Which factor is NOT evaluated by the local health department during a site evaluation?

The factor that is not evaluated by the local health department during a site evaluation is related to building materials used. The primary focus of a site evaluation is to assess the natural characteristics of the land to determine its suitability for a septic system installation. This includes evaluating topography and landscape position, soil depth, and soil wetness, as these factors directly influence how well the septic system will function and how effectively it will treat waste.

Topography and landscape position affect drainage and the potential for runoff, whereas soil depth is crucial for ensuring that there is enough soil to effectively treat effluent. Soil wetness is also a critical consideration because saturated soils can hinder proper absorption and treatment of wastewater.

In contrast, the construction materials of a building do not impact the soil's filtration capacity or the effectiveness of the septic system directly. While understanding building materials may play a role in overall site management and planning, it is not a critical factor in the specific evaluation of land for septic system suitability.