Under the Unregulated Contaminant Monitoring Rule, the EPA gathers data about select unregulated contaminants to determine how often they appear in drinking water and at what levels.  GenX is considered an "emerging contaminant".  The EPA uses the data along with relevant health effect studies to determine if regulation is necessary, and if so, at what levels.  For more information on this monitoring rule, please visit the EPA’s website www.epa.gov