Utilization of Tryptophan-like Fluorescence as a Proxy for E. coli Contamination in a Mixed-Land-Use Karst Basin

Karst aquifers are susceptible to contamination by pathogenic microorganisms, such as those found in human and animal waste, because the surface subsurface drainage well integrated through dissolution features. Fecal of water is commonly assessed concentration thermotolerant coliform bacteria, especially E. coli. This method time-consuming, taking ≥18 h between start incubation subsequent enumeration, time required collect transport samples. We examined utility continuous monitoring tryptophan-like fluorescence (TLF) a real-time proxy for coli mixed-land-use karst basin Inner Bluegrass region central Kentucky (USA). Two logging fluorometers were sequentially deployed at outlet spring. During storm flow, TLF typically peaked after discharge, which suggests that phreatic conduit likely related sediment transport. The ability other parameters (48 antecedent precipitation, turbidity, air temperature) predict concentrations was using Akaike information criterion (AIC) applied linear regression models. Because both models baseline differed fluorometers, instrument interaction accounted AIC. positively correlated with and, conjunction best predictor However, model included temperature precipitation but not predicted similarly well. Given expense performance alternate model, may be cost-effective this basin.