This chapter shall be known and may be cited as the "Soil Erosion, Sedimentation and Grading Control Ordinance," implementing Title 25, Rules and Regulations, Part I, Commonwealth of Pennsylvania, Department of Environmental Protection, Subpart C, Protection of Natural Resources, Article II, Water Resources, Chapter
102, Erosion Control.
The purpose of this chapter is to regulate the modification
of the natural terrain and the alteration of drainage and to provide
for certain erosion and sediment control measures within the Borough
of Canonsburg to assure and safeguard health, safety, ecology and
the general welfare in the Borough.
From and after the effective date of this chapter, any subdivision
and/or land development approved under the Subdivision and Land Development
Ordinance, if any, or Chapter
170, Zoning, or any activity qualified under §
102-5 and §
102-6 herein shall be in conformity with this chapter. In the event of a conflict between this chapter and floodplain regulations, the floodplain regulations shall take precedent.
As used in this chapter, the following terms shall have the
meanings indicated, unless a different meaning clearly appears from
the context:
ALLUVIAL SOILS
An azonal great group of soils, developed from transported
and relatively recently deposited material (alluvium), characterized
by a weak modification (or none) of the original material by soil-forming
processes.
CUT and/or FILL
The process of earthmoving by excavating part of an area
and/or using excavated material for embankments or fill areas.
EROSION
A.
The wearing away of the land surface by running water, wind,
ice, chemical or other geological agents.
B.
Detachment and movement of soil or rock fragments by water,
wind, ice or gravity.
GRADE
A.
The slope of a road, channel or natural ground.
B.
The finished surface of a canal bed, roadbed, top of embankment
or bottom of excavation; any surface prepared for the support of construction
like paving or laying a conduit.
C.
To finish the surface of a canal bed, roadbed, top of embankment
or bottom or excavation.
RUNOFF (HYDRAULICS)
That portion of the precipitation on a drainage area or watershed
that is discharged from the area in stream channels; types include
surface runoff, groundwater runoff or seepage.
SEDIMENT
Solid material, both mineral and organic, that is in suspension,
is being transported or has been moved from its site of origin by
air, water, gravity or ice and has come to rest on the earth's surface
either above or below sea level.
SLOPE
Degree of deviation of a surface from the horizontal, usually
expressed in percent or degrees.
SOIL DRAINAGE
A condition of the soil, referring to the frequency and duration
of periods when the soil is free of saturation.
WATERCOURSE
A natural drainage route or channel for the flow of water.
Whenever the landscape is to be permanently disturbed as to
either contours, soil or slope characteristics or vegetation or any
ground cover is to be permanently removed, a plan is required showing
how resulting erosion and sediment shall be controlled. This plan
shall include the following:
A. The amount of site alteration proposed;
B. The development schedule; and
C. Erosion and sediment control practices (both temporary and permanent)
and the operation and maintenance arrangements.
The following activities require a grading permit:
A. Modifying, disturbing, blocking, diverting or otherwise adversely
affecting the natural overland or subsurface flow of stormwater;
B. Construction, erection or installation of any drainage dam, ditch,
culvert, drainpipe, bridge or any other structure or obstruction affecting
the drainage of any premises;
C. Paving, filling, stripping, excavating, grading or regrading of any
land; and
D. Disturbing the landscape, vegetation or any ground cover by any proposal
involving an area in excess of 3,000 square feet.
The following activities require no grading permit:
A. Improvements, such as erection of retaining walls, driveway paving,
minor regrading or activities on a property which do not adversely
affect the natural overland or subsurface flow of stormwater, drainage
of any premises or adversely disturb the landscape, in a gross area
of less than 10,000 square feet and less than 300 cubic feet of earthmoving
on any one property.
[Amended at time of adoption of Code (see Ch. 1, General
Provisions, Art. I)]
B. Farming, gardening or lawn restoration, but not including sod farming.
The plan for a grading permit shall include:
A. A valid boundary line survey of the site on which the work is to
be performed;
B. A description of the features, existing and proposed, surrounding
the site and which are of importance to the proposed development;
C. A plan of the general topography (including drainage) and soil conditions
on the site (the latter available through the County Conservation
District);
D. The location and a description of existing and future man-made features
of importance to the proposed development (i.e., cuts and/or fills,
buildings, roads and driveways);
E. Plans and specifications of soil erosion and sediment control measures
in accordance with standards and specifications of the Borough and
the County Conservation District; and
F. A development schedule indicating the anticipated starting and completion
dates of the development sequence and the time of exposure of each
area prior to the completion of effective erosion and sediment control
measures.
[Amended at time of adoption of Code (see Ch. 1, General
Provisions, Art. I)]
For any project proposing to disturb one acre or greater, a Chapter
102 permit shall be required. In addition to the requirements of §
102-9 and where deemed necessary by the Borough Engineer and the Planning Commission or the Borough Council, the applicant shall submit with the plan a detailed drainage study, prepared by a registered professional engineer qualified in hydrology in the commonwealth. This study shall include:
A. A plan of the property showing the location of all present and proposed
ditches, streams, pipes and other drainage structures and proposed
cuts and/or fills. In addition to showing present elevations and dimensions
and the location and extent of all proposed grading and/or drainage,
the plan shall clearly indicate all woodlands, buildings, parking
areas and driveways. Further, the plan shall indicate the present
and proposed sources, storage and disposition of water being channeled
through or across the premises, together with elevations, gradients
and maximum flow rates. The plan shall describe the work to be performed
and disposition of cut and/or fill, the materials to be used and the
manner or method of performance, including provisions for protecting
and maintaining existing drainage facilities, whether on public or
private property. The applicant shall also supply the supporting data
for the plan, as developed by the engineer.
B. Calculations to determine runoff, which shall be based on the Soil-Cover
Complex Method, a description of which is available from the United
States Department of Agriculture (USDA) Natural Resources Conservation
Service and outlined in the "Erosion and Sediment Control Handbook,
Washington County, Pennsylvania."
(1) The design criteria for storm sewer piping on inlet systems within
a subdivision being developed shall be designed for a twenty-five-year
frequency storm; culverts across roadways shall be designed for a
fifty-year frequency storm; open watercourses or swales shall be designed
for a one-hundred-year frequency storm as prescribed in accordance
with the following:
(a)
The coefficient of runoff used for all areas upstream of any
drainage structure shall be computed on the basis of existing land
use and the projected land use described and shown on the Borough
Comprehensive Plan and adjacent municipalities' comprehensive plans,
where applicable.
(2) The following provisions apply to the carrying and disposal of stormwater
runoff:
(a)
All drainage facilities shall be designed to carry surface water
in such a manner as to prevent erosion or overflow.
(b)
The applicant shall agree to the granting and recording of easements
covering the installation and maintenance of drainage facilities.
(c)
The rate of runoff shall be no greater during and after a one-hundred-year
frequency storm when the development is completed than that which
existed before the development began and appropriate measurements
of calculations shall be provided to verify such provisions.
C. A soils investigation report, if load-bearing fill is proposed, which
shall consist of test borings, laboratory testing and engineering
analysis to correlate surface and subsurface conditions with the proposed
grading plan. The results of the investigation shall be presented
in a report by a registered professional soils engineer and shall
include data regarding the nature, distribution and supporting ability
of existing soils and rocks on the site and conclusions and recommendations
to ensure stable soil conditions and groundwater control as applicable.
The Borough may require such supplemental reports and data as is deemed
necessary by the Borough Engineer. Recommendations included in such
reports and approved by the Borough Engineer shall be incorporated
in the plan or specifications. The following provisions are in addition
to the above:
(1) Fills toeing out on natural slopes steeper than four horizontal to
one vertical shall not be made unless a report is received which is
deemed acceptable by the Borough Engineer and approved by the Borough
Council. The report shall be made by a registered professional soils
engineer, certifying that he has investigated the property, made soils
tests and that, in his opinion, such steeper slopes will safely support
the proposed fill.
(2) Natural and/or existing slopes exceeding five horizontal to one vertical
shall be benched or continuously stepped into competent materials
prior to placing all classes of fill.
Upon the approval of the plan by the Borough Engineer, the Building
Inspector shall issue the necessary grading permit.
Permittees shall bear all costs of inspections required or permitted
hereunder and shall deposit with the Borough such sum as the Borough
Council shall determine to guarantee payment of the costs of such
inspections. The costs of inspections shall be in accordance with
the established schedule of fees and collection procedure for matters
pertaining to this chapter.
The fee for a grading permit shall be fixed by resolution of
the Borough Council from time to time.