Thomas Kwader looks at soil contamination, how it occurs and its impact on ground water.
There have been many articles written on the occurrence of metals in ground water due to the turbidity of the samples, which contain suspended inorganic particles that release excess metals into solution when the sample is processed. A similar phenomenon occurs when collected soil samples contain a large percentage of clay. Clays are nature's “junk” deposits that often concentrate leftover minerals sorted from the sedimentary processes. Phosphatic clays in the Hawthorn Formation (southeastern U.S. Coastal Plain) and Wyoming bentonite clays (drilling mud) for example, often contain high concentrations of arsenic, lead, mercury, chromium, etc. If these elements are occurring in soil or ground water samples above action levels, it may be prudent to obtain background samples.