An erosion and sedimentation control plan shall be submitted with all grading permit applications, the erosion and sedimentation control plan shall show how the erosion and sediment resulting from the earthmoving and stripping activities will be controlled. Any proposed erosion and sedimentation control measures to be used during construction shall strictly conform to the standards and specifications of the Montgomery County Conservation District, all Township Codes, and the Township’s Engineering and Construction Standards, Improvement Procedures (“ECSIP”), as amended from time to time. (The ECSIP is found at Appendix “B” which is attached to Ordinance 22-1378 and incorporated herein by reference as if set out in full).
A. An erosion and sedimentation control plan shall include the following:
(1) The amount of site alteration proposed and all proposed erosion and sedimentation control measures.
(2) A construction schedule indicating the anticipated starting and completion dates of the development sequence; the expected date of completion of construction of each protective measure provided for in the erosion and sediment control plan and the stormwater management plan; the sequence of earthmoving activities; and the time of exposure of each area prior to completion of such measures.
(3) Provisions for maintenance of control facilities, including operation and maintenance agreements, easements, and estimates of the cost of maintenance.
(4) Seeding mixtures and rates, types of sod, method of seedbed preparation, expected seeding dates, type and rate of lime and fertilizer application, and kind and quantity of mulching for both temporary and permanent vegetative control measures. See Appendix “C” (attached to Ordinance 22-1378 and incorporated herein by reference as if set out in full).
(5) Identification of the person(s) or entity(ies) which will have legal responsibility for maintenance of the erosion and sedimentation control structures and measures after development is completed.
B. Any erosion and sedimentation control plan shall incorporate the following erosion and sediment control practices and principles:
(1) Development shall reflect the topography and soils of the site so as to create the least potential for erosion. The smallest practical area of land shall be exposed for the shortest practical time during development.
(2) Stripping of vegetation, regrading, or other earthmoving activities shall be completed in a way that will minimize erosion and resulting sedimentation. Wherever feasible, natural vegetation shall be retained, protected, and supplemented.
(3) Cut and fill operations shall be kept to a minimum. In the design of cut and fill slopes, consideration must be given to the length and steepness of the slope, the soil type, upslope drainage area, groundwater conditions and other applicable factors. Areas of steep slopes where high cuts and fills may be required shall be avoided wherever possible. Where unavoidable, cuts and fills on steep slopes must be immediately seeded, and natural contours must be followed as closely as possible.
(4) The disturbed earthen area and the duration of exposure shall be kept to a practical minimum. All disturbed soils and topsoil stockpile areas shall be stabilized as quickly as possible and, if necessary, seeded and mulched immediately. Any stockpile areas located on sloping ground or near waters of the Commonwealth shall be enclosed with silt fencing.
(5) Procedures for protecting soils or geologic structures with water supply potential from contamination by surface water or other disruption by earthmoving activity must be established to the satisfaction of the Township.
(6) Sediment basins, debris basins, desilting basins, silt traps or filters shall be installed and maintained to remove sediment from runoff waters from land undergoing development. All runoff from the site shall be collected and diverted to these facilities for the removal of sediment. Sedimentation in the runoff water shall be trapped and filtered by these facilities until the disturbed area is stabilized to the satisfaction of the Township Engineer.
(7) All plans, wherein a sump pump or basement drain is proposed to be installed, shall provide for discharge of the sump pump/drain to a natural watercourse, drainage swale, stormwater easement, storm sewer system, or open space area. No sump pump or basement drain discharge shall be permitted to a grassed lawn area of residential or non-residential buildings, unless such area is part of a stormwater easement or drainage swale.
(8) Provisions shall be made to minimize any runoff caused by changed soil and surface conditions during and after development. All drainage facilities shall be designed to carry surface water in such a manner as to prevent erosion or overflow. Drainage facilities shall be designed and constructed to withstand the expected velocity of flow from a ten-year frequency storm without erosion. Stabilization adequate to prevent erosion must also be provided at the outlets of all pipes and paved channels.
(9) Natural vegetation shall be retained, protected, and supplemented wherever possible. Permanent vegetation shall be established on denuded areas not otherwise permanently stabilized. Permanent vegetation and related structures shall be installed as soon as practical. Permanent vegetation shall not be considered established until a ground cover is achieved that is mature enough to control the soil erosion satisfactorily and to survive severe weather conditions to the Township Engineer’s satisfaction.
(10) Permanent or temporary soil stabilization must be applied to denuded areas within one day after final grade is reached on any portion of the site. Soil stabilization must also be applied immediately to denuded areas which may not be at final grade but will remain dormant (undisturbed) for longer than one day.
(11) Properties adjacent to the site of a land-disturbing activity shall be protected from sediment disposition by preserving a well-vegetated buffer strip around the lower perimeter of the land-disturbing activity; by installing perimeter controls such as sediment barriers; filters, dikes, interceptor drains or sediment basins; or by a combination of such measures.
(a) Vegetated buffer strips may not be used alone except where only runoff in sheet flow is expected.
(b) Buffer strips shall be at least 20 feet in width and shall contain preexisting, permanent vegetation, excluding trees and shrubs that cover 95% of the ground within the buffer strip.
(c) If at any time, the Township Engineer finds that a vegetated buffer strip alone is ineffective in preventing sediment movement onto adjacent property, additional perimeter controls must be provided by the permittee or then-owner of the property within a time period specified by the Township Engineer.
(12) In the design of erosion control facilities and practices, aesthetics and the requirements of continuing maintenance shall be considered.
C. The selection of erosion and sedimentation control measures shall be based on assessment of the probable frequency of climatic and other events likely to contribute to erosion, on an evaluation of the risks, costs and benefits involved and in accordance with best management practices.