A.
For all regulated activities, unless preparation of an SWM site plan is specifically exempted in § 268-11:
B.
SWM site plans approved by the Township, in accordance with § 268-21, shall be on site throughout the duration of the regulated activity.
C.
The Township may, after consultation with PADEP, 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.[1] The Township shall maintain a record of consultations
with PADEP pursuant to this subsection.
[1]
Editor's Note: See 35 P.S. § 691.1 et seq.
D.
For all regulated earth-disturbance activities, erosion and sediment
control BMPs shall be designed, implemented, operated, and maintained
during the regulated earth-disturbance activities, i.e., 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) (Reference 2)[2], No. 363-2134-008 (April 15, 2000), as amended and updated.
F.
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 phases.
(2)
For development taking place in phases, the entire development plan
must be used in determining conformance with this chapter.
(3)
For projects that add impervious area to a parcel the total impervious area on the parcel is subject to the requirements of this chapter, except that the volume controls in § 268-12 and the peak rate controls of § 268-13 do not need to be retrofitted to existing impervious areas that are not being altered by the proposed regulated activity.
G.
Stormwater flows onto adjacent property shall not be created, increased,
decreased, relocated, or otherwise altered without written notification
of the adjacent property owner(s) by the developer or applicant. Such
stormwater flows shall be subject to the requirements of this chapter.
H.
All regulated activities shall include such measures as necessary
to:
(1)
Protect health, safety, and property;
(2)
Meet the water quality goals of this chapter, as stated in § 268-3, Purpose, by implementing measures to:
(a)
Minimize disturbance to floodplains, wetlands, wooded areas,
and existing vegetation.
(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.
(f)
Minimize soil disturbance and compaction. If removed, topsoil
shall be replaced to a minimum depth equal to its depth prior to removal
or four inches, whichever is greater. (Additional topsoil may be needed
for vegetation other than sod.)
(3)
To the maximum extent practicable, incorporate the techniques for
low-impact development practices described in the Pennsylvania Stormwater
Best Management Practices Manual (BMP Manual).
I.
The design of all facilities in areas of karst topography and/or
carbonate geology shall include an evaluation of measures to minimize
adverse effects, including hydrogeologic studies if required by the
Township.
J.
Infiltration BMPs shall 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. In addition,
infiltration BMPs shall include pretreatment BMPs where appropriate.
K.
All natural streams, channels, swales, drainage systems and/or areas of surface water concentration shall be maintained in their existing condition unless the Township approves an alteration. All encroachment activities shall comply with the requirements of PADEP, 25 Pa. Code Chapter 105 (Water Obstructions and Encroachments), Rules and Regulations of PADEP. Any approvals or permits issued do not relieve compliance as referenced in § 268-6, Compatibility with other requirements.
L.
Normally dry, open-top storage facilities, designed as such, 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. However, any designed infiltration
at such facilities is exempt from the minimum twenty-four-hour standard,
i.e., may infiltrate in a shorter period of time, so long as none
of the stormwater flowing into the infiltration facility is discharged
directly into the surface waters of this commonwealth. (Inordinately
rapid infiltration rates may indicate the presence of large fractures
or other conditions for which an additional soil buffer may be required.)
M.
The design storm volumes and precipitation intensities to be used
in the analysis of discharge or runoff shall 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/.
N.
O.
Various BMPs and their design standards are listed in the BMP Manual.
P.
All work shall be in accordance with the Township's Standard Construction
Details and PennDOT Publications 408 and 72M.
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 this 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 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 chapter.
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 chapter.
C.
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.
D.
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.
E.
The use of land for domestic (i.e., for a single individual dwelling
unit) gardening and landscaping is exempt from specific approval and
permitting under this chapter so long as such activities comply with
all other applicable ordinances and statutes.
G.
The Township may deny or revoke any exemption pursuant to this section
at any time for any project that the Township 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 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)
There shall be no increase in the post-development total runoff volume
for all storms equal to or less than the two-year twenty-four-hour
duration precipitation.
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.
(1)
For new impervious surfaces.
(a)
Stormwater facilities shall capture at least the first two inches
of runoff from all new impervious surfaces.
(b)
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 the commonwealth. Removal
options include reuse, evaporation, transpiration, and infiltration.
(c)
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 shall be infiltrated.
A.
For computation of predevelopment peak discharge rates, 20% of the
existing impervious area of a project site, when present, shall be
considered meadow.
B.
Post-development discharge rates shall not exceed the predevelopment
discharge rates for the one-, two-, five-, ten-, twenty-five-, fifty-,
and 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 pre-development analysis for one-, two-, five-, ten-, twenty-five-,
fifty-, and 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.
A.
For the purposes of the Act 167[1] Stormwater Management Plan elements, contained within the York County Integrated Water Resources Plan, and this chapter, design policy pertaining to stormwater management facilities for Pennsylvania Department of Transportation (PennDOT) and Pennsylvania Turnpike Commission (PTC) roadways and associated facilities is provided in Section 13.7 (Antidegradation and Post Construction Stormwater Management Policy) of PennDOT Publication No. 13M, Design Manual Part 2 (August 2009), as developed, updated, and amended in consultation with the Pennsylvania Department of Environmental Resources (PADEP). As stated in DM-2.13.7.D (Act 167 and municipal ordinances), PennDOT and PTC roadways and associated facilities shall be consistent with Act 167 Plans. DM-2.13.7.B (Policy on Antidegradation and Post Construction Stormwater Management) was developed as a cooperative effort between PennDOT and DEP. DM-2.13.7.C (Project Categories) discusses the anticipated impact on the quality, volume, and rate of stormwater runoff.
[1]
Editor's Note: See 32 P.S. § 680.1 et seq.
B.
Where standards in the Act 167 elements of the IWRP and this chapter
are impractical, PennDOT or the PTC may request assistance from PADEP,
in consultation with the county, to develop an alternative strategy
for meeting state water quality requirements and the goals and objectives
of the Act 167 elements within the IWRP.
C.
For the purposes of the Act 167 elements in the IWRP and this chapter,
road maintenance activities are regulated under 25 Pa. Code Chapter
102.
B.
Detention and retention basins.
(1)
Basin maximum water depth shall be less than eight feet for a one-through-one-hundred-year
twenty-four-hour post development storm event.
(2)
Embankment top widths shall be at least eight feet.
(3)
The maximum permitted side slopes shall be 4.0 horizontal to 1.0
vertical. In order to obtain a waiver for slopes steeper than 4:1,
the plan must include a planting schedule to stabilize the embankments.
The proposed vegetation shall be of the low-maintenance variety.
(4)
Any open-top facility shall be subject to the following fencing requirements:
(a)
The facility must be completely surrounded by a chain-link fence
of not less than four feet in height. Alternative fences and barriers
may be permitted upon request to and approval by the Township.
(b)
The fence shall not be installed on earth fill embankment tops,
on fill embankment downstream face slopes, across emergency spillway
weirs, or across emergency spillway downstream face channel sections
(above the toe of embankment slopes.)
(c)
All gate or door openings through such enclosure shall be equipped
with a self-closing and self-latching device for keeping the gate
or door securely closed at all times when not in actual use.
(5)
The
use of retaining walls within a retention or detention basin shall
be prohibited.
[Added 12-20-2021 by Ord. No. 843]
C.
Stormwater collection and conveyance facilities and/or systems.
(1)
All stormwater pipes, other than those for existing channels, which
discharge from residential lots to a street or from a street to residential
lots, shall extend from the street right-of-way a minimum distance
of 67% of the length of the longest adjacent lot dimension.
(2)
SWM collection and conveyance facilities not located within a public
right-of-way shall be centered in an easement.
D.
Miscellaneous SWM site plans and SWM BMP requirements and standards.
(1)
Roof drain and sump pump connections shall not discharge into sanitary
sewers, streets, gutters, roadside channels, or into the legal street
or road right-of-way.
(2)
Every person owning or leasing property through which a watercourse
passes shall maintain that part of the watercourse within the property
and keep it free from trash or debris; substances that could contaminate
or pollute the waters of this commonwealth; any obstacles that could
alter the bed slope, cross section, or path of the watercourse. In
addition, the owner or lessee shall maintain existing privately owned
structures within or adjacent to a watercourse so that those structures
will not become a hazard to the use, function, or physical integrity
of the watercourse.
