Susceptibility Analysis

After the inventory of PSOCs is completed, the susceptibility of the water source to possible contaminants  is analyzed.  This analysis only provides information regarding PSOCs that were included in the inventory.  The analysis tool is not designed to predict or to show that a contamination event has taken place.  Moreover, numeric values are not placed on contaminant concentrations. 

The analysis process is divided into two categories:   Physical setting vulnerability of the water source describes how susceptible one water source is in relation to its physical location.  Vulnerability is influenced by biological and geographical conditions such as land area, average annual precipitation, soil infiltration rate, vegetation density, and structural integrity of the water intake.  Contaminant source threat is a measure of the direct threat posed by a PSOC, and is dependent on the potential for contaminant migration, the likelihood that contaminants will be released, contaminant hazards and volume.  The combination of vulnerability  and threat gives a projected level of susceptibility of the water source to contamination.  The State of Colorado created a susceptibility analysis model, which was used to conduct susceptibility analyses for over 3,000 individual water sources.