[Added 3-23-2006 by Ord. No. 5-2006]
§ 114-210 Scope and purpose.
§ 114-211 Definitions.
§ 114-212 General standards.
§ 114-213 Stormwater management requirements for major development.
§ 114-214 Calculation of stormwater runoff and groundwater recharge.
§ 114-215 Standards for structural stormwater management measures.
§ 114-216 Sources for technical guidance.
§ 114-217 Safety standards for stormwater management basins.
§ 114-218 Requirements for a site development stormwater plan.
§ 114-219 Maintenance and repair.
§ 114-220 Violations and penalties.
§ 114-221 Effective date.
§ 114-210 Scope and purpose.
A.
Policy statement. Stormwater flood control, groundwater recharge, and pollutant reduction through nonstructural or low-impact techniques shall be explored before relying on structural best management practices (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. In some areas prone to tidal flooding, the municipal stormwater system conveys and controls tidal stormwater. All stormwater structures and flow pathways at elevations below the base flood elevation must be compatible with the tidal stormwater control standards and requirements set forth in § 114-213H of this article.
B.
Purpose. It is the purpose of this article to establish minimum stormwater management requirements and controls for major development, as defined in § 114-211.
C.
D.
Compatibility with other permit and ordinance requirements.
Development approvals issued for subdivisions and site plans pursuant
to this article are to be considered an integral part of development
approvals under the subdivision and site plan review process and do
not relieve the applicant of the responsibility to secure required
permits or approvals for activities regulated by any other applicable
code, rule, act, or ordinance. In their interpretation and application,
the provisions of this article shall be held to be the minimum requirements
for the promotion of the public health, safety, and general welfare.
This article is not intended to interfere with, abrogate, or annul
any other ordinance, rule or regulation, statute, or other provision
of law except that, where any provision of this article imposes restrictions
different from those imposed by any other ordinance, rule or regulation,
or other provision of law, the more restrictive provisions or higher
standards shall control.
§ 114-211 Definitions.
Unless specifically defined below, words or
phrases used in this article shall be interpreted so as to give them
the meaning they have in common usage and to give this article 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.
- CAFRA CENTERS, CORES OR NODES
- Those areas within boundaries accepted by the Department pursuant to N.J.A.C. 7:8E-5B.
- CAFRA PLANNING MAP
- 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.
- COMPACTION
- The increase in soil bulk density.
- CORE
- A pedestrian-oriented area of commercial and civic uses serving the surrounding municipality, generally including housing and access to public transportation.
- COUNTY REVIEW AGENCY
- An agency designated by the County Board of Chosen Freeholders to review municipal stormwater management plans and implementing ordinance(s). The county review agency may either be:
- DEPARTMENT
- The New Jersey Department of Environmental Protection.
- DESIGNATED CENTER
- A state development and redevelopment plan center as designated by the State Planning Commission, such as urban, regional, town, village, or hamlet.
- DESIGN ENGINEER
- A person professionally qualified and duly licensed in New Jersey to perform engineering services that may include, but not necessarily be limited to, development of project requirements, creation and development of project design and preparation of drawings and specifications.
- DEVELOPMENT
- The division of a parcel of land into two or more parcels; the construction, reconstruction, conversion, structural alteration, relocation or enlargement of any building or structure; any mining excavation or landfill; and any use or change in the use of any building or other structure, or land or extension of use of land, by any person, for which permission is required under the Municipal Land Use Law, N.J.S.A. 40:55D-1 et seq. In the case of development of agricultural lands, "development" means: any activity that requires a state permit; any activity reviewed by the County Agricultural Board (CAB) and the State Agricultural Development Committee (SADC), and municipal review of any activity not exempted by the Right to Farm Act, N.J.S.A. 4:1C-1 et seq.
- DRAINAGE AREA
- A geographic area within which stormwater, sediments, or dissolved materials drain to a particular receiving water body or to a particular point along a receiving water body.
- ENVIRONMENTALLY CRITICAL AREAS
- 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 wellhead protection and groundwater recharge areas. Habitats of endangered or threatened species are identified using the Department's Landscape Project, as approved by the Department's Endangered and Nongame Species Program.
- EMPOWERMENT NEIGHBORHOOD
- 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.
- EROSION
- The detachment and movement of soil or rock fragments by water, wind, ice or gravity.
- IMPERVIOUS SURFACE
- A surface that has been covered with a layer of material so that it is highly resistant to infiltration by water.
- INFILTRATION
- The process by which water seeps into the soil from precipitation.
- MAJOR DEVELOPMENT
- 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.
- MUNICIPALITY
- Any city, borough, town, township, or village.
- NODE
- An area designated by the State Planning Commission concentrating facilities and activities which are not organized in a compact form.
- NUTRIENT
- A chemical element or compound, such as nitrogen or phosphorus, which is essential to and promotes the development of organisms.
- PERSON
- Any individual, corporation, company, partnership, firm, association, the City of Somers Point, or political subdivision of this State subject to municipal jurisdiction pursuant to the Municipal Land Use Law, N.J.S.A. 40:55D-1 et seq.
- POLLUTANT
- Any dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, refuse, oil, grease, sewage sludge, munitions, chemical wastes, biological materials, medical wastes, radioactive substance [except those regulated under the Atomic Energy Act of 1954, as amended (42 U.S.C. 2011 et seq.)], thermal waste, wrecked or discarded equipment, rock, sand, cellar dirt, industrial, municipal, agricultural, and construction waste or runoff, or other residue discharged directly or indirectly to the land, groundwaters or surface waters of the state, or to a domestic treatment works. "Pollutant" includes both hazardous and nonhazardous pollutants.
- RECHARGE
- The amount of water from precipitation that infiltrates into the ground and is not evapotranspired.
- SEDIMENT
- Solid material, mineral or organic, that is in suspension, is being transported, or has been moved from its site of origin by air, water or gravity as a product of erosion.
- SITE
- The lot or lots upon which a major development is to occur or has occurred.
- SOIL
- All unconsolidated mineral and organic material of any origin.
- STATE DEVELOPMENT AND REDEVELOPMENT PLAN METROPOLITAN PLANNING AREA (PA1)
- An area delineated on the State Plan Policy Map and adopted by the State Planning Commission that is intended to be the focus for much of the state's future redevelopment and revitalization efforts.
- STATE PLAN POLICY MAP
- The geographic application of the State Development and Redevelopment Plan's goals and statewide policies, and the official map of these goals and policies.
- STORMWATER
- Water resulting from precipitation (including rain and snow) that runs off the land's surface, is transmitted to the subsurface, or is captured by separate storm sewers or other sewage or drainage facilities, or conveyed by snow removal equipment.
- STORMWATER RUNOFF
- Water flow on the surface of the ground or in storm sewers, resulting from precipitation.
- STORMWATER MANAGEMENT BASIN
- 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).
- STORMWATER MANAGEMENT MEASURE
- Any structural or nonstructural strategy, practice, technology, process, program, or other method intended to control or reduce stormwater runoff and associated pollutants, or to induce or control the infiltration or groundwater recharge of stormwater or to eliminate illicit or illegal nonstormwater discharges into stormwater conveyances.
- TIDAL FLOOD HAZARD AREA
- A flood hazard area, which may be influenced by stormwater runoff from inland areas, but which is primarily caused by the Atlantic Ocean.
- URBAN COORDINATING COUNCIL EMPOWERMENT NEIGHBORHOOD
- A neighborhood given priority access to state resources through the New Jersey Redevelopment Authority.
- URBAN ENTERPRISE ZONES
- A zone designated by the New Jersey Enterprise Zone Authority pursuant to the New Jersey Urban Enterprise Zones Act, N.J.S.A. 52:27H-60 et seq.
- URBAN REDEVELOPMENT AREA
- Previously developed portions of areas:
- WATERS OF THE STATE
- 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.
- WETLANDS or WETLAND
- An area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions, commonly known as "hydrophytic vegetation."
§ 114-212 General standards.
Design and performance standards for stormwater
management measures.
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 § 114-213. 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 article apply only to new major
development and are intended to minimize the impact of stormwater
runoff on water quality and water quantity in receiving water bodies
and maintain groundwater recharge. The standards do not apply to new
major development to the extent that alternative design and performance
standards are applicable under a regional stormwater management plan
or water quality management plan adopted in accordance with Department
rules.
§ 114-213 Stormwater management requirements for major development.
A.
The development shall incorporate a maintenance plan for the stormwater management measures incorporated into the design of a major development in accordance with § 114-219.
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
muhlnebergi (bog turtle).
C.
The following linear development projects are exempt from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of Subsections F and G:
(1)
The construction of an underground utility line,
provided that the disturbed areas are revegetated upon completion;
(2)
The construction of an aboveground utility line,
provided that the existing conditions are maintained to the maximum
extent practicable; and
(3)
The construction of a public pedestrian access,
such as a sidewalk or trail, with a maximum width of 14 feet, provided
that the access is made of permeable material.
D.
A waiver from strict compliance from the groundwater recharge, stormwater runoff quantity, and stormwater runoff quality requirements of Subsections F and G may be obtained for the enlargement of an existing public roadway or railroad; or the construction or enlargement of a public pedestrian access, provided that the following conditions are met:
(1)
The applicant demonstrates that there is a public
need for the project that cannot be accomplished by any other means;
(4)
The applicant demonstrates that it does not own or have other rights to areas, including the potential to obtain through condemnation lands not falling under Subsection D(3) above within the upstream drainage area of the receiving stream, that would provide additional opportunities to mitigate the requirements of Subsections F and G that were not achievable on site.
E.
Nonstructural stormwater management strategies.
(1)
To the maximum extent practicable, the standards in Subsections F and G shall be met by incorporating nonstructural stormwater management strategies set forth at Subsection E into the design. The applicant shall identify the nonstructural measures incorporated into the design of the project. If the applicant contends that it is not feasible for engineering, environmental, or safety reasons to incorporate any nonstructural stormwater management measures identified in Subsection E(2) below into the design of a particular project, the applicant shall identify the strategy considered and provide a basis for the contention.
(2)
Nonstructural stormwater management strategies
incorporated into site design shall:
(a)
Protect areas that provide water quality benefits
or areas particularly susceptible to erosion and sediment loss and
tidal flooding;
(b)
Minimize impervious surfaces and break up or
disconnect the flow of runoff over impervious surfaces;
(c)
Maximize the protection of natural drainage
features and vegetation;
(d)
Minimize the decrease in the time of concentration
from preconstruction to postconstruction. "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;
(e)
Minimize land disturbance including clearing
and grading;
(f)
Minimize soil compaction;
(g)
Provide low-maintenance landscaping that encourages
retention and planting of native vegetation and minimizes the use
of lawns, fertilizers and pesticides;
(h)
Provide vegetated open-channel conveyance systems
discharging into and through stable vegetated areas;
(i)
Provide other source controls to prevent or
minimize the use or exposure of pollutants at the site, in order to
prevent or minimize the release of those pollutants into stormwater
runoff. Such source controls include, but are not limited to:
[1]
Site design features that help to prevent accumulation of trash and debris in drainage systems, including features that satisfy Subsection E(3) below;
[2]
Site design features that help to prevent discharge
of trash and debris from drainage systems;
[3]
Site design features that help to prevent and/or
contain spills or other harmful accumulations of pollutants at industrial
or commercial developments; and
[4]
When establishing vegetation after land disturbance,
applying fertilizer in accordance with the requirements established
under the Soil Erosion and Sediment Control Act, N.J.S.A. 4:24-39
et seq., and implementing rules.
(3)
Site design features identified under Subsection E(2)(i)[2] above shall comply with the following standard to control passage of solid and floatable materials through storm drain inlets. For purposes of this paragraph, "solid and floatable materials" means sediment, debris, trash, and other floating, suspended, or settleable solids. For exemptions to this standard see Subsection E(3)(c) below.
(a)
Design engineers shall use either of the following
grates whenever they use a grate in pavement or another ground surface
to collect stormwater from that surface into a storm drain or surface
water body under that grate:
[1]
The New Jersey Department of Transportation
(NJDOT) bicycle-safe grate, which is described in Chapter 2.4 of the
NJDOT Bicycle Compatible Roadways and Bikeways Planning and Design
Guidelines (April 1996); or
[2]
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 (non-curb-opening
portion) of combination inlets, grates on storm sewer manholes, ditch
grates, trench grates, and grates of spacer bars in slotted drains.
Examples of ground surfaces include surfaces of roads (including bridges),
driveways, parking areas, bikeways, plazas, sidewalks, lawns, fields,
open channels, and stormwater basin floors.
|
(b)
Whenever design engineers use a curb-opening
inlet, the clear space in that curb opening (or each individual clear
space, if the curb opening has two or more clear spaces) shall have
an area of no more than 7.0 square inches, or be no greater than 2.0
inches across the smallest dimension.
(c)
This standard does not apply:
[1]
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;
[2]
Where flows from the water quality design storm as specified in Subsection G(1) are conveyed through any device (e.g., end-of-pipe netting facility, manufactured treatment device, or a catch basin hood) that is designed, at a minimum, to prevent delivery of all solid and floatable materials that could not pass through one of the following:
[3]
Where flows are conveyed through a trash rack that has parallel bars with one-inch spacing between the bars, to the elevation of the water quality design storm as specified in Subsection G(1); or
[4]
Where the 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.
(4)
Any land area used as a nonstructural stormwater management measure to meet the performance standards in Subsections F and G 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.
F.
Erosion control, groundwater recharge and runoff quantity
standards.
(1)
This subsection contains minimum design and
performance standards to control erosion, encourage and control infiltration
and groundwater recharge, and control stormwater runoff quantity impacts
of major development.
(a)
The minimum design and performance standards
for erosion control are those established under the Soil Erosion and
Sediment Control Act, N.J.S.A. 4:24-39 et seq., and implementing rules.
(b)
The minimum design and performance standards
for groundwater recharge are as follows:
[1]
The design engineer shall, using the assumptions and factors for stormwater runoff and groundwater recharge calculations at § 114-214, either:
[a]
Demonstrate through hydrologic
and hydraulic analysis that the site and its stormwater management
measures maintain 100% of the average annual preconstruction groundwater
recharge volume for the site; or
[b]
Demonstrate through hydrologic
and hydraulic analysis that the increase of stormwater runoff volume
from preconstruction to postconstruction for the two-year storm is
infiltrated.
[2]
This groundwater recharge requirement does not apply to projects within the urban redevelopment area, or to projects subject to Subsection F(1)(b)[3] below.
[3]
The following types of stormwater shall not
be recharged:
[a]
Stormwater from areas of high pollutant
loading. High pollutant loading areas are areas in industrial and
commercial developments where solvents and/or petroleum products are
loaded/unloaded, stored, or applied; areas where pesticides are loaded/unloaded
or stored; areas where hazardous materials are expected to be present
in greater than "reportable quantities" as defined by the United States
Environmental Protection Agency (EPA) at 40 CFR 302.4; 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.
[4]
The design engineer shall assess the hydraulic
impact on the groundwater table and design the site so as to avoid
adverse hydraulic impacts. Potential adverse hydraulic impacts include,
but are not limited to, exacerbating a naturally or seasonally high
water table so as to cause surficial ponding, flooding of basements,
or interference with the proper operation of subsurface sewage disposal
systems and other subsurface structures in the vicinity or downgradient
of the groundwater recharge area.
(c)
In order to control stormwater runoff quantity impacts, the design engineer shall, using the assumptions and factors for stormwater runoff calculations at § 114-214, complete one of the following:
[1]
Demonstrate through hydrologic and hydraulic
analysis that for stormwater leaving the site, postconstruction runoff
hydrographs for the two-, ten-, and one-hundred-year storm events
do not exceed, at any point in time, the preconstruction runoff hydrographs
for the same storm events;
[2]
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 one-hundred-year storm events and that the
increased volume or change in timing of stormwater runoff will not
increase flood damage at or downstream of the site. This analysis
shall include the analysis of impacts of existing land uses and projected
land uses assuming full development under existing zoning and land
use ordinances in the drainage area;
[3]
Design stormwater management measures so that
the postconstruction peak runoff rates for the two-, ten-, and one-hundred-year
storm events are 50%, 75% and 80%, respectively, of the preconstruction
peak runoff rates. The percentages apply only to the postconstruction
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 postconstruction 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
[4]
In tidal flood hazard areas, stormwater runoff
quantity analysis in accordance with Subsection F(3)(c)[1], [2] and
[3] above shall only be applied if the increased volume of stormwater
runoff could increase flood damages below the point of discharge.
(2)
Any application for a new agricultural development that meets the definition of major development at § 114-211 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.
G.
Stormwater runoff quality standards.
(1)
Stormwater management measures shall be designed
to reduce the postconstruction 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
nonstructural 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
|
(2)
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 § 114-216 or found on the Department's Web site at www.njstormwater.org. The BMP Manual and other sources of technical guidance are listed in § 114-216. 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.
(3)
If more than one BMP in series is necessary
to achieve the required eighty-percent 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
| |
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 § 114-215C
| |
Sand Filter
|
80
| |
Vegetative Filter Strip
|
60-80
| |
Wet Pond
|
50-90
|
(4)
If there is more than one on-site drainage area,
the eighty-percent 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.
(5)
Stormwater management measures shall also be designed to reduce, to the maximum extent feasible, the postconstruction nutrient load of the anticipated load from the developed site in stormwater runoff generated from the water quality design storm. In achieving reduction of nutrients to the maximum extent feasible, the design of the site shall include nonstructural strategies and structural measures that optimize nutrient removal while still achieving the performance standards in Subsections F and G.
(6)
Additional information and examples are contained in the New Jersey Stormwater Best Management Practices Manual, which may be obtained from the address identified in § 114-216.
(7)
In accordance with the definition of FW1 at
N.J.A.C. 7:9B-1.4, stormwater management measures shall be designed
to prevent any increase in stormwater runoff to waters classified
as FW1.
(8)
Special water resource protection areas shall
be established along all waters designated Category One at N.J.A.C.
7:9B, and perennial or intermittent streams that drain into or upstream
of the Category One waters as shown on the USGS Quadrangle Maps or
in the County Soil Surveys, within the associated HUC14 drainage area.
These areas shall be established for the protection of water quality,
aesthetic value, exceptional ecological significance, exceptional
recreational significance, exceptional water supply significance,
and exceptional fisheries significance of those established Category
One waters. These areas shall be designated and protected as follows:
(a)
The applicant shall preserve and maintain a
special water resource protection area in accordance with one of the
following:
[1]
A three-hundred-foot special water resource
protection area shall be provided on each side of the waterway, measured
perpendicular to the waterway from the top of the bank outwards or
from the center line of the waterway where the bank is not defined,
consisting of existing vegetation or vegetation allowed to follow
natural succession.
[2]
Encroachment within the designated special water resource protection area under Subsection G(8)(a)[1] above shall only be allowed where previous development or disturbance has occurred (for example, active agricultural use, parking area or maintained lawn area). The encroachment shall only be allowed where applicant demonstrates that the functional value and overall condition of the special water resource protection area will be maintained to the maximum extent practicable. In no case shall the remaining special water resource protection area be reduced to less than 150 feet as measured perpendicular to the top-of-bank of the waterway or center line of the waterway where the bank is undefined. All encroachments proposed under this subparagraph shall be subject to review and approval by the Department.
(b)
All stormwater shall be discharged outside of
and flow through the special water resource protection area and shall
comply with the standard for off-site stability in the standards for
Soil Erosion and Sediment Control in New Jersey established under
the Soil Erosion and Sediment Control Act, N.J.S.A. 4:24-39 et seq.
(c)
If stormwater discharged outside of and flowing
through the special water resource protection area cannot comply with
the standard for offsite stability in the Standards for Soil Erosion
and Sediment Control in New Jersey established under the Soil Erosion
and Sediment Control Act, N.J.S.A. 4:24-39 et seq., then the stabilization
measures in accordance with the requirements of the above standards
may be placed within the special water resource protection area, provided
that:
[1]
Stabilization measures shall not be placed within
150 feet of the Category One waterway;
[2]
Stormwater associated with discharges allowed
by this section shall achieve a ninety-five-percent TSS postconstruction
removal rate;
[3]
Temperature shall be addressed to ensure no
impact on the receiving waterway;
[4]
The encroachment shall only be allowed where
the applicant demonstrates that the functional value and overall condition
of the special water resource protection area will be maintained to
the maximum extent practicable;
[5]
A conceptual project design meeting shall be
held with the appropriate Department staff and soil conservation district
staff to identify necessary stabilization measures; and
[6]
All encroachments proposed under this section
shall be subject to review and approval by the Department.
(d)
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 § 114-213G(8) 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 G(8) shall maintain or enhance the current functional value and overall condition of the special water resource protection area as defined in Subsection G(8)(a)[1] above. In no case shall a stream corridor protection plan allow the reduction of the special water resource protection area to less than 150 feet as measured perpendicular to the waterway, subject to this subsection.
H.
Standards and requirements for stormwater areas subject
to tidal flooding:
(1)
All new stormwater and tidal stormwater outfalls
that drain areas that are subject to tidal flooding shall have watertight
joints and be fitted with check valves.
(2)
All new stormwater systems that tie into an
existing stormwater system shall use check valves.
(3)
Where a new bulkhead is to be constructed, a
minimum elevation of the top of bulkhead shall be established to minimize
tidal flooding from breaching of the bulkhead.
(4)
All stormwater structures within areas subject
to tidal flooding shall be constructed of precast concrete and be
watertight.
(5)
New stormwater pipes for use of outfalls through
an existing or proposed bulkhead shall be ductile iron pipe, Class
50 or 52. The class of pipe shall be determined due to location of
the outfall and check valve.
(6)
The last 20 feet of any pipe section that is
an outfall shall not have any stone bedding to transmit tidalwaters.
Soils with low permeability shall be used as backfill material where
required.
(7)
The design engineer shall take into account
all groundwater actions on any proposed stormwater system.
§ 114-214 Calculation of stormwater runoff and groundwater recharge.
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 the NRCS National Engineering Handbook
Section 4 — Hydrology and Technical Release 55 — Urban
Hydrology for Small Watersheds; or
(b)
The rational method for peak flow and the modified
rational method for hydrograph computations.
(2)
For the purpose of calculating runoff coefficients and groundwater recharge, there is a presumption that the 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 § 114-214A(1)(a) and the rational and modified rational methods at § 114-214A(1)(b). A runoff coefficient or a groundwater recharge land cover for an existing condition may be used on all or a portion of the site if the design engineer verifies that the hydrologic condition has existed on the site or portion of the site for at least five years without interruption prior to the time of application. If more than one land cover 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 preconstruction stormwater runoff rates
and volumes.
(4)
In computing stormwater runoff from all design
storms, the design engineer shall consider the relative stormwater
runoff rates and/or volumes of pervious and impervious surfaces separately
to accurately compute the rates and volume of stormwater runoff from
the site. To calculate runoff from unconnected impervious cover, urban
impervious area modifications as described in the NRCS Technical Release
55 — Urban Hydrology for Small Watersheds and other methods
may be employed.
(5)
If the invert of the outlet structure of a stormwater
management measure is below the flood hazard design flood elevation
as defined at N.J.A.C. 7:13, the design engineer shall take into account
the effects of tailwater in the design of structural stormwater management
measures.
B.
Groundwater recharge may be calculated in accordance
with the following:
(1)
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.
§ 114-215 Standards for structural stormwater management measures.
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; flood-prone
areas; slopes; depth to seasonal high-water table; soil type, permeability
and texture; drainage area and drainage patterns; and the presence
of solution-prone carbonate rocks (limestone).
(2)
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 § 114-217D.
(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 § 114-213 of this article.
§ 114-216 Sources for technical guidance.
A.
Technical guidance for stormwater management measures can be found in the documents listed at Subsection A(1) and (2) below, which are available from Maps and Publications, New Jersey Department of Environmental Protection, 428 East State Street, P.O. Box 420, Trenton, New Jersey, 08625; 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, 732-932-9306;
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.
§ 114-217 Safety standards for stormwater management basins.
A.
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 pounds per square
foot.
(2)
An overflow grate is designed to prevent obstruction
of the overflow structure. If an outlet structure has an overflow
grate, such grate shall meet the following requirements:
(a)
The overflow grate shall be secured to the outlet
structure but removable for emergencies and maintenance.
(b)
The overflow grate spacing shall be no less
than two inches across the smallest dimension.
(c)
The overflow grate shall be constructed and
installed to be rigid, durable, and corrosion-resistant, and shall
be designed to withstand a perpendicular live loading of 300 pounds
per square foot.
(3)
For purposes of this Subsection A(3), "escape
provisions" means the permanent installation of ladders, steps, rungs,
or other features that provide easily accessible means of egress from
stormwater management basins. Stormwater management basins shall include
escape provisions as follows:
(a)
If a stormwater management basin has an outlet structure, escape provisions shall be incorporated in or on the structure. With the prior approval of the reviewing agency identified in § 114-217C, a freestanding outlet structure may be exempted from this requirement.
(b)
Safety ledges shall be constructed on the slopes of all new stormwater management basins having a permanent pool of water deeper than 2 1/2 feet. Such safety ledges shall be comprised of two steps. Each step shall be four to six feet in width. One step shall be located approximately 2 1/2 feet below the permanent water surface, and the second step shall be located one to 1 1/2 feet above the permanent water surface. See Subsection D 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 three horizontal to one 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.
§ 114-218 Requirements for a site development stormwater plan.
A.
Submission of site development stormwater plan.
(1)
Whenever an applicant seeks municipal approval of a development subject to this article, the applicant shall submit all of the required components of the Checklist for the Site Development Stormwater Plan at Subsection C below as part of the submission of the applicant's application for subdivision or site plan approval.
(2)
The applicant shall demonstrate that the project
meets the standards set forth in this article.
B.
Site development stormwater plan approval. The applicant's
site development project shall be reviewed as a part of the subdivision
or site plan review process by the municipal board or official from
which municipal approval is sought. That municipal board or official
shall consult the engineer retained by the Planning and/or Zoning
Board (as appropriate) to determine if all of the checklist requirements
have been satisfied and to determine if the project meets the standards
set forth in this article.
C.
Checklist requirements. The following information
shall be required:
(1)
Topographic base map. The reviewing engineer
may require upstream tributary drainage system information as necessary.
It is recommended that the topographic base map of the site be submitted
which extends a minimum of 200 feet beyond the limits of the proposed
development, at a scale of one inch equals 200 feet or greater, showing
one-foot contour intervals. The map, as appropriate, may indicate
the following: existing surface water drainage; shorelines; steep
slopes; soils; erodible soils; perennial or intermittent streams that
drain into or upstream of the Category One waters; wetlands and floodplains
along with their appropriate buffer strips; marshlands and other wetlands;
pervious or vegetative surfaces; existing man-made structures; roads;
bearings and distances of property lines; and significant natural
and man-made features not otherwise shown.
(2)
Environmental site analysis. A written and graphic
description of the natural and man-made features of the site and its
environs. This description should include a discussion of soil conditions,
slopes, wetlands, waterways and vegetation on the site. Particular
attention should be given to unique, unusual, or environmentally sensitive
features and to those that provide particular opportunities or constraints
for development.
(3)
Project description and site plan(s). A map
(or maps) at the scale of the topographical base map indicating the
location of existing and proposed buildings, roads, parking areas,
utilities, structural facilities for stormwater management and sediment
control, and other permanent structures. The map(s) shall also clearly
show areas where alterations occur in the natural terrain and cover,
including lawns and other landscaping, and seasonal high groundwater
elevations. A written description of the site plan and justification
of proposed changes in natural conditions may also be provided.
(4)
Land use planning and source control plan. This plan shall provide a demonstration of how the goals and standards of § § 114-212 through 114-215 are being met. The focus of this plan shall be to describe how the site is being developed to meet the objective of controlling groundwater recharge, stormwater quality and stormwater quantity problems at the source by land management and source controls whenever possible.
(5)
Stormwater management facilities map. The following
information, illustrated on a map of the same scale as the topographic
base map, shall be included:
(a)
Total area to be paved or built upon, proposed
surface contours, land area to be occupied by the stormwater management
facilities and the type of vegetation thereon, and details of the
proposed plan to control and dispose of stormwater.
(b)
Details of all stormwater management facility
designs, during and after construction, including discharge provisions,
discharge capacity for each outlet at different levels of detention
and emergency spillway provisions with maximum discharge capacity
of each spillway.
(6)
Calculations.
(a)
Comprehensive hydrologic and hydraulic design calculations for the predevelopment and postdevelopment conditions for the design storms specified in § 114-213 of this article.
(b)
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.
(7)
Maintenance and repair plan. The design and planning of the stormwater management facility shall meet the maintenance requirements of § 114-219.
(8)
Waiver from submission requirements. The municipal official or board reviewing an application under this article may, in consultation with the Municipal Engineer, waive submission of any of the requirements in § 114-218C(1) through C(6) of this article when it can be demonstrated that the information requested is impossible to obtain or it would create a hardship on the applicant to obtain and its absence will not materially affect the review process.
§ 114-219 Maintenance and repair.
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 Subsection B(2) above is not a public agency, the maintenance plan and any future revisions based on Subsection B(7) below shall be recorded upon the deed of record for each property on which the maintenance described in the maintenance plan must be undertaken.
(5)
Preventative and corrective maintenance shall
be performed to maintain the function of the stormwater management
measure, including repairs or replacement to the structure; removal
of sediment, debris, or trash; restoration of eroded areas; snow and
ice removal; fence repair or replacement; restoration of vegetation;
and repair or replacement of nonvegetated linings.
(6)
The person responsible for maintenance identified under Subsection B(2) above shall maintain a detailed log 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 Subsection B(2) above shall evaluate the effectiveness of the maintenance plan at least once per year and adjust the plan and the deed as needed.
(8)
The person responsible for maintenance identified under Subsection B(2) above shall retain and make available, upon request by any public entity with administrative, health, environmental, or safety authority over the site, the maintenance plan and the documentation required by Subsections B(6) and B(7) above.
(10)
In the event that the stormwater management
facility becomes a danger to public safety or public health, or if
it is in need of maintenance or repair, the 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.
§ 114-220 Violations and penalties.
Any person who erects, constructs, alters, repairs,
converts, maintains, or uses any building, structure or land in violation
of this article shall be subject to a fine not to exceed $500 or imprisonment
not to exceed 30 days. Each day that a violation shall continue shall
constitute a separate violation. Nothing in this article shall be
construed to limit the City of Somers Point's right to institute and
maintain a civil action, from seeking active injunctive relief, or
to set aside or invalidate any conveyance made pursuant to a contract
of sale.
§ 114-221 Effective date.
This article shall take effect immediately upon
the approval by the county review agency or 60 days from the receipt
of the ordinance by the county review agency if the county review
agency should fail to act.