[HISTORY: Adopted by the Mayor and Council of the Borough
of Penns Grove 9-5-2006 by Ord.
No. 2006-23 (Ch. 188 of the 1986 Code). Amendments
noted where applicable.]
A.
Policy statement. Flood control, groundwater recharge, and pollutant
reduction through nonstructural stormwater management strategies per
this chapter, and all low-impact stormwater management strategies,
shall be explored before relying on structural BMPs. Structural BMPs
should be integrated with nonstructural stormwater management strategies
and proper maintenance plans. Nonstructural strategies include both
environmentally sensitive site design and source controls that prevent
pollutants from being placed on the site or from being exposed to
stormwater. Source control plans 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. The purpose of this chapter is to establish minimum stormwater management requirements and controls for major development, as defined in § 387-2.
C.
Applicability. This chapter shall be applicable to all site plans,
subdivisions, variance, conditional use, and general development plans
for the following major developments that require preliminary or final
site plan or subdivision review:
D.
Compatibility with other permit and ordinance requirements. Compliance
with the requirements of this chapter is to be considered an integral
part of development approvals under the review process for applicable
major developments and does 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 chapter shall be held to be
the minimum stormwater management requirements for the promotion of
the public health, safety, and general welfare. This chapter is not
intended to interfere with, abrogate, or annul any other ordinance,
rule or regulation, statute, or other provision of law, except that,
where any provision of this chapter 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.
E.
Residential development subject to Residential Site Improvement Standards.
All residential development shall remain subject to applicable requirements
of the Residential Site Improvement Standards at N.J.A.C. 5:21 et
seq.
Whenever the following terms, or pronouns in place of them,
are used, the intent and meaning, unless a different intent or meaning
is clearly indicated, shall be interpreted as set forth in the following
unless specifically defined below:
The New Jersey Stormwater Best Management Practices Manual.
The geographic depiction of the boundaries for coastal planning
areas, CAFRA centers, CAFRA cores and CAFRA nodes pursuant to N.J.A.C.
7:7-13.
[Amended 7-5-2017 by Ord.
No. 2017-5]
An increase in soil bulk density.
An interest in land less than fee simple absolute, stated
in the form of a right, restriction, easement, covenant, or condition,
in any deed, will or other instrument, other than a lease, executed
by or on behalf of the person vested with a greater interest therein,
appropriate to retaining land or water areas predominantly in their
natural, scenic, open or wooded condition, or for conservation of
suitable habitat for plants or animals.
An interest in land less than fee simple absolute, stated
in the form of a right, restriction, easement, covenant, or condition,
in any deed, will or other instrument, other than a lease, executed
by or on behalf of the owner of the land, appropriate to retaining
land or water areas predominantly in their natural, scenic or open
or wooded condition, or for conservation of soil or wildlife, or for
outdoor recreation or park use, or as suitable habitat for fish or
wildlife, to forbid or limit any or all:
Construction or placing of buildings, roads, signs, billboards
or other advertising, or other structures on or above the ground.
Dumping or placing of soil or other substance or material as
landfill, or dumping or placing of trash, waste or unsightly or offensive
materials.
Removal or destruction of trees, shrubs or other vegetation.
Excavation, dredging or removal of loam, peat, gravel, soil,
rock or other mineral substance.
Surface use except for purposes permitting the land or water
area to remain predominantly in its natural condition.
Activities detrimental to drainage, flood control, water conservation,
erosion control or soil conservation, or fish and wildlife habitat
preservation.
Other acts or uses detrimental to the retention of land or water
areas according to the purposes of any conservation or environmental
laws or regulations.
A pedestrian-oriented area of commercial and civic uses serving
the surrounding municipality, generally including housing and access
to public transportation.
Unless otherwise specified, the Salem County Planning Board,
or such other agency as may be designated by the Salem County Board
of Chosen Freeholders to review municipal stormwater management plans
and implementing ordinances, and the Salem County Soil Conservation
District.
A state development and redevelopment plan center as designated
by the State Planning Commission, such as urban, regional, town, village,
or hamlet.
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.
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; any forestry or logging activities; 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/or the State Agricultural
Development Council (SADC), and municipal review of any activity not
exempted by the Right to Farm Act, N.J.S.A. 4:1C-1 et seq.
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.
Areas where the physical alteration of the land is in some
way restricted, either through regulation, easement, deed restriction
or ownership, such as but not limited to wetlands, floodplains, threatened
and endangered species sites or designated habitats, and parks and
preserves. Habitats of endangered or threatened species are identified
using the NJDEP's Landscape Project as approved by the NJDEP'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 NJDEP's Landscape
Project as approved by the NJDEP's Endangered and Nongame Species
Program.
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.
Any development (as defined herein) that provides for ultimately
disturbing one or more acres of land or increasing impervious surface
by 1/4 acre or more. Projects undertaken by any government agency
which 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.
Any city, borough, town, township or village.
The New Jersey Department of Environmental Protection.
An area designated by the State Planning Commission concentrating
facilities and activities which are not organized in a compact form.
A chemical element or compound, such as nitrogen or phosphorus,
which is essential to and promotes the development of organisms.
Any individual, corporation, company, partnership, firm,
association, the Borough of Penns Grove, 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.
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 amount of water from precipitation that infiltrates into
the ground and is not evapotranspired.
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 development is to occur or has
occurred.
All unconsolidated mineral and organic material of any origin.
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 basin 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 structural or nonstructural strategy, 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.
Chapter 387 of the Code of the Borough of Penns Grove.
The water flow on the surface of the ground or in storm sewers
that results from precipitation.
A flood hazard area which may be influenced by stormwater
runoff from inland areas but which is primarily caused by the Atlantic
Ocean.
The time required for runoff to travel from the hydraulically
most distant point of the watershed to the point of interest within
a watershed.
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:
The ocean and its estuaries and 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 developed
to meet the erosion control, groundwater recharge, stormwater runoff
quantity, and stormwater runoff quality standards in this chapter.
To the maximum extent practicable, these standards shall be met by
incorporating nonstructural stormwater management strategies into
the design. If these strategies alone are not sufficient to meet these
standards, structural stormwater management measures necessary to
meet these standards shall be incorporated into the design.
B.
The standards in this chapter 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 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 NJDEP rules.
C.
Stormwater management measures shall be designed in accordance with
N.J.A.C. 5:21-7 unless otherwise required herein.
A.
Each major development must include a maintenance plan for the stormwater management measures in accordance with § 387-10 below and Appendix D of the New Jersey Stormwater Best Management Practices Manual, as amended.
B.
Stormwater management measures shall avoid adverse impacts of concentrated
flow on environmentally constrained areas, environmentally critical
areas, or any habitat for threatened and endangered species as documented
in the NJDEP'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 muhlenbergi (bog turtle).
C.
The following municipal, county, state, and federal linear development projects, and linear development projects that have been approved by the Board of Public Utilities, are exempt from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of Subsections F 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.
The Planning Board may grant a waiver from strict compliance with the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of Subsections F and G below for the enlargement of an existing public roadway or railroad, or the construction or enlargement of a public pedestrian access, provided that all of the following conditions are met:
[Amended 7-5-2017 by Ord.
No. 2017-5]
(1)
The applicant demonstrates that there is a public need for the project
that cannot be accomplished by any other means;
(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 Subsection D(3) above, within the upstream drainage area of the receiving stream that would provide additional opportunities to mitigate the requirements of Subsections F and G that were not achievable on site.
E.
Nonstructural stormwater management strategies.
(1)
To the maximum extent practicable, the standards in Subsections F and G shall be met by incorporating nonstructural stormwater management strategies set forth in this subsection into the design. The applicant shall identify the nonstructural measures incorporated into the design of the project. If the applicant contends that it is not feasible for engineering, environmental, or safety reasons to incorporate any nonstructural stormwater management measures identified in Subsection E(2) below into the design of a particular project, the applicant shall identify the strategy considered and provide a basis for the contention.
(2)
Nonstructural stormwater management strategies incorporated into
site design shall:
(a)
Protect environmentally constrained areas, environmentally critical
areas, and other areas that provide water quality benefits or which
are particularly susceptible to erosion and sediment loss.
(b)
Minimize impervious surfaces and break up or disconnect the
flow of runoff over impervious surfaces.
(c)
Maximize the protection of natural drainage features and vegetation.
(d)
Minimize the decrease in the time of concentration from pre-construction
to post-construction.
(e)
Minimize land disturbance, including clearing and grading.
(f)
Minimize soil compaction.
(g)
Provide low-maintenance landscaping that encourages retention
and planting of native vegetation and minimizes the use of lawns,
fertilizers and pesticides.
(h)
Provide vegetated open-channel conveyance systems discharging
into and through stable vegetated areas.
(i)
Provide other source controls to prevent or minimize the use
or exposure of pollutants at the site, in order to prevent or minimize
the release of those pollutants into stormwater runoff. Such source
controls include, but are not limited to:
[1]
Site design features that help to prevent accumulation of trash and debris in drainage systems, including features that satisfy Subsection E(3) below;
[2]
Site design features that help to prevent discharge of trash
and debris from drainage systems;
[3]
Site design features that help to prevent and/or contain spills
or other harmful accumulations of pollutants at industrial or commercial
developments; and
[4]
When establishing vegetation after land disturbance, applying
fertilizer in accordance with the requirements established under the
Soil Erosion and Sediment Control Act, N.J.S.A. 4:24-39 et seq., and
implementing rules.
(3)
Site design features identified under Subsection E(2)(i)[2] above 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 E(3)(c) below.
(a)
Design engineers shall use either 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:
[1]
The New Jersey Department of Transportation (NJDOT) bicycle-safe
grate, as described in the NJDOT Bicycle Compatible Roadways and Bikeways
Planning and Design Guidelines, as amended; or
[2]
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. 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 basin
floors.
(b)
Whenever design engineers use a curb opening inlet, 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.
(c)
This standard does not apply:
[1]
Where the Planning Board 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;
[2]
Where flows from the water quality design storm as specified in Subsection G(1) 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:
[3]
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 Subsection G(1); or
[4]
Where the NJDEP 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.
(4)
Any land area used as a nonstructural stormwater management measure to meet the performance standards in Subsections F and G below shall be dedicated to a government agency other than the Borough of Penns Grove, subjected to a conservation restriction filed with the Salem County Clerk's office, or subject to an approved equivalent restriction that ensures that measure or an equivalent stormwater management measure approved by the Planning Board is maintained in perpetuity.
F.
Erosion control, groundwater recharge and runoff quantity standards.
(1)
This subsection contains minimum design and performance standards
to control erosion, encourage and control infiltration and groundwater
recharge, and control stormwater runoff quantity impacts of major
development.
(a)
The minimum design and performance 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.
(b)
The minimum design and performance standards for groundwater
recharge are as follows:
[1]
The design engineer shall, using the assumptions and factors for stormwater runoff and groundwater recharge calculations at § 387-5, either:
[a]
Demonstrate through hydrologic and hydraulic analysis
that the site and its stormwater management measures maintain 100%
of the average annual pre-construction groundwater recharge volume
for the site; or
[b]
Demonstrate through hydrologic and hydraulic analysis
that the increase of stormwater runoff volume from pre-construction
to post-construction for the two-year storm is infiltrated.
[2]
This groundwater recharge requirement does not apply to projects with any urban redevelopment areas or to projects that are subject to Subsection F(1)(b)[3] below.
[3]
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, or any subsequent
amendments thereto; areas where recharge would be inconsistent with
a NJDEP 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.
[4]
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 and
other subsurface structures in the vicinity or downgradient of the
groundwater recharge area.
(c)
In order to control stormwater runoff quantity impacts, the design engineer shall, using the methods and procedures for stormwater runoff calculations at § 387-5, complete one of the following to the Board's satisfaction:
[1]
Demonstrate through hydrologic and hydraulic analysis that for
stormwater leaving the site, post-construction runoff hydrographs
for the two-, ten- and one-hundred-year storm events do not exceed,
at any point in time, the pre-construction runoff hydrographs for
the same storm events.
[2]
Demonstrate through hydrologic and hydraulic analysis that there
is no increase, as compared to the pre-construction condition, in
the peak runoff rates of stormwater leaving the site for the two-,
ten- and one-hundred-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.
[3]
Design stormwater management measures so that the post-construction
peak runoff rates for the two-, ten-, and one-hundred-year storm events
are 50%, 75% and 80%, respectively, of the pre-construction 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. The percentages
shall not be applied to post-construction stormwater runoff into tidal
flood hazard areas if the increased volume of stormwater runoff will
not increase flood damages below the point of discharge.
[4]
In tidal flood hazard areas, stormwater runoff quantity analysis in accordance with Subsection F(1)(c)[1], [2] and [3] above shall only be applied if the increased volume of stormwater runoff could increase flood damages below the point of discharge.
(2)
A minimum of two soil borings shall be required for each basin. For
each basin with surface area of 1/2 acre or more, borings will be
required at a rate of one soil boring per each 1/2 acre in addition
to the initial two borings per facility.
(3)
Any application for a new agricultural development that meets the
definition of "major development" for purposes of this chapter shall
be submitted to the appropriate Soil Conservation District for review
and approval in accordance with the requirements of this section,
any applicable Soil Conservation District guidelines for stormwater
runoff quantity and erosion control, and the Rutgers Farmland Management
Best Management Practices. For the purposes of this section, "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 manufacturing
of agriculturally related products.
G.
Stormwater runoff quality standards.
(1)
Stormwater management measures shall be designed to reduce the post-construction
load of total suspended solids (TSS) in stormwater runoff by 80% of
the anticipated load from the developed site, expressed as an annual
average. Stormwater management measures shall only be required for
water quality control if an additional 1/4 acre of impervious surface
is being proposed on a development site. 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. 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 1 of the New Jersey Stormwater Best Management
Practices Manual Chapter 5, as amended. The calculation of the volume
of runoff may take into account the implementation of nonstructural
and structural stormwater management measures.
(2)
For purposes of TSS reduction calculations, Table 4-1 in Chapter
4 of the New Jersey Stormwater Best Management Practices Manual, as
amended, presents the presumed removal rates for certain BMPs designed
in accordance with the New Jersey Stormwater Best Management Practices
Manual. The BMP Manual and other sources of technical guidance are
listed in § 384-7 or found on the Department's website
at www.njstormwater.org. Total suspended solids reduction shall be
calculated based on the removal rates for the BMPs in the aforementioned
Table 4-1 as amended. Alternative removal rates and methods of calculating
removal rates may be used if the design engineer provides documentation
demonstrating the capability of these alternative rates and methods
to the review agency. The applicant must provide a copy of any approved
alternative rate or method of calculating the removal rate to the
NJDEP at the following address prior to signature of plans or any
clearing, grading, demolition, installation of improvements or other
construction-related activities at the site: Division of Watershed
Management, New Jersey Department of Environmental Protection, P.O.
Box 418, Trenton, New Jersey 08625-0418.
(3)
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.
| ||
(4)
If there is more than one on-site drainage area, the 80% TSS removal
rate shall apply to each drainage area, unless the runoff from the
subareas converges on site, in which case the removal rate can be
demonstrated through a calculation using a weighted average.
(5)
Stormwater management measures shall also be designed according to standards set forth in Subsections B and C above 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 nonstructural strategies and structural measures that optimize nutrient removal while still achieving the performance standards in Subsections F and G above.
(6)
Additional information and examples are contained in the New Jersey
Stormwater Best Management Practices Manual, as amended.
(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)
Special water resource protection areas shall be established by the
applicant along all waters designated Category One at N.J.A.C. 7:9B,
and perennial or intermittent streams that drain into or upstream
of the Category One waters as shown on the USGS quadrangle maps or
in the county soil surveys, within the associated HUC14 drainage area.
These areas shall be established for the protection of water quality,
aesthetic value, exceptional ecological significance, exceptional
recreational significance, exceptional water supply significance,
and exceptional fisheries significance of those established Category
One waters. These areas shall be designated and protected as follows:
(a)
The applicant shall preserve and maintain a special water resource
protection area in accordance with one of the following:
[1]
A three-hundred-foot special water resource protection area
shall be provided by means of conservation easements and conservation
restrictions in favor of the Borough on each side of the waterway,
measured perpendicular to the waterway from the top of the bank outwards
or from the center line of the waterway where the bank is not defined,
to preserve existing vegetation and/or to promote the natural succession
of new vegetation.
[2]
Encroachment within the designated special water resource protection area under Subsection G(8)(a)[1] above shall only be allowed where previous development or disturbance has occurred (for example, active agricultural use, parking area or maintained lawn area). The encroachment shall only be allowed where the applicant demonstrates that the functional value and overall condition of the special water resource protection area will be maintained to the maximum extent practicable. In no case shall the remaining special water resource protection area be reduced to less than 150 feet as measured perpendicular to the top of bank of the waterway or center line of the waterway where the bank is undefined. All encroachments proposed under this subsection shall be subject to review and approval by the NJDEP.
(b)
All stormwater shall be discharged outside of and flow through
the special water resource protection area and shall comply with the
standard for off-site stability in the Standards for Soil Erosion
and Sediment Control in New Jersey, established under the Soil Erosion
and Sediment Control Act, N.J.S.A. 4:24-39 et seq.
(c)
If stormwater discharged outside of and flowing through the
special water resource protection area cannot comply with the standard
for off-site stability in the Standards for Soil Erosion and Sediment
Control in New Jersey, established under the Soil Erosion and Sediment
Control Act, N.J.S.A. 4:24-39 et seq., then the stabilization measures
in accordance with the requirements of the above standards may be
placed within the special water resource protection area, provided
that:
[1]
Stabilization measures shall not be placed within 150 feet of
the Category One waterway;
[2]
Stormwater associated with discharges allowed by this section
shall achieve a 95% TSS post-construction removal rate;
[3]
Temperature shall be addressed to ensure no impact on the receiving
waterway;
[4]
The encroachment shall only be allowed where the applicant demonstrates
that the functional value and overall condition of the special water
resource protection area will be maintained to the maximum extent
practicable;
[5]
A conceptual project design meeting shall be held with the appropriate
NJDEP staff and Soil Conservation District staff to identify necessary
stabilization measures; and
[6]
All encroachments proposed under this section shall be subject
to review and approval by the NJDEP.
(d)
A stream corridor protection plan may be developed by a regional stormwater management planning council as an element of a regional stormwater management plan or by the Borough through an adopted municipal stormwater management plan. If a stream corridor protection plan for a waterway subject to Subsection G(8) has been approved by the NJDEP, then the provisions of the plan shall be the applicable special water resource protection area requirements for that waterway. A stream corridor protection plan for a waterway subject to Subsection G(8) shall maintain or enhance the current functional value and overall condition of the special water resource protection area as defined in Subsection G(8)(a)[1] above. In no case shall a stream corridor protection plan allow the reduction of the special water resource protection area to less than 150 feet as measured perpendicular to the waterway subject to this subsection.
A.
Stormwater runoff shall be calculated in accordance with the following:
(1)
The design engineer shall calculate runoff using one of the following
methods:
(a)
The United States Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) methodology, including the NRCS runoff
equation and dimensionless unit hydrograph, as described in the NRCS
National Engineering Handbook Section 4, Hydrology, and Technical
Release 55, as amended, Urban Hydrology for Small Watersheds; or
(b)
The rational method for peak flow and the modified rational
method for hydrograph computations.
(2)
For the purpose of calculating runoff coefficients and groundwater recharge, there is a presumption that the pre-construction 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 Subsection A(1)(a) and the rational and modified rational methods at Subsection A(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 pre-construction 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 pre-construction stormwater runoff rates and volumes.
(4)
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, and other methods may be employed.
(5)
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, and information regarding the methodology
is available from the New Jersey Best Management Practices Manual
or the New Jersey Geological Survey, 29 Arctic Parkway, P.O. Box 427,
Trenton, New Jersey 08625-0427.
A.
Standards for structural stormwater management measures are as follows:
(1)
Structural stormwater management measures shall be designed to meet the standards of § 387-4, Stormwater management requirements for major development, and § 387-5, Calculation of stormwater runoff and groundwater recharge, while taking into account the existing site conditions, including for example environmentally critical areas; wetlands; flood-prone areas; slopes; depth to seasonal high-water table; soil type, permeability and texture; and drainage area and drainage patterns.
(2)
Structural stormwater management measures shall be designed to minimize maintenance, facilitate maintenance and repairs, and ensure proper functioning to meet the standards of § 387-4, Stormwater management requirements for major development, and § 387-5, Calculation of stormwater runoff and groundwater recharge. 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 § 387-8B.
(3)
Structural 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,
as amended, shall be deemed to meet this requirement.
(4)
At the intake to the outlet from the stormwater management basin,
the orifice size shall be a minimum of 2 1/2 inches in diameter.
B.
Stormwater management measure guidelines are available in the New Jersey Stormwater Best Management Practices Manual. Other stormwater management measures may be utilized provided the design engineer demonstrates that the proposed measure and its design will accomplish the required water quantity, groundwater recharge and water quality design and performance standards established by § 387-4 of this chapter.
C.
Manufactured treatment devices may be used to meet the requirements of § 387-4 of this chapter, provided the pollutant removal rates are verified by the New Jersey Corporation for Advanced Technology and certified by the NJDEP.
D.
A stormwater basin that serves more than one residential lot must
be located on a separate lot that is not used for residential purposes.
A.
Technical guidance for stormwater management measures can be found in the documents listed at Subsection A(1) and (2) below, which are available from Maps and Publications, New Jersey Department of Environmental Protection, 428 East State Street, P.O. Box 420, Trenton, New Jersey 08625.
(1)
Guidelines for stormwater management measures are contained in the
New Jersey Stormwater Best Management Practices Manual, as amended.
Information is provided on stormwater management measures such as
bioretention systems, constructed stormwater wetlands, dry wells,
extended detention basins, infiltration structures, manufactured treatment
devices, pervious paving, sand filters, vegetative filter strips,
and wet ponds.
(2)
The New Jersey Department of Environmental Protection Stormwater
Management Facilities Maintenance Manual, as amended.
B.
Additional technical guidance for stormwater management measures
can be obtained from the following:
A.
This section sets forth minimum requirements to protect public safety
through the proper design and operation of stormwater management basins.
B.
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 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)
For purposes of this Subsection B(3), "escape provisions" means the permanent installation of ladders, steps, rungs, or other features that provide easily accessible means of egress from stormwater management basins. Stormwater management basins 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. The Planning Board may exempt a freestanding outlet structure from this requirement pursuant to Subsection C below.
(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 the New Jersey Residential
Site Improvement Standards (RSIS), N.J.A.C. 5:21-1.1 et seq., for
an illustration of safety ledges in a stormwater management basin.
(c)
In new stormwater management basins, the maximum interior slope
for an earthen dam, embankment, or berm shall not be steeper than
four horizontal to one vertical. A forty-two-inch-high wooden double
split-rail fence or six-foot-high galvanized chain-link fence, for
purposes of delineation, must surround any basin where there is a
possibility of standing water of 30 inches or more.
C.
Waiver or exemption from safety standards. A waiver or exemption
from the safety standards for stormwater management basins may be
granted only upon a written finding by the Planning Board that the
waiver or exemption will not constitute a threat to public safety.
D.
Safety ledges in a new stormwater management basin shall comply with
the New Jersey Stormwater Best Management Practices Manual Appendix
D and this section, as amended.
A.
Submission of major development stormwater plan.
(1)
Whenever an applicant seeks municipal approval of a development subject to this chapter, the applicant shall submit all of the information and materials required in the checklist for the site development stormwater plan referred to in Subsection C below as part of the submission of the applicant's application for subdivision, site plan, or other development approval.
(2)
The applicant shall demonstrate that the project meets the standards
set forth in this chapter.
B.
The applicant's site development stormwater plan shall be reviewed
as a part of the subdivision, site plan or other development application
review process by the Planning Board or Borough official from whom
approval is sought. The Planning Board or Borough official shall consult
the engineer retained by the Planning and/or Borough to determine
if all of the checklist requirements have been satisfied and to determine
if the project meets the standards set forth in this chapter.
C.
Checklist.
(2)
Waiver from submission requirements. The Planning Board may, in consultation
with the Planning Board Engineer, waive submission of any of the checklist
submission requirements when appropriate under the circumstances of
a particular application if is determined that granting such a waiver
will not materially affect the application review process.
B.
General maintenance.
(1)
The design engineer shall prepare a maintenance plan for the structural
and nonstructural 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). If the maintenance plan identifies
an individual other than the developer (for example, the present and
future owners of the property, a public agency or a homeowners'
or lot owners' association) as having the responsibility for
maintenance, the plan shall include documentation confirming such
person's assumption of or agreement to assume this responsibility
and/or of the developer's obligation to dedicate a stormwater
management facility to such person.
(3)
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.
(4)
If the person responsible for maintenance identified under Subsection B(2) above is not a public agency, the maintenance plan and any future revisions based on Subsection B(7) below shall be incorporated into easements and covenants to be recorded upon the deed of record for each property on which the maintenance described in the maintenance plan must be undertaken. The Planning Board and/or the Borough may require that any such easements and restrictions contain terms and conditions that will carry out the purposes of this chapter on an ongoing basis at no cost to the Borough. The Planning Board and/or the Borough may require the responsible person to post and periodically renew bonds or other guarantees to ensure that the purposes of this chapter will be carried out at no cost to the Borough in the event of any failure by the responsible person.
(5)
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.
(6)
The person responsible for maintenance identified under Subsection B(2) above shall maintain a detailed log providing a quantitative and qualitative record 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 observations made during the same, and copies of all maintenance-related work orders.
(7)
The person responsible for maintenance identified under Subsection B(2) above shall evaluate the effectiveness of the maintenance plan at least once per year and adjust the plan and the deed as needed.
(8)
The person responsible for maintenance identified under Subsection B(2) above shall 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 Subsection B(6) and (7) above.
(10)
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 Borough may 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 Borough Engineer or his designee. The
Borough, 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 Borough or
county may immediately proceed to do so and thereafter bill the cost
thereof to the responsible person, in which event the responsible
person must pay the full amount of the bill and all related administrative
costs within 14 days following the issuance of such notification.
C.
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.
Any person who erects, constructs, alters, repairs, converts,
maintains or uses any building, structure or land in violation of
this chapter shall be subject to a fine of $500 per day.
This chapter shall take effect upon the filing thereof with
the Salem County Planning Board and after final passage and publication
in the manner prescribed by law.
