Several studies have been conducted on behalf of the U.S. Environmental Protection Agency (EPA) to identify detection monitoring parameters for specific industries. One outcome of these studies was the evolution of an empirical multi-variant contaminant fingerprinting process. This process, Fingerprint Analysis of Leachate Contaminants (FALCON), was developed through the EPA's Technical Support Center (TSC) in response to the need for identifying the source of contaminant plumes. FALCON combines data for several contaminants to develop a distinctive graphical fingerprint or multi-parameter chemical signature. These fingerprint patterns can be used to characterize the source of a contaminant plume, differentiate the contaminant plume from background conditions at the source, and monitor the migration of leachate into the environment. It can be applied to both organic and inorganic contaminants and is effective over a wide range of contaminant concentrations. This data evaluation process is analogous to using fingerprints to identify individuals. However, rather than using the size and location of ridges and swirls on the fingertip, the relative abundance of selected constituents is used to develop distinctive chemical signatures. The objective of this paper is to demonstrate that FALCON is a quantitative, defensible fingerprinting process. A description of the stepwise FALCON technique is provided in Section 2.0. Examples are presented to illustrate the range of situations in which fingerprinting can be applied to characterize the occurrence and distribution of environmental contaminants. These examples were developed using routine monitoring data obtained from a variety of ongoing site characterization and monitoring programs. Case studies of FALCON applications are presented in Section 3.0.

Caption title. "May 2004." "EPA/600/5-04/054." Includes bibliographical references (p. 26-27).