Certain types of bacteria (like coliform bacteria) are used as indicators of pathogenic bacterial contamination in water samples.  The coliform bacteria are ubiquitous in the environment, even growing in soils.  Fecal coliform bacteria grow only in the intestinal tracts of mammals.  While most coliform are harmless, the levels of Total Coliform (TC) and Fecal Coliform (FC) (a subset of TC) are used as an indicator for the potential presence of other pathogenic, disease-causing bacteria.  Samples are analyzed by culturing any TC/FC bacteria present, counting the number of colonies, and using statistical models to generate a Most Probable Number (MPN) of bacteria present in 100mL of sample water.  Because it is an indirect measure of potential threat to human health, fecal coliform bacteria is widely-acknowledged to be an inadequate method for identifying levels of pathogens in water.  While new methods of determining source organisms and direct pathogen detection are emerging, they remain inconsistent and prohibitively expensive at present.   The RWQCB's Basin Plan (RWQCB 2007) established numeric objectives for total and fecal coliform bacteria in surface waters based on three beneficial uses: Contact Recreation, Non-Contact Recreation and Shellfish Harvesting.  (see table 1 for numeric targets).