Assessing the Likelihood of Pathogen Transport in Groundwater

The EPA, through the Groundwater Rule, has found that pathogens can survive and transport in groundwater. Alternatively, the NRC and the NBP have stated that pathogen movement through groundwater is limited. Protecting human health from pathogen transport requires bridging between these two divergent points of view. This paper develops a framework for completing determinations of the susceptibility of aquifers to support pathogen transport. Through a thorough literature review regarding properties that affect pathogen removal in porous media and documented pathogen transport through groundwater, a framework is developed, and then confirmed, that allows for the straightforward assessment of the likelihood of pathogen transport. The literature review regarding the properties that control removal shows that a predominance of aquifer soils and pathogens has similarly low values for pH of zero point of surface charge. The literature review regarding documented pathogen transport in natural groundwaters shows that in the cases of considerable pathogen transport, the types of soils and pathogens had similarly low values for pH of zero point of surface charge. This work shows that defining the likelihood of pathogen transport only requires knowing the aquifer pH and velocity and type of aquifer soil.