Expansive soil is any soil with an expansion index greater than 20, or as otherwise determined by the Building Code. Whenever expansive soils are encountered within four feet of the finish grade of an area intended or designed as a location for a building, then one of the following shall apply.
(A) The permittee shall remove such expansive soil to a minimum depth of four feet below finish grade within the building footprint area. Non-expansive, properly compacted soil shall be installed in the area where the expansive soil was removed.
(B) If sufficient non-expansive material is not readily available on site, the permittee may at his or her option import non-expansive material to be used as fill or the soil engineer may waive or reduce the requirement for removal and replacement of the expansive soils for the project. The soil engineer, however, shall make recommendations for the design of footings, foundations, slabs and other load bearing features or other special procedures to alleviate any potential problem created by the remaining expansive soils.
(C) Based on recommendations of the soil engineer, expansive soil from cut areas may be placed in the lower extremities of embankments, and non-expansive materials shall be reserved and stockpiled for placement as a cap over the expansive soil. Whenever expansive soil is placed closer than four feet of finish grade, the soil engineer shall so indicate and make corrective recommendations as noted above.
(Ord. 3378 § 5 (part), 2023; Ord. 2568 § 1, 2002.)