Trace element distribution in US groundwaters: a probabilistic assessment using public domain data

A large database of dissolved-fraction groundwater concentrations for Ag, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, Sn, V and Zn was constructed using public domain data. Data analysis techniques for multiply-censored sample populations were used to extract salient information regarding sample populations from the raw data. The results of this work show that trace element concentrations are approximately log-normally distributed. Median values for <90% censored sample populations range from 0.2 to 35 μg l−1. Minimum to maximum concentrations range as high as 7 orders of magnitude for certain elements (e.g. Zn). This work provides a rapid, cost-effective screening tool for evaluating groundwater quality based on observed trace element concentration data.