No activity regulated by this chapter may commence until the
applicant has received written approval of a SWM site plan from the
municipality.
The SWM site plan and SWM site report shall consist of all applicable 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 be rejected. Appropriate sections from Chapter
220, Subdivision and Land Development, and other applicable local ordinances, shall be followed in preparing the SWM Site plan.
A. SWM site plan shall include, but not be limited to:
(1) Plans shall be of one size and in a form that meets the requirements
for recording in the Office of the Recorder of Deeds of Montour County.
(a)
Scale:
[1]
Plans for tracts of less than 20 acres: one inch equals 50 feet
or less;
[2]
Plans for tracts of 20 acres or more: no greater than one inch
equals 100 feet;
(b)
All lettering and details shall be drawn to a size to be legible
if the plans are reduced to half-size.
(2) The name of the development; name and location address of the property
site; name, address, and telephone number of the applicant/owner of
the property; and name, address, telephone number, email address,
and the seal and signature of the qualified professional preparing
the SWM site plan.
(3) The date of submission and dates of all revisions.
(4) A graphical and written scale on all drawings and maps.
(5) A North arrow on all drawings and maps.
(6) A location map at a minimum scale of one inch equals 1,000 feet and
illustrates the project relative to highways, municipalities or other
identifiable landmarks.
(7) Metes and bounds description of the entire tract perimeter.
(8) Existing and final contours at intervals:
(a)
Slopes less than 5%: no greater than one foot;
(b)
Slopes between 5% to 15%: no greater than two feet;
(c)
Steep slopes (greater than 15% or 15%), five-foot contour intervals
may be used.
(9) Perimeters of existing water bodies within the project area including
stream banks, lakes, ponds, springs, field delineated wetlands or
other bodies of water, sinkholes, flood hazard boundaries (FEMA delineated
floodplains and floodways), areas of natural vegetation to be preserved,
the total extent of the upstream area draining through the site, and
overland drainage paths. In addition, any areas necessary to determine
downstream impacts, where required for proposed stormwater management
facilities must be shown.
(10)
The location of all existing and proposed utilities, on-lot
wastewater facilities, water supply wells, sanitary sewers, and water
lines on and within 50 feet of property lines including inlets, manholes,
valves, meters, poles, chambers, junction boxes, and other utility
system components.
(11)
A key map showing all existing man-made features beyond the
property boundary that may be affected by the project.
(12)
Soil names and boundaries with identification of the Hydraulic
Soil Group classification including rock outcroppings.
(13)
Proposed impervious surfaces (structures, roads, paved areas,
and buildings), including plans and profiles of roads and paved areas
and floor elevations of buildings.
(14)
Existing and proposed land use(s).
(15)
Horizontal alignment, vertical profiles, and cross sections
of all open channels, pipes, swales and other BMPs.
(16)
The location and clear identification of the nature of permanent
stormwater BMPs.
(17)
The location of all erosion and sedimentation control facilities,
shown on a separate from the SWM site plan (typically an erosion and
sedimentation plan).
(18)
The location of easements as requested by the municipality or
where required by this chapter. In lieu of providing an easement to
the public right-of-way, a note may be added to the plan granting
the municipality or their designees access to all easements via the
nearest public right-of-way.
(19)
Construction details for all drainage and stormwater BMPs.
(20)
Identification of short-term and long-term ownership, operations,
and maintenance responsibilities.
(21)
Notes and statements:
(a)
A statement, signed by the landowner, acknowledging that the
stormwater BMPs are fixtures that cannot be altered or removed without
prior approval by the municipality.
(b)
A statement referencing the Operation and Maintenance (O&M)
Agreement and stating that the O&M Agreement is part of the SWM
site plan.
(c)
A note indicating that record drawings will be provided for
all stormwater facilities prior to occupancy, or the release of the
surety bond.
(d)
The following signature block for the qualified professional
preparing the stormwater management plan:
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"I, ____________________, hereby certify that the Stormwater
Management Plan meets all design standards and criteria of the Danville
Borough Stormwater Management Ordinance."
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(e)
The following signature block for the Municipal Engineer review
of the stormwater management plan:
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"I, ____________________, have reviewed the Stormwater Management
Plan in accordance with the Design Standards and Criteria of Danville
Borough's Stormwater Management Ordinance."
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B. SWM site report shall include (but not limited to):
(1) General data, including:
(b)
Project location: address of the property site;
(c)
Name, address, and telephone number of the applicant/owner of
the property;
(d)
Name, address, telephone number, email address, and engineering
seal of the individual preparing the SWM site report;
(e)
Date of submission and revisions.
(2) Project description narrative that clearly discusses the project
and provides the following information:
(a)
Narrative.
[1]
Statement of the regulated activity describing what is being
proposed. Overall stormwater management concept with description of
permanent stormwater management techniques, including construction
specifications and materials to be used for stormwater management
facilities.
[2]
Expected project schedule.
[3]
Location map showing the project site and its location relative
to release rate districts.
[4]
Detailed description of the existing site conditions including
a site evaluation completed for projects proposed in areas of carbonate
geology or karst topography, and other environmentally sensitive areas
such as brownfields.
[5]
Total site area, pre and post, which must be equal or have an
explanation as to why it is not.
[6]
Total site impervious area.
[8]
Number and description of stormwater management facilities.
[11] Whether site is a water quality sensitive (WQS)
development.
[12] Whether site is in a defined sensitive area.
[13] Types of water quality and recharge systems used,
if applicable.
[14] Complete hydrologic, hydraulic, and structural
computations for all stormwater management facilities.
[15] A written maintenance plan for all stormwater
features including detention facilities and other stormwater management
elements.
[16] Identification of ownership and maintenance responsibility
for all permanent stormwater management facilities.
[17] Other pertinent information, as required.
(b)
Summary tables.
[1]
Predevelopment hydrologic soil group (HSG) assumptions, curve
numbers (CN), Computation of average slope, hydraulic length, computed
time of concentration.
[2]
Existing conditions runoff volume and peak rate of runoff.
[3]
Postdevelopment runoff volume and peak rate of runoff.
[4]
Undetained areas, areas to ponds.
[5]
Land use for each subarea.
[6]
Hydrologic soil group (HSG) assumptions, curve numbers (CN).
[7]
Time of concentration computed for each subarea.
[8]
Postdevelopment peak rate of runoff routed to ponds and out.
[9]
Pond maximum return period design data including: maximum water
surface elevation, berm elevation, and emergency spillway elevation.
[10] Water quality depth and volume requirements.
(c)
Calculations.
[1]
Complete hydrologic, hydraulic and structural computations,
calculations, assumptions, and criteria for the design of all stormwater
BMPs.
[2]
Details of the berm embankment and outlet structure indicating
the embankment top elevation, embankment side slopes, top width of
embankment, emergency spillway elevation, perforated riser dimensions,
pipe barrel dimensions and dimensions and spacing of antiseep collars.
[3]
Design computations for the control structures (pipe barrel
and riser, etc.).
[4]
A plot or table of the stage-storage (volume vs. elevation)
and all supporting computations.
(d)
Drawings.
[1]
Drainage area maps for all watersheds and inlets depicting the
time of concentration path for both existing conditions and post-developed
condition.
[2]
All stormwater management facilities must be located on a plan
and described in detail including easements and buffers boundaries.
(3) Reports that do not clearly indicate the above information may be
rejected for review by the municipality and will be returned to the
applicant.
(4) Description of, justification, and actual field results for infiltration
testing with respect to the type of test and test location for the
design of infiltration BMPs.
(5) 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 municipal stormwater collection system that may receive
runoff from the project site.
(6) Description of the proposed changes to the land surface and vegetative
cover including the type and amount of impervious area to be added.
(7) Identification of short-term and long-term ownership, operation,
and maintenance responsibilities as well as schedules and costs for
inspection and maintenance activities for each permanent stormwater
or drainage BMP, including provisions for permanent access or maintenance
easements.
C. Supplemental information to be provided prior to recording of the
SWM site plan, as applicable:
(1) Signed and executed Operations and Maintenance Agreement (Appendix
A).
(2) Signed and executed easements, as required for all on-site and off-site
work.
(3) An erosion and sedimentation control plan and approval letter from
the Montour County Conservation District.
(5) Permits from PADEP and ACOE.
(7) Soils investigation report, including boring logs, compaction requirements,
and recommendations for construction of detention basins.
(8) A highway occupancy permit from PENNDOT when utilization of a PENNDOT
storm drainage system is proposed or when proposed facilities would
encroach onto a PENNDOT right-of-way.
A modification to a submitted SWM site plan and report for a
development site that involves a change in stormwater management facilities
or techniques, or that involves the relocation or redesign of stormwater
management facilities, or that is necessary because soil or other
conditions are not as stated on the SWM site plan as determined by
the municipality, shall require a resubmission of the modified SWM
site plan in accordance with this chapter.
A disapproved SWM site plan and report may be resubmitted with
the revisions addressing the municipality's concerns documented in
writing, to the municipality in accordance with this chapter. The
applicable municipal review fee must accompany a resubmission of a
disapproved SWM site plan and report.
The municipality's approval of a SWM site plan and report 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
a SWM site plan. If stormwater management facilities included in the
approved SWM site plan have not been constructed, or if a record drawing
of these facilities has not been approved within this time, then the
municipality may consider the SWM site plan disapproved and may revoke
any and all permits or approvals.