The Las Vegas Wash, the only drainage channel for the Las Vegas hydrographic basin, drains to Lake Mead, the major source of drinking water for the Las Vegas valley. High levels of fecally-associated bacteria are observed in the Wash, particularly during the summer months; Several studies were undertaken to investigate the indicator organisms in the Las Vegas Wash. Attempts were made to determine the source(s) of fecal bacteria, with results pointing toward overall species being environmentally-associated as opposed to being a result of human contributions. Wash enterococci showed high resistance to low levels of vancomycin. Regrowth potential of Escherichia coli in Wash water generally demonstrated low growth. Coliform resuscitation from wastewater effluent was attempted from wastewater disinfected by chlorination, chloramination or UV. Data indicate statistically insignificant recovery from wastewater disinfected by chlorination or chloramination, but UV irradiation induced bacterial resuscitation in UV-disinfected wastewater effluent
