http://www.epa.gov/ogwdw/pdfs/factsheet ... barium.pdfBarium is found in waste streams from a large number of manufacturing plants in quantities that seldom exceed the normal levels found in soil. Background levels for soil range from 100-3000 ppm barium. Occurs naturally in almost all (99.4%) surface waters examined, in concentration of 2 to 340 ug/l, with an average of 43 ug/l. The drainage basins with low mean concentration of barium (15 ug/l) occur in the western Great Lakes, & the highest mean concentration of 90 ug/l is in the southwestern drainage basins of the lower Mississippi Valley. In stream water & most groundwater, only traces of the element are present.
There are limited survey data on the occurrence of barium in drinking water. Most supplies contain less than 200 ug/l of barium. The average concentration of barium in USA drinking water is 28.6 ug/l (1977 data). The drinking water of many communities in Illinois, Kentucky, Pennsylvania, & New Mexico contains concentrations of barium that may be 10 times higher than the drinking water standard. The source of these supplies is usually well water. Currently 60 ground water supplies and 1 surface water supply exceeds 1000 ug/l.
http://rais.ornl.gov/documents/eco-ssl_aluminum.pdfAluminum (Al) is the most commonly occurring metallic element comprising eight percent of the earth's crust (Press and Siever, 1974). It is a major component of almost all common inorganic soil particles with the exceptions of quartz sand, chert fragments, and ferromanganiferous concretions. The typical range of aluminum in soils is from 1% to 30% (10,000 to 300,000 mg Al kg-1) (Lindsay, 1979 and Dragun, 1988) with naturally occurring concentrations variable over several orders of magnitude.
EPA recognizes that due to the ubiquitous nature of aluminum, the natural variability of aluminum soil concentrations and the availability of conservative soil screening benchmarks (Efroymson, 1997b), aluminum is often identified as a contaminant of potential concern (COPC) for ecological risk assessments. The commonly used soil screening benchmarks (Efroymson, 1997b) are based on laboratory toxicity testing using aluminum solution amendments to test soils. Comparisons of total aluminum soil concentrations to solution based screening values are deemed by EPA to be inappropriate.