In the case where lots created within a subdivision are large
enough to accommodate either further subdivision or a higher intensity
of development and thus may result in higher traffic levels, the Township
may require that additional rights-of-way be provided to permit the
future development of a higher-order street.
All materials entering into the construction of streets and
the methods of construction and drainage shall be in accordance with
the applicable requirements of the Pennsylvania Department of Transportation
Specifications, Form 408, or the latest revision thereof.
A. Subgrade.
(1) The area within the limits of the proposed road surface shall be
shaped to conform to the line, grade and cross section of the proposed
road.
(2) All unsuitable subgrade materials shall be removed or stabilized.
(3) Wet or swampy areas shall be permanently drained and stabilized.
Details to be furnished on the method of drainage and stabilization
shall be approved by the Township Engineer.
(4) Fills shall be made with suitable materials and thoroughly compacted
for full width in uniform layers of not more than eight inches thick.
(5) The subgrade shall be thoroughly compacted by rolling with a minimum
ten-ton roller and/or a sheep's-foot roller in layers not over six
inches.
(6) Backfill or trenches within the cartway and curb area shall be thoroughly
compacted prior to application of the base course.
(7) All stone used to replace unsuitable subgrade materials shall be
approved by the Township Engineer.
B. Base course.
(1) The base course shall consist of eight inches of AASHTO No. 1 crushed
stone placed on a two-inch initial layer of screenings and rolled
uniformly and thoroughly with a ten-ton roller. Rolling shall continue
until the material does not creep or wave ahead of the roller wheels.
[Amended 10-10-1995 by Ord. No. 1-1995]
(2) After compaction of the base stone, dry screenings shall be applied
in sufficient quantity to fill all of the voids in the rolled stone
base. A vibratory roller of PennDOT-approved design must be used in
this step of construction, and rolling shall continue until all voids
are filled. Small areas around inlets and manholes that cannot be
reached by the vibratory roller shall be compacted with a mechanical
tamper or whacker.
(3) When the stone surface is tight and will accept no more screenings,
all loose screenings shall be broomed from the surface to expose the
top of 1/2 inch of the aggregate over at least 75% of the road.
(4) No base materials shall be placed on a wet or frozen subgrade.
(5) As an alternate, an aggregate-lime-pozzolan base course may be used
when approved by the Township. This possopac base course must be applied
with an approved paver to a thickness to be determined by the Township
Engineer.
(6) Application of a possopac base course shall be followed immediately
by application of the binder course.
C. Bituminous surface.
(1) Bituminous material shall be ID-2 or FB-1 hot mix with four inches
of binder course and 1 1/2 inches of surface course after compaction.
[Amended 10-10-1995 by Ord. No. 1-1995]
(2) The completed road surface shall have a uniform slope of 1/4 inch
per foot from edge to center line, except that, on super-elevated
curves, this slope shall not be less than 1/4 inch per foot and shall
extend from the inside edge to the outside edge of the paving.
D. Grading and shoulders.
(1) Roadways shall be graded for not less than 10 feet beyond the edge
of the proposed paving on each side. This grading width shall be increased
as necessary where sidewalks and/or planting strips are to be provided.
Shoulders shall be graded with a slope of one inch per foot. Beyond
the limits of this grading, banks shall be sloped to prevent erosion,
but this slope shall not exceed three horizontal to one vertical with
the top of the slope in cuts rounded. (See typical cross section Appendix
E.)
[Amended 10-10-1995 by Ord. No. 1-1995]
(2) The Board of Supervisors may modify the two-to-one ratio relative
to site conditions where a cut to attain the maximum grade for a road
exceeds eight feet.
(3) Shoulders shall be constructed in accordance with the design standards for streets as contained in §
123-26 of Article
V.
[Amended 10-10-1995 by Ord. No. 1-1995]
The management of stormwater on the site, both during and upon
completion of the disturbances associated with the proposed subdivision
or land development, shall be accomplished in accordance with the
standards and criteria of this section. The design of any temporary
or permanent facilities and structures and the utilization of any
natural drainage systems shall be in full compliance with this chapter
and the interpretations of the Township Engineer. At the time of application
for a building permit for any approved lot created by a subdivision
and/or improved as a land development under the terms of this chapter,
issuance of the permit shall be conditioned upon adherence to the
terms of this section.
A. Erosion and sedimentation. All activities involving land disturbance,
whether or not a plan is prepared in accordance with this chapter,
shall be consistent with the following performance standards.
(1) All land-disturbance activities shall be conducted in such a way
as to prevent accelerated erosion and resulting sedimentation. To
accomplish this, all persons engaged in land-disturbance activities
shall design, implement and maintain erosion and sedimentation control
measures which effectively prevent accelerated erosion and sedimentation.
(2) In order to prevent accelerated erosion and resulting sedimentation,
land-disturbance activities related to earthmoving operations, to
construction (including but not limited to construction of buildings
and other structures) and to paving activities shall be conducted
only in conformance with the following principles:
(a)
During the period of earthmoving and, in the case of subdivisions
or land developments, prior to the completion of roads, parking areas,
buildings and other improvements and the establishment of vegetation
or soil stabilization measures, facilities shall be installed to ensure
the following:
[1]
There shall be no discharge of sediment or other solid materials
from the site as a result of stormwater runoff.
[2]
During the period of earthmoving, peak discharges and discharge volumes from the site shall comply with Subsection
B(1) through
(3) and, where applicable, Subsection
B(4), with the following exceptions and additions:
[a] Any person conducting a business or personal venture
involving periodic or regular earthmoving (quarrying, topsoil removal,
etc.) shall calculate runoff for the facility design based upon runoff
before earthmoving and runoff during the maximum period of exposure.
[b] Wherever soils, topography or other conditions
suggest substantial erosion potential during subdivision and land
development or earthmoving, the Township as recommended by the Township
Engineer may require that the entire volume of a two-year storm be
retained on site or that special sediment-trapping facilities be installed.
(b)
No earthmoving or stripping of vegetation shall be conducted
in areas of greater than twenty-five-percent slope unless specific
approval is obtained from the Board of Supervisors with recommendations
from the Township Engineer.
(c)
Earthmoving and the addition of fill will be minimized to preserve
the natural features and topography.
(d)
Stripping of vegetation, regrading or other development shall
be done in such a way that will minimize erosion.
(e)
To the maximum extent practical, natural vegetation shall not
be removed, except as provided in the approved final subdivision or
land development plan or the zoning permit. The stockpiling of soil
over the roots of trees to be preserved is prohibited within the dripline
of the tree.
(f)
The amount of disturbed area and the duration or exposure shall
be kept to a practical minimum.
(g)
The permanent (final) vegetative and structural erosion control
and drainage measures shall be installed as soon as practical.
(h)
Sediment in runoff water shall be trapped and removed through
means approved by the Township Engineer to assure adequate capacity
in basins or traps.
(i)
Procedures for protecting soils or geologic formations with
water supply potential from contamination by surface water or other
disruption by construction activity shall be established.
(j)
Such other requirements or exceptions as are consistent with
these terms in the foregoing principles may be imposed or allowed
by the Township Engineer.
(3) To prevent accelerated erosion and resulting sedimentation, land-disturbance
activities relating to agricultural and/or logging and woodcutting
operations shall be conducted only in conformance with the following
principles.
(a)
Agricultural operations. All agricultural operations shall conform
to the following principles:
[1]
Unless clearly impractical or unwarranted, plowing will generally
conform to the contours of the property.
[2]
Drainage swales will be maintained with permanent cover of grasses,
plants or trees.
[3]
Permanent cover will be maintained within a minimum of 20 feet
of a stream and will be maintained 10 feet up slope from property
lines, unless a written waiver is received from the abutting landowner.
[4]
Runoff from buildings and other impervious surfaces shall be
directed around areas where spent mushroom compost is stored, where
sod or plants are regularly removed, where livestock are confined
or where tillage crops are planted or shall be otherwise controlled
to prevent direct transport of pollutants (including sediments) to
streams.
[5]
Tillage and nursery operations shall not be conducted on slopes
exceeding 15%, and sod operations shall not be conducted on slopes
exceeding 8%, except where minimum tillage methods approved by the
Natural Resources Conservation Service or Columbia County Conservation
District are followed.
[6]
Diversion terraces or cover crops no less than 10 feet in width
shall be provided at a minimum of two-hundred-foot intervals on slopes
of 8% to 15% where tillage or sod crops are planted.
[7]
Any earthmoving other than tillage operations shall conform
to all earthmoving standards of this section.
[8]
A vegetative cover strip extending 10 feet from the edge of
the cartway of any road shall be permanently maintained.
[9]
All culverts and inlets to pipes and open pipes for surface
drainage shall be protected by a grate.
(b)
Logging or woodcutting operations. All logging or woodcutting
operations conducted with or prior to a land development shall be
conducted only in conformance with the following principles and standards:
[1]
Stumps, ground cover and root mat must be left intact until
land development plans are approved and erosion and sedimentation
control facilities are installed.
[2]
Methods for removal of logs and the removal routes shall be
specified in a plan approved by the Township Engineer and shall not
include traversing slopes of 15% to 25% at more than the minimum gradient
possible.
[3]
On slopes of 10% to 25%, logging will be limited to the cutting
or removal of less than 1/3 of even-aged and noncontiguous trees.
[4]
On slopes exceeding 25%, logging and woodcutting shall be by
specific approval of the Board of Supervisors and shall be limited
to highly selected removal of trees. Maximum precautions shall be
taken to avoid destruction or injury of understory brush and trees.
(4) Protection of adjacent property.
(a)
No person shall engage in earthmoving sufficiently close to
a property line to endanger any adjoining public street, sidewalk,
alley or other public property from settling, cracking or other damage
which might result from such earthmoving. If in the opinion of the
Township Engineer the nature of the earthmoving is such as to create
a hazard to life or property unless adequately safeguarded, the applicant
shall construct walls, fences, guard rails or other structures to
safeguard the public street, sidewalks, alley or other public property
and persons.
(b)
No person shall dump, move or place any soil or bedrock or increase
the flow of water so as to cause the same to be deposited upon or
roll, flow or wash upon or over the premises of another without the
express consent of the owner of such premises so affected or upon
or over any public street, street improvement, road, storm sewer drain,
watercourse or right-of-way or any public property.
(c)
No persons shall, when hauling soil, bedrock or other material
over any public street, road, alley or public property, allow such
material to blow or spill over and upon such street, road, alley or
public property or adjacent private property.
(d)
If any soil, bedrock or other material or water or liquid is
caused to be deposited upon or to roll, flow or wash upon any public
property or right-of-way in violation of this subsection, the Township
shall cause such removal, and the cost of such removal shall be paid
to Scott Township by the person who failed to so remove the material
and shall be a debt due the Township. The cost of such removal shall
be a lien against all property and all rights to property, real or
personal, of any person liable to pay the same from and after the
time said cost is due and payable. The cost of such removal shall
be collected in the manner of said taxes or from escrow funds established
for the land development activity.
B. Permanent stormwater management. All subdivision and land development
activities involving an increase in impervious cover shall be conducted
in conformance with the following performance standards:
(1) After installation of impervious cover, peak discharge from the site
shall not exceed the before-construction peak discharge rate from
a two-year, twenty-four-hour storm of 3.2 inches of rainfall for all
storms up to a ten-year, twenty-four-hour storm of 5.0 inches of rainfall.
Peak discharges for any storms of greater than ten-year frequency
up to and including a one-hundred-year storm shall not exceed the
peak discharges from the site before development of such storms, including:
(a)
A twenty-five-year, twenty-four-hour storm of 5.7 inches of
rainfall.
(b)
A fifty-year, twenty-four-hour storm of 6.4 inches of rainfall.
(c)
A one-hundred-year, twenty-four-hour storm of 7.2 inches of
rainfall.
(2) After installation of impervious cover or during land disturbance activities under Subsection
A(2) and where the Township has not required that the entire volume of a two-year storm be retained on site, there shall be no increase in the total volume of stormwater runoff over that which was discharged prior to development as a result of a two-year, twenty-four-hour storm.
(3) In calculating runoff prior to development or change in use, the
following assumptions shall apply:
(a)
Woodland shall be used as the prior condition for those portions
of the site having trees of greater than six inches' caliper diameter
at breast height or where such trees existed within 18 months of application.
(b)
Meadow shall be used for all other areas, including areas which
are presently covered by impervious surfaces.
(c)
Average antecedent moisture conditions shall be used.
(d)
A Type II distribution storm shall be assumed.
(4) Under certain conditions, the Township, upon recommendation by the
Township Engineer, may impose the following additional restrictions
on stormwater discharges:
(a)
Peak discharge rates on storm in excess of the ten-year storm
may be further restricted when it can be shown that a probable risk
to downstream structures or unique natural areas exists or that an
existing flooding problem would be further aggravated.
(b)
Measures may be imposed to protect against groundwater or surface
water pollution where the type of business or the nature of the soils
underlying a runoff structure would constitute a substantial risk
of contamination.
(5) All plans and designs for stormwater management facilities submitted
to the Township Engineer for approval shall determine stormwater peak
discharge and runoff by use of the Soil-Cover-Complex Method as set
forth in Urban Hydrology for Small Watersheds, Technical Release No.
55, with specific attention given to antecedent moisture conditions,
flood routing and peak discharge specifications included therein,
and in Hydrology National Engineering Handbook, Section 4, both by
the United States Department of Agriculture. The Township Engineer,
however, may permit the use of the Rational Method for calculation
of runoff on land developments of 10 acres or less and for the design
of storm sewers.
(6) Storm sewer and drainage swale design shall be approved by the Township
Engineer.
(7) In calculating runoff after development, those areas covered by concrete
lattice blocks on an appropriate base, porous pavement areas on an
appropriate base, and roof areas which drain to properly designed
and installed seepage beds shall not be considered to result in increased
runoff from a two-year storm. Concrete lattice blocks or porous paving
and seepage roof drainage shall be required under the following conditions:
(a)
Cisterns and/or infiltration structures of appropriate design
and size shall be provided to hold and/or infiltrate roof drainage
whenever total impervious surfaces (streets, buildings, parking areas,
driveways, etc.) will exceed 10% of a residential tract or lot or
30% of a nonresidential tract or lot and the subject tract or lot
or a contiguous property(ies) is dependent on well water supplies
on its own site.
(b)
Total impervious coverage shall be restricted to the amounts
noted below by substituting concrete lattice blocks and/or porous
paving for the amount of conventional paving materials which would
exceed the total impervious coverage limits; provided, however, that
buildings or other impervious surfaces shall not exceed the maximum
limits noted:
[1]
Whenever the tract or lot or a contiguous property is dependent
on well water supplies on site, total impervious coverage shall not
exceed 25% of a residential tract or lot or 60% of a nonresidential
tract or lot.
[2]
Whenever the tract or lot or a contiguous property does not
depend on well water supplies on site, total impervious coverage shall
not exceed the maximum required by the base zoning district of the
tract or lot.
(8) In order to improve the quality and general utility of stormwater
management plans, subdivision and land development and building construction
shall be planned, designed and constructed only in conformance with
the following principles:
(a)
Erosion and sediment control and stormwater management control
facilities shall be incorporated into all building site designs and
the overall design of any subdivision or land development or improvement
in such ways that they may serve multiple purposes such as wildlife
areas, recreational areas, fire prevention ponds, etc.
(b)
The natural infiltration and water resource potential shall
guide design, construction and vegetation decisions. Runoff in excess
of natural conditions from roofs and other surfaces which are unlikely
to contain pollutants shall be recharged to the groundwater table
or stored for nonpotable water uses to the maximum extent possible.
(c)
Existing trees and shrubs shall be preserved and protected to
the maximum extent possible.
(d)
All natural streams, channels, drainage swales and areas of
surface water concentration shall be maintained in their existing
condition, except where changes can be justified on the basis of other
design standards of this chapter.
At least two off-street parking spaces with access to a public street shall be provided for each proposed dwelling unit. Such spaces shall be constructed of a durable all-weather material. Where such access is to other than a residential service street, adequate turnaround space shall be provided on the lot. Parking areas shall be provided for commercial and industrial uses as required by the Board. Reference should be made to Chapter
135, Zoning.