All fills shall be compacted throughout their full extent to a minimum of 90 percent of maximum density as determined by the appropriate CalTrans standard method (Test Method No. Calif 216-C of the Materials and Research Department, state of California, Transportation Department, Division of Highways) or other alternate methods approved by the Planning Department. Tests to determine the density of compacted fills shall be made on the basis of not less than one test for each two-foot vertical lift of the fill but not less than one test for each 1,000 cubic yards of material placed. Additional density tests at a point approximately one foot below the fill slope surface shall be made on the basis of not less than one test for each 1,000 square feet in slope surface but not less than one test for each 10-foot vertical increase of slope height. All tests shall be reasonably uniformly distributed within the fill or fill slope surface. Results of such testing and location of tests shall be presented in the periodic and final reports. Compaction may be less than 90 percent of maximum density, as determined by the above test, within six inches of the slope surface when such surface material is placed and compacted by a method acceptable to the Planning Department for the planting of the slopes. Compaction of temporary stockpile fills, to be used for a period of not greater than six months, shall not be required, except where the Planning Department determines that compaction is necessary as a safety measure to aid in preventing saturation, sliding, or erosion of the fill.