Indicators can be used for various purposes as part of a recreational water quality management plan. Fecal indicators signal the likely presence of fecal contamination. Common fecal indicators include E. coli and enterococci, as well as source-specific fecal indicators, such as the HF183 Bacteroides genetic marker for detecting human sewage (Harwood et al., 2014). E. coli or enterococci are used as the primary indicators of fecal material in fresh waters, with enterococci the preferred indicator for marine waters. Source-specific fecal indicators are used when microbial source tracking is recommended.