A. 
No person shall commence or otherwise perform any land development activity (major or minor) in the Town of Greenburgh that involves 500 or more square feet without first obtaining the proper stormwater management control permit from the Town Engineer, and all other necessary local, state and federal permits, and thereafter comply with the requirements of this chapter.
B. 
A stormwater pollution prevention plan (SWPPP) or stormwater management plan must be prepared by a New York State licensed professional engineer, architect, landscape architect, or soil scientist and submitted for review and approval by the Town Engineer prior to commencement of any major land development activity as defined by § 248-7 of this chapter.
Stormwater control measures shall be selected by giving preference to the best management practices for pollutant removal and flow attenuation as specified in the NYS Stormwater Management Design Manual, the NYSDEC's Reducing the Impacts of Stormwater Runoff from New Development, and the Westchester County Best Management Practices Manual for Erosion and Sediment Control. The following minimum design requirements shall apply to minor projects:
A. 
It is the responsibility of an applicant to include sufficient information in the stormwater management and erosion control and sediment plans so that the plans may be evaluated with respect to the environmental characteristics of the affected areas, the potential and predicted impacts of the proposed activity on community waters and the effectiveness and acceptability of those measures proposed for reducing or mitigating adverse impacts.
B. 
An application for stormwater management and erosion and sediment control permits shall be made on forms provided by the Town, and shall include the name(s) and address(es) of the owner, contract vendee, or developer of the site, and of any consulting firm retained by the applicant, together with the name and telephone number of the applicant's principal contact at such firm. Each application shall include a certification that any land clearing, construction, or development involving the movement of earth shall be in accordance with the plans approved and the permit issued. The permit will be valid for the same period as the associated building or other municipal permits. Where a building or other municipal permit is not issued, the stormwater management and erosion and sediment control permits shall expire within 180 days from the date of approval unless renewed by the Town Engineer.
C. 
Required information.
(1) 
Each application shall be accompanied by the following, unless specifically waived by the Town Engineer based on the scope of the project:
(a) 
A vicinity map.
(b) 
A stormwater management and erosion and sediment control plan for the site showing drainage patterns, on-site stormwater appurtenances, wetlands, one-hundred-year floodplain, and proposed use of the site, including areas of excavation, grading and filling.
(c) 
Stormwater management improvements, including calculations, designs and special measures regarding safety and maintenance operations.
(d) 
Stormwater conveyance system, including plans, designs and materials to be used for improvements and erosion control in channel sections of stormwater conveyance systems and erosion control measures at culvert inlets and outfalls.
(2) 
Stormwater shall be managed on site using stormwater control measures designed to afford optimum protection of ground- and surface waters. Stormwater shall be calculated in accordance with the methodology for determining stormwater volume and flow rates using any one of the following methods:
(a) 
For small watershed areas (up to 20 acres), the Rational Method or TR-55.
(b) 
For larger watersheds areas (up to 2,000 acres), TR-55 or an equivalent widely accepted methodology.
(3) 
Stormwater control measures shall be designed based upon the minimum twenty-five-year design storm for local conditions. The design shall consider all existing and new impervious surfaces, including but not limited to roof areas, driveways, patios, deck areas, and walkways.
(4) 
Stormwater control measures may include, but shall not be limited to, dry wells of precast concrete, recharge structures, and infiltration trenches. Such measures may also include natural and human-made landscape features such as depressions, blind ditches, retention ponds, swales and other such measures. Inlets to infiltration devices shall be protected from sediment at all times in order to maintain their capacity.
(5) 
Infiltration devices shall not be installed upgradient within 20 feet of the subsurface treatment system of a wastewater treatment system. Infiltration devices for roadways, parking lots, and other areas subject to vehicle traffic shall not be installed within 100 feet of any water well, wetland or water body.
(6) 
Infiltration devices and buildings shall be designed to maintain maximum attainable horizontal distance separation from wells, water bodies and wetlands.
(7) 
The bottom of any infiltration device shall be a minimum of two feet above seasonal high groundwater mark and two feet above bedrock.
(8) 
Temporary erosion controls shall be required to prevent siltation of water bodies during construction.
A. 
It is the responsibility of an applicant to include sufficient information in the stormwater management and erosion and sediment control plans so that the plans may be evaluated with respect to the environmental characteristics of the affected areas, the potential and predicted impacts of the proposed activity on community waters and the effectiveness and acceptability of those measures proposed for reducing or mitigating adverse impacts.
B. 
An application for stormwater management and erosion and sediment control permits shall be made on forms provided by the Town, and shall include the name(s) and address(es) of the owner, contract vendee, or developer of the site, and of any consulting firm retained by the applicant, together with the name and telephone number of the applicant's principal contact at such firm. Each application shall include a certification that any land clearing, construction, or development involving the movement of earth shall be in accordance with the plans approved and the permit issued. The permit will be valid for the same period as the associated building or other municipal permits.
C. 
Required information. Each application shall be accompanied by the following, unless specifically waived by the Town Engineer based on the scope of the project:
(1) 
All SWPPPs shall provide the following background information and erosion and sediment controls:
(a) 
Background information about the scope of the project, including location, type and size of the project, the existing zoning, North arrow, scale and legend.
(b) 
Site map/construction drawing(s) for the project, including a general location map. At a minimum, the site map should show the total site area, all improvements, areas of disturbance, areas that will not be disturbed, existing vegetation, on-site and adjacent off-site surface water(s), wetlands and drainage patterns that could be affected by the construction activity, existing and final slopes, locations of off-site material, waste, borrow or equipment storage areas, and the location(s) of stormwater discharges(s). The site map should be at a scale no smaller than one inch equals 100 feet (e.g., one inch equals 500 feet is smaller than one inch equals 100 feet).
(c) 
Existing topography of the site and adjacent land clearly portraying the drainage patterns of the area, including ditches, culverts, permanent or intermittent streams, wetlands or water bodies, existing roads and sizes of existing culverts.
(d) 
The location of existing buildings, structures, utilities, water bodies, floodplains, drainage facilities, vegetative cover, the size and species of all trees with a trunk diameter of six inches or greater at a point 4 1/2 feet above ground level, paved areas, watershed divides, and other significant natural or man-made features on the site, and adjacent land within approximately 100 feet of the property boundaries.
(e) 
Description of the soil(s) present at the site.
(f) 
Construction phasing plan describing the intended sequence of construction activities, including clearing and grubbing, excavation and grading, utility and infrastructure installation and any other activity at the site that results in soil disturbance. Consistent with the New York Standards and Specifications for Erosion and Sediment Control (Erosion Control Manual), not more than five acres shall be disturbed at any one time unless pursuant to an approved SWPPP.
(g) 
Description of the pollution prevention measures that will be used to control litter, construction chemicals and construction debris from becoming a pollutant source in stormwater runoff.
(h) 
Description of construction and waste materials expected to be stored on site, with updates as appropriate, and a description of controls to reduce pollutants from these materials, including storage practices to minimize exposure of the materials to stormwater and spill prevention and response.
(i) 
Temporary and permanent structural and vegetative measures to be used for soil stabilization, runoff control and sediment control for each stage of the project from initial land clearing and grubbing to project closeout.
(j) 
A site map/construction drawing specifying the location(s), size(s) and length(s) of each erosion and sediment control measure.
(k) 
Dimensions, material specifications and installation details for all erosion and sediment control practices, including the siting and sizing of any temporary sediment basins.
(l) 
Temporary measures that will be converted to permanent control measures.
(m) 
Implementation schedule for staging temporary erosion and sediment control practices, including the timing of initial placement and duration that each practice should remain in place.
(n) 
Maintenance schedule to ensure continuous and effective operation of the erosion and sediment control practice.
(o) 
Name(s) of the receiving water(s).
(p) 
Delineation of SWPPP implementation responsibilities for each part of the site.
(q) 
Description of structural practices designed to divert flows from exposed soils, store flows, or otherwise limit runoff and the discharge of pollutants from exposed areas of the site to the degree attainable.
(r) 
Any existing data that describes the stormwater runoff at the site.
D. 
Land development activities, as defined in § 248-7 of this chapter and meeting Condition 1, 2 or 3 below, shall also include water quantity and water quality controls (post construction stormwater runoff controls) as set forth in § 248-11C as applicable:
(1) 
Condition 1. Stormwater runoff from land development activities discharging a pollutant of concern to either an impaired water identified on the Department's 303(d) list of impaired waters or a total maximum daily load (TMDL) designated watershed for which pollutants in stormwater have been identified as a source of the impairment.
(2) 
Condition 2. Stormwater runoff from land development activities disturbing five or more acres.
(3) 
Condition 3. Stormwater runoff from a land development activity disturbing between one and five acres of land during the course of the project, exclusive of the construction of single-family residences and construction activities at agricultural properties.
E. 
SWPPP requirements for land development activities meeting Condition 1, 2 or 3:
(1) 
All information required by § 248-11C of this chapter.
(2) 
Description of each post construction stormwater management practice.
(3) 
Site map/construction drawing(s) showing the specific location(s) and size(s) of each post construction stormwater management practice.
(4) 
Hydrologic and hydraulic analysis for all structural components of the stormwater management system for the applicable design storms.
(5) 
Comparison of post development stormwater runoff conditions with predevelopment conditions.
(6) 
Dimensions, material specifications and installation details for each post construction stormwater management practice.
(7) 
Maintenance schedule to ensure continuous and effective operation of each post construction stormwater management practice.
(8) 
Maintenance easements, pursuant to § 248-19, to ensure access to all stormwater management practices at the site for the purpose of inspection and repair. Easements shall be recorded on the plan and shall run with the land, remaining in effect with transfer of title to the property.
(9) 
Inspection and maintenance agreement binding on all subsequent landowners served by the on-site stormwater management measures in accordance with § 248-21 of this chapter.
The SWPPP shall be prepared by a New York State licensed professional engineer, architect, landscape architect or soil scientist, and must be signed by the professional preparing the plan who shall certify that the design of all stormwater management practices meet the requirements in this chapter.
The applicant shall assure that all other applicable environmental permits have been or will be acquired for the land development activity prior to approval of the final stormwater design plan.
A. 
Each contractor and subcontractor identified in the SWPPP to be involved in soil disturbance and/or stormwater management practice installation shall sign and date a copy of the following certification statement before undertaking any land development activity: "I certify under penalty of law that I understand and agree to comply with the terms and conditions of the stormwater pollution prevention plan. I also understand that it is unlawful for any person to cause or contribute to a violation of water quality standards."
B. 
The certification must include the name and title of the person providing the signature, the address and telephone number of the contracting firm, the address (or other identifying description) of the site and the date the certification is made.
C. 
The certification statement(s) shall become part of the SWPPP for the land development activity.
A copy of the approved SWPPP shall be retained at the site of the land development activity during construction, from the date of initiation of construction activities to the date of final stabilization.