Coliforms are naturally present in the environment. Fecal Coliforms and E.coli only come from human and animal fecal waste as well as faces. Total Coliform is used to indicate whether other potentially harmful bacteria may be present. The EPA maximum contaminant level of Total coliform allowed in drinking water is Zero per 100ml of water volume. If the result of Total Coliform is present in any drinking water, Fecal Coliform and E. coli must be analyzed immediately. The maximum contaminant level allowed in drinking water for Fecal Coliform and E. coli are zero per 100ml of water volume. The presence of any Fecal Coliform or E. coli bacteria indicates that the water may be contaminated with human or animal wastes. Disease-causing, microbes (pathogens) in these waters can cause diarrhea, cramps, nausea, headaches or other symptoms. These pathogens many pose a special health risk for infants, young children, and others.

Heterotrophic Plate Count (HPC) is an indicator bacteria usually to be used in drinking water monitoring test to measure the variety of bacteria that are common in water. The lower concentration of HPC bacteria in drinking water, the better maintained the water system is. Heterotrophic Plate Count (HPC) bacteria has no health effects in low concentration. The recommended limit for Heterotrophic Plate Count is less than 500 Colony Forming Unit (CFU) per milliliter of water volume

　　　　　　　　　　Total Coliform
　　　　　　　　　　Fecal Coliform
　　　　　　　　　　E. coli
　　　　　　　　　　Heterotrophic Plate Count (HPC)