Application of the standards for determining an Acceptable Separation Distance (ASD) for a HUD-assisted project from a potential hazard of an explosion or fire prone nature is predicated on level topography with no intervening object(s) between the hazard and the project. Application of the standards can be eliminated or modified if:
(a) The nature of the topography shields the proposed project from the hazard.
(b) An existing permanent fire resistant structure of adequate size and strength will shield the proposed project from the hazard.
(c) A barrier is constructed surrounding the hazard, at the site of the project, or in between the potential hazard and the proposed project.
(d) The structure and outdoor areas used by people are designed to withstand blast overpressure and thermal radiation anticipated from the potential hazard (e.g., the project is of masonry and steel or reinforced concrete and steel construction).