(1) The Zoning Board of Adjustment may in its discretion, after a public hearing, issue a Zoning Board of Adjustment Certificate permitting:

(a) The use of ground as an airport or landing field;

(b) The opening or operation of quarries or gravel pits in commercial or industrial districts;

(c) The use of ground for a dump or for landfill operation in commercial or industrial districts.

(2) Landfills in all Residential Districts that involve any of the following conditions shall not be permitted by the City of Philadelphia unless authorized by an ordinance of City Council:^[238]

(a) The filling of one-half acre or more of land when such filling involves the replacement of more than forty-thousand cubic feet of fill.

(b) The grading of one-half acre or more of land which results in the regrading of slopes in excess of twenty-five percent or creation of slopes in excess of thirty-five percent.

(c) The filling or grading of one-half acre or more of land which involves the relocation, dredging, or covering of any existing streams or surface bodies of water.

(d) Provided, that this regulation shall not apply to filling and/or grading that is part of any development or redevelopment plan approved or authorized by the City Council as part of a Zoning Change Ordinance, Streets Ordinance, Utility Ordinance, Redevelopment Agreement, Urban Renewal Plan, Capital Program or Capital Budget Ordinance.

(e) Further provided, that this regulation shall not apply to any filling and/or grading that is part of a development plan approved by the Zoning Board of Adjustment or any Subdivision approved in accordance with Chapter 14-2100 of the Philadelphia Code.