[Ord. No. 20-05 § 1]
Flood control, groundwater recharge, and pollutant reduction
through nonstructural or low impact techniques 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.
[Ord. No. 20-05 § 1]
It is the purpose of this Chapter to establish minimum stormwater management requirements and controls for "major development," as defined in Section 25-2.
[Ord. No. 20-05 § 1]
[Ord. No. 20-05 § 1]
Development approvals issued for subdivisions and site plans
pursuant to this Chapter are to be considered an integral part of
development approvals under the subdivision and site plan review process
and do not relieve the applicant of the responsibility to secure required
permits or approvals for activities regulated by any other applicable
code, rule, act, or ordinance. In their interpretation and application,
the provisions of this Chapter shall be held to be the minimum 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 ordinances, 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.
[Ord. No. 20-05 § 2]
Unless specifically defined below, words or phrases used in
this Chapter shall be interpreted so as to give them the meaning they
have in common usage and to give this Chapter its most reasonable
application. 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. 7:8E-5B.
Shall mean the geographic depiction of the boundaries for
Coastal Planning Areas, CAFRA Centers, CAFRA Cores and CAFRA Nodes
pursuant to N.J.A.C. 7:7E-5B.3.
Shall mean the increase in soil bulk density.
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 Board of Chosen
Freeholders to review municipal stormwater management plans and implementing
ordinance(s). The County review agency may either be:
A County planning agency; or
A County water resource association created under N.J.S.A.
58:16A-55.5, if the ordinance or resolution delegates authority to
approve, conditionally approve, or disapprove municipal stormwater
management plans and implementing ordinances.
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, by any person, for which permission is required under the Municipal
Land Use Law, N.J.S.A. 40:55D-1 at 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 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.
Shall mean a neighborhood designated by the Urban Coordinating
Council "in consultation and conjunction with" the New Jersey Redevelopment
Authority pursuant to N.J.S.A. 55:19-69.
Shall mean an area or feature which is of significant environmental
value, including but not limited to: stream corridors; natural heritage
priority sites; habitat 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 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 any "development" that provides for ultimately
disturbing one or more acres of land. Disturbance for the purpose
of this rule is the placement of impervious surface or exposure and/or
movement of soil or bedrock or clearing, cutting, or removing of vegetation.
Shall mean any city, borough, town, township, or village.
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, the Borough of Jamesburg, 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.
Includes both hazardous and nonhazardous pollutants.
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.
Shall mean the amount of water from precipitation that infiltrates
into the ground and is not evapotranspired.
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 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).
Shall mean 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 non-stormwater discharges into
stormwater conveyances.
Shall mean water flow on the surface of the ground or in
storm sewers, resulting from precipitation.
Shall mean a flood hazard area, which may be influenced by
stormwater runoff from inland areas, but which is primarily caused
by the Atlantic Ocean.
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 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.
[Ord. No. 20-05 § 3]
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 Section 25-4. 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 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.
[Ord. No. 20-05 § 4A]
The development shall incorporate a maintenance plan for the stormwater management measures incorporated into the design of a major development in accordance with Section 25-10.
[Ord. No. 20-05 § 4B]
Stormwater management measures shall avoid adverse impacts of
concentrated flow on habitat for threatened and endangered species
as documented in the Department Landscape Project or Natural Heritage
Database established under N.J.S.A. 13:1B-15.147 through 15.150, particularly
Helonias bullata (swamp pink) and/or Clemmys muhlnebergi (bog turtle).
[Ord. No. 20-05 § 4C]
The following linear development projects are exempt from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of subsections 25-4.6 and 25-4.7.
a.
The construction of an underground utility line provided that the
disturbed areas are revegetated upon completion;
b.
The construction of an aboveground utility line provided that the
existing conditions are maintained to the maximum extent practicable;
and
c.
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.
[Ord. No. 20-05 § 4D]
A waiver from strict compliance from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of subsections 25-4.6 and 25-4.7 may be obtained for the enlargement of an existing public roadway or railroad; or the construction or enlargement of a public pedestrian access, provided that the following conditions are met:
a.
The applicant demonstrates that there is a public need for the project
that cannot be accomplished by any other means;
d.
The applicant demonstrates that it does not own or have other rights to areas, including the potential to obtain through condemnation lands not falling under subsection 25-4.4c above within the upstream drainage area of the receiving stream, that would provide additional opportunities to mitigate the requirements of subsections 25-4.6 and 25-4.7 that were not achievable on site.
[Ord. No. 20-05 § 4E]
a.
To the maximum extent practicable, the standards in subsections 25-4.6 and 25-4.7 shall be met by incorporating nonstructural stormwater management strategies set forth at subsection 25-4.5 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 paragraph b below into the design of a particular project, the applicant shall identify the strategy considered and provide a basis for the contention.
b.
Nonstructural stormwater management strategies incorporated into
site design shall:
1.
Protect areas that provide water quality benefits or areas particularly
susceptible to erosion and sediment loss;
2.
Minimize impervious surfaces and break up or disconnect the flow
of runoff over impervious surfaces;
3.
Maximize the protection of natural drainage features and vegetation;
4.
Minimize the decrease in the "time of concentration" from preconstruction
to post construction. "Time of concentration" is defined as the time
it takes for runoff to travel from the hydraulically most distant
point of the watershed to the point of interest within a watershed;
5.
Minimize land disturbance including clearing and grading;
6.
Minimize soil compaction;
7.
Provide low-maintenance landscaping that encourages retention and
planting of native vegetation and minimizes the use of lawns, fertilizers
and pesticides;
8.
Provide vegetated open-channel conveyance systems discharging into
and through stable vegetated areas;
9.
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:
(a)
Site design features that help to prevent accumulation of trash and debris in drainage systems, including features that satisfy subsection 25-4.5c below;
(b)
Site design features that help to prevent discharge of trash
and debris from drainage systems;
(c)
Site design features that help to prevent and/or contain spills
or other harmful accumulations of pollutants at industrial or commercial
developments; and
(d)
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.
c.
Site design features identified under subsection 25-4.5b,9(b) above 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 subsection 25-4.5c,3.
1.
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:
(a)
The New Jersey Department of Transportation (NJDOT) bicycle
safe grate, which is described in Chapter 2.4 of the NJDOT Bicycle
Compatible Roadways and Bikeways Planning and Design Guidelines (April
1996); or
(b)
A different grate, if each individual clear space in that grate
has an area of no more than 7.0 square inches, or is no greater than
0.5 inches across the smallest dimension.
Examples of grates subject to this standard include grates in
grate inlets, the grate portion (noncurb-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.
2.
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 7.0 square inches, or be no greater than two inches across the
smallest dimension.
3.
This standard does not apply:
(a)
Where the review agency 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;
(b)
Where flows from the water quality design storm as specified in subsection 25-4.7a 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:
(c)
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 25-4.7a., or
(d)
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.
d.
Any land area used as a nonstructural stormwater management measure to meet the performance standards in subsections 25-4.6 and 25-4.7 shall be dedicated to a government agency, subjected to a conservation restriction filed with the appropriate County Clerk's office, or subject to an approved equivalent restriction that ensures that measure or an equivalent stormwater management measure approved by the reviewing agency is maintained in perpetuity.
[Ord. No. 20-05 § 4F]
a.
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.
1.
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.
2.
The minimum design and performance standards for groundwater recharge
are as follows:
(a)
The design engineer shall, using the assumptions and factors for stormwater runoff and groundwater recharge calculations at Section 25-5, either:
(1)
Demonstrate through hydrologic and hydraulic analysis that the
site and its stormwater management measures maintain 100% of the average
annual preconstruction groundwater recharge volume for the site; or
(2)
Demonstrate through hydrologic and hydraulic analysis that the
increase of stormwater runoff volume from preconstruction to post-construction
for the two-year storm is infiltrated.
(b)
This groundwater recharge requirement does not apply to projects
within the "urban redevelopment area," or to projects subject to paragraph
(c) below.
(c)
The following types of stormwater shall not be recharged:
(1)
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
(2)
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.
(d)
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.
3.
In order to control stormwater runoff quantity impacts, the design engineer shall, using the assumptions and factors for stormwater runoff calculations at Section 25-5, complete one of the following:
(a)
Demonstrate through hydrologic and hydraulic analysis that for
stormwater leaving the site, post-construction runoff hydrographs
for the two-, ten-, and 100-year storm events do not exceed, at any
point in time, the preconstruction runoff hydrographs for the same
storm events;
(b)
Demonstrate through hydrologic and hydraulic analysis that there
is no increase, as compared to the preconstruction condition, in the
peak runoff rates of stormwater leaving the site for the two-, ten-,
and 100-year storm events and that the increased volume or change
in timing of stormwater runoff will not increase flood damage at or
downstream of the site. This analysis shall include the analysis of
impacts of existing land uses and projected land uses assuming full
development under existing zoning and land use ordinances in the drainage
area;
(c)
Design stormwater management measures so that the post-construction
peak runoff rates for the two-, ten-, and 100-year storm events are
50%, 75% and 80%, respectively, of the preconstruction peak runoff
rates. The percentages apply only to the post-construction stormwater
runoff that is attributable to the portion of the site on which the
proposed development or project is to be constructed. 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; or
(d)
In tidal flood hazard areas, stormwater runoff quantity analysis
in accordance with paragraphs (a), (b) and (c) above shall only be
applied if the increased volume of stormwater runoff could increase
flood damages below the point of discharge.
b.
Any application for a new agricultural development that meets the definition of major development at Section 25-2 shall be submitted to the appropriate Soil Conservation District for review and approval in accordance with the requirements of this section and any applicable Soil Conservation District guidelines for stormwater runoff quantity and erosion control. For 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.
[Ord. No. 20-05 § 4G]
a.
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 Pollution 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. The calculation of the volume of runoff may
take into account the implementation of non-structural and structural
stormwater management measures.
|
Table 1: Water Quality Design Storm Distribution
| |||
|---|---|---|---|
|
Time
(Minutes)
|
Cumulative Rainfall
(Inches)
|
Time
(Minutes)
|
Cumulative Rainfall
(Inches)
|
|
0
|
0.0000
|
65
|
0.8917
|
|
5
|
0.0083
|
70
|
0.9917
|
|
10
|
0.0166
|
75
|
1.0500
|
|
15
|
0.0250
|
80
|
1.0840
|
|
20
|
0.0500
|
85
|
1.1170
|
|
25
|
0.0750
|
90
|
1.1500
|
|
30
|
0.1000
|
95
|
1.1750
|
|
35
|
0.1330
|
100
|
1.2000
|
|
40
|
0.1660
|
105
|
1.2250
|
|
45
|
0.2000
|
110
|
1.2334
|
|
50
|
0.2583
|
115
|
1.2417
|
|
55
|
0.3583
|
120
|
1.2500
|
|
60
|
0.6250
| ||
b.
For purposes of TSS reduction calculations, Table 2 below presents the presumed removal rates for certain BMPs designed in accordance with the New Jersey Stormwater Best Management Practices Manual. The BMP Manual may be obtained from the address identified in Section 25-7, or found on the Department's website at www.njstormwater.org. The BMP Manual and other sources of technical guidance are listed in Section 25-7. TSS reduction shall be calculated based on the removal rates for the BMPs in Table 2 below. 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. A copy of any approved alternative rate or method of calculating the removal rate shall be provided to the Department at the following address: Division of Watershed Management, New Jersey Department of Environmental Protection, PO Box 418, Trenton, New Jersey, 08625-0418.
c.
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,
and
|
|
A
|
=
|
the TSS percent removal rate applicable to the first BMP
|
|
B
|
=
|
the TSS percent removal rate applicable to the second BMP
|
|
Table 2: TSS Removal Rates for BMPs
| |
|---|---|
|
Best Management Practice
|
TSS Percent Removal Rate
|
|
Bioretention Systems
|
90
|
|
Constructed Stormwater Wetland
|
90
|
|
Extended Detention Basin
|
40-60
|
|
Infiltration Structure
|
80
|
|
Manufactured Treatment Device
|
See Section 25-6c
|
|
Sand Filter
|
80
|
|
Vegetative Filter Strip
|
60-80
|
|
Wet Pond
|
50-90
|
d.
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 converge on site in which case the removal rate can be demonstrated
through a calculation using a weighted average.
e.
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 nonstructural strategies and structural measures that optimize nutrient removal while still achieving the performance standards in subsections 25-4.6 and 25-4.7.
f.
Additional information and examples are contained in the New Jersey Stormwater Best Management Practices Manual, which may be obtained from the address identified in Section 25-7.
g.
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.
h.
Special water resource protection areas shall be established 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:
1.
The applicant shall preserve and maintain a special water resource
protection area in accordance with one of the following:
(a)
A 300-foot special water resource protection area shall be provided
on each side of the waterway, measured perpendicular to the waterway
from the top of the bank outwards or from the centerline of the waterway
where the bank is not defined, consisting of existing vegetation or
vegetation allowed to follow natural succession is provided.
(b)
Encroachment within the designated special water resource protection
area under paragraph (a) 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 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 centerline of the waterway where the bank is undefined.
All encroachments proposed under this subparagraph shall be subject
to review and approval by the Department
2.
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.
3.
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:
(a)
Stabilization measures shall not be placed within 150 feet of
the Category One waterway;
(b)
Stormwater associated with discharges allowed by this section
shall achieve a 95% TSS post-construction removal rate;
(c)
Temperature shall be addressed to ensure no impact on the receiving
waterway;
(d)
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:
(e)
A conceptual project design meeting shall be held with the appropriate
Department staff and Soil Conservation District staff to identify
necessary stabilization measures; and
(f)
All encroachments proposed under this section shall be subject
to review and approval by the Department.
4.
A stream corridor protection plan may be developed by a regional stormwater management planning committee as an element of a regional stormwater management plan, or by a municipality through an adopted municipal stormwater management plan. If a stream corridor protection plan for a waterway subject to subsection 25-4.7h has been approved by the Department of Environmental Protection, 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 25-4.7h shall maintain or enhance the current functional value and overall condition of the special water resource protection area as defined in subsection 25-4.7h,1(a) 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.
[Ord. No. 20-05 § 5]
Stormwater runoff shall be calculated in accordance with the
following:
a.
The design engineer shall calculate runoff using one of the following
methods:
1.
The 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 - Urban Hydrology for Small Watersheds:
or
2.
The Rational Method for peak flow and the Modified Rational Method
for hydrograph computations.
b.
For the purpose of calculating runoff coefficients and groundwater recharge, there is a presumption that the preconstruction condition of a site or portion thereof is a wooded land use with good hydrologic condition. The term "runoff coefficient" applies to both the NRCS methodology at subsection 25-5.1a,1 and the Rational and Modified Rational Methods at subsection 25-5.1a,2. 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).
c.
In computing preconstruction stormwater runoff, the design engineer
shall account for all significant land features and structures, such
as ponds, wetlands, depressions, hedgerows, or culverts, that may
reduce preconstruction stormwater runoff rates and volumes.
d.
In computing stormwater runoff from all design storms, the design
engineer shall consider the relative stormwater runoff rates and/or
volumes of pervious and impervious surfaces separately to accurately
compute the rates and volume of stormwater runoff from the site. To
calculate runoff from unconnected impervious cover, urban impervious
area modifications as described in the NRCS Technical Release 55 -
Urban Hydrology for Small Watersheds and other methods may be employed.
e.
If the invert of the outlet structure of a stormwater management
measure is below the flood hazard design flood elevation as defined
at N.J.A.C. 7:13, the design engineer shall take into account the
effects of tailwater in the design of structural stormwater management
measures.
[Ord. No. 20-05 § 5]
Groundwater recharge may be calculated in accordance with the
following:
a.
The New Jersey Geological Survey Report GSR-32 A Method for Evaluating
Ground-Water 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 http://www.state.nj.us/dep/njgs/; or at New Jersey Geological
Survey, 29 Arctic Parkway, P.O. Box 427, Trenton, New Jersey, 08625-0427;
(609) 984-6587.
[Ord. No. 20-05 § 6]
a.
Standards for structural stormwater management measures are as follows:
1.
Structural stormwater management measures shall be designed to take
into account the existing site conditions, including, for example,
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.
Structural 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 subsection 25-8b.
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, 7.4, and 7.5 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 Section 25-4 of this Chapter.
[Ord. No. 20-05 § 7]
a.
Technical guidance for stormwater management measures can be found
in the documents listed at paragraphs 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; telephone (609) 777-1038.
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:
1.
The "Standards for Soil Erosion and Sediment Control in New Jersey"
promulgated by the State Soil Conservation Committee and incorporated
into N.J.A.C. 2:90. Copies of these standards may be obtained by contacting
the State Soil Conservation Committee or any of the Soil Conservation
Districts listed in N.J.A.C. 2:90-1.3(a)4. The location, address,
and telephone number of each Soil Conservation District may be obtained
from the State Soil Conservation Committee, P.O. Box 330, Trenton,
New Jersey, 08625; (609) 292-5540;
2.
The Rutgers Cooperative Extension Service, 732932-9306; and
3.
The Soil Conservation Districts listed in N.J.A.C. 2:90-1.3(a)4.
The location, address, and telephone number of each Soil Conservation
District may be obtained from the State Soil Conservation Committee,
P.O. Box 330, Trenton, New Jersey, 08625, (609) 292-5540.
[Ord. No. 20-05 § 8]
a.
Applicability. This section sets forth requirements to protect public
safety through the proper design and operation of stormwater management
basins. This section applies to any new stormwater management basin.
b.
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 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.
For purposes of this paragraph 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:
(b)
Safety ledges shall be constructed on the slopes of all new stormwater
management basins having a permanent pool of water deeper than 2.5
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 2.5 feet below the permanent water surface, and the second step shall be located one to one and 1.5 feet above the permanent water surface. See Section 25-8d 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 3 horizontal
to 1 vertical.
c.
Variance or Exemption from Safety Standards.
1.
A variance or exemption from the safety standards for stormwater
management basins may be granted only upon a written finding by the
appropriate reviewing agency (municipality, County or Department)
that the variance or exemption will not constitute a threat to public
safety.
d.
Illustration of Safety Ledges in a New Stormwater Management Basin.
NOTE: REFER TO NEW JERSEY STORMWATER BMP MANUAL - Appendix
D: Model Stormwater Control Ordinance for Municipalities.
[Ord. No. 20-05 § 9A]
a.
Whenever an applicant seeks municipal approval of a development subject to this Chapter, the applicant shall submit all of the required components of the Checklist for the Site Development Stormwater Plan at subsection 25-9.3 below as part of the submission of the applicants application for subdivision or site plan approval.
b.
The applicant shall demonstrate that the project meets the standards
set forth in this Chapter.
[Ord. No. 20-05 § 9B]
The applicant's site development project shall be reviewed
as a part of the subdivision or site plan review process by the municipal
board or official from which municipal approval is sought. That municipal
board or official shall consult the engineer retained by the Planning
and/or Zoning Board (as appropriate) to determine if all of the checklist
requirements have been satisfied and to determine if the project meets
the standards set forth in this Chapter.
[Ord. No. 20-05 § 9C]
The following information shall be required:
a.
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 manmade structures, roads,
bearing and distances of property lines, and significant natural and
manmade features not otherwise shown.
b.
Environmental Site Analysis. A written and graphic description of
the natural and manmade features of the site and its environs. This
description should include a discussion of soil conditions, slopes,
wetlands, waterways and vegetation on the site. Particular attention
should be given to unique, unusual, or environmentally sensitive features
and to those that provide particular opportunities or constraints
for development.
c.
Project Description and Site Plan(s). A map (or maps) at the scale
of the topographical base map indicating the location of existing
and proposed buildings, roads, parking areas, utilities, structural
facilities for stormwater management and sediment control, and other
permanent structures. The map(s) shall also clearly show areas where
alterations occur in the natural terrain and cover, including lawns
and other landscaping, and seasonal high groundwater elevations. A
written description of the site plan and justification of proposed
changes in natural conditions may also be provided.
d.
Land Use Planning and Source Control Plan. This plan shall provide a demonstration of how the goals and standards of Sections 25-3 through 25-6 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.
e.
Stormwater Management Facilities Map. The following information,
illustrated on a map of the same scale as the topographic base map,
shall be included:
1.
Total area to be paved or built upon, proposed surface contours,
land area to be occupied by the stormwater management facilities and
the type of vegetation thereon, and details of the proposed plan to
control and dispose of stormwater.
2.
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.
f.
Calculations.
1.
Comprehensive hydrologic and hydraulic design calculations for the predevelopment and post-development conditions for the design storms specified in Section 25-4 of this Chapter.
2.
When the proposed stormwater management control measures (e.g., infiltration
basins) depends on the hydrologic properties of soils, then a soils
report shall be submitted. The soils report shall be based on on-site
boring logs or soil pit profiles. The number and location of required
soil borings or soil pits shall be determined based on what is needed
to determine the suitability and distribution of soils present at
the location of the control measure.
g.
Maintenance and Repair Plan. The design and planning of the stormwater management facility shall meet the maintenance requirements of Section 25-10.
h.
Waiver from Submission Requirements. The municipal official or board reviewing an application under this Chapter may, in consultation with the municipal engineer, waive submission of any of the requirements in Sections 25-9.3a through 25-9.3f of this Chapter 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.
[Ord. No. 20-05 § 10]
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). Maintenance guidelines for stormwater
management measures are available in the New Jersey Stormwater Best
Management Practices Manual. If the maintenance plan identifies a
person other than the developer (for example, a public agency or homeowners'
association) as having the responsibility for maintenance, the plan
shall include documentation of such person's agreement to assume
this responsibility, or of the developer's obligation to dedicate
a stormwater management facility to such person under an applicable
ordinance or regulation.
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 Section 25-10b,2 above is not a public agency, the maintenance plan and any future revisions based on Section 25-10b,7 below shall be recorded upon the deed of record for each property on which the maintenance described in the maintenance plan must be undertaken.
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 Section 25-10b,2 above shall 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.
7.
The person responsible for maintenance identified under Section 25-10b,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 (or maintenance identified under Section 25-10b,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 Section 25-10b,6 and 7 above.
9.
The requirements of Section 25-10b,3 and 4 do not apply to stormwater management facilities that are dedicated to and accepted by the municipality or another governmental agency. If the Borough of Jamesburg does not want to take this responsibility, there shall be a requirement for the posting of a two year maintenance guarantee in accordance with N.J.S.A. 40:55D-53.
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 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.
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.
[Ord. No. 20-05 § 11]
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 the following penalties: $1,200.
[Ord. No. 20-05 § 12]
This Chapter shall take effect immediately upon the approval
by the County review agency, or 60 days from the receipt of the Chapter
by the County review agency if the County review agency should fail
to act.
