A.
For all regulated activities, unless specifically exempted in § 371-13:
(1)
Preparation and implementation of an approved SWM site plan is required.
(2)
No regulated activities shall commence until Peters Township issues
written approval of a SWM site plan, which demonstrates compliance
with the requirements of this chapter.
(4)
The SWM site plan approved by Peters Township shall be on site throughout
the duration of the regulated activities.
B.
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 (including,
but not limited to Chapter 102, Erosion and Sediment Control) 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.
C.
For all regulated activities, stormwater BMPs shall be designed,
installed, implemented, operated, and maintained 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, conform
to the state water quality requirements, meet all requirements under
the Stormwater Management Act and any more stringent requirements
as determined by Peters Township.
D.
Peters Township may, after consultation with the Pennsylvania Department
of Environmental Protection (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.
E.
All regulated activities shall include, to the maximum extent practicable,
measures 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, natural slopes,
existing native vegetation and woodlands.
(b)
Create, maintain, or extend riparian buffers and protect existing
forested buffers.
(c)
Provide trees and woodlands adjacent to impervious areas whenever
feasible.
(d)
Minimize the creation of impervious surfaces and the degradation
of waters of the commonwealth and promote groundwater recharge.
(e)
Protect natural systems and processes (drainageways, vegetation,
soils, and sensitive areas) and maintain, as much as possible, the
natural hydrologic regime.
(f)
Incorporate natural site elements (wetlands, stream corridors,
mature forests) as design elements.
(g)
Avoid erosive flow conditions in natural flow pathways.
(h)
Minimize soil disturbance and soil compaction.
(i)
Minimize thermal impacts to waters of the commonwealth.
(j)
Disconnect impervious surfaces by directing runoff to pervious
areas, wherever possible and decentralize and manage stormwater at
its source.
F.
Impervious areas.
G.
If diffused flow is proposed to be concentrated and discharged onto
adjacent property, the applicant must document that adequate downstream
conveyance facilities exist to safely transport the concentrated discharge,
or otherwise prove that no erosion, sedimentation, flooding, or other
harm will result from the concentrated discharge.
H.
Except when a permit from the PADEP is acquired, where natural watercourses
traverse a development site, drainage easements (encompassing the
one-hundred-year elevation with a minimum width of 20 feet) shall
be provided conforming to the line of such watercourses. The terms
of the easement shall prohibit excavation, the placing of fill or
structures, and any alterations that may adversely affect the flow
of stormwater within any portion of the easement. Also, maintenance,
including mowing of vegetation within the easement, may be required,
except as approved by the appropriate governing authority.
I.
When it can be shown that, due to topographic conditions, natural drainageways on the site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such natural drainageways. Work within natural drainageways shall be subject to approval by PADEP under regulations at 25 Pa. Code Chapter 105 through the joint permit application process, or, where deemed appropriate by PADEP, through the general permit process.
J.
Any stormwater management facilities or any facilities that constitute water obstructions (e.g., culverts, bridges, outfalls, or stream enclosures, etc.) that are regulated by this chapter, that will be located in or adjacent to waters of the commonwealth (including wetlands), shall be subject to approval by PADEP under regulations at 25 Pa. Code Chapter 105 through the joint permit application process, or, where deemed appropriate by PADEP, the general permit process. When there is a question whether wetlands may be involved, it is the responsibility of the applicant or his agent to show that the land in question cannot be classified as wetlands; otherwise, approval to work in the area must be obtained from PADEP.
L.
Any stormwater management facilities regulated by this chapter that
will be located on, or discharged onto state highway rights-of-way
shall be subject to approval by the Pennsylvania Department of Transportation
(PennDOT). These facilities may be required by PennDOT to be owned
and maintained by Peters Township. In such case, PennDOT and Peters
Township may require a written agreement between the Township and
the developer in a form acceptable to PennDOT in accordance with their
latest policies.
M.
Minimization of impervious surfaces and infiltration of runoff through
seepage beds, infiltration trenches, etc., are encouraged, where soil
conditions and geology permit, to reduce the size or eliminate the
need for detention facilities.
N.
Infiltration BMPs should be dispersed throughout the site, 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.
O.
Roof drain discharges shall be designed to promote overland flow
and infiltration/percolation of stormwater where it is advantageous
to do so and will not create a drainage problem on adjacent property.
When it is more advantageous to connect directly to streets or storm
sewers, then Peters Township shall permit it on a case-by-case basis.
P.
When appropriate and allowed by other portions of the Township Code,
applicants are encouraged to use low-impact development practices
to comply with the requirements of this chapter and the state water
quality requirements.
Q.
When stormwater management facilities are proposed within 1,000 feet
of a downstream Township, the developer shall notify the downstream
Township and supply a copy of the SWM plan, if requested, for review
and comment.
A.
Under no circumstance shall the applicant be exempt from implementing
such measures as necessary to:
B.
The applicant must utilize the following BMPs to the maximum extent
practicable to receive consideration for the exemptions:
(1)
Design around and limit disturbance of floodplains, wetlands, natural
slopes over 15%, existing native vegetation, and other sensitive and
special value features.
(2)
Maintain riparian and forested buffers.
(3)
Limit grading and maintain nonerosive flow conditions in natural
flow paths.
(4)
Maintain existing tree canopies near impervious areas.
(5)
Minimize soil disturbance and reclaim disturbed areas with topsoil
and vegetation.
(6)
Direct runoff to pervious areas.
C.
The applicant's proposed development/additional impervious area
may not adversely impact the following:
D.
Single-family residential activities are exempt from these requirements,
provided the constructions:
E.
An applicant proposing regulated activities, after demonstrating compliance with § 371-13A, B and C, may be exempted from various requirements of this chapter according to the following table:
|
New Impervious Area1, 2
(square footage)
|
Applicant Must Provide
| |
|---|---|---|
|
0 to 2,500
|
No submission
| |
|
2,500 to 5,000
|
Documentation of impervious surfaces
(Small Project SWM Application)3
| |
|
> 5,000
|
Rate controls, volume controls and SWM site plan
|
|
NOTES:
| ||
|---|---|---|
|
1
|
New impervious area since the date of adoption of this chapter.
| |
|
2
|
Gravel in existing condition shall be considered pervious, and
gravel in proposed condition shall be considered impervious.
| |
|
3
|
The first page of the Small Project Stormwater Management Application
included in Appendix D[1] may be used to document new impervious surfaces.
| |
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
F.
An applicant proposing regulated activities, after demonstrating compliance with § 371-13A, B and C, may be exempted from various requirements of this chapter if documentation can be provided that a downstream man-made water body (i.e., reservoir, lake, or man-made wetlands) has been designed or modified to address the potential stormwater flooding impacts of the proposed development.
G.
The purpose of this section is to ensure consistency of stormwater
management planning between local ordinances and NPDES permitting
(when required) and to ensure that the applicant has a single and
clear set of stormwater management standards to which the applicant
is subject. Peters Township may accept alternative stormwater management
controls under this section provided that:
(1)
Peters Township, in consultation with the PADEP, determines that meeting the volume control requirements (See § 371-15.) is not possible or places an undue hardship on the applicant.
(2)
The alternative controls are documented to be acceptable to PADEP,
for NPDES requirements pertaining to post-construction stormwater
management requirements.
H.
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.
I.
Forest management and timber operations are exempt from the rate
and volume control requirement and SWM site plan preparation requirement
of this chapter, provided the activities are performed according to
the requirements of 25 Pa. Code Chapter 102. It should be noted that
temporary roadways are not exempt.
(1)
All temporary and permanent haul roads that are not to receive an
asphalt wearing course shall be designed and constructed consistent
with recommendations of the Center for Dirt and Gravel Road Studies
and the Pennsylvania State Conservation Commission's Dirt and
Gravel Road Maintenance Program.
A.
The provisions of this chapter are the minimum standards for the
protection of the public welfare.
B.
Waiver requests.
(1)
(2)
Municipalities will then consider waivers in accordance with § 371-12D, which states that Peters 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.
C.
If an applicant demonstrates to the satisfaction of the governing body of Peters Township that any mandatory provision of this chapter is unreasonable or causes unique or undue unreasonableness or hardship as it applies to the proposed project, or that an alternate design may result in a superior result within the context of §§ 371-2 and 371-3 of this chapter, the governing body of Peters Township upon obtaining the comments and recommendations of the Municipal Engineer may grant a waiver or relief so that substantial justice may be done and the public interest is secured; provided that such waiver will not have the effect of nullifying the intent and purpose of this chapter.
D.
The applicant shall submit all requests for waivers in writing and
shall include such requests as a part of the plan review and approval
process. The applicant shall state in full the facts of unreasonableness
or hardship on which the request is based, the provision or provisions
of the chapter that are involved, and the minimum waiver or relief
that is necessary. The applicant shall state how the requested waiver
and how the applicant's proposal shall result in an equal or
better means of complying with the intent or purpose and general principles
of this chapter.
E.
Peters Township shall keep a written record of all actions on waiver
requests.
F.
Peters Township may charge a fee for each waiver request, which shall
be used to offset the administrative costs of reviewing the waiver
request. The applicant shall also agree to reimburse Peters Township
for reasonable and necessary fees that may be incurred by the Municipal
Engineer in any review of a waiver request.[1]
G.
In granting waivers, Peters Township may impose reasonable conditions
that will, in its judgment, secure substantially the objectives of
the standards or requirements that are to be modified.
H.
Peters Township may grant applications for waivers when the following
findings are made, as relevant:
(1)
That the waiver shall result in an equal or better means of complying
with the intent of this chapter.
(a)
The waiver is the minimum necessary to provide relief.
(b)
The applicant is not requesting a waiver based on cost considerations.
(c)
Existing down-gradient stormwater problems will not be exacerbated.
(d)
Runoff is not being diverted to a different drainage area.
(e)
Increased flooding or ponding on off-site properties or roadways
will not occur.
(f)
Potential icing conditions will not occur.
(g)
Increase of peak flow or volume from the site will not occur.
(h)
Erosive conditions due to increased peak flows or volume will
not occur.
(i)
Adverse impact to water quality will not result.
(j)
Increased one-hundred-year floodplain levels will not result.
(k)
Infiltration of runoff throughout the proposed site has been
provided where practicable and predevelopment groundwater recharge
protected.
(l)
Peak flow attenuation of runoff has been provided.
(m)
Long-term operation and maintenance activities are established.
(n)
The receiving streams and/or water bodies will not be adversely
impacted in flood-carrying capacity, aquatic habitat, channel stability
and erosion and sedimentation.
A.
The low-impact development practices provided in the BMP Manual and
in Appendix B[1] of this chapter shall be utilized for all regulated activities
to the maximum extent practicable when appropriate and allowed by
other portions of the Township Code.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
B.
The Small Project Stormwater Management Application included in Appendix
D[2] may be used for
projects under 5,000 square feet of new impervious surface and single-family
home construction. The Small Project SWM Application allows documentation
of new impervious surface, credits through disconnection of impervious
surfaces and tree planting, and sizing of volume control BMPs that
may be required.
[2]
Editor's Note: Said appendix is included as an attachment to this chapter.
C.
Stormwater runoff volume controls shall be implemented using the
Design Storm Method or the Simplified Method as defined below. For
regulated activity, areas equal to or less than one acre that do not
require hydrologic routing to design the stormwater facilities, this
chapter establishes no preference for either method; therefore, the
applicant may select either method on the basis of economic considerations,
the intrinsic limitations on applicability of the analytical procedures
associated with each methodology, and other factors.
(1)
The Design Storm Method (CG-1 in the Pennsylvania BMP Manual) is
applicable to any sized regulated activity. This method requires detailed
modeling based on site conditions.
(a)
Do not increase the post-development total runoff volume when
compared to the predevelopment total runoff volume for the two-year/twenty-four-hour
storm event.
(b)
For hydrologic modeling purposes:
[1]
Existing nonforested pervious areas must be considered meadow
(good condition) for predevelopment hydrologic calculations.
[2]
Twenty percent of existing impervious area, when present within
the proposed project site, shall be considered meadow (good condition)
for predevelopment hydrologic calculations for redevelopment.
(2)
The Simplified Method (CG-2 in the Pennsylvania BMP Manual) 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 detailed design
of stormwater storage facilities. 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 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 should be infiltrated.
(d)
Actual field infiltration tests at the location and proposed
elevation of the stormwater BMPs are required. Infiltration tests
shall be conducted in accordance with the BMP Manual.
(3)
In cases where it is not possible or desirable to use infiltration-based best management practices to partially fulfill the requirements in either § 371-15C(1) or (2), the following procedure shall be used:
(a)
At a minimum, the following documentation shall be provided
to justify the decision to not use infiltration BMPs:
[1]
Description of and justification for field infiltration/permeability
testing with respect to the type of test and test locations.
[2]
An interpretive narrative describing existing site soils and
their structure as these relate to the interaction between soils and
water occurring on the site. In addition to providing soil and soil
profile descriptions, this narrative shall identify depth to seasonal
high-water tables and depth to bedrock, and provide a description
of all subsurface elements (fragipans and other restrictive layers,
geology, etc.) that influence the direction and rate of subsurface
water movement.
[3]
A qualitative assessment of the site's contribution to
annual aquifer recharge shall be made, along with identification of
any restrictions or limitations associated with the use of engineered
infiltration facilities.
[4]
The provided documentation must be signed and sealed by a professional
engineer or geologist.
(b)
The following water quality pollutant load reductions will be
required for all disturbed areas within the proposed development:
|
Pollutant Load
|
Units
|
Required Reduction
(%)
| |
|---|---|---|---|
|
Total suspended solids (TSS)
|
Pounds
|
85
| |
|
Total phosphorous (TP)
|
Pounds
|
85
| |
|
Total nitrate (NO3)
|
Pounds
|
50
|
(c)
The performance criteria for water quality best management practices
shall be determined from the Pennsylvania Stormwater Best Management
Practices Manual, most current version.
D.
The applicable worksheets from the Pennsylvania BMP Manual must be
used in calculations to establish volume control.
A.
Lands contained within Washington County that have not had release
rates established under an approved Act 167 Stormwater Management
Plan:
(1)
Post-development discharge rates shall not exceed the predevelopment
discharge rates for the one-, two-, ten-, twenty-five-, fifty-, and
one-hundred-year storms.
B.
Lands contained within Washington County that have had release rates
established under an approved Act 167 Stormwater Management Plan:
(1)
Chartiers Creek Watershed. The post-development peak discharge rates
shall be in accordance with the approved release rate map for the
individual watershed. Release rates within the Chartiers Creek Watershed
include 50%, 70% and 100% for the ten-, twenty-five-, fifty- and one-hundred-year
storms. However, within the portion of the watershed contained in
Peters Township, the release rate is 100%.
