For any of the activities regulated by this chapter, the preliminary
or final approval of subdivision and/or land development plans, the
issuance of any building or occupancy permit, the commencement of
any earth disturbance, or activity may not proceed until the property
owner or applicant or his/her agent has received written approval
of a SWM site plan from the Township and an approval of an adequate
erosion and sediment (E&S) control plan review from the Township
or County Conservation District.
The SWM site plan shall consist of a general description of
the project, including calculations, maps, and plans. All SWM site
plan materials shall be submitted to the municipality in a format
that is clear, concise, legible, neat, and well organized; otherwise,
the SWM site plan shall not be accepted for review and shall be returned
to the applicant. The following items shall be included with the SWM
site plan:
A. General.
(1) General description of the project including plan contents described in §
242-21B. The narrative should include references to all applicable items as noted in the SWM Site Plan Checklist (
Appendix C-2). It is not necessary to submit the checklist if a comprehensive
narrative has been submitted.
(2) The overall stormwater management concept for the project, and a
general description of proposed SWM techniques to be used for SWM
facilities.
(3) Stormwater runoff design computations and documentation as specified in this chapter, or as otherwise necessary to demonstrate that the maximum practicable measures have been taken to meet the requirements of this chapter, including the recommendations and general requirements in §
242-12. All calculations shall be prepared by an engineer licensed to practice in the Commonwealth of Pennsylvania. Computations of the stormwater runoff for all points of runoff concentration before and after development, including all supporting data, including but not limited to:
(a)
Design computations for the sizing of the basin pipe barrel
and outlet structure as well as the perforated riser.
(b)
The stage storage curve for basin(s).
(c)
Basin routing calculations including stage versus storage versus
outflow rating curve.
(d)
A plan depicting the basin(s) berm embankment and outlet structure,
including the top of berm, berm side slopes, emergency spillway elevation,
width, lining material type, size, number and spacing of the anti-seep
collars, and size and location of the basin berm cutoff trench, etc.
(e)
A detailed plan of all proposed off-site improvements (if any).
(4) A general description of proposed nonpoint source pollution controls
and erosion control measures.
(5) A post-construction stormwater management plan to identify the ownership
and maintenance responsibilities for all stormwater management facilities.
At a minimum, the maintenance plan shall include the following:
(a)
Any obligations concerning perpetuation and/or maintenance of
natural drainage or infiltration facilities, and other facilities
identified within the stormwater management plan.
(b)
A description of the facilities and systems on the lot, as called
for above, setting forth in deed restrictions binding on the landowner's
successors in interest.
(c)
Assurances that no action will be taken by any lot owner to
disrupt or in any way impair the effectiveness of any stormwater management
system, setting forth in deed restrictions the ability of the stipulated
permanent stormwater management facilities have been eliminated, altered,
or improperly maintained, including the ability of the Township to
cause the work to be done and lien all costs against the property
should the required corrective measures not be taken by the lot owner
within a period of time set by the Township Engineer.
(6) The SWM site plan application and associated fee for all regulated
activities not already paying fees under the SALDO regulations.
(7) Appropriate sections from the Hatfield Township Subdivision and Land
Development Ordinance, and other applicable local ordinances, shall be followed
in preparing the SWM site plan.
B. Plans. The SWM site plan shall provide the following information:
(1) A determination of natural site conditions and stormwater management
needs. This shall include, but not be limited to:
(a)
Site features:
[1]
The location of the project relative to highways, municipal
boundaries or other identifiable landmarks.
[2]
The locations of all existing and proposed utilities, sanitary
sewers, and waterlines on site and to within 100 feet of property
lines.
[3]
Proposed structures, roads, paved areas, and buildings.
[4]
The total tract boundary and size with distances marked to the
nearest foot and bearings to the nearest degree.
[5]
Plan and profile drawings of all SWM BMPs, including drainage
structures, pipes, open channels, and swales. At a minimum, this should
include pre- and post-drainage area maps, an overall post-construction
stormwater management plan, stormwater detail sheets, and landscape
plans (if proposing bio-retention facilities, low-impact development,
bio-retention, or vegetative basins).
[6]
The locations and minimum setback distances of existing and
proposed on-lot wastewater facilities and water supply wells.
[7]
The location of all erosion and sediment control facilities.
[8]
The location of proposed septic tank infiltration areas and
wells in cases where groundwater recharge measures such as seepage
pits, beds or trenches are proposed.
(b)
Environmentally sensitive areas, including but not limited to: steep slopes, ponds, lakes, streams, wetlands, hydric soils, stream buffers, open channels, existing recharge areas and floodplains. The area of each of these sensitive areas shall be calculated and should be consistent with the runoff volume calculation §
242-14C(1).
(c)
As applicable, a detailed site evaluation for projects proposed
in areas of frequent flooding, karst topography, and other environmentally
sensitive areas, such as brownfields and source water protection areas.
(d)
Existing and proposed contour lines (two feet minimum).
(e)
The total extent of the drainage area upstream from the site
and all down gradient receiving channels, swales and waters to which
stormwater runoff or drainage will be discharged.
(f)
The effect of the project (in terms of runoff volumes, water
quality, and peak flows) on surrounding properties and aquatic features
and on any existing stormwater conveyance system that may be affected
by the project.
(2) The format of the plan shall include the following:
(a)
The expected project time schedule and proposed sequence of
construction.
(b)
The name of the development, the name and address of the owner
of the property, and the name of the individual or firm preparing
the plan.
(d)
A graphic and written scale of one inch equals no more than
50 feet. For tracts of 20 acres or more, the scale can be one inch
equals no more than 100 feet, provided that areas of proposed grading
shall be shown at no less than one inch equals 50 feet.
(f)
An access easement around all stormwater management facilities
is required that will provide ingress to and egress from a public
right-of-way. The size of the easement shall commensurate with the
maintenance and access requirements determined in the design of the
BMP.
(g)
A key map showing all existing man-made features beyond the
property boundary that would be affected by the project.
(h)
A note on the plan indicating the location and responsibility
for maintenance of stormwater management facilities. All facilities
shall meet the performance standards and design criteria specified
in this chapter.
(i)
The following signature block for the Design Engineer: "I, (Design
Engineer), on this date (date of signature), hereby certify that the
SWM Site Plan meets all design standards and criteria of Hatfield
Township."
(j)
A statement, signed by the applicant, acknowledging that any
revision to the approved SWM site plan must be approved by the municipality
and that a revised E&S plan must be submitted to the Conservation
District.
(3) An erosion and sediment control plan, where applicable. The erosion
control plan shall be prepared to ensure that the requirements of
25 Pa. Code 102 have been met.
(4) The plan shall contain the following notes:
(a)
No person shall modify, remove, fill, landscape, or alter any
stormwater management (SWM) best management practices (BMPs), facilities,
areas, or structures unless it is part of an approved maintenance
program and written approval of the Township has been obtained.
(b)
No person shall place any structure, fill, landscaping, or vegetation
into a stormwater facility or BMP or within a drainage easement which
would limit or alter the functioning of the stormwater facility or
BMP without the written approval of the Township.
(c)
All disturbed topsoil on site is to be redistributed on site
in areas not covered by impervious surfaces. No removal of topsoil
from a site is allowed unless approved by Hatfield Township.
(5) When subdivisions or land developments are submitted to the Township
for approval in sections, a complete stormwater management design
for the proposed subdivision and land development shall be submitted.
The proposed design must include the entire tract and not just a portion.
If only a section of a subdivision or land development is contemplated
for construction, the design engineer shall show how he proposes to
handle stormwater from this section in order to prevent damage to
adjacent properties. If temporary construction is required, the design
engineer shall include such structures in the plan(s) submitted.
The municipality requires submission of a complete SWM site
plan, as specified in this chapter. If the project is also being submitted
as a subdivision and land development plan, the required submittal
materials may be combined with the subdivision and land development
application requirements.
A. Proof of application or documentation of required permit(s) or approvals
for the programs listed below shall be part of the plan:
(1) NPDES Permit for Stormwater Discharges from Construction Activities.
(2) Any other permit under applicable state or federal regulations.
B. Six copies of the SWM site plan shall be submitted to the following
agencies:
(1) Two copies to the municipality accompanied by the requisite municipal
review fee, as specified in this chapter.
(2) Two copies to the County Conservation District.
(3) One copy to the Municipal Engineer (where applicable).
(4) One copy to the County Planning Commission/Department if the regulated
activity is also required to submit a subdivision and/or land development
plan to the County Planning Commission in accordance with the Pennsylvania
Municipal Planning Code.
C. Any submissions to the agencies listed above that are found to be
incomplete shall not be accepted for review and shall be returned
to the applicant with a notification in writing of the specific manner
in which the submission is incomplete.
D. Additional copies shall be submitted as requested by the municipality
or PADEP.
The municipality's approval of an SWM site plan authorizes
the regulated activities contained in the SWM site plan for a maximum
term of validity of five years following the date of approval. The
municipality may specify a term of validity shorter than five years
in the approval for any specific SWM site plan. Terms of validity
shall commence on the date the municipality signs the approval for
an SWM site plan. If an approved SWM site plan is not completed according
to this section within the term of validity, the Township may consider
the SWM site plan disapproved and may revoke any and all permits.