A.
For all regulated activities, submission of the stormwater management
permit application provided in Appendix B is required.[1]
[1]
Editor's Note: Appendix B is included as an attachment to this chapter.
B.
For all regulated activities, unless preparation of a SWM site plan is specifically exempted in § 419-10:
C.
SWM site plans approved by the City, in accordance with § 419-18, shall be on site throughout the duration of the regulated activity.
D.
The City 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.[2]
[2]
Editor's Note: See 35 P.S. § 691.1 et seq.
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), 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) 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). If methods other than green
infrastructure and low-impact development (LID) methods are proposed
to achieve the volume and rate controls required under this chapter,
the stormwater management site plan must include a detailed justification
demonstrating the use of LID and green infrastructure is not practicable.
[Amended 8-17-2022 by Ord. No. 10-2022]
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 City 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/.
O.
P.
Various BMPs and their design standards are listed in the BMP Manual.
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
| |||||
|---|---|---|---|---|---|
|
Proposed Impervious Area
(square feet)
|
Proposed Total Earth Disturbance
(square feet)
|
Chapter Exemptions
|
Stormwater Management Requirements
|
Which is Required to Submit to Municipality?
| |
|
<1,000
|
<5,000
|
N/A
|
N/A
|
N/A
| |
|
1,000 to 5,000
|
5,000 to 10,000
|
Disconnected impervious area (DIA) as in Appendix C.1[1]
|
Appendix C.1 worksheet and sketch (or equivalent)
| ||
|
OR
|
OR
| ||||
|
Capture and control firm 1 inch of runoff over proposed impervious
areas as in Appendix E[2]
|
Appendix E worksheet and sketch (or equivalent)
| ||||
|
5,000 to 10,000
|
10,000 to 20,000
|
Capture and permanently remove the first 2 inches of runoff over proposed impervious areas as in § 419-11B of this chapter
|
Appendix D worksheet and sketch (or equivalent)[3]
| ||
|
>10,000
|
>20,000
|
None
|
All requirements of this chapter
|
SWM site plan
| |
[1]
Editor's Note: Appendix C.1 is included as an attachment to this chapter.
[2]
Editor's Note: Appendix E is included as an attachment to this chapter.
[3]
Editor's Note: Appendix D is included as an attachment to 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
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) 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) 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
for alternative mitigation measures that do not require infiltration.
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.
[Added 8-17-2022 by Ord. No. 10-2022]
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 required by Article I of this chapter, 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. Wherever 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.
(2)
The riparian buffer easement shall be enforceable by the city
and shall be recorded in the Luzerne 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 required
by the City zoning ordinance unless the zoning ordinance specifies
otherwise.
(3)
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.
