Any regulated activity that meets the following exemption criteria is exempt from the part(s) of this Part
2 as specified herein. However, the requirements of this Part
2 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 Part
2 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 Part
2 or compliance with any NPDES permit requirements.
A. Regulated activities that create DIAs equal to or less than 1,000
square feet are exempt from the peak rate control and the SWM site
plan preparation requirements of this Part 2, and therefore, no formal
submission to the Borough is necessary.
B. Regulated activities that create DIAs greater than 1,000 square feet
and equal to or less than 5,000 square feet are exempt only from the
peak rate control requirement of this Part 2.
C. Agricultural activity is exempt from the rate control and SWM site plan preparation requirements of this Part
2, provided the activities are performed according to the requirements of 25 Pa. Code Chapter 102. For regulated activities that meet this exemption criteria, no formal application to the Borough is required.
D. Forest management and timber operations are exempt from the rate control and SWM site plan preparation requirements of this Part
2, provided the activities are performed according to the requirements of 25 Pa. Code Chapter 102. For regulated activities that meet this exemption criteria, no formal application to the Borough is required.
E. Domestic gardening and landscaping are exempt from specific approval
and permitting under this Part 2 so long as those activities are associated
with one, and only one, dwelling unit and the activities comply with
all other applicable ordinances and statutes.
F. Exemptions from certain provisions of this Part
2 shall not relieve the applicant from the requirements in §
144-301D through
N of this Part
2.
G. The Borough may deny or revoke any exemption pursuant to this section
at any time for any project that the Borough determines poses a threat
to public health, safety, property or the environment.
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 Part
2 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)
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.
(2)
For modeling purposes:
(a)
Existing (predevelopment) nonforested pervious areas must be
considered meadow.
(b)
For computation of predevelopment runoff volume, 20% of existing
impervious areas, when present, shall be considered meadow.
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.
(4)
This method is exempt from the requirements of §
144-304, Rate controls.