[1]
Editor's Note: This ordinance also repealed
former Art. I, Regulations, adopted 4-5-2005 by Ord. No. 1281. Its
preamble also stated that this ordinance "shall govern where this
ordinance conflicts with the existing Land Development Ordinance."
A.
Policy statement. 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.
B.
Purpose. It is the purpose of this article to establish minimum stormwater management requirements and controls for major development, as defined in § 247-2, and to reduce the amount of nonpoint source pollution entering surface and ground water. Unmitigated stormwaters from areas altered by development may pose public health and safety threats. This article establishes the administrative mechanisms necessary for the Borough of Emerson to ensure proper stormwater management. This article is written to work in conjunction with current state and federal regulations. This article guides development in a manner that is proactive and minimizes harmful impacts to natural resources. Specifically, this article shall:
(1)
Reduce artificially induced flood damage to public health, life,
and property;
(2)
Minimize increased stormwater runoff rates and volumes;
(3)
Minimize the deterioration of existing structures that would result
from increased rates of stormwater runoff;
(4)
Induce water recharge into the ground wherever suitable infiltration,
soil permeability and favorable geological conditions exist;
(5)
Prevent an increase in nonpoint source pollution;
(6)
Maintain the integrity and stability of stream channels and buffers
for their ecological functions, as well as for drainage, the conveyance
of floodwater, and other purposes;
(7)
Control and minimize soil erosion and the transport of sediment;
(8)
Minimize public safety hazards at any stormwater detention facility
constructed pursuant to subdivision or site plan approval;
(9)
Maintain adequate base flow and natural flow regimes in all streams
and other surface water bodies to protect the aquatic ecosystem;
(10)
Protect all surface water resources from degradation; and
(11)
Protect groundwater resources from degradation and diminution.
C.
D.
Compatibility with other permit and ordinance requirements. Development
approvals issued for subdivisions and site plans pursuant to this
article are to be considered an integral part of development approvals
under the subdivision and site plan review process 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.
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.
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 manufacturing of
agriculturally related products.
Structural device, measure, facility, or activity that helps
to achieve stormwater management control objectives at a designated
site.
Those areas with boundaries incorporated by reference or
revised by the Department in accordance with N.J.A.C. 7:7-13.16.
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).
Waters of the state, including unnamed waterways that appear
on Soil Survey and USGS Topographic Quadrangle Maps within the same
HUC-14 watershed, designated in N.J.A.C. 7:9B-1.15(c) through (h)
for purposes of implementing the antidegradation policies set forth
at N.J.A.C. 7:9B-1.5(d) for protection from measurable changes in
water quality characteristics because of their clarity, color, scenic
setting, other characteristics of aesthetic value, exceptional ecological
significance, exceptional recreational significance, exceptional water
supply significance, or exceptional fisheries resources.
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 article.
The increase in soil bulk density.
The area from which stormwater runoff drains to a stormwater
management measure, not including the area of the stormwater management
measure itself.
A pedestrian-oriented area of commercial and civic uses serving
the surrounding municipality, generally including housing and access
to public transportation.
An agency designated by the Bergen County Commissioners to
review municipal stormwater management plans and implementing ordinance(s).
The county review agency may either be:
The New Jersey Department of Environmental Protection.
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.
A State Development and Redevelopment Plan Center as designated
by the State Planning Commission, such as urban, regional, town, village,
or hamlet.
The division of a parcel of land into two or more parcels;
the construction, reconstruction, conversion, structural alteration,
relocation or 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, by any person,
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
lands, "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.
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.
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.
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.
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.
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.
The detachment and movement of soil or rock fragments by
water, wind, ice, or gravity.
The permanent installation of ladders, steps, rungs, or other
features that provide easily accessible means of egress from stormwater
management basins.
A stormwater management measure that manages stormwater close
to its source by:
A body of water below the surface of the land in a zone of
saturation where the spaces between the soil or geological materials
are fully saturated with water.
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.
A surface that has been covered with a layer of material
so that it is highly resistant to infiltration by water.
The process by which water seeps into the soil from precipitation.
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.
An individual development, as well as multiple developments
that individually or collectively result in:
The disturbance of one or more acres of land since February
2, 2004;
The creation of 1/4 acre or more of regulated impervious surface
since February 2, 2004;
The creation of 1/4 acre or more of regulated motor vehicle
surface since March 2, 2021 (or the effective date of this article,
whichever is earlier); or
A combination of Subsection A(2) and (3) 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.
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 A(1), (2), (3), or (4) 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.
An action by an applicant providing compensation or offset
actions for on-site stormwater management requirements where the applicant
has demonstrated the inability or impracticality of strict compliance
with the stormwater management requirements set forth in N.J.A.C.
7:8 in an adopted regional stormwater management plan or in this local
ordinance and has received a waiver from strict compliance from the
Borough of Emerson. Mitigation for the purposes of this article includes
both the mitigation plan detailing how the project's failure
to strictly comply will be compensated, and the implementation of
the approved mitigation plan.
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.
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.
Any city, Borough, town, township, or village.
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 article. 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 article. Alternative stormwater management measures, removal rates, or calculation methods may be utilized, subject to any limitations specified in this article, provided the design engineer demonstrates to the municipality, in accordance with § 247-4F of this article 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 article.
An area designated by the State Planning Commission concentrating
facilities and activities which are not organized in a compact form.
Techniques that control or reduce stormwater runoff in the
absence of stormwater structures (e.g., basins and pipe conveyances),
such as minimizing site disturbance, preserving important site features,
including but not limited to natural vegetation, reducing and disconnecting
impervious cover, minimizing slopes, utilizing native vegetation,
minimizing turf grass lawns, increasing time of concentration, and
maintaining and enhancing natural drainage features and characteristics.
A chemical element or compound, such as nitrogen or phosphorus,
which is essential to and promotes the development of organisms.
A surface or land cover capable of transmitting or percolating
a significant amount of precipitation into the underlying soils.
Any individual, corporation, company, partnership, firm,
association, Borough of Emerson or political subdivision of this state
and any state, interstate, or federal agency.
A document approved at the site design phase that outlines
the measures and practices used to control stormwater runoff at the
site.
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.
The man-made or man-induced alteration of the chemical, physical,
biological, and radiological integrity of water to the extent that
the pollutant concentration or level violates either the groundwater
quality standards (N.J.A.C. 7:9-6) or the surface water quality standards
(N.J.A.C. 7:9B) of New Jersey.
The amount of water from precipitation that infiltrates into
the ground and is not evapotranspired.
Any of the following, alone or in combination:
A net increase of impervious surface;
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);
The total area of impervious surface proposed to be newly collected
by an existing stormwater conveyance system; and/or
The total area of impervious surface collected by an existing
stormwater conveyance system where the capacity of that conveyance
system is increased.
Any of the following, alone or in combination:
The total area of motor vehicle surface that is currently receiving
water;
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.
The municipal body or official that is responsible for the
review of a major development project for compliance with the stormwater
management requirements.
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.
The lot or lots upon which a major development is to occur
or has occurred.
All unconsolidated mineral and organic material of any origin.
Sediment, debris, trash and other floating, suspended or
settleable solids.
Any material(s) or machinery, located at an industrial facility
that is directly or indirectly related to process, manufacturing,
or other industrial activities, that could be a source of pollutants
in any industrial stormwater discharge to groundwater or surface water.
Source materials include, but are not limited to, raw materials, intermediate
products, final products, water 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.
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.
The geographic application of the State Development and Redevelopment
Plan's goals and statewide policies, and the official map of
these goals and policies.
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.
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 basin), retain
water in a permanent pool (a retention basin), or be planted mainly
with wetland vegetation (most constructed stormwater wetlands).
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.
A public body authorized by legislation to prepare stormwater
management plans.
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.
Water flow on the surface of the ground or in storm sewers,
resulting from precipitation.
A strip of land located immediately adjacent to a stream
channel consisting of natural, undisturbed vegetative cover, which
serves as a transition area between uplands and riparian lands. A
stream buffer may encompass wetlands, may be contained with a floodplain
or floodway or may extend beyond a wetland, floodplain, or floodway
boundary.
A stormwater management measure that involves control of
concentrated stormwater runoff or filtration such as stormwater basins,
piped conveyance systems and manufactured stormwater devices and can
include various types of basins, filters, surfaces, and devices located
on individual lots in a residential development or throughout a commercial,
industrial or institutional development site in areas not typically
suited for larger, centralized structural facilities.
Endangered species are those whose prospects for survival
in New Jersey are in immediate danger because of a loss or change
in habitat, over-exploitation, predation, competition, disease, disturbance,
or contamination. Assistance is needed to prevent future extinction
in New Jersey. Threatened species are those who may become endangered
if conditions surrounding them begin to or continue to deteriorate.
Habitats of endangered or threatened species are those identified
by the Department's Landscape Project as approved by the Department's
Endangered and Nongame Species Program.
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.
The time it takes for stormwater runoff to travel from the
hydraulically most distant point of the watershed to the point of
interest within a watershed.
An area of protected upland adjacent to a freshwater wetland
that minimizes adverse impacts on the wetland or serves as an integral
component of the wetlands ecosystem. Also known as "buffer area."
A neighborhood given priority access to state resources through
the New Jersey Redevelopment Authority.
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.
Previously developed portions of areas:
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.
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.
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.
Stormwater management measures for major development shall be designed
to provide erosion control, groundwater 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 Erosion 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.
B.
The standards in this article 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.
A.
Maintenance plan. The development shall incorporate a maintenance plan for the stormwater management measures incorporated into the design of a major development in accordance with § 247-10.
B.
Threatened and endangered species. Stormwater management measures
shall be implemented in order to avoid adverse impacts of concentrated
flow on habitat(s) 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.
Exemptions. The following linear development projects are exempt from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of § 247-4F and G:
(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 from strict compliance.
(1)
A waiver from strict compliance from the green infrastructure, groundwater recharge, stormwater runoff quality, and stormwater runoff quantity requirements of § 247-4F and G 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:
(a)
The applicant demonstrates that there is a public need for the
project that cannot be accomplished by any other means;
(d)
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 Subsection D(1)(c) above within the upstream drainage area of the receiving stream, that would provide additional opportunities to mitigate the requirements of § 247-4F and G that were not achievable on-site.
(2)
A waiver from strict compliance from such projects can only be obtained
if the applicant agrees to undertake a suitable mitigation measure
identified in the mitigation section of the Borough of Emerson's
stormwater management plan. In such cases, the applicant must submit
a mitigation plan detailing how the project's failure to strictly
comply will be compensated. In cases where a waiver is granted, the
applicant should provide mitigation within the same watershed within
which the subject project is proposed. If mitigation within the same
watershed is not possible and/or practical, the applicant shall contribute
funding toward a regional stormwater control project or provide for
equivalent treatment at an alternate location or other equivalent
water quality benefit, in lieu of implementing the required stormwater
control measures on their specific site. Said mitigation must be reviewed
and agreed upon by the Borough of Emerson and Borough Engineer prior
to commencement of mitigation work.
E.
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 § 247-4Q, R, S, and T. 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. 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
|
Stormwater Runoff Quality TSS Removal Rate
|
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% to 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
|
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
|
|
Sand filter(b)
|
80%
|
Yes
|
Yes
|
2
|
|
Standard constructed wetland
|
90%
|
Yes
|
No
|
N/A
|
|
Wet pond(d)
|
50% to 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
|
Stormwater Runoff Quantity
|
Groundwater Recharge
|
Minimum Separation From Seasonal High Water Table
(feet)
|
|
Blue roof
|
0%
|
Yes
|
No
|
N/A
|
|
Extended detention basin
|
40% to 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% to 90%
|
Yes
|
No
|
N/A
|
|
NOTES TO TABLES 1, 2, AND 3:
| |
|
(a)
|
Subject to the applicable contributory drainage area limitation specified at § 247-4O(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 § 247-2.
|
|
(h)
|
Manufactured treatment devices that do not meet the definition of green infrastructure at § 247-2.
|
G.
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 § 247-7B. Alternative stormwater management measures may be used to satisfy the requirements at § 247-4Q only if the measures meet the definition of green infrastructure at § 247-2. Alternative stormwater management measures that function in a similar manner to a BMP listed at § 247-4Q(2) are subject to the contributory drainage area limitation specified at § 247-4Q(2) 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 § 247-4Q(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. 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 § 247-4D is granted from § 247-4Q.
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 § 247-9C;
(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, 5:21-7.4, and 5:21-7.5
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 § 247-9; 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 subsection, 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 § 247-2 may be used only under the circumstances described at § 247-9P(3).
K.
Any application for a new agricultural development that meets the definition of major development at § 247-2 shall be submitted to the Soil Conservation District for review and approval in accordance with the requirements at § 247-4O, P, Q and R 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 § 247-4P, 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 Bergen County Clerk of the county in which the development, project, project site, or mitigation area containing the stormwater management measure is located, as appropriate, to the municipality. A form of deed notice shall be submitted to the municipality for approval prior to filing. 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 § 247-4O, P, 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 § 247-10B(5). Prior to the commencement of construction, proof that the above-required deed notice has been filed shall be submitted to the municipality. 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 clerk or other proof of recordation provided by the recording office. However, if the initial proof provided to the municipality 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 municipality.
N.
A stormwater management measure approved under the municipal stormwater management plan or ordinance may be altered or replaced with the approval of the municipality, if the municipality determines that the proposed alteration or replacement meets the design and performance standards pursuant to § 247-4 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 municipality for approval and subsequently recorded with the office of the Bergen 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 municipality 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 § 247-4P and Q, the design engineer shall utilize green infrastructure BMPs identified in Table 1 at § 247-4F and/or an alternative stormwater management measure approved in accordance with § 247-4G. 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 device
|
2.5 acres
|
|
Pervious pavement systems
|
Area of additional inflow cannot exceed 3 times the area occupied
by the BMP
|
|
Small-scale bioretention systems
|
2.5 acres
|
|
Small-scale infiltration basin
|
2.5 acres
|
|
Small-scale sand filter
|
2.5 acres
|
(4)
If a variance in accordance with N.J.A.C. 7:8-4.6 or a waiver from strict compliance in accordance with § 247-4D 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 § 247-4G may be used to meet the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity standards at § 247-4P, 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 § 247-4P, Q and R, unless the project is granted a waiver from strict compliance in accordance with § 247-4D.
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 § 247-5, 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
|
0.2350
|
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
|
1.0383
|
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 - (AXB)/100
|
|
Where:
| ||
|
R
|
=
|
Total TSS percent load removal from application of both BMPs.
|
|
A
|
=
|
The TSS percent removal rate (whole number) applicable to the
first (upstream) BMP.
|
|
B
|
=
|
The TSS percent removal rate (whole number) applicable to the
second (downstream) BMP.
|
In cases where three or more BMPs are used in series,
the applicant shall calculate the TSS reduction for the two most upstream
BMPs in the series using the above formula, then substitute the result
of that calculation in the formula for "A" when calculating the combined
result with the next BMP in the series.
(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 § 247-4P, 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)3i,
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)
This stormwater runoff quality standards do 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 § 247-5, complete one of the following:
(a)
Demonstrate through hydrologic and hydraulic analysis that for
stormwater leaving the site, post-construction runoff hydrographs
for the two-, ten-, and 100-year storm events 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 two-, ten-
and 100-year storm events 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 two-, ten- and 100-year storm events 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.
A.
Stormwater runoff shall be calculated in accordance with the following:
(1)
The design engineer shall calculate stormwater runoff in accordance
with one of the following methods:
(a)
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://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044171.pdf or at United States Department of Agriculture Natural Resources Conservation Service, 220 Davison Avenue, Somerset, New Jersey 08873; or
(b)
The Rational Method for peak flow and the Modified Rational
Method for hydrograph computations. The Rational and Modified Rational
Methods are described in "Appendix A-9 Modified Rational Method" in
the Standards for Soil Erosion and Sediment Control in New Jersey,
January 2014. This document is available from the State Soil Conservation
Committee or any of the Soil Conservation Districts listed at N.J.A.C.
2:90-1.3(a)3. The location, address, and telephone number for each
Soil Conservation District is available from the State Soil Conservation
Committee, PO Box 330, Trenton, New Jersey 08625. The document is
also available at http://www.nj.gov/agriculture/divisions/anr/pdf/2014NJSoilErosionControlStandardsComplete.pdf.
(c)
Alternative groundwater recharge calculation methods may be
used upon approval by the Borough Engineer.
(2)
For the purpose of calculating runoff coefficients 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 "runoff coefficient" applies to both the NRCS methodology at § 247-5A(1)(a) and the Rational and Modified Rational Methods at § 247-5A(1)(b). A runoff coefficient 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).
(3)
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/or volumes.
(4)
In computing stormwater runoff from all design storms, the design
engineer shall consider the relative stormwater runoff rates and/or
volumes of previous 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.
(5)
Calculation of stormwater runoff from unconnected impervious surfaces
shall be based, as applicable, upon the two-step methodology as described
in the Department's current Stormwater Best Management Practices
Manual or the methodology as described in the NRCS Technical Release
55, Urban Hydrology for Small Watersheds.
(6)
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:
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.
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 http://www.nj.gov/dep/stormwater/bmp_manual2.htm.
(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://www.njstormwater.org/maintenance_guidance.htm.
B.
Submissions required for review by the Department should be mailed
to: The Division of Water Quality, New Jersey Department of Environmental
Protection, Mail Code 401-02B, PO Box 420, Trenton, New Jersey 08625-0420.
A.
Site design features identified under § 247-4F above, or alternative designs in accordance with § 247-4G 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 section, "solid and floatable materials" means sediment, debris, trash, and other floating, suspended, or settleable solids. For exemptions to this standard see § 247-7A(2) 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; or
(b)
A different grate, if each individual clear space in that grate
has an area of no more than 7.0 square inches or is no greater than
0.5 inches 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.
(c)
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 7.0 square inches, or be no greater than 2.0
inches across the smallest dimension.
(2)
The standard in Subsection A(1) above 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 9.0 square inches;
(b)
Where the municipality agrees that the standards would cause
inadequate hydraulic performance that could not practicably be overcome
by using additional or larger storm drain inlets;
(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 4.625 inches long and 1.5 inches wide (this
option does not apply for outfall netting facilities); or
[2]
A bar screen having a bar spacing of 0.5 inch.
[3]
Note that these exemptions do not authorize any infringement
of requirements in the Residential Site Improvement Standards for
bicycle-safe grates in new residential development [N.J.A.C. 5:21-4.18(b)2
and 7.4(b)1].
(d)
Where flows are conveyed through a trash rack that has parallel
bars with 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.
General scope. This section sets forth requirements to protect public
safety through the proper design and operation of stormwater management
basins. This section applies to any new stormwater management basin.
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 § 247-8C(1), (2), and (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.
(d)
The trash rack 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.
(2)
An overflow grate is intended to protect the opening in the top of
a stormwater management measure outlet structure. It 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 BMP 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 reviewing agency and/or the Borough Engineer identified in § 247-8C, a freestanding outlet structure may be exempted from this requirement;
(b)
Safety ledges shall be constructed on the slopes of all new stormwater management BMPs having a permanent pool of water deeper than 2 1/2 feet. Safety ledges shall be comprised of two steps. Each step shall be four feet 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 feet 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 horizontals to one vertical.
(d)
An emergency drawdown method for detention basins is required
where the permanent pool will be more than 2 1/2 feet deep. This
drawdown method must consider downstream or off-site stability at
the outfall in accordance with the Standards for Soil Erosion and
Sediment Control in New Jersey.
D.
A variance or exemption from the safety standards for stormwater
management basins 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.
 |
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 § 247-9C below as part of the submission of the applicant's application for subdivision or site plan approval.
(2)
The applicant shall demonstrate through submission requirements that
the project meets the standards set forth in 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.
Checklist requirements. 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 environs. 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 plans. 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 will 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 for proposed
changes in natural conditions shall also be provided.
(4)
Land use planning and source control plan. This plan shall provide a demonstration of how the goals and standards of § 247-3 through § 247-5 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. The applicant should refer to the Borough of Emerson Stormwater Management Plan and the Borough of Emerson Stormwater Pollution Prevention Plan for additional requirements.
(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 disturbed, 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.
(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 § 247-4 of this article.
(b)
When the proposed stormwater management control measures depend
on the hydrologic properties of soils or require certain separation
from the seasonal high-water table, 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. The Borough of Emerson shall be notified of site
investigation activities and given the opportunity to have a witness,
either prior to approval or as a condition of approval, as appropriate
for the specific type of measure. Subsequent to approval of the development,
post-construction bulk soil density and infiltration testing shall
be required for all infiltration measures that were used as justification
for meeting the recharge standards, to ensure that they were properly
constructed.
(7)
Maintenance and repair plan. The design and planning of the stormwater management facility shall meet the maintenance requirements of § 247-10.
(8)
Waiver from submission requirements. The municipal official or board reviewing an application under this article may, in consultation with the municipality's review engineer, waive submission of any of the requirements in § 247-9C(1) through (6) 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.
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.
This plan shall be separate from all other documents and designed
for ongoing use by the site owner(s) or operator(s) in performing
and documenting maintenance and repair, and by the Borough of Emerson
in ensuring implementation of the maintenance plan. The final maintenance
plan shall be updated and provided to the Borough of Emerson post-construction
to include an evaluation based on the specifications of the initial
maintenance plan and as-built conditions.
(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 developer, a public agency, or homeowners'
association) as having the responsibility for maintenance, the plan
shall include documentation of such person's or entity'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 required.
(5)
If the person responsible for maintenance identified under Subsection B(3) above is not a public agency, the maintenance plan and any future revisions based on Subsection B(7) 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 function of the stormwater management measure, including 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 Subsection B(3) 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; and
(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, enforce penalties
and/or liens as determined by the Borough of Emerson and described
below. Nonpayment of such bill may result in a lien on the property.
C.
Performance and maintenance guarantee. Nothing in this section shall
preclude the municipality in which the major development is located
form requiring the posting of a performance or maintenance guarantee
in accordance with N.J.S.A. 40:55D-53.
D.
Maintenance access. The maintenance plan shall specifically provide
a specific municipal right of access, which may include stormwater
easements or covenants. The maintenance access shall be provided by
the property owner(s) for access regarding facility inspections and
maintenance as required. Easements and covenants shall be recorded
with the Borough of Emerson prior to issuance of a permit.
E.
Alteration of maintenance plan. Any alteration in maintenance responsibility
or alterations to maintenance plans and agreements must be reviewed
and approved by the Borough of Emerson Building Department Official
or board that reviewed the application under this article in consultation
with the Borough Engineer, Superintendent of Public Works and Building
Department Official.
F.
Recording of information. All maintenance information and alterations to maintenance agreements shall be recorded with the office of the Borough of Emerson Building Department Official as described in Subsection B(8). Copies of the maintenance agreements and alterations to maintenance agreements shall be included in the applicant's stormwater management plans and documents. Recording of the maintenance agreements in accordance with this article shall be the responsibility of the owner.
Any person who erects, constructs, alters, repairs, converts,
maintains, or uses any building, structure, or land in violation of
this article shall be subject to the following penalties:
A.
Responsibility for administration. The Superintendent of the Department
of Public Works, Borough Engineer and Building Department Official
shall administer, implement, and enforce the provisions of this article.
Any powers granted or duties imposed upon the Superintendent of the
Department of Public Works, Borough Engineer or Building Department
Official may be delegated, in writing, to the person(s) or entities
acting in the best interest of or in the employment of the Borough
of Emerson.
B.
Enforcement of penalties and liens.
(1)
Should the applicant/owner fail to take the corrective actions, the
Borough of Emerson shall then have the right to take the available
appropriate remedies it deems necessary to correct the violations,
including fining the owner pursuant to penalties for violations of
the Borough of Emerson Land Development Ordinance and to assert a
lien on the subject property in an amount equal to the costs of remedial
actions. The lien shall be enforced in the manner provided or authorized
by law for the enforcement of common law liens on personal property.
The lien shall be recorded with the Borough of Emerson and shall incur
legal interest from the date of recording. The imposition of any penalty
shall not exempt the offender from compliance with the provisions
of this article, including assessment of a lien on the property.
(2)
Whenever a structural BMP is not implemented, operated, and/or maintained
in accordance with the stormwater management plan which has been approved
in accordance with this article. Any penalty invoked shall be in accordance
with penalties for violations of the Borough of Emerson Land Development
Ordinance.
Each section, subsection, sentence, clause, and phrase of this
article is declared to be an independent section, subsection, sentence,
clause and phrase, and the finding or holding of any such portion
of this article to be unconstitutional, void, or ineffective for any
cause, or reason, shall not affect any other portion of this article.
This article shall take effect immediately upon the approval
by the county review agency, or 60 days from the receipt of the article
by the county review agency if the county review agency should fail
to act.
