Soil permeability is one of the controlling factors for the rate at which a contaminant travels through soils. Soils with higher permeability facilitate the transport of pollutants into ground water. Thus, high permeability is an indicator of increased risk of ground water contamination. Click on the data layer of interest to find documentation. No data sufficiency threshold was applied.
Soil permeability can indicate potential ground water contamination.
Actual contamination depends on several other factors that facilitate pollutant transport and increased risk of ground water contamination and how much pollution is available to percolate into ground water. Plans to Improve this Data EPA plans to develop more robust ground water data layers in future phases of the Index of Watershed Indicators through collaboration with states, other federal agencies and associations. This and other candidate ground water layers are presented with IWI Version 1.2 to begin these discussions. EPA is working with states, tribes, other federal agencies, and other partners to develop a more thorough approach to assessing both ground waters and surface waters following the work of the National Water Quality Monitoring Council. States are continuing to improve and establish ground water monitoring programs which should lead to better and more accurate data and to make this information available to the public.