(1) The minimum setback of all principal buildings and all other structures that are in excess of 100 square feet (other than boardwalks, shoreline promenades, docks, bulkheads, piers, wharves, pilings, dolphins, or boathouses and structures typically located on docks, piers or wharves) shall be 75 feet landward from the most landward edge of any tidal wetland. Provided, however, within the boundaries of the city of New York the minimum setback required by this paragraph shall be 30 feet. Further provided, where numerous and substantially all structures which are (i) of the type proposed by the applicant, (ii) lawfully existing on August 20, 1977, and (iii) within 500 feet of the subject property, are located closer to the subject tidal wetland than the minimum setback required by this paragraph, placement of a structure as close as the average setback of these existing structures from the subject tidal wetland shall fulfill the requirements of this paragraph.

(2) The minimum setback of any on-site sewage disposal septic tank, cesspool, leach field or seepage pit shall be 100 feet landward from the most landward edge of any tidal wetland.

(3) For any on-site sewage disposal cesspool, septic tank, leach field or seepage pit, there shall be a minimum of two feet of soil between the bottom of such pool, tank, field or pit and the seasonal high ground water level, rock, hardpan, or other impermeable materials.

(4) Not more than 20 percent of the adjacent area, as such term is defined in this Part, on any lot shall be covered by existing and new structures and other impervious surfaces. Provided, however, this paragraph shall not be deemed to prohibit the coverage of 3,000 square feet or less of adjacent area on any individual lot, lawfully existing on August 20, 1977, by existing and new structures and other impervious surfaces.

(5) The minimum lot area for any principal building constructed within the area regulated by this Part, which minimum lot area shall include any wetland portion and any adjacent area portion of such lot, shall be as follows:

(6) Notwithstanding the minimum lot size provisions contained in paragraph (5) of this subdivision, the clustering of principal buildings utilized for residential purposes, including multiple family dwellings, shall be permitted at the request of an applicant for a permit under this Part in order to encourage the maintenance of undeveloped areas in or adjoining tidal wetlands. Provided, such clustering procedure shall in no case result in more principal buildings on the area regulated by this Part than would be permitted by the application of the minimum lot size criteria in paragraph (5) of this subdivision.

(7) The minimum setback of all hard surface driveways, roads and parking lots and similar impervious surfaces exceeding 500 square feet in size on the property involved, overhead utility line poles and railroads, shall be 75 feet from any tidal wetland. Provided, within the boundaries of the city of New York the minimum setback required by this paragraph shall be 30 feet. Further provided, this provision shall not be applicable to any portion of a regulated activity that involves a crossing or direct access to a tidal wetland on the subject property.

(8) Any substantial increase in surface water runoff to tidal waters classified SA, as defined in section 701.5 of this Title, or to any other surface waters which are within 1,000 feet of any SA waters and are adjacent or tributary to such SA waters, shall be prevented from directly running into any such waters by the utilization of sufficient runoff control measures, including but not limited to the installation of dry wells, retention basins, filters, open swales or ponds. Any such dry well, retention basin, filter, open swale or pond to be constructed in order to prevent direct surface water runoff to said SA and other surface waters shall be designed and constructed to handle the water runoff produced on the project site by a five-year storm.