The E&S Grounding Solutions Soil Resistivity Atlas is an interactive map of soil resistivity values across the United States and selected international regions. It is intended for preliminary grounding system design, site screening, and project budgeting.
Soil resistivity values in the atlas are derived from published USGS soil surveys, state geological surveys, and E&S Grounding Solutions field measurement data. Values are presented as typical ranges for soil classification units and should not be used as a substitute for site-specific Wenner four-pin testing per IEEE Std. 81.
The atlas is particularly useful for: comparing soil conditions across multiple candidate sites, estimating ground grid size and cost during the feasibility phase, and identifying sites that may require deep ground rods or chemical ground enhancement due to high-resistivity soils.
For site-specific soil resistivity testing and IEEE 80 grounding design, contact E&S Grounding Solutions at +1-310-318-7151 or info@esgrounding.com.