Sources Of Fecal Indicator Bacteria Research Articles

Modeling the dry-weather tidal cycling of fecal indicator bacteria in surface waters of an intertidal wetland

Recreational water quality at beaches in California and elsewhere is often poor near the outlets of rivers, estuaries, and lagoons. This condition has prompted interest in the role of wetlands in modulating surface water concentrations of fecal indicator bacteria (FIB), the basis of water quality standards internationally. A model was developed and applied to predict the dry-weather tidal cycling of FIB in Talbert Marsh, an estuarine, intertidal wetland in Huntington Beach, California, in response to loads from urban runoff, bird feces, and resuspended sediments. The model predicts the advection, dispersion and die-off of total coliform, Escherichia coli, and enterococci using a depth-integrated formulation. We find that urban runoff and resuspension of contaminated wetland sediments are responsible for surface water concentrations of FIB in the wetland. Model predictions show that urban runoff controls surface water concentrations at inland sites and sediment resuspension controls surface water concentrations near the mouth. Direct wash-off of bird feces into the surface water is not a significant contributor, although bird feces can contribute to the sediment bacteria load. The key parameters needed to accurately predict FIB concentrations, using a validated hydrodynamic model, are: the load due to urban runoff, sediment erodibility parameters, and sediment concentrations and surface water die-off rates of enteric bacteria. In the present study, literature values for sediment erodibility and water column die-off rates are used and average concentrations of FIB are predicted within 1/2 log unit of measurements. Total coliform are predicted more accurately than E. coli or enterococci, both in terms of magnitude and tidal variability. Since wetland-dependent animals are natural sources of FIB, and FIB survive for long periods of time and may multiply in wetland sediments, these results highlight limitations of FIB as indicators of human fecal pollution in and near wetlands.

Use of Fecal Steroids To Infer the Sources of Fecal Indicator Bacteria in the Lower Santa Ana River Watershed, California: Sewage Is Unlikely a Significant Source

The Santa Ana River (SAR), CA and adjacent wetlands have been identified as potential sources of fecal indicator bacteria (FIB) to the surf zone at Huntington Beach, CA. A suite of fecal steroids, including coprostanol (COP), epicoprostanol (eCOP), cholesterol (CHOE), cholestanol (CHOA), alpha-cholestanone (aONE), beta-cholestanone (bONE), beta-sitosterol (bSIT), stigmasterol (STIG), stigmastanol (STAN), and campesterol (CAM), were used as chemical markers to examine whether sewage was a significant source of FIB within the lower Santa Ana River watershed. A total of 54 water samples were collected from three locations in the intertidal zone near the mouth of the Santa Ana River at different tidal stages. Steroid ratios in SAR samples were different from those found in raw and treated sewage from a local wastewater treatment plant or in nearby effluent plume and did not appear to be influenced by the sampling location, daily tides, and spring/neap tidal cycle. The characteristics of steroid ratios suggested a diagenetic ratherthan a biogenic source forthe COP content of the samples. The log-based concentrations of COP and FIB in the SAR samples were not significantly correlated, inconsistent with sewage being the source of FIB in the study area. In addition, multivariate statistical analysis showed that the concentrations of FIB were better correlated with bird fecal steroids than with the typical sewage sterols. The results implied that sewage was not a significant source of fecal steroids, and therefore perhaps FIB to the study area. Instead, birds may be one possible source of the intermittently high levels of FIB observed in the lower Santa Ana River watershed and the nearby surf zone.

Tiered approach for identification of a human fecal pollution source at a recreational beach: case study at Avalon Bay, Catalina Island, California.

Recreational marine beaches in California are posted as unfit for swimming when the concentration of fecal indicator bacteria (FIB) exceeds any of seven concentration standards. Finding and mitigating sources of shoreline FIB is complicated by the many potential human and nonhuman sources of these organisms and the complex fate and transport processes that control their concentrations. In this study, a three-tiered approach is used to identify human and nonhuman sources of FIB in Avalon Bay, a popular resort community on Catalina Island in southern California. The first and second tiers utilize standard FIB tests to spatially isolate the FIB signal, to characterize the variability of FIB over a range of temporal scales, and to measure FIB concentrations in potential sources of these organisms. In the third tier, water samples from FIB "hot spots" and sources are tested for human-specific bacteria Bacteroides/Prevotella and enterovirus to determine whether the FIB are from human sewage or from nonhuman sources such as bird feces. FIB in Avalon Bay appear to be from multiple, primarily land-based, sources including bird droppings, contaminated subsurface water, leaking drains, and runoff from street wash-down actvities. Multiple shoreline samples and two subsurface water samples tested positive for human-specific bacteria and enterovirus, suggesting that at least a portion of the FIB contamination is from human sewage.

Identification of the sources of fecal coliforms in an urban watershed using antibiotic resistance analysis

Bacteria such as fecal coliforms are used as indicators of fecal pollution in natural waters. These bacteria are found in the feces of most wild and domestic animals and thus provide no information as to the source of fecal contamination, yet identification of indicator bacteria sources allows improved risk assessment, remediation, and total daily maximum load (TDML) assessment of environmental waters. This bacterial source tracking study was initiated in order to identify the dominant source(s) of fecal contamination in the urban watershed of Stevenson Creek in Clearwater, Florida. Five sites that represent areas where routine monitoring has previously shown high levels of fecal coliforms were sampled over 7 months. Fecal coliforms were enumerated by membrane filtration, and antibiotic resistance analysis was used to “fingerprint” a subset of randomly selected isolates and statistically match them to fingerprints of fecal coliforms from known sources (the library). A field test of the classification accuracy of the library was carried out by isolating fecal coliforms from the soil and waters surrounding a failing onsite wastewater treatment and disposal system (OSTDS). The vast majority of the isolates were classified into the human category. The major sources of fecal pollution in Stevenson Creek over the course of the study were wild animal, human, and, to a lesser extent, dog. Overall, wild animal feces were identified as the dominant source when fecal coliform levels were high, but when fecal coliform levels were low, the dominant source was identified as human. The results of this study demonstrate that the sources of fecal indicator bacteria within one urban watershed can vary substantially over temporal and spatial distances.

Sources of faecal indicator bacteria in a brackish, tropical stream and their impact on recreational water quality

This study assessed the contribution of water from a stream on the microbial quality of a swimming beach. The faecal indicator bacterial concentrations/100mL in Kaelepulu Stream greatly exceeded the three USEPA recreational water quality standards (200 faecal coliform, 126 E. coli, 33 enterococci). The primary sources for these indicator bacteria were determined to be environmental/non-point sources (tributary streams, storm drains, duck faeces, soil, rain). Sewage discharge is another, although sporadic source. Monitoring waters for C. perfringens was the most reliable indicator of sewage contamination primarily because soil is not a major source of this bacterium. Water from this inland system was a source of faecal indicator recovered from shoreline water samples obtained from Kailua Beach, one of the most popular beaches in the state of Hawaii.

Sources of faecal indicator bacteria in a brackish, tropical stream and their impact on recreational water quality

This study assessed the contribution of water from a stream on the microbial quality of a swimming beach. The faecal indicator bacterial concentrations/100mL in Kaelepulu Stream greatly exceeded the three USEPA recreational water quality standards (200 faecal coliform, 126 E. coli, 33 enterococci). The primary sources for these indicator bacteria were determined to be environmental/non-point sources (tributary streams, storm drains, duck faeces, soil, rain). Sewage discharge is another, although sporadic source. Monitoring waters for C. perfringens was the most reliable indicator of sewage contamination primarily because soil is not a major source of this bacterium. Water from this inland system was a source of faecal indicator recovered from shoreline water samples obtained from Kailua Beach, one of the most popular beaches in the state of Hawaii.

INDICATOR BACTERIA CONCENTRATIONS OF TWO NORTHWEST ARKANSAS STREAMS IN RELATION TO FLOW AND SEASON

Concentrations of indicator bacteria such as fecal coliform (FC) and fecal streptococcus (FS) are often usedto assess the suitability of waters for their intended use(s) and to allocate resources for water quality improvementmeasures. There is evidence, however, that concentrations of FC and FS can be influenced by variables such as seasonand flow rate during sampling, which could lead to biased results. The objective of this study was to assess the impacts ofseason and flow rate on concentrations of FC and FS. Fecal indicator bacteria concentrations were measured forapproximately three years at five sites on two Northwest Arkansas streams. Flow data were collected at two of the fivesites. Land use in the basins draining the streams was primarily pasture (57-90%) and forest (6-40%). Significantseasonal influences on FC and FS concentrations were detected for all sampling sites, with the highest concentrationsoccurring in summer. On the two sites with flow data, flow rate generally had a significant effect on FC and FSconcentrations during all seasons, with FC and FS concentrations increasing with flow rate. Ratios of FC and FS, whichhave been used in the past to differentiate between animal and human sources of fecal pollution, did not appear toreliably indicate the major sources of fecal indicator bacteria. The findings of this study suggest a potential for fixedsampling intervals to contribute to biased results. The issue of biased results might be avoided by sampling during timesof year and flow conditions that support the intended use(s) of the waters.

Clostridium perfringens as a point source indicator in non-point polluted streams

Clostridium perfringens spores were evaluated as an indicator of point source pollution in small streams whose bacteriological water quality was influenced by both point and non-point sources. Samples were collected from small streams (the Rio San Jose, New Mexico and Worm Creek, Idaho/Utah); the Grants, New Mexico; Preston, Idaho; Hyrum, Utah; and San Jose/Santa Clara, California; sewage treatment plant effluents; and the Franklin, Idaho; Logan, Utah; and Wellsville, Utah: facultative sewage lagoons. In both of the small streams, C. perfringens spores could be detected, in decreasing concentrations, for more than 10 km downstream from municipal wastewater treatment plant effluents. Coliform and fecal streptococci concentrations varied widely along the streams in apparent response to non-point sources. Samples of cow, horse and sheep feces; farmlot runoff; oxbow lakes that receive fecal material from animal feeding facilities; and from animal grazing area soil were low in C. perfringens spores, but contained high concentrations of other fecal indictor bacteria. C. perfringens spores appear to be a sensitive indicator for microorganisms entering streams with municipal wastewater, even when agricultural non-point sources of fecal indicator bacteria are important in the receiving stream. Samples of effluents taken from sewage treatment plants with sand filtration processes, and from facultative sewage lagoons, indicate that C. perfringens spores concentrations may be low in these effluents.

Some effects of shoreline cottage development on lake bacteriological water quality

Eighteen cottaged lakes and one uncottaged lake in Southern Ontario, and their inflowing streams were surveyed for bacterial indicators of pollution by membrane filter techniques. Water samples were taken on 5 consecutive days in the spring, summer, and fall of the year. Inputs of fecal indicator bacteria were determined through an analysis of variance. Fecal coliform and fecal streptococcus levels in lakewater varied in a seemingly erratic manner. When the bacterial densities at different points on the lake were examined by an analysis of variance, the locations with significantly higher densities of fecal coliforms and fecal streptococci were most often found along the cottaged shoreline. Total coliform densities did not show this relationship with the cottaged shoreline. In addition, after rainfall, a large increase in numbers of fecal coliforms were found in the cottaged lakes but not in the uncottaged lake. These findings indicated that the cottaged shoreline was a greater source of fecal indicator bacteria than the uncottaged shoreline. However, the highest concentrations of fecal indicator bacteria in these lakes were found in the inflowing streams. The bacteria in these streams arose from stormwater from undeveloped forested watersheds and were probably, therefore, of soil or animal origin.

Some effects of pulp and paper wastewater on microbiological water quality of a river

A study was conducted to detect the source of fecal indicator bacteria and measure the resulting impairment of water quality of the Sturgeon River at Sturgeon Falls, Ontario, Canada. The bacteriological water quality of the river above the dam at Sturgeon Falls was fairly good, while below the dam the water quality was degraded. The principal input of fecal indicator bacteria was traced to the paper mill at Sturgeon Falls. The impairment of water quality was detected all the way to recreational areas near the mouth of the river. The impaired stretch of the river had diminished aesthetic appeal. Other sources of indicator bacteria could be masked by the large numbers of similar bacteria discharged from the paper mill. The principal fecal coliform was Klebsiella pneumoniae. In pulp mill wastes the fecal origin of this bacterium can be disputed, and so its presence in large numbers interfered with the interpretation of fecal coliform results. K. pneumoniae is also an opportunistic pathogen which causes infections in humans. Thermotolerant oxidase positive bacteria which were isolated from the paper mill wastes, register as false positives in the fecal coliform test causing problems in interpretation. Pseudomonas aeruginosa was detected in the pulp mill wastewater, and at a level of 82 PA 100 ml −1 in recreational areas of the river. This was considered to be of some hazard to users of the water. In addition, Escherichia coli was detected in the mill wastewater, at about 200 EC 100 ml −1, and this probably indicated some measure of fecal pollution though likely of animal origin. Finally the nutrient rich wastewater led to an approx. 50-fold increase in density of aerobic heterotrophic bacteria in the river water, as well as the production of a slimy filamentous growth on surfaces, stones and wooden pilings, in the river. The principal organism in this slime was the fungus Leptomitus.

Some effects of land use on bacteriological water quality in a recreational lake

A study was conducted to detect the source of fecal indicator bacteria and the resulting degree of bacteriological water quality impairment of Mississippi Lake, a shallow eutrophic lake in southern Ontario, Canada. The lake was intensively sampled during two 5-day periods in late May-early June, and in July of 1976. The main detectable sources of fecal coliform were cattle watering sites, farms, public beaches, some flooded and substandard septic tanks, and a bird sanctuary. The impairment of water quality was localized to shoreline locations near the suspected source of the input of bacteria. After rainfall, about a 10-fold increase was noted in the levels of fecal coliforms and fecal steptococci in all lake surface water sampled. The effect was short-lived lasting only 2 or 3 days after the main rainfall. The levels of indicator bacteria were low and did not exceed maximum levels set down for Water Quality Management in Ontario, of 1000 TC(100 ml) −1 and 100 FC(100 ml) −1 at recreational areas. For this lake and six others in southern Ontario, the LOG of spring densities of aerobic heterotrophic bacteria correlated significantly with the LOG of mean summer chlorophyll a concentration ( r = 0.80). Cottagers on Mississippi Lake were surveyed for their swimming habits and for the incidence of disease associated with swimming. The largest cause of disease associated with bathing, 57 of 67 reported infections, was infection of the ear; 3.28% of bathers at shoreline cottages suffered ear infections. The frequency of ear infections in the population of swimmers was significantly associated with the amount of swimming in the lake. Males and females were infected at equal rates. Young people suffered a significantly higher rate of ear infections than adult bathers. Frequency of water contact was probably greater in young people than in adults and may explain the greater number of ear infections in young swimmers. These studies provided the basis for recommendations designed to improve lakewater quality.