Development proposals on sites containing mapped seismic hazard areas may make alterations to a seismic hazard area only when the applicant demonstrates and Orting concludes that:
A. Evaluation of site specific subsurface conditions shows that the site is not located in a seismic hazard area; or
B. Mitigation is implemented which renders the proposed development as safe as if it were not located in a seismic hazard area, as certified by a professional engineer licensed by the state of Washington. (1973 Code § 15.24.040)