Factors influencing the challenges of modelling and treating fecal indicator bacteria in surface waters

Abstract

In the United States, thousands of creeks, rivers, and coastal zones are listed as impaired in the Clean Water Act's 303(d) list. The number one general cause of impairments is denoted as 'pathogens', which can include known pathogenic organisms or, more commonly, fecal indicator bacteria (FIB), such as fecal coliform bacteria, Escherichia coli, and enterococci bacteria. Despite efforts by water quality managers to reduce FIB in surface waters via treatment, successful and significant reduction of FIB has been difficult to achieve to meet water quality standards. In addition, current efforts to numerically model FIB concentrations in surface waters do not consider many complexities associated with FIB as a pollutant. Reasons for the challenge of treating and modelling FIB are their varied sources and mechanisms of survival and decay in the environment. This technical note addresses this challenge by discussing the nature of FIB, their sources, and their fate and transport mechanisms. Sources of FIB to surface waters include wastewater, stormwater and dry-weather runoff, and animals. Mechanisms of pathogen indicator occurrence in surface waters are transport in stormwater, ecological proliferation, and interaction with sediments.

Effects of Feral Pig (Sus scrofa) Exclusion on Enterococci in Runoff from the Forested Headwaters of a Hawaiian Watershed

“…They are found in fecal material at high concentrations and are relatively easy to measure in the environment. The high diversity of pathogenic microorganisms transmitted by contaminated water and the difficulty and cost of directly measuring these microbial pathogens in environmental samples have led to the use of FIB to test for the presence of fecal contamination (Gersberg et al 2006;Wade et al 2006;Surbeck 2009). The US Environmental Protection Agency (US EPA) recommends the use of Escherichia coli, a member of the fecal coliform group, as a FIB for recreational freshwater bodies and members of the genus Enterococcus for both freshwater and saltwater (US EPA 2000).…”

“…The US Environmental Protection Agency (US EPA) recommends the use of Escherichia coli, a member of the fecal coliform group, as a FIB for recreational freshwater bodies and members of the genus Enterococcus for both freshwater and saltwater (US EPA 2000). FIB are commonly used as an indicator that guides development of water management plans (Plummer and Long 2007;Surbeck 2009). Such plans generally involve interventions to reduce FIB loadings to receiving waters.…”

Water-quality data and Escherichia coli predictions for selected karst catchments of the upper Duck River watershed in central Tennessee, 2007–10

“…These markers were identified according to previously described methods for HuBac (Layton and others, 2006), HF183, and BoBac (Surbeck, 2009). The two human Bacteroides spp.…”

The Nearshore Heat Budget: Effects of Stratification and Surfzone Dynamics

“…For instance, temperature fluctuations can directly affect the nearshore ecosystem by altering growth rates, egg mass production rates (e.g., Broitman, Blanchette, & Gaines, ; Fischer & Thatje, ; Phillips, . ), coral health (Safaie et al, ; Schramek et al, ), and pathogen ecology and mortality (e.g., Goodwin et al, ; Surbeck, ). Temperature is a useful indicator of nutrient delivery to the nearshore (e.g., Omand et al, ), nearshore mixing and exchange due to (for example) rip currents (e.g., Hally‐Rosendahl et al, ; Kumar & Feddersen, ) or internal waves, which can transport larvae and nutrients (Pineda, ) as far as the surfzone (Sinnett et al, ).…”