Survival rates for individual types of fecal organisms are quite different. Although some pathogens may persist as long as 5 years in soil, most fecal pathogens from human and animal waste usually die very quickly. Two to three months is sufficient in most cases to reduce pathogens to negligible numbers once they have been excreted or land-applied in animal wastes.
It is expensive and time- consuming to test for individual pathogens. Consequently, nonpathogenic fecal indicator bacteria, which are easily and inexpensively detected, are often used to study pathogen survival in soil and water. Current methods for rapidly detecting fecal indicator bacteria use the capacity of fecal coliforms (e.g. Escherichia coli) to metabolize a fluorescent indicator compound, 4-methylumbelliferyl ß-D-glucuronide (MUG) as evidence for fecal contamination.
Mubiru, D. N.; Coyne, Mark S.; and Grove, John H., "Escherichia coli Pathogen O157:H7 Does Not Survive Longer In Soil Than A Nonpathogenic Fecal Coliform" (2000). Agronomy Notes. 4.