Changes in Concentration of Two Contaminants over Time

This method assumes that if two or more contaminants were released from a single, slug-type release, the date upon which these contaminants entered the water table or aquifer is equivalent to the time when their relative concentrations were the same as the source material. This method does not require initial concentration information, and is not dependent on changes due to a particular subsurface process (i.e., 

Alvarez, P. J., Heathcote, R. C., and Powers, S. E., 1998, Caution Against Interpreting Gasoline Release Dates Based on BTEX Ratios Ground Water Monitoring Review, Fall, 1998, pp. 69-76. 

Vanadium and nickel in crude petroleum of South America and Middle East Origin Journal of Chemistry and Engineering News, Vol. 42, No. 15, pp. 307-308. 

and Davidson, R. L., 1967, Petroleum Processing Handbook. McGraw-Hill Book Company, New York. 

Oil Storage Tanks and Reservoirs with a Brief Discussion of Losses of Oil in Storage and Methods of Prevention US. Department of the Interior Bureau of Mines Bulletin, No. 155, Petroleum Technology No. 41, 76 pp. 

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