A.
For all regulated activities, submission of the Stormwater Management
Permit Application provided in chapter Appendix B is required.[1] "Level 1" projects, as described in Appendix B, may use
the City of Nanticoke "simplified" stormwater management application.
[1]
Editor's Note: Appendix B, Stormwater Management Permit Application, is included at the end of this chapter.
B.
For all regulated activities, unless preparation of a SWM site plan is specifically exempted in § 446-10:
C.
SWM site plans approved by the City of Nanticoke, in accordance with § 446-18, shall be on site throughout the duration of the regulated activity.
D.
The City of Nanticoke may, after consultation with DEP, approve measures
for meeting the state water quality requirements other than those
in this chapter, provided that they meet the minimum requirements
of and do not conflict with state law, including, but not limited
to, the Clean Streams Law.
E.
For all regulated earth disturbance activities, erosion and sediment
control BMPs shall be designed, implemented, operated and maintained
during the regulated earth disturbance activities (e.g., during construction)
to meet the purposes and requirements of this chapter and to meet
all requirements under Title 25 of the Pennsylvania Code and the Clean
Streams Law. Various BMPs and their design standards are listed in
the Erosion and Sediment Pollution Control Program Manual (E&S
Manual[2]), No. 363-2134-008 (April 15, 2000), as amended and updated.
G.
Impervious areas:
(1)
The measurement of impervious areas shall include all of the impervious
areas in the total proposed development even if development is to
take place in stages.
(2)
For development taking place in stages, the entire development plan
must be used in determining conformance with this chapter.
(3)
For projects that add impervious area to a parcel, only the proposed
impervious area on the parcel must be considered and summed to determine
the plan preparation and approval requirements of this chapter.
(4)
For redevelopment projects in which the existing site is disturbed,
the entire proposed site is subject to the plan preparation and approval
requirements of this chapter. Existing conditions are considered to
be the existing site prior to disturbance, and 20% of the existing
impervious area must be considered as meadow in good condition for
all stormwater calculations. For redevelopment projects in which the
existing site is already controlled by a stormwater management facility,
the requirement to consider 20% of existing impervious area as meadow
is waived, provided the existing facility meets the water quality,
volume and peak rate standards and criteria of this chapter.
H.
Stormwater flows onto adjacent property shall not be created, increased,
decreased, relocated or otherwise altered without written notification
of the adjacent property owner(s). Such stormwater flows shall be
subject to the requirements of this chapter.
I.
All regulated activities shall include measures to:
(1)
Protect health, safety and property;
(2)
Meet the water quality goals of this chapter by implementing measures
outlined in the Pennsylvania Stormwater Best Management Practices
Manual (BMP Manual[3]) to:
(a)
Minimize disturbance to floodplains, wetlands and wooded areas.
(b)
Maintain or extend riparian buffers.
(c)
Avoid erosive flow conditions in natural flow pathways.
(d)
Minimize thermal impacts to waters of this commonwealth.
(e)
Disconnect impervious surfaces by directing runoff to pervious
areas wherever possible.
(3)
Incorporate methods described in the Pennsylvania Stormwater Best
Management Practices Manual ("BMP Manual").[4] If methods other than green infrastructure and LID methods
are proposed to achieve the volume and rate controls required under
this chapter, the SWM site plan must include a detailed justification
demonstrating that the use of LID and green infrastructure is not
practicable.
[Amended 6-15-2022 by Ord. No. 4-2022]
J.
The design of all facilities over karst and mined areas shall include
an evaluation of measures to minimize adverse effects.
K.
Infiltration BMPs should be spread out, made as shallow as practicable,
and located to maximize use of natural on-site infiltration features
while still meeting the other requirements of this chapter.
L.
Storage facilities, to the greatest extent possible and at the discretion
of the Municipal Engineer, shall completely drain both the volume
control and rate control capacities over a period of time not less
than 24 hours and not more than 72 hours from the end of the design
storm.
M.
Storage facilities shall incorporate features to maximize the length
of the flow path and increase the travel time through the facility.
N.
The design storm volumes to be used in the analysis of peak rates
of discharge should be obtained from the Precipitation-Frequency Atlas
of the United States, Atlas 14, Volume 2, Version 3.0, U.S. Department
of Commerce, National Oceanic and Atmospheric Administration (NOAA),
National Weather Service, Hydrometeorological Design Studies Center,
Silver Spring, Maryland. NOAA's Atlas 14 can be accessed at: http://hdsc.nws.noaa.gov/hdsc/pfds/.[5]
O.
For all regulated activities, SWM BMPs shall be designed, implemented,
operated and maintained to meet the purposes and requirements of this
chapter and to meet all requirements under Title 25 of the Pennsylvania
Code, the Clean Streams Law, and the Stormwater Management Act.
A.
Regulated activities that create impervious areas or earth disturbance
shall adhere to Table III.1 to meet the requirements of this chapter.
The larger of the two areas determines the applicable requirements
of this chapter (i.e., if only 500 square feet of impervious area
is proposed, but 15,000 square feet of earth disturbance, the requirements
follow Row 3 of Table III.1).
|
Table III.1. Stormwater Management Requirements and Exemptions[1]
| |||||
|---|---|---|---|---|---|
|
Proposed Impervious Area
(square feet)
|
Proposed Total Earth Disturbance
(square feet)
|
Ordinance Exemptions
|
Stormwater Management Requirements
|
What is required to submit to municipality?*
| |
|
<1,000
|
<5,000
|
Ensure § 446-9, General requirements, is met
|
NA
| ||
|
1,000 to 5,000
|
5,000 to 10,000
|
Disconnected Impervious Area (DIA) as in chapter Appendix C.1
|
Chapter Appendix C.1 worksheet and sketch (or equivalent)
| ||
|
OR
|
OR
| ||||
|
Capture and control first one inch of runoff over proposed impervious
areas as in chapter Appendix E
|
Chapter Appendix E worksheet and sketch (or equivalent)
| ||||
|
5,000 to 10,000
|
10,000 to 20,000
|
Capture and permanently remove the first two inches of runoff over proposed impervious areas as in § 446-11B of this chapter
|
Chapter Appendix D worksheet and sketch (or equivalent)
| ||
|
>10,000
|
>20,000
|
None
|
All requirements of this chapter
|
SWM site plan
| |
|
NOTE:
| ||
|---|---|---|
|
*
|
In addition to the stormwater management permit application
provided in chapter Appendix B.
| |
[1]
Editor's Note: Chapter appendixes cited in this table are
included at the end of this chapter.
B.
Agricultural activity is exempt from the rate control and SWM site
plan preparation requirements of this chapter, provided the activities
are performed according to the requirements of 25 Pa. Code Chapter
102.
C.
Forest management and timber operations are exempt from the rate
control and SWM site plan preparation requirements of this chapter,
provided the activities are performed according to the requirements
of 25 Pa. Code Chapter 102.
The low-impact development practices provided in the BMP Manual[1] shall be utilized for all regulated activities to the
maximum extent practicable. Water volume controls shall be implemented
using the Design Storm Method in Subsection A or the Simplified Method
in Subsection B below. For all regulated activities that require submission
of a formal SWM site plan, both the Design Storm Method and the Simplified
Method shall be calculated; the larger control volume based on the
two calculations shall be controlled. Subsection C below provides
requirements for mined, karst or other geologically limiting areas
where infiltration shall not occur.
A.
The Design Storm Method (CG-1 in the BMP Manual[2]) is applicable to any size of regulated activity. This
method requires detailed modeling based on site conditions.
(1)
Do not increase the post-development total runoff volume for all
storms equal to or less than the two-year twenty-four-hour duration
precipitation.
B.
When Design Storm Method CG-1 guidelines are not used, the Simplified
Method (CG-2 in the BMP Manual[3]) has been modified to accommodate two inches of permanently
removed runoff volume. This method (provided below) is independent
of site conditions and should be used if the Design Storm Method is
not followed. For new impervious surfaces:
(1)
The first two inches of runoff from new impervious surfaces shall
be permanently removed from the runoff flow (i.e., it shall not be
released into the surface waters of this commonwealth). Removal options
include reuse, evaporation, transpiration and infiltration.
(2)
Wherever possible, infiltration facilities should be designed to
accommodate infiltration of the entire permanently removed runoff;
however, in all cases at least the first 0.5 inch of the permanently
removed runoff should be infiltrated.
(3)
Facilities, to the greatest extent possible and subject to the Municipal
Engineer's discretion, shall be designed to drain the permanently
removed runoff volume in a period no less than 24 hours and no greater
than 72 hours.
(4)
Runoff volume in excess of two inches shall be safely conveyed to
existing stormwater collection systems or streams, in the direction
of the existing drainagecourse.
C.
Before infiltration is proposed on a site, site conditions shall
be evaluated by a qualified design professional through subsurface
investigation and testing to determine if site conditions are suitable
to support proposed infiltration facilities to manage runoff. If it
is determined that infiltration is not feasible due to physical constraints
of the site, or will adversely impact the environment as demonstrated
by the presence of acid mine drainage, sinkhole formation, or other
serious environmental issues, then the above volume controls must
be achieved through surface BMP mitigation. Reference the BMP Manual[4] for alternative mitigation measures that do not require
infiltration.
A.
Areas not covered by a Stormwater Management District Map contained
in Appendix F.1[1] of the chapter: Post-development discharge rates shall
not exceed the predevelopment discharge rates for the one- through
one-hundred-year, twenty-four-hour storms. If it is shown that the
peak rates of discharge indicated by the post-development analysis
are less than or equal to the peak rates of discharge indicated by
the predevelopment analysis for one- through one-hundred-year, twenty-four-hour
storms, then the requirements of this section have been met. Otherwise,
the applicant shall provide additional controls as necessary to satisfy
the peak rate of discharge requirement.
[1]
Editor's Note: The Stormwater Management District Maps are
available in the City offices.
B.
Areas covered by a Stormwater Management District Map contained in
Appendix F.1[2] of the chapter: For the one- through one-hundred-year
storms, the post-development peak discharge rates will follow the
applicable approved Stormwater Management District Maps. For any areas
not shown on the Stormwater Management District Maps, the post-development
discharge rates shall not exceed the predevelopment discharge rates.
[2]
Editor's Note: The Stormwater Management District Maps are
available in the City offices.
[Added 6-15-2022 by Ord. No. 4-2022]
A.
In order
to protect and improve water quality, a riparian buffer easement shall
be created and recorded as part of any subdivision or land development
that encompasses a riparian buffer.
B.
Except
as may otherwise be required, the riparian buffer easement shall be
measured to be the greater of the limit of the 100-year floodplain
or a minimum of 35 feet from the top of the streambank (on each side).
C.
Minimum
management requirements for riparian buffers.
(1)
Existing native vegetation shall be protected and maintained within
the riparian buffer easement.
(2)
Whenever practicable, invasive vegetation shall be actively removed
and the riparian buffer easement shall be planted with native trees,
shrubs and other vegetation to create a diverse native plant community
appropriate to the intended ecological context of the site.
D.
The
riparian buffer easement shall be enforceable by the municipality
and shall be recorded in the appropriate County Recorder of Deeds
office so that it shall run with the land and shall limit the use
of the property located therein. The easement shall allow for the
continued private ownership and shall count toward the minimum lot
area a required by zoning, unless otherwise specified in the municipal
Zoning Ordinance.[1]
E.
Any
permitted use within the riparian buffer easement shall be conducted
in a manner that will maintain the extent of the existing 100-year
floodplain, improve or maintain the stream stability, and preserve
and protect the ecological function of the floodplain.
G.
Septic
drainfields and sewage disposal systems shall not be permitted within
the riparian buffer easement and shall comply with setback requirements
established under 25 Pa. Code Chapter 73.
