Where some or all of the proposed protected open space on the tract is to be used for agriculture in accordance with § 27-1310, Subsection 1D(3), such use shall be a factor in the design of the site for residential purposes. Proposed dwelling units, roads, and sewage facilities shall, where feasible and practical, be located so as to minimize disturbance to the tract's Class I, Class II, and/or Class III agriculturally-suitable soils, as those soils are designated in the Soils Survey of Chester and Delaware Counties (U.S. Dept. of Agriculture, 1963, as amended and updated).