Diurnal variability in concentrations and sources of Escherichia coli in three streams.

Microbial contamination is a major concern for drinking water worldwide. Many monitoring protocols that use one or very few samples are inadequate and introduce a very large margin of error. An intensive sampling program needs to be conducted to characterize the Escherichia coli concentrations of a source water stream prior to establishing a monitoring program so that the sample frequency can be determined statistically, based on an acceptable margin of error.

Spatial and annual variability in concentrations and sources of Escherichia coli in multiple watersheds.

Nonpoint source fecal contamination is a concern for drinking water supplies worldwide. In this study, 4812 E. coli isolates were classified to source.