A.
For all regulated activities, unless preparation of an SWM site plan is specifically exempted in § 173-15:
B.
SWM site plans approved by the Township, in accordance with § 173-25, shall be on-site throughout the duration of the regulated activity.
C.
These standards apply to the landowner and any person engaged in
regulated activities.
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 (e.g., during construction)
to meet the purposes and requirements of this chapter and to meet
all requirements under Title 25 of the Pa. 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[1]), No. 363-2134-008, as amended and updated. Comment on
the adequacy of the erosion and sedimentation controls may be provided
by the Township per the requirements of Beaver County Conservation
District (BCCD).
E.
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, the total impervious area on the parcel is subject to the requirements of this chapter; except that the volume controls in § 173-16 and the peak rate controls of § 173-17 do not need to be retrofitted to existing impervious areas that are not being altered by the proposed regulated activity.
F.
Stormwater flows onto adjacent or downstream properties shall not
be created, increased, decreased, relocated, impeded, or otherwise
altered without written notification to the affected property owner(s).
Notification shall include a description of the proposed development
and the stormwater flows that are being created, increased, decreased,
relocated, impeded, or otherwise altered. Adjacent property shall
at a minimum include any property having a shared boundary with the
subject property of the SWM site plan; however, if in the judgment
of the Township additional properties are being affected, additional
notifications may be required. Proof of notification (signed postal
receipt, for example) shall be included as part of the SWM plan submission
to the Township. Such stormwater flows shall be subject to the requirements
of this chapter.
G.
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 by implementing measures
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 the 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[2]). 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,
acceptable to the Township, demonstrating that the use of LID and
green infrastructure is not practicable.
H.
Infiltration BMPs should be dispersed throughout the project site
at strategic locations, 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.
I.
Normally dry, open top, storage facilities should completely drain
both the volume control and rate control capacities over a period
of time not less than 24 and not more than 72 hours from the end of
the design storm. Infiltration tests performed at the facility locations
and proposed basin bottom depths, in accordance with the BMP Manual,
must support time-to-empty calculations if infiltration is a factor.
J.
The design storm precipitation depths to be used in the analysis
of peak rates of discharge shall be as obtained in PaDOT's Drainage
Manual, Publication 584, Appendix 7A; or obtained from the latest
version of the Precipitation-Frequency Atlas of the United States,
National Oceanic and Atmospheric Administration (NOAA), National Weather
Service, Hydrometeorological Design Studies Center, Silver Spring,
Maryland. NOAA's Atlas 14[3] can be accessed at http://hdsc.nws.noaa.gov/hdsc/pfds/.
K.
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 Pa.
Code, the Clean Streams Law, and the Storm Water Management Act.
M.
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.
A.
Regulated activities that propose an increase in impervious area
of less than 1,000 square feet are exempt from the requirements of
this chapter. Documentation of proposed impervious area increase must
be provided.
B.
Regulated activities that propose an increase in impervious area of at least 1,000 square feet but less than 5,000 square feet with an earth disturbances less than one acre (43,560 square feet) must submit an SWM site plan to the Township which shall consist of the following items and related supportive material needed to determine compliance with §§ 173-16 through 173-18. The applicant can use the protocols in the small project stormwater management site plan, as adopted by resolution by the Board of Supervisors.
(1)
General description of proposed stormwater management techniques,
including construction specifications of the materials to be used
for stormwater management facilities.
(2)
An erosion and sediment control plan, including all reviews and letters
of adequacy from the Beaver County Conservation District where appropriate.
(3)
Limits of earth disturbance, including the type and amount of impervious
area that is proposed; proposed structures, roads, paved areas, and
buildings; and a statement, signed by the applicant, acknowledging
that any revision to the approved drainage plan must be approved by
the Township, and that a revised erosion and sediment control plan
must be submitted to the Township or Beaver County Conservation District
for approval.
(4)
All stormwater management facilities must be located on a plan and
described in detail; and all calculations, assumptions, and criteria
used in the design of the stormwater management facilities must be
shown.
C.
Agricultural activity is exempt from the 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 SWM site
plan preparation requirements of this chapter, provided the activities
are performed according to the requirements of 25 Pa. Code Chapter
102.
E.
Roadway resurfacing and maintenance projects, which do not increase impervious area, and underground infrastructure projects are exempt from the provisions of this chapter, provided the activities meet the requirements of all other Township, state and federal requirements. Exemptions from any provisions of this chapter shall not relieve the applicant from the requirements in § 173-14D through J.
F.
The Township may deny or revoke any exemption pursuant to this section
at any time for any project that the Township believes may pose a
threat to public health and safety or the environment.
G.
Voluntary green stormwater infrastructure (GSI) retrofit projects
that are solely intended to better manage runoff from existing development
and are not part of new development or redevelopment are exempt from
the stormwater management provisions of this chapter. This does not
exempt such projects from any other municipal, state, or federal regulation.
The green infrastructure and low-impact development practices
provided in the BMP Manual[1] shall be utilized for all regulated activities wherever
possible. Water volume controls shall be implemented using the Design
Storm Method in Subsection A or the Simplified Method in Subsection
B below. Water volume controls shall be implemented using the Design
Storm Method in Subsection A or the Simplified Method in Subsection
B below, or alternative design criteria as allowed by 25 Pa. Code
Chapter 102.
A.
The Design Storm Method (CG-1 in the BMP Manual[2]) is applicable as a method to any size of regulated activity.
This method requires detailed modeling based on site conditions. The
following shall be incorporated into the CG-1 method:
(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)
At least the first one inch of runoff from the net increase in impervious
surfaces shall be permanently removed from the runoff flow, i.e.,
it shall not be released into surface waters of the commonwealth.
Removal options include reuse, evaporation, transpiration, and infiltration.
If the developer provides justification that the listed removal options
are not feasible, and the Township agrees, runoff shall be detained
in a facility designed for a forty-eight-to-seventy-two-hour dewatering
time in an area with a dedicated stormwater system (not contributory
to a combined sewer system) before discharge to local stormwater systems
or the environment. Justification, as prepared and sealed by a qualified
professional, for assertion that permanent removal is not feasible
must be provided, at a minimum, in the form of field measured infiltration
rate testing and geotechnical evaluation of the existing site soils
with regard to the impact of proposed infiltration. Applications omitting
this justification, including infiltration rate testing, will be considered
incomplete. BMPs proposing use of extended detention in lieu of permanent
reduction through the listed methods shall include a valve to adjust
or regulate dewatering time to achieve the performance standards noted
herein. The valve system shall include an inspection/monitoring port
for review of dewatering.
B.
The Simplified Method (CG-2 in the BMP Manual[3]) 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 the net increase in impervious surfaces.
(2)
At least the first one inch of runoff from the net increase in 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.
If the developer provides justification that the listed removal options
are not feasible, and the Township agrees, runoff shall be detained
in a facility designed for a twenty-four-hour dewatering time in an
area with a dedicated stormwater system (not contributory to a combined
sewer system) and shall be detained in a facility designed for a seventy-two-hour
dewatering time in an area contributory to a combined sewer system
before discharge to local stormwater systems or the environment.
(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 1/2 inch (0.5) of the permanently
removed runoff should be infiltrated.
A.
For areas not covered by a release rate map from an approved Act
167 stormwater management plan:
(1)
Post-development discharge rates shall not exceed the predevelopment
discharge rates for the one-, two-, five-, ten-, twenty-five-, fifty-,
and 100-year, twenty-four-hour storm events. This is the equivalent
to a 100% release rate area when compared to those rates shown in
the maps contained in Appendix A (Release Rate Management Districts).
This predevelopment to post-development control is not to be misconstrued
as the same as the "conditional direct discharge" areas on the release
rate maps. For comparison of peak flow rates, flows shall be rounded
to a tenth of a cubic foot per second (cfs). 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-, two-, five-, ten-, twenty-five-,
fifty-, and 100-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. Peak flows should be computed using the methods included
in the chapter titled "Stormwater Calculations and Methodology" of
the PaDEP Stormwater Management BMP Manual. Except, however, where
documented downstream flooding problems exist, the Township may impose
a reduced release rate criteria.
B.
For areas covered by a release rate map from an approved Act 167
stormwater management plan:
(1)
For the one-, two-, five-, ten-, twenty-five-, fifty-, and 100-year,
twenty-four-hour storm events, the post-development peak discharge
rates will follow the applicable approved release rate maps. These
maps are contained in Appendix A (Release Rate Management Districts)
of this chapter. For comparison of peak flow rates, flows shall be
rounded to a tenth of a cubic foot per second (cfs). For any areas
not shown on the release rate maps, the post-development discharge
rates shall not exceed the predevelopment discharge rates for the
specified design events. Peak flows should be computed using the methods
included in Chapter 8 of the PaDEP Stormwater Management BMP Manual.
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. The intent
of this chapter in establishing a riparian buffer is to protect and
improve stream water quality. The riparian buffer is intended to slow
overland flow to the stream through the presence of native grasses,
trees and shrubs, allowing infiltration/groundwater recharge; causing
deposition of sediment, nutrients, pesticides, and other pollutants
in the buffer rather than in the stream; and reducing erosion by providing
stream bank stabilization. The trees provide shade for streams, keeping
waters cooler and reducing evaporation.
B.
Except as required by 25 Pa. Code Chapter 102, the riparian buffer easement shall be required for all streams (as defined in Article II) with a contributing watershed area of greater than 10 acres. The riparian buffer easement shall be measured to be a minimum of 35 feet from the top of the streambank (on each side) and shall be shown on the SWM site plan.
C.
Minimum management requirements for riparian buffers.
(1)
No use or construction within the riparian buffer shall be permitted that is inconsistent with the intent of the riparian buffer as described in § 173-18A.
(2)
Existing native vegetation shall be protected and maintained within
the riparian buffer easement.
(3)
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 Township
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 required by zoning, unless otherwise specified in the Brighton
Township Zoning Code.[1]
F.
Roadway crossings, when authorized by Pa Chapter 105 Permitting as
issued by PaDEP (unless otherwise exempt), and stormwater drainage
pipes shall be permitted within the riparian buffer easement, but
they shall cross the easement in the shortest practical distance.
Other structural stormwater management facilities are not permitted
within the riparian buffer easement.
G.
The following conditions shall apply when public and/or private recreation
trails are permitted by the Township within riparian buffers:
H.
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.
I.
Underground utilities shall be permitted within the riparian buffer
easement; however, work shall be performed to minimize disturbance
area and removal of trees. Restoration within the riparian buffer
easement shall be with native species of trees, grasses, and other
plantings. One tree shall be planted for each tree removed; the tree
size to be planted shall be 1.5 inch caliper trees and the restoration
shall be designed by a registered professional with the requisite
experience. Aboveground utilities shall only be permitted to cross
the riparian buffer easement perpendicular to the riparian buffer
easement or in the shortest practical distance. Existing utilities
may remain and be maintained as required.
A.
If the solar PV installation complies with all of the following conditions,
the project area of the solar PV installation may be considered pervious
cover; and a detailed stormwater analysis is not needed and PCSM BMPs
are not necessary:
(1)
Projects where earth disturbance and grading activities are minimized
and where natural vegetative cover is preserved and/or restored. The
utilization of LID construction techniques must be used.
(2)
Vegetative cover must have a 90% or better uniform coverage and shall
not be subject to chemical fertilization and herbicides/pesticides.
A meadow condition is preferable, particularly for projects located
upon slopes between 5% to 10%. If areas under the solar PV modules
must be mowed, the vegetative cover should be kept to a minimum of
four inches in height.
(3)
The individual solar PV modules within an "array" shall be arranged
in a fashion that allows the passage of runoff between each solar
PV module. The solar PV modules shall be arranged to allow the growth
of vegetation beneath the solar PV modules and between the rows of
solar PV modules. The use of gravel/stone under solar PV modules is
not considered pervious cover. If the width of the vegetative strip
between rows of solar PV modules is not a minimum of 12 feet wide
(i.e., there is inadequate vegetated spacing between rows of solar
PV modules), then stormwater BMPs such as infiltration trenches (minimum
12 inches wide by 12 inches deep) or infiltration berms shall be installed
down gradient between each solar PV array.
(4)
Ground-mounted solar PV modules shall be supported with structures/foundations
occupying a maximum of 5% of the total project area (not the parcel
area, but that area within the boundary of the setback/buffer surrounding
the solar farm equipment as required by the Brighton Township Zoning
Code[1]). This area shall be delineated and dimensioned on the
SWM site plans, along with a note of the total area and a calculation
of the percent of impervious area occupied by the support structures/foundation.
(5)
Solar PV modules shall be situated upon slopes of 10% or less. If
greater than 10% slopes are proposed, then stormwater BMPs such as
infiltration trenches (minimum 12 inches wide by 12 inches deep) or
infiltration berms shall be installed down gradient between each solar
PV array, in addition to providing the minimum twelve-foot spacing
between the rows of solar PV modules.
(6)
The lowest vertical clearance of the solar PV module shall be at
an elevation of 10 feet or less from the surface of the ground, but
must be of adequate height to promote vegetative growth below the
solar PV module.
(7)
No erosion or transport of sediment shall be allowed. An erosion
and sediment control plan shall be submitted as part of the stormwater
report. Permanent erosion and sediment control BMPs shall be provided
to address the potential for erosion at the drip edge of solar PV
modules.
B.
The developer shall submit documentation in the form of a stormwater
report, which demonstrates that all of the above conditions are satisfied,
to Brighton Township for review and approval. At the time of submission,
the developer shall pay a nonrefundable review fee in accordance with
the established fee schedule. The stormwater report shall be prepared,
signed, and sealed by a professional engineer registered to practice
in the Commonwealth of Pennsylvania. The stormwater report shall be
approved prior to issuance of the building permit. If all of the above
conditions cannot be met, then the project will be treated as impervious
cover and shall fall under the jurisdiction of this chapter and storm
and quantity control shall be provided.
C.
If the earth disturbance associated with construction of solar PV
modules is one acre or more, an NPDES permit is required per 25 Pa.
Code § 102.5(a).
