance and repair of the facility in a manner that is approved by the Municipal Engineer or his designee. The municipality, in its discretion, may extend the time allowed for effecting maintenance and repair for good cause. If the responsible person fails or refuses to perform such maintenance and repair, the municipality or county may immediately proceed to do so and shall bill the cost thereof to the responsible person. Nonpayment of such bill may result in a lien on the property.
C. 
Posting of performance or maintenance guarantee. Nothing in this section shall preclude the municipality in which the major development is located from requiring the posting of a performance or maintenance guarantee in accordance with N.J.S.A. 40:55D-53.
D. 
Penalties. Any person who erects, constructs, alters, repairs, converts, maintains or uses any building, structure or land in violation of this article shall be subject, upon conviction thereof, to a fine of not more than $2,000 or incarceration for a period not to exceed 90 days, or both such fine and imprisonment, in the discretion of the Municipal Judge.