Editor's Note: Ord. No. 2021-11 replaced Chapter 18 in entirety.
Prior history includes Ord. No. 03-2006 and Ord. No. 2013-17.
[Added 6-28-2021 by Ord.
No. 2021-11]
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.
[Added 6-28-2021 by Ord.
No. 2021-11]
It is the purpose of this chapter to establish minimum stormwater management requirements and controls for "major development", as defined below in Section 18-2.
[Added 6-28-2021 by Ord.
No. 2021-11]
[Added 6-28-2021 by Ord.
No. 2021-11]
Development approvals issued pursuant to this ordinance are
to be considered an integral part of development approvals and do
not relieve the applicant of the responsibility to secure required
permits or approvals for activities regulated by any other applicable
code, rule, act, or ordinance. In their interpretation and application,
the provisions of this ordinance shall be held to be the minimum requirements
for the promotion of the public health, safety, and general welfare.
This ordinance 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 ordinance 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.
[Added 6-28-2021 by Ord.
No. 2021-11]
For purpose of this ordinance, the following terms, phrases,
words and their derivations shall have the meanings stated herein
unless their use in the text of this Chapter clearly demonstrates
a different meaning. When not inconsistent with the context, words
used in the present tense include the future, 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.
Shall mean those areas within boundaries accepted by the
Department pursuant to N.J.A.C. 7:7-13.16.
Shall mean 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).
Shall mean an infiltration system, sand filter designed to
infiltrate, standard constructed wetland, or wet pond, established
in accordance with N.J.A.C. 7:8-4.2(c)14, that is designed and constructed
in accordance with the New Jersey Stormwater Best Management Practices
Manual, or an alternate design, approved in accordance with N.J.A.C.
7:8- 5.2(g), for an infiltration system, sand filter designed to infiltrate,
standard constructed wetland, or wet pond and that complies with the
requirements of this chapter.
Shall mean the increase in soil bulk density.
Shall mean the area from which stormwater runoff drains to
a stormwater management measure, not including the area of the stormwater
management measure itself.
Shall mean a pedestrian-oriented area of commercial and civic
uses serving the surrounding municipality, generally including housing
and access to public transportation.
Shall mean an agency designated by the County Commissioners
to review municipal stormwater management plans and implementing ordinance(s).
The County Review Agency may either be:
Shall mean the New Jersey Department of Environmental Protection.
Shall mean 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.
Shall mean a State Development and Redevelopment Plan Center
as designated by the State Planning Commission such as urban, regional,
town, village, or hamlet.
Shall mean 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, 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.
Shall mean 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.
Shall mean a geographic area within which stormwater, sediments,
or dissolved materials drain to a particular receiving waterbody or
to a particular point along a receiving waterbody.
Shall mean neighborhoods 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.
Shall mean 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.
Shall mean 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
well head 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.
Shall mean the detachment and movement of soil or rock fragments
by water, wind, ice or gravity.
Shall mean a stormwater management measure that manages stormwater
close to its source by:
Shall mean an area within which water drains to a particular
receiving surface water body, also known as a subwatershed, which
is identified by a 14-digit hydrologic unit boundary designation,
delineated within New Jersey by the United States Geological Survey.
Shall mean a surface that has been covered with a layer of
material so that it is highly resistant to infiltration by water.
Shall mean the process by which water seeps into the soil
from precipitation.
Shall mean 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.
Shall mean 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
A combination of paragraphs b and c above that totals an area
of 1/4 acre or more. The same surface shall not be counted twice when
determining if the combination area equals 1/4 acre or more.
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Major development includes all developments that are part of
a common plan of development or sale (for example, phased regional
development) that collectively or individually meet any one or more
of paragraphs a, b, c or d above. Projects undertaken by any government
agency that otherwise meet the definition of "major development" but
which do not require approval under the Municipal Land Use Law, N.J.S.A.
40:55D-1 et seq., are also considered "major development".
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Shall mean 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.
Shall mean 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.
Shall mean any city, borough, town, township, or village.
Shall mean the manual maintained by the Department providing, in part, design specifications, removal rates, calculation methods, and soil testing procedures approved by the Department as being capable of contributing to the achievement of the stormwater management standards specified in this chapter. The BMP Manual is periodically amended by the Department as necessary to provide design specifications on additional best management practices and new information on already included practices reflecting the best available current information regarding the particular practice and the Department's determination as to the ability of that best management practice to contribute to compliance with the standards contained in this chapter. Alternative stormwater management measures, removal rates, or calculation methods may be utilized, subject to any limitations specified in this chapter, provided the design engineer demonstrates to the municipality, in accordance with Section 18-4f and N.J.A.C. 7:8-5.2(g), that the proposed measure and its design will contribute to achievement of the design and performance standards established by this chapter.
Shall mean an area designated by the State Planning Commission
concentrating facilities and activities which are not organized in
a compact form.
Shall mean a chemical element or compound, such as nitrogen
or phosphorus, which is essential to and promotes the development
of organisms.
Shall mean any individual, corporation, company, partnership,
firm, association, political subdivision of this State and any state,
interstate or Federal agency.
Shall mean 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, ground waters
or surface waters of the State, or to a domestic treatment works.
"Pollutant" includes both hazardous and nonhazardous pollutants.
Shall mean the amount of water from precipitation that infiltrates
into the ground and is not evapotranspired.
Shall mean 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.
Shall mean 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.
Shall mean 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.
Shall mean the lot or lots upon which a major development
is to occur or has occurred.
Shall mean all unconsolidated mineral and organic material
of any origin.
Shall mean 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.
Shall mean the geographic application of the State Development
and Redevelopment Plan's goals and Statewide policies, and the
official map of these goals and policies.
Shall mean 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.
Shall mean an excavation or embankment and related areas
designed to retain stormwater runoff. A stormwater management BMP
may either be normally dry (that is, a detention basin or infiltration
system), retain water in a permanent pool (a retention basin), or
be planted mainly with wetland vegetation (most constructed stormwater
wetlands).
Shall mean 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 non-stormwater
discharges into stormwater conveyances.
Shall mean a public body authorized by legislation to prepare
stormwater management plans.
Shall mean 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.
Shall mean water flow on the surface of the ground or in
storm sewers, resulting from precipitation.
Shall mean 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 flood 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.
Shall mean a neighborhood given priority access to State
resources through the New Jersey Redevelopment Authority.
Shall mean 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.
Shall mean previously developed portions of areas:
Shall mean a structure within, or adjacent to, a water, which
intentionally or coincidentally alters the hydraulic capacity, the
flood elevation resulting from the two-, ten-, 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.
Shall mean the ocean and its estuaries, all springs, streams,
wetlands, and bodies of surface or ground water, whether natural or
artificial, within the boundaries of the State of New Jersey or subject
to its jurisdiction.
Shall mean an area that is inundated or saturated by surface
water or ground water 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.
[Added 6-28-2021 by Ord.
No. 2021-11]
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 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 ordinance 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.
Note: Alternative standards shall provide at least as much protection
from stormwater-related loss of groundwater recharge, stormwater quantity
and water quality impacts of major development projects as would be
provided under the standards in N.J.A.C. 7:8-5.
[Added 6-28-2021 by Ord.
No. 2021-11]
a.
The development shall incorporate a maintenance plan for the stormwater management measures incorporated into the design of a major development in accordance with Section 18-10.
b.
Stormwater management measures shall avoid adverse impacts of concentrated
flow on habitat for threatened and endangered species as documented
in the Department's Landscape Project or Natural Heritage Database
established under N.J.S.A. 13:1B-15.147 through 15.150, particularly
Helonias bullata (swamp pink) and/or Clemmys muhlenbergii (bog turtle).
c.
The following linear development projects are exempt from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of Sections 18-4p, q, and r.
1.
The construction of an underground utility line provided that the
disturbed areas are revegetated upon completion;
2.
The construction of an aboveground utility line provided that the
existing conditions are maintained to the maximum extent practicable;
and
3.
The construction of a public pedestrian access, such as a sidewalk
or trail with a maximum width of 14 feet, provided that the access
is made of permeable material.
d.
A waiver from strict compliance from the green infrastructure, groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of Sections 18-4o, p, q, and r may be obtained for the enlargement of an existing public roadway or railroad; or the construction or enlargement of a public pedestrian access, provided that the following conditions are met:
1.
The applicant demonstrates that there is a public need for the project
that cannot be accomplished by any other means;
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 Section 18-4d3. above within the upstream drainage area of the receiving stream, that would provide additional opportunities to mitigate the requirements of Sections 18-4o, p, q, and r that were not achievable on-site.
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 Section 18-4o, p, q, and r. 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 the ordinance the
BMP Tables in the Stormwater Management rule at N.J.A.C. 7:8-5.2(f)
shall take precedence.
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Table 1
Green Infrastructure BMPs for Groundwater Recharge, Stormwater
Runoff Quality, and/or Stormwater Runoff Quantity
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|---|---|---|---|---|
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Best Management Practice
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Stormwater Runoff Quality TSS Removal Rate
(percent)
|
Stormwater Runoff Quantity
|
Groundwater Recharge
|
Minimum Separation from Seasonal High Water Table
(feet)
|
|
Cistern
|
0
|
Yes
|
No
|
—
|
|
Dry well(a)
|
0
|
No
|
Yes
|
2
|
|
Grass swale
|
50 or less
|
No
|
No
|
2(e)
1(f)
|
|
Green roof
|
0
|
Yes
|
No
|
—
|
|
Manufactured treatment device(a) (g)
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50 or 80
|
No
|
No
|
Dependent upon the device
|
|
Pervious paving system(a)
|
80
|
Yes
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Yes(b)
No(c)
|
2(b)
1(c)
|
|
Small-scale bioretention basin(a)
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80 or 90
|
Yes
|
Yes(b)
No(c)
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2(b)
1(c)
|
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Small-scale infiltration basin(a)
|
80
|
Yes
|
Yes
|
2
|
|
Small-scale sand filter
|
80
|
Yes
|
Yes
|
2
|
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Vegetative filter strip
|
60-80
|
No
|
No
|
—
|
|
(Notes corresponding to annotations (a) through (g) are found
after Table 3.)
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Table 2
Green Infrastructure BMPs for Stormwater Runoff Quantity
(or for Groundwater Recharge and/or Stormwater Runoff Quality
with a Waiver or Variance from N.J.A.C. 7:8-5.3)
| ||||
|---|---|---|---|---|
|
Best Management Practice
|
Stormwater Runoff Quality TSS Removal Rate
(percent)
|
Stormwater Runoff Quantity
|
Groundwater Recharge
|
Minimum Separation from Seasonal High Water Table
(feet)
|
|
Bioretention system
|
80 or 90
|
Yes
|
Yes(b)
No(c)
|
2(b)
1(c)
|
|
Infiltration basin
|
80
|
Yes
|
Yes
|
2
|
|
Sand filter(b)
|
80
|
Yes
|
Yes
|
2
|
|
Standard constructed wetland
|
90
|
Yes
|
No
|
N/A
|
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Wet pond(d)
|
50-90
|
Yes
|
No
|
N/A
|
|
(Notes corresponding to annotations (b) through (d) are found
after Table 3.)
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|
Table 3
BMPs for Groundwater Recharge, Stormwater Runoff Quality, and/or
Stormwater Runoff Quantity
only with a Waiver or Variance from N.J.A.C. 7:8-5.3
| ||||
|---|---|---|---|---|
|
Best Management Practice
|
Stormwater Runoff Quality TSS Removal Rate
(percent)
|
Stormwater Runoff Quantity
|
Groundwater Recharge
|
Minimum Separation from Seasonal High Water Table
(feet)
|
|
Blue roof
|
0
|
Yes
|
No
|
N/A
|
|
Extended detention basin
|
40-60
|
Yes
|
No
|
1
|
|
Manufactured treatment device(h)
|
50 or 80
|
No
|
No
|
Dependent upon the device
|
|
Sand filter(c)
|
80
|
Yes
|
No
|
1
|
|
Subsurface gravel wetland
|
90
|
No
|
No
|
1
|
|
Wet pond
|
50-90
|
Yes
|
No
|
N/A
|
|
Notes to Tables 1, 2, and 3:
| |
|
(a)
|
Subject to the applicable contributory drainage area limitation specified in Section 18-4o2;
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(b)
|
Designed to infiltrate into the subsoil;
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(c)
|
Designed with underdrains;
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(d)
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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;
|
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(e)
|
Designed with a slope of less than 2%;
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(f)
|
Designed with a slope of equal to or greater than 2%;
|
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(g)
|
Manufactured treatment devices that meet the definition of green infrastructure at Section 18-2;
|
|
(h)
|
Manufactured treatment devices that do not meet the definition of green infrastructure at Section 18-2.
|
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 Section 18-6b. Alternative stormwater management measures may be used to satisfy the requirements at Section 18-4o only if the measures meet the definition of green infrastructure at Section 18-2. Alternative stormwater management measures that function in a similar manner to a BMP listed at Section 18-4o2 are subject to the contributory drainage area limitation specified at Section 18-4o2 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 Section 18-4o2 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, vegetated 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 Section 18-4d is granted from Section 18-4o.
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; floodprone 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 Section 18-8c;
3.
Stormwater management measures shall be designed, constructed, and
installed to be strong, durable, and corrosion resistant. Measures
that are consistent with the relevant portions of the Residential
Site Improvement Standards at N.J.A.C. 5:21-7.3, 7.4, and 7.5 shall
be deemed to meet this requirement;
4.
Stormwater management BMPs shall be designed to meet the minimum safety standards for stormwater management BMPs at Section 18-8; 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 subchapter, 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 Section 18-2 may be used only under the circumstances described at Section 18-4o4.
k.
Any application for new agricultural development that meets the definition of major development at Section 18-2 shall be submitted to the Soil Conservation District for review and approval in accordance with the requirements at Sections 18-4o, 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 Sections 18-4p, q, and r shall be met in each drainage area, unless the runoff for the drainage areas converge onsite 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 in a deed notice recorded in the Office of the Ocean County Clerk. 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 Sections 18-4o, 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 Section 18-10b5. 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 Section 18-4 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 Ocean 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 paragraph 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 paragraph 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 Section 18-4p and q, the design engineer shall utilize green infrastructure BMPs identified in Table 1 at Section 18-4f and/or an alternative stormwater management measure approved in accordance with Section 18-4g. 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 three 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 Section 18-4d 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 Section 18-4g may be used to meet the groundwater recharge, stormwater runoff quality, and stormwater runoff quantity standards at Sections 18-4p, 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 Sections 18-4p, q, and r, unless the project is granted a waiver from strict compliance in accordance with Section 18-4d.
p.
Groundwater Recharge Standards.
1.
This subsection contains 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 Section 18-5, 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.
3.
This groundwater recharge requirement does not apply to projects
within the "urban redevelopment area," or to projects subject to paragraph
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 paragraph 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 applicable to the first BMP; and
|
|
B
|
=
|
the TSS percent removal rate applicable to the second BMP.
|
6.
Stormwater management measures shall also be designed to reduce, to the maximum extent feasible, the post-construction nutrient load of the anticipated load from the developed site in stormwater runoff generated from the water quality design storm. In achieving reduction of nutrients to the maximum extent feasible, the design of the site shall include green infrastructure BMPs that optimize nutrient removal while still achieving the performance standards in Sections 18-4p, 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)3.i,
runoff from the water quality design storm that is discharged within
a 300-foot riparian zone shall be treated in accordance with this
subsection to reduce the post-construction load of total suspended
solids by 95% of the anticipated load from the developed site, expressed
as an annual average.
10.
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 Section 18-5, 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 pre-construction runoff hydrographs for the same storm events;
(b)
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 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 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; or
(d)
In tidal flood hazard areas, stormwater runoff quantity analysis
in accordance with paragraphs 2(a), 2(b) and 2(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.
[Added 6-28-2021 by Ord.
No. 2021-11]
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 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/2014NJSoilErosionControl
StandardsComplete.pdf.
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 Section 18-5a1(a) and the Rational and Modified Rational Methods at Section 18-5a1(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 have 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 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 or 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. 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/price1st/gsreport/gsr32.pdf
or at New Jersey Geological and Water Survey, 29 Arctic Parkway, P.O.
Box 420 Mail Code 29-01 Trenton, New Jersey 08625-0420
[Added 6-28-2021 by Ord.
No. 2021-11]
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.
[Added 6-28-2021 by Ord.
No. 2021-11]
a.
Site design features identified under Section 18-4f above, or alternative designs in accordance with Section 18-4g 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 paragraph, "solid and floatable materials" means sediment, debris, trash, and other floating, suspended, or settleable solids. For exemptions to this standard see Section 18-7a2 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
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 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 paragraph a1 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.
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.
[Added 6-28-2021 by Ord.
No. 2021-11]
a.
This section sets forth requirements to protect public safety through
the proper design and operation of stormwater management BMPs. This
section applies to any new stormwater management BMPs.
b.
The provisions of this section are not intended to preempt more stringent municipal or county safety requirements for new or existing stormwater management BMPs. Municipal and county stormwater management plans and ordinances may, pursuant to their authority, require existing stormwater management BMPs to be retrofitted to meet one or more of the safety standards in Sections 18-8c1, 18-8c2, and 18-8c3 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 BMP to
ensure proper functioning of the BMP 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 1/2 feet per second under the full range of stage and
discharge. Velocity is to be computed on the basis of the net area
of opening through the rack; and
(d)
The trash rack shall be constructed and installed to be rigid, durable,
and corrosion resistant, and shall be designed to withstand a perpendicular
live loading of 300 lbs./ft. sq.
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 lbs./ft. sq.
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 municipality pursuant to Section 18-8c, a free-standing 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 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 Section 18-8e for an illustration of safety ledges in a stormwater management BMP; and
(c)
In new stormwater management BMPs, the maximum interior slope for
an earthen dam, embankment, or berm shall not be steeper than three
horizontal to one vertical.
d.
Variance or Exemption from Safety Standard. A variance or exemption
from the safety standards for stormwater management BMPs may be granted
only upon a written finding by the municipality that the variance
or exemption will not constitute a threat to public safety.
e.
Safety Ledge Illustration.
|
Elevation View - Basin Safety Ledge Configuration
 |
[Added 6-28-2021 by Ord.
No. 2021-11]
a.
Submission of Site Development Stormwater Plan.
1.
Whenever an applicant seeks municipal approval of a development subject to this ordinance, the applicant shall submit all of the required components of the Checklist for the Site Development Stormwater Plan at Section 18-9c below as part of the submission of the applicant's application for approval.
2.
The applicant shall demonstrate that the project meets the standards
set forth in this ordinance.
b.
Site Development Stormwater Plan Approval. The applicant's site
development project shall be reviewed as a part of the review process
by the municipal board or official from which municipal approval is
sought. That municipal board or official shall consult the municipality's
review engineer to determine if all of the checklist requirements
have been satisfied and to determine if the project meets the standards
set forth in this ordinance.
c.
Submission of Site Development Stormwater Plan. The following information
shall be required:
1.
Topographic Base Map. The reviewing engineer may require upstream
tributary drainage system information as necessary. It is recommended
that the topographic base map of the site be submitted which extends
a minimum of 200 feet beyond the limits of the proposed development,
at a scale of one inch equals 200 feet or greater, showing two-foot
contour intervals. The map as appropriate may indicate the following:
existing surface water drainage, shorelines, steep slopes, soils,
erodible soils, perennial or intermittent streams that drain into
or upstream of the Category One waters, wetlands and flood plains
along with their appropriate buffer strips, marshlands and other wetlands,
pervious or vegetative surfaces, existing man-made structures, roads,
bearing and distances of property lines, and significant natural and
man-made features not otherwise shown.
2.
Environmental Site Analysis. A written and graphic description of
the natural and man-made features of the site and its surroundings
should be submitted. This description should include a discussion
of soil conditions, slopes, wetlands, waterways and vegetation on
the site. Particular attention should be given to unique, unusual,
or environmentally sensitive features and to those that provide particular
opportunities or constraints for development.
3.
Project Description and Site 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 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 Sections 18-3 through 18-5 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.
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 pre-development and post-development conditions for the design storms specified in Section 18-4.
(b)
When the proposed stormwater management control measures depends
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.
7.
Maintenance and Repair Plan. The design and planning of the stormwater management facility shall meet the maintenance requirements of Section 18-10.
8.
Waiver from Submission Requirements. The municipal official or board reviewing an application under this ordinance may, in consultation with the municipality's review engineer, waive submission of any of the requirements in Sections 18-9c1 through 18-9c6 of this ordinance 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.
[Added 6-28-2021 by Ord.
No. 2021-11]
b.
General Maintenance.
1.
The design engineer shall prepare a maintenance plan for the stormwater
management measures incorporated into the design of a major development.
2.
The maintenance plan shall contain specific preventative maintenance tasks and schedules; cost estimates, including estimated cost of sediment, debris, or trash removal; and the name, address, and telephone number of the person or persons responsible for preventative and corrective maintenance (including replacement). The plan shall contain information on BMP location, design, ownership, maintenance tasks and frequencies, and other details as specified in Chapter 8 of the NJ BMP Manual, as well as the tasks specific to the type of BMP, as described in the applicable chapter containing design specifics.
3.
If the maintenance plan identifies a person other than the property
owner (for example, a 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 party responsible for maintenance identified under Section 18-10b3 above is not a public agency, the maintenance plan and any future revisions based on Section 18-10b7 below shall be recorded upon the deed of record for each property on which the maintenance described in the maintenance plan must be undertaken.
6.
Preventative and corrective maintenance shall be performed to maintain
the functional standards (storage volume, infiltration rates, inflow/outflow
capacity, etc.) of the stormwater management measure, including, but
not limited to, repairs or replacement to the structure; removal of
sediment, debris, or trash; restoration of eroded areas; snow and
ice removal; fence repair or replacement; restoration of vegetation;
and repair or replacement of non-vegetated linings.
7.
The party responsible for maintenance identified under Section 18-10b3 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
(c)
Retain and make available, upon request by any public entity
with administrative, health, environmental, or safety authority over
the site, the maintenance plan and the documentation required by Section
18-10.b.6 and 18-10.b.7 above.
9.
In the event that the stormwater management facility becomes a danger
to public safety or public health, or if it is in need of maintenance
or repair, the municipality shall so notify the responsible person
in writing. Upon receipt of that notice, the responsible person shall
have 14 days to effect maintenance and repair of the facility in a
manner that is approved by the municipal engineer or his designee.
The municipality, in its discretion, may extend the time allowed for
effecting maintenance and repair for good cause. If the responsible
person fails or refuses to perform such maintenance and repair, the
municipality or County may immediately proceed to do so and shall
bill the cost thereof to the responsible person. Nonpayment of such
bill may result in a lien on the property.
c.
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.
[Added 6-28-2021 by Ord.
No. 2021-11]
Any person(s) who erects, constructs, alters, repairs, converts, maintains, or uses any building, structure or land in violation of this ordinance shall be subject to the penalties outlined in Section 19-30.4 of the Code of the Borough of Point Pleasant.
