Any regulated activity that meets the following exemption criteria
is exempt from the part(s) of this chapter as specified herein. However,
the requirements of the chapter shall otherwise remain in effect.
The criteria for exemption in this section apply to the total development
proposed, including instances in which the development is proposed
to take place in phases. The date of enactment of this chapter shall
be the starting point from which future development and the respective
proposed impervious surface computations shall be cumulatively considered
and regulated. Exemption shall not relieve an applicant from implementing
such measures as necessary to meet the intent of this chapter or compliance
with any NPDES permit requirements.
A. Regulated activities that create impervious areas equal to or less
than those set forth on Table 1 (cumulative) shall be exempt from the SWM site plan preparation
requirements of this chapter, provided that the activity will not
adversely affect downstream property owners and will not cause erosion.
The Borough reserves the right to have its designee make the determination
of adverse affect after review of the stormwater permit application
and review of the proposed site.
(1) Notwithstanding the provisions of this Subsection
A and Table 1, activities that would otherwise be regulated activities pursuant to this chapter but are 100 square feet or less shall be exempt from the stormwater management site plan preparation, volume control, peak rate control and municipal review and approval provisions of this chapter, provided that the regulated activity does not adversely affect adjoining properties or cause erosion. A stormwater permit application must still be submitted for record purposes. All new impervious surfaces shall be considered in the cumulative totals in determining exemption status.
B. Regulated activities that do not receive an exemption from SWM site plan preparation requirements per §
195-13A or regulated activities that create impervious areas greater than those set forth on Table 1 (cumulative) may qualify for submission of a simplified SWM site plan per §
195-18D. The Borough's designee shall determine if a simplified SWM site plan may be submitted in lieu of a full SWM site plan (per §
195-18) after review of the stormwater management permit application and review of the proposed site. The simplified SWM site plan must demonstrate that the proposed activity will not adversely affect adjoining property owners or cause erosion.
C. Agricultural activity is exempt from the SWM site plan preparation
requirements of this chapter, provided that the activities are performed
according to the requirements of 25 Pa. Code Chapter 102 and no adverse
impacts to adjoining property owners will occur because of stormwater
runoff.
D. Forest management and timber operations may be exempt from the SWM
site plan preparation requirements of this chapter, provided that
the activities are performed according to the requirements of 25 Pa.
Code Chapter 102 and no adverse impacts to adjoining property owners
will occur because of stormwater runoff.
E. Domestic gardening and landscaping are exempt from specific approval
and permitting under this chapter so long as those activities are
associated with one, and only one, dwelling unit and the activities
comply with all other applicable chapters and statutes.
F. Exemptions from certain provisions of this chapter shall not relieve the applicant from the requirements in §
195-12D through
O of this chapter.
G. The municipality may deny or revoke any exemption pursuant to this
section at any time for any project that poses a threat to public
health, safety, property or the environment.
|
Table 1
|
---|
|
Existing Lot Size
(acres)
|
Maximum New Impervious Area Cumulative per § 195-13A
(square feet)
|
---|
|
0 to 0.25
|
250
|
|
Greater than 0.25 to 0.50
|
500
|
|
Greater than 0.50 to 0.75
|
750
|
|
Greater than 0.75
|
1,000
|
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 regulated activity areas equal or less than one acre
that do not require hydrologic routing to design the stormwater facilities,
this chapter establishes no preference for either methodology; therefore,
the applicant may select either methodology on the basis of economic
considerations, the intrinsic limitations on applicability of the
analytical procedures associated with each methodology, and other
factors.
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) No plan shall increase the post-development total runoff volume for
all storms equal to or less than the two-year twenty-four-hour-duration
precipitation to more than the pre-development total runoff volume.
(2) For modeling purposes:
(a)
Existing (pre-development) nonforested pervious areas must be
considered meadow.
(b)
Twenty percent of the existing impervious area of a project
site, when present, shall be considered meadow in the model for existing
conditions, if the existing impervious area is being altered by the
proposed regulated activity.
B. The Simplified Method (CG-2 in the BMP Manual) provided below is
independent of site conditions and should be used if the Design Storm
Method is not followed. This method is not applicable to regulated
activities greater than one acre or for projects that require design
of stormwater storage facilities. For new impervious surfaces:
(1) Stormwater facilities shall capture at least the first two inches
of runoff from all new impervious surfaces.
(2) At least the first one inch 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 for the first one inch of runoff include reuse, evaporation,
transpiration, and infiltration.
(3) 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 stormwater runoff shall be infiltrated.