A.
For all regulated activities, unless specifically exempted in § 112-14:
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.[1] Various BMPs and their design standards are listed in
the E&S Manual.
[1]
Editor's Note: See 35 P.S. § 691.1 et seq.
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 Storm Water Management Act[2] and any more stringent requirements as determined by the
municipality.
[2]
Editor's Note: See 32 P.S. § 680.1 et seq.
D.
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 surface and ground waters 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 surface waters.
(j)
Disconnect impervious surfaces by directing runoff to pervious
areas, wherever possible and decentralize and manage stormwater at
its source.
(k)
Utilize low impact development and conservation design principles,
as discussed in the BMP Manual as "nonstructural BMPs."
(l)
Provide plantings as an integral part of Best Management Practices
(BMPs) pursuant to the recommendation of the BMP Manual, utilizing
appropriate native plant species at the quantities recommended by
the BMP Manual.
[Added 6-16-2015 by Ord.
No. 2-15]
E.
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.
F.
Stormwater drainage systems shall be provided in order to permit
unimpeded flow along natural watercourses, except as modified by stormwater
management facilities or drainage ways consistent with this chapter.
G.
All regulated activities subject to the requirements of 25 Pa. Code Chapter 105 (regarding dam safety and water management), including but not limited to wetland encroachments, shall be approved by PADEP by issuance of a permit by PADEP. 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.
H.
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). Structural BMPs should be of the distributed, decentralized
BMPs type, rather than management of stormwater at one single large
location. If this is not feasible, then a written statement must be
provided explaining the reasons for providing the single large location.
[Amended 6-16-2015 by Ord. No. 2-15]
I.
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.
J.
Roof drains should not be connected to streets, sanitary or storm
sewers, or roadside ditches.
K.
When stormwater management facilities are proposed within 1,000 feet
of a downstream municipality, the developer shall notify the downstream
municipality and, upon request, provide the SWM site plan and report
to the downstream municipality for review and comment.
L.
Driveways shall be constructed so that runoff does not flow out onto
Township or state road cartways.
M.
No person shall impound water, cause water to be impounded, allow
water to be impounded under conditions or factors within or under
the person's jurisdiction, or otherwise impound water against or within
a Township road right-of-way without the written approval of the Township.
The applicant must meet the requirements of this chapter and must
demonstrate through an engineering study and analysis that the impoundment
will have no adverse effect upon the roadway including the structural
integrity of the roadway and the road surface, and the road drainage.
N.
No person shall fill, alter, change the cross-section or gradient,
or enclose in a culvert a Township roadside drainage ditch, its outlet,
or downstream drainageway without the written approval of the Township.
O.
Applicants for regulated activities within the Zone 1 Wellhead Protection
Area of a public water supply (as defined by 25 Pa. Code Chapter 109),
or that have the potential to endanger a public water supply, must
provide written notice to the owner of the public water supply; shall
prepare and implement a preparedness, prevention, and contingency
plan (PPC plan) per PADEP guidelines; and should consider avoiding
the use of infiltration BMPs.
P.
Applicants for regulated activities that have a high potential to
endanger local groundwater and surface water quality shall prepare
and implement a preparedness, prevention, and contingency plan (PPC
plan) per PADEP guidelines; and must use an acceptable pretreatment
BMP based on filtering or settling prior to volume control and/or
rate control BMPs.
A.
One thousand square feet exemption. Regulated activities that create
new impervious areas smaller than 1,000 square feet are exempt from
the requirement to prepare a stormwater management site plan and report,
and volume control and rate control requirements.
B.
Two thousand five hundred square feet exemption. Regulated activities
that create new impervious areas greater than 1,000 square feet and
smaller than 2,500 square feet, are exempt from the requirement to
prepare a stormwater management site plan and report, and volume control
and rate control requirements if:
C.
Five thousand square feet exemption. Regulated activities that create
new impervious areas greater than 2,500 square feet and smaller than
5,000 square feet, are not exempt from the volume control requirements
of this chapter, but are exempt from the requirement to prepare a
stormwater management site plan and report, and rate control requirements
if:
D.
Single-family home exemption. Regulated activities that are associated
with one single-family home are exempt from the requirement to prepare
a stormwater management site plan and report, and rate control requirements
if:
(1)
The developer demonstrates to the satisfaction of the enforcement
officer that the regulated activities are associated with one single-family
home.
(3)
The volume control requirement is met. The small project stormwater
management application in Appendix C[3] may be used to calculate the volume control requirement.
However, the volume control requirement shall be considered to be
met if:
(a)
The home is set back 75 feet from downstream property lines.
(b)
Runoff from driveways discharge onto a pervious surface with
a gravel strip or other flow spreading device; no more than 1,000
square feet of paved driveway surface may discharge to any one point;
and the length of discharge flow across the pervious surface must
exceed the length of flow across the driveway.
[3]
Editor's Note: Appendix C is on file in the Township offices.
F.
All exempt regulated activities shall, to the maximum extent practicable:
(1)
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.
G.
No exempt regulated activity shall cause a substantial adverse impact
on the following:
H.
Impervious areas. For purposes of application of these exemptions,
a calculation of new impervious areas shall include all areas of a
parcel on which impervious areas have been created by regulated activities
since the effective date of this chapter. For subdivisions and phased
developments, the impervious area calculation shall include all impervious
areas constructed after the effective date of this chapter. Any graveled
surfaces created after the effective date of this chapter shall be
considered impervious. Any impervious area replacing an existing graveled
surface shall be considered as having replaced a pervious surface.
I.
Agricultural activity is exempt from the rate control and SWM site
plan and report preparation requirements of this chapter provided
the activities are performed according to the requirements of 25 Pa.
Code Chapter 102.
J.
Forest management and timber operations are exempt from the rate
control and volume control requirement and SWM site plan and report
preparation requirement of this chapter, provided that the activities
are performed according to the requirements of 25 Pa. Code Chapter
102. It should be noted that temporary roadways are not exempt.
K.
Regulated activities may be exempted from the rate control and volume
control requirements of this chapter if documentation can be provided
that an existing downstream BMP has been designed or modified to provide
for rate control and volume control for the regulated activities.
A.
Waivers. Waivers from the strict requirements of this chapter may
be granted by Washington Township Council under the standards set
forth in this section.
B.
Grounds for waiver. If an applicant demonstrates to the satisfaction
of Washington Township Council that a requirement of this chapter
causes undue hardship as it applies to the applicant's project, and
that an alternate design produces equal or better results in meeting
the purpose and requirements of this chapter, Washington Township
Council, after completing a thorough technical review of the waiver
request, and in consultation with the Municipal Engineer and Municipal
Solicitor, may grant a waiver request.
C.
Application for waiver. Applicants shall submit requests for waivers
in writing. In the request for waiver, the applicant shall state in
full the facts of undue hardship on which the request is based, identify
the provision or provisions of the ordinance that are causing such
undue hardship, and state the minimum waiver or relief that is necessary.
The applicant shall state how the proposal in the applicant's waiver
request provides equal or better results in meeting the purpose and
requirements of this chapter.
D.
Fees. The municipality 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 the
municipality for reasonable and necessary fees that may be incurred
by the Municipal Engineer and Solicitor in any review of a waiver
request.
E.
Standards for waivers. The municipality may grant requests for waivers
when the following findings are made by the municipality, when each
is determined by the municipality to be applicable and relevant:
(1)
That the waiver shall result in an equal or better means of complying
with the purpose and requirements of this chapter.
(2)
That the waiver is the minimum necessary to provide relief from undue
hardship.
(3)
That the applicant is not requesting a waiver based solely on cost
considerations.
(4)
That existing downgradient stormwater problems will not be exacerbated.
(5)
That runoff is not being diverted to a different drainage area in
a manner that may cause hardship to others.
(6)
That increased flooding or ponding on off-site properties or roadways
will not be caused by the waiver request.
(7)
That potential hazardous Icing conditions will not result.
(8)
That increased or unusual municipal maintenance expenses will not
result from the waiver request.
(9)
That operation and maintenance requirements are not reduced by the
waiver request.
(10)
That state water quality standards and requirements will be
met.
(11)
That the waiver will not have adverse impact on health, safety
and property.
F.
Record. The municipality shall keep a written record of all actions
on waiver requests.
G.
Conditions. In granting waivers, the municipality may impose reasonable
conditions that will, in its sole judgment, resolve the undue hardship
while meeting the purpose and requirements of this chapter.
A.
The use of nonstructural BMPs as described in the BMP Manual shall
be utilized for all regulated activities to the maximum extent practicable.
B.
Stormwater runoff volume controls shall be implemented using the
Design Storm Method or, if applicable, the Simplified Method.
(1)
The Design Storm Method (CG-1 in the BMP Manual) is applicable to
any sized regulated activity. This method requires detailed calculations
based on site conditions.
(a)
The post-development total runoff volume shall not exceed the
predevelopment total runoff volume for the two-year, twenty-four-hour
storm event.
(b)
For the purposes of predevelopment runoff volume determination,
existing nonforested pervious areas conditions shall be considered
as meadow (good condition).
(c)
For the purposes of predevelopment runoff volume determination,
20% of existing impervious area, when present, shall be considered
meadow (good condition).
(2)
The Simplified Method (CG-2 in the 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 discharged into drainageways. 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 of the proposed
elevation of the stormwater BMPs are required. Infiltration tests
shall be conducted in accordance with the BMP Manual. Notification
of the municipality shall be provided to allow witnessing of the testing.
(e)
Proposed graveled areas shall be considered impervious.
(3)
In cases where it is not possible or desirable to use infiltration-based best management practices to partially fulfill the requirements in either Subsection B(1) or (2) above, 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 BMP Manual.
A.
The peak post-development flow rates shall not exceed the peak predevelopment
flow rates for the one-year, two-year, ten-year, twenty-five-year,
fifty-year and one-hundred-year, twenty-four-hour storm events.
B.
For the purposes of predevelopment flow rate determination, existing
nonforested pervious areas conditions shall be considered as meadow
(good condition).
C.
For the purposes of predevelopment peak flow rate determination,
20% of existing impervious area, when present, shall be considered
meadow (good condition).
D.
For comparison of peak flow rates, flows shall be rounded to the
nearest tenth of a cubic foot per second.
