A. 
Allowable activities. The following activities within a steep slope area shall be allowed without a permit:
(1) 
Normal ground maintenance which does not require disturbance of existing terrain, including mowing, trimming of vegetation and removal of dead or diseased vegetation, provided that such activity does not involve regrading, and further provided that such activity conforms with all other applicable laws and regulations, including but not limited to the Tree Protection Law of the Town of Ossining (Chapter 183).
(2) 
The disturbance to steep slopes under temporary emergency conditions, as determined by the Building Inspector, where such disturbance is necessary to protect persons or property from present and imminent danger.
(3) 
Repair of existing walkways and walls.
(4) 
Installation of a standard-size mailbox.
(5) 
Public health activities and emergency uses pursuant to orders of the Westchester County Department of Health and/or the New York State Department of Health.
B. 
Regulated activities.
[Amended 12-15-2015 by L.L. No. 8-2015]
(1) 
It shall be unlawful to create a new steep slope area or to create any disturbance, other than an allowable activity as defined in § 167-5A hereof, on any existing or proposed steep slope in the absence of a steep slope permit issued by the approval authority and a work permit issued by the Building Inspector.
(2) 
Extremely steep slopes.
(a) 
It shall be unlawful to create or disturb any extremely steep slope, as defined herein, except that the Planning Board may waive this prohibition with respect to ingress and egress for the property and in other circumstances, subject to the following provisions of this section. In these cases, the applicant shall have the burden of demonstrating that the applicant's circumstances warrant the waiver, including, at a minimum, an analysis of the relative environmental impacts of alternatives and demonstration by the applicant that:
[1] 
The site, lot or parcel cannot be reasonably used without the creation or disturbance of an extremely steep slope; or
[2] 
A traffic hazard relative to sight distance(s) would result without the creation or disturbance of an extremely steep slope.
(b) 
In addition, the Planning Board may only permit the creation or disturbance of an extremely steep slope if in doing so adverse environmental impacts can be mitigated to the extent acceptable to said Board.
A. 
Consideration. In granting, denying or conditioning any permit, the approval authority shall consider all relevant facts and circumstances, including, but not limited to, the following:
(1) 
The environmental impact of the proposed action.
(2) 
The alternatives to the proposed action, including avoidance of the disturbance of the steep slope area and the availability of preferable alternative locations on the subject parcel or on any other adjacent parcel under the control of the applicant.
(3) 
The suitability or unsuitability of the proposed activity to the area for which it is proposed.
(4) 
The effect of the proposed activity with reference to the protection of steep slopes.
(5) 
The availability of technical improvements, safeguards or other mitigation measures that could feasibly be added to the proposal.
B. 
Conditions. During its review of the application, the approving authority shall establish conditions of approval deemed necessary by the approval authority to satisfy the goals, objectives and review standards set forth in §§ 167-1 and 167-6 of this chapter, including but not limited to the following:
(1) 
Lot layouts shall be designed so that sanitary sewage disposal systems entirely avoid all areas of steep slope and are in compliance with all standards and regulations of the Westchester County Health Department.
(2) 
The padding or terracing of building sites, including mounding of septic tile fields, shall be minimized to the maximum extent practicable.
(3) 
The alignment of roads and driveways shall follow the natural topography, minimize regrading and comply with design standards for maximum grades set forth in the Town Code.
(4) 
The natural elevations and vegetative cover of ridge lines shall be protected from disturbance to the maximum extent possible.
(5) 
All regrading shall blend in with the natural contours of the land.
(6) 
Cuts and fills shall be rounded off to eliminate sharp angles at the top, bottom and side of regraded slopes.
(7) 
The angle of cut and fill slopes shall not exceed the natural angle of repose of the soil or rock materials in the cut or fill, except where retaining walls or other structural stabilization is used; generally, for soils, cut and fill slopes should be not steeper than two horizontal to one vertical (50% slope).
(8) 
Fill slopes shall avoid all natural slopes of two horizontal to one vertical (50% slope) or steeper. The toe of the fill slope shall not be located within 12 feet horizontally of the top of an existing or proposed cut slope.
(9) 
Tops and bottoms of cut and fill slopes shall be set back from existing and proposed property lines a distance at least equal to the lesser of three feet plus 1/5 of the height of the cut or fill or 10 feet.
(10) 
Tops and bottoms of cut and fill slopes shall be set back from structures a distance that will ensure the safety of the structure in the event of the collapse of the cut or fill slopes; generally, such distance will be considered to be six feet plus 1/5 the height of the cut or fill but need not exceed 10 feet. Nevertheless, a structure may be built on a slope or at the toe of a slope if it is designed to retain the slope and to withstand the forces exerted on it by the retained slope.
(11) 
The use of explosives shall be avoided to the maximum extent practicable. Generally, disturbance of rock outcrops shall be by means of explosives only if manual labor and machines are not effective and only if rock blasting is conducted in accordance with the Town Code and all other applicable regulations by a person holding a current Class A or Class B certificate of competence from the New York State Department of Labor.
(12) 
Any disturbance of steep slopes shall be completed within one construction season, and disturbed areas shall not be left bare and exposed during the winter and spring thaw periods.
(13) 
The disturbance of existing vegetative ground cover shall not take place more than seven days prior to commencing grading and construction.
(14) 
Permanent vegetative cover, as specified in the Westchester County Best Management Practices Manual for Erosion and Sediment Control (1991), as may be amended, shall be planted within three days after completion of grading. Where final grading and permanent planting cannot be established within a short period of time, temporary seeding or mulching shall be applied. Upon good cause shown and based upon consideration of the time of year, slopes, soils and environmental sensitivity of the area involved, the Building Inspector may modify these specified time periods.
(15) 
Measures for the control of erosion and sedimentation shall be undertaken in accordance with the Westchester County Best Management Practices Manual for Erosion and Sediment Control (1991), as may be amended, and in accordance with the most recent version of the Soil and Water Conservation Society's publication entitled "New York Guidelines for Erosion and Sediment Control," or their equivalents as may be deemed satisfactory to the approval authority.
(16) 
Topsoil that will be stripped from all areas of disturbance shall be stockpiled in a manner so as to minimize erosion and sedimentation and shall be replaced on the site at the time of final grading.
(17) 
Fill material shall be composed only of nonorganic material, including rock with a diameter that will allow for appropriate compaction and cover by topsoil. No voids are to be created or left remaining in the fill material that will allow further settlement of the fill or habitat for rodents, vermin or other unwanted species.
(18) 
Compaction of fill materials in fill areas shall be such that it ensures support of proposed structures and stabilization for intended uses.
C. 
Determinations. In granting a steep slope permit under this chapter, the approval authority shall determine the following:
(1) 
That the proposed activity and the manner in which it is to be accomplished are in accordance with the findings and policy set forth in § 167-1 of this chapter.
(2) 
That the proposed activity and the manner in which it is to be accomplished can be completed without increasing the possibility of creep or sudden slope failure and will minimize erosion to the maximum extent practicable.
(3) 
That the proposed activity and the manner in which it is to be accomplished will not adversely affect the preservation and protection of existing wetlands, water bodies, watercourses and floodplains.
(4) 
That the proposed activity and the manner in which it is to be accomplished can be completed in such a way so as not to adversely affect existing, proposed or future wells or sewage disposal systems or any threatened or endangered species of flora or fauna.
(5) 
That the proposed regulated activity is compatible with the public health and welfare.
(6) 
That the proposed regulated activity cannot practicably be relocated on the site so as to eliminate or reduce the disturbance of the steep slope area.
D. 
Burden of proof. The applicant shall have the burden of proof to demonstrate compliance with this chapter.