The E&S Grounding Solutions soil resistivity map displays measured soil resistivity data across the United States, organized by geographic region and soil type. Engineers use this data as a starting point for grounding system design before conducting site-specific four-point Wenner testing per IEEE Std. 81.
Select a region to view typical soil resistivity ranges in ohm-meters. These values are general estimates based on soil classification; actual site conditions vary significantly with moisture content, temperature, and depth. Always perform on-site soil resistivity testing before finalizing a grounding system design.
For a full soil resistivity analysis and grounding system design, contact E&S Grounding Solutions or use the soil resistivity calculator to model your site data.