On farm properties of 50 acres or more qualified under the Farmland Assessment Act, which have been permanently preserved (the development rights have been acquired by any federal, state, county or Township entity, agency or program), including, but not limited to, preservation pursuant to the Farmland Preservation Act (N.J.S.A. 4:16-1 et seq.) not in excess of two single-family residential dwelling houses may be established, providing that: each of the residences is served by a driveway, which may be a common driveway (or farm lane), conforming to the requirements of Chapter 130, Driveways; each of the dwelling houses is served by a separate well and separate septic system unless common wells and/or common septic systems are permitted by law and are approved by the Warren County Board of Health and/or the New Jersey Department of Environmental Protection; all applicable front, side and rear yard setbacks shall be met; and the dwelling houses and the parcels upon which they are located and which are attributable to each of the dwelling houses (the curtilages), shall be nonseverable (not subdividable) and a deed covenant and restriction to that effect shall be required to be established.