What is the purpose of the Heterotrophic Plate Count (HPC) analysis and is it a replacement for Total Coliform analysis? What are the action limits for the HPC analysis?
TestAmerica Expert: Alex Spears
Expert's Response:
The purpose of the HPC (heterotrophic plate count) test is to determine the total heterotrophic (environmental) bacteria load present in the water sample, and is not used in lieu of the total coliform test, as the total (and fecal) coliform tests are used in determining the possible presence of pathogens in the water. The EPA action limit for potable (drinking) water is 500 cfu/mL. More information about the EPA guidelines and action limits can be found at http://water.epa.gov/drink/contaminants/index.cfm#3.
