A Bayesian statistical water quality model is demonstrated to predict fecal-indicator bacterial concentrations for waterbodies without sufficient monitoring data for data-intensive modeling ...techniques. Using a truncated bivariate normal likelihood function and the readily available observations of flow and bacterial concentration, the Bayesian approach propagates the uncertainty in the model parameterization to the final predictions of in-stream bacterial concentration. The proposed model captures the variation in the magnitude of bacterial loading between dry and wet conditions by estimating separate sets of model parameters for different flow conditions, but also has the capability to pool the data among flow conditions. The model can be used in two ways: first, the model specifies the percent of time that the recreational season in-stream concentration is not in compliance with the relevant water quality standard, and second, the model estimates the necessary bacterial load reduction for multiple flow conditions to meet the relevant water quality standard. Using an eleven year monitoring record for a site sampled at a monthly frequency on the Youghiogheny River in southwestern Pennsylvania, USA, the model parameters are updated and posterior predictions are generated for each 2-year increment. After six years of sampling, the predicted percent of time that the recreational season in-stream bacterial concentration is not in compliance with the relevant water quality is 82% with 95% CI(80,85), and the bacterial load reductions required to meet the standard are 14.7 CI(14.6,14.8), 14.5 CI(14.3, 14.6), and 14.0 CI(13.9, 14.2) log
10(cfu/day) for the high, normal, and dry flow conditions, respectively. The change in estimated load reduction and percent exceedance resulting from additional monitoring for this site becomes small after six years of sampling, indicating that a decision does not need to be postponed for additional monitoring.
We present the kinetics of fecal indicator bacteria (FIB) after dilution of wastewater in seawater under laboratory conditions (at 208C). We studied the decay rates of FIB, which were found in raw ...sewage and in the effluent of secondary treatment. After dilution in seawater there was a rapid destruction of the microorganisms at a rate faster than that has undergone through a secondary treatment.
Use of holy springs and holy water is inherent in religious activities. Holy spring water is also used extensively for personal drinking water, although not assessed according to drinking water ...standards. Holy water in churches and chapels may cause infections via wetting of lips and sprinkling on persons. Our aim was to assess the microbiological and chemical water quality of holy springs and holy water in churches and hospital chapels. Of the holy springs investigated, only 14% met the microbiological and chemical requirements of national drinking water regulations. Considering results from sanitary inspections of the water catchments, no spring was assessed as a reliable drinking water source. All holy water samples from churches and hospital chapels showed extremely high concentrations of HPC; fecal indicators, Pseudomonas aeruginosa and Staphylococcus aureus occurred only in the most frequently visited churches. We conclude that it is highly necessary to include holy springs in programs for assessment and management of water quality. Public awareness has to be raised to perceive holy springs as potential sources of illness. Holy water can be another source of infection, especially in hospital chapels and frequently visited churches. Recommendations are made for proper water quality management of both water types.
Point and nonpoint sources contribute to fecal contamination of surface waters by human pathogens that exist at low concentrations and are difficult, expensive, and/or impossible to easily detect. ...Therefore, fecal indicator bacteria (FIB) are used as surrogates in identification of fecal contamination, including Escherichia coli (EC) and Enterococcus spp. (ENT), at recreational beaches to protect from adverse health effects from exposure to water-borne pathogens. The objective of the current study was to conduct a preliminary investigation of the environmental processes contributing to the nature and significance of FIB (EC and ENT) over 30 d at Sandpoint beach (Windsor, Ontario) and Holiday beach (Amherstburg, Ontario). Daily, three 100 mL samples were collected for EC and ENT for analysis by Colilert® and Entrolert®, respectively. Additionally, physicochemical and hydrometerological data were measured or taken from data archives. Both EC and ENT populations were dynamic and well correlated to each other (p < 0.05; analysis of variance (ANOVA)) and both FIB correlated with turbidity and wave height (p < 0.10; ANOVA). Despite being geographically close and therefore having similar meteorological data, both beaches exhibited markedly different FIB, turbidity and wave height data, suggesting that beach-specific data should be considered for any future predictive applications.
Aims: The object of this study was to assess the usefulness of the H 2 S test for detection of fecal pollution of water in comparison to fecal indicator bacteria (FIB). Materials and Methods: A total ...of 70 raw water samples were collected from drinking water sources in Isfahan province of Iran, aseptically in sterile containers during May-October 2012.The modified H 2 S test medium of Manja et al. was used except that L-cysteine was added as an additional medium component. Total coliforms (TCs), fecal coliforms (FCs), and fecal streptococci (FS) were also estimated by multiple-tube fermentation method. Statistical analyses were carried out using SPSS 20 at the 95% confidence level (α = 0.05). Results: It was found that out of 70 water samples assessed, 48.3%, 30.0%, 34.6%, and 32.9% of the samples were positive for TCs, FCs, FS, and H 2 S, respectively. Analysis of data showed that 95.6%, 69.5%, and 76.9% of water samples, which were positive for H 2 S test were also positive for TCs, FCs, and FS, respectively. The H 2 S test was found to have the highest accuracy for the detection of FS, but it was not a suitable indicator for the prediction of FCs. Conclusions: Our results showed that H 2 S test is not a suitable alternative approach for routine water quality monitoring. However, the H 2 S test could be used as an easy and economic test to assess the quality of drinking water in communities where manpower and sophisticated equipment are inadequate. More laboratory and field studies are required to assess the reliability of the method as an alternative method of traditional indicators.
California’s Clean Beach Initiative (CBI) funds projects to reduce loads of fecal indicator bacteria (FIB) impacting beaches, thus providing an opportunity to judge the effectiveness of various CBI ...water pollution control strategies. Seventeen initial projects were selected for assessment to determine their effectiveness on reducing FIB in the receiving waters along beaches nearest to the projects. Control strategies included low-flow diversions, sterilization facilities, sewer improvements, pier best management practices (BMPs), vegetative swales, and enclosed beach BMPs. Assessments were based on statistical changes in pre- and postproject mean densities of FIB at shoreline monitoring stations targeted by the projects. Most low-flow diversions and the wetland swale project were effective in removing all contaminated runoff from beaches. UV sterilization was effective when coupled with pretreatment filtration and where effluent was released within a few hundred meters of the beach to avoid FIB regrowth. Other BMPs were less effective because they treated only a portion of contaminant sources impacting their target beach. These findings should be useful to other coastal states and agencies faced with similar pollution control problems.
Marine recreational beaches are monitored for fecal contamination by
Enterococcus spp. (ENT) counts. Although different ENT species in the environment tend to thrive in and originate from distinct ...hosts, the current monitoring method does not differentiate among species. Time-consuming isolation-based species identification precludes routine analysis of environmental ENT communities. Therefore, an isolation-independent DNA fingerprinting method was developed to characterize environmental ENT communities using DNA length polymorphism of the spacer region between the
groES and
groEL genes common to most ENT species. Capillary electrophoresis resulted in distinct peak sizes of PCR products that carried polymorphic
groESL spacers (300–335 bp in length) among 8 different ENT species (
Enterococcus avium,
Enterococcus gallinarum,
Enterococcus casseliflavus,
Enterococcus mundtii,
Enterococcus hirae,
Enterococcus faecium,
Enterococcus durans, and
Enterococcus faecalis). Distortions in true species ratios observed in electropherograms were caused by PCR biases arising in a mixed ENT community DNA template.
E. faecalis was overestimated and
E. avium and
E. faecium were underestimated compared to the original species ratios in the mixed community. The PCR product bias was constant between species, so good approximation of the species ratio in ENT communities is possible. In environmental samples, a high percentage of
E. faecalis (96%) together with high total ENT counts were observed in samples collected from a sewer line and from several sites in a storm drain system where sewage leaks were suspected. In contrast, samples with <400 CFU 100 ml
−1 ENT were either dominated by
E. mundtii or had 4 or more ENT species. The latter ENT community profiles are considered to be signatures of enterococci rarely associated with animals with low or of non-fecal origin.
Water samples from sites potentially impacted by septic tanks, cattle, sewage treatment plant (STP) and natural forests were collected at regular monthly intervals and within 48
h of rainfall events ...between October 2004 and June 2006. All samples (
n=296) were analysed for faecal coliforms and faecal sterols including coprostanol, epicoprostanol, cholestanol, cholesterol and 24-ethylcoprostanol. Faecal sterol ratios were used to assign human and/or herbivore contamination sources and to estimate their percentage relative contributions in water samples. The catchments had significantly different profiles of designated contamination origins (
p<0.05), which were consistent with land use patterns. The STP impacted site had the highest incidence of human contamination assignations and the highest mean levels of coprostanol, whilst the forested site had the highest incidence of uncontaminated samples and the lowest mean concentration of coprostanol. Coprostanol concentrations were not always correlated with faecal coliform counts.
When Enterococcus faecalis is isolated from fresh feces, its host range appears to be limited to humans and birds. Although E. faecalis is found in human sewage, the extent to which the bacterium is ...found in broiler litter and in the feces of wild birds is unclear. These results have implications for bacterial source tracking. We determined if media designed for the isolation of fecal enterococci affected this host range, and if E. faecalis was routinely found in broiler litter and in the feces of wild birds. Of five different isolation media, none affected the isolation of E. faecalis. Enterococcus faecalis was routinely found in fresh broiler feces (522 of 1092 isolates; 48%), but rarely in broiler litter (12 of 1452 isolates; <2%). Therefore, broiler litter selects against this bacterium, and broiler litter is an unlikely environmental source of this bacterium. The presence of E. faecalis in eight wild bird species was highly variable. Unless the fecal loading rate from migratory or resident wild birds is high, water samples collected during baseflow conditions with high numbers of E. faecalis may indicate human fecal contamination.
Monitoring of Fecal Bacteria in Oita River, Oita, Japan FURUKAWA, Takashi; NONAKA, Hirofumi; HIRAOKA, Tohru ...
Journal of Japan Society on Water Environment,
2015, 2015-00-00, 20150101, Letnik:
38, Številka:
6
Journal Article
Odprti dostop
This study was aimed at accumulating information on bacterial water quality to define a numerical target of a sanitary indicator in river management. Fecal bacteria (total coliform bacteria, fecal ...coliform bacteria, Escherichia coli, enterococci) in Oita River, Oita, Japan were monitored. Water samples were collected from a total of 17 stations along Oita River between December 2013 and November 2014 (total of 12 sampling events). A high total coliform bacteria count, which was used as a river-water-quality standard, was detected in water samples from most of the sampling stations (mean: 1.1 x 104 MPN·100 mL-1). The other three types of bacteria were also often detected at high concentrations. All bacterial counts tend to be high in the summer season. In particular, at stations 1 to 6, the bacterial counts greatly varied. From the results of analyzing the correlation coefficients of each bacterial count, it was found that there is little correlation between individual bacterial counts with the exception of the upstream area of Oita River. Furthermore, multiple regression model analysis revealed that there were no water quality parameters that affect the counts of fecal indicator bacteria. The results indicated that bacterial water quality might be difficult to estimate using water quality parameters.
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