Indicator Bacteria-Sediment Relationships: Implications for Water Quality Modeling and Monitoring

Irvine, Kim N.; Pettibone, Gary W.; Droppo, Ian G.

doi:10.14796/jwmm.r183-14

Cited by 9 publications

(11 citation statements)

References 35 publications

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“…3) towards smaller particle sizes (significant difference at α = 0.5, Modified Kolmogorov-Smirnov test, Goldman and Lewis, 1984). Similar results have been observed in temperate climates (Droppo and Ongley, 1994;Irvine, et al, 1995).…”

Section: Resultssupporting

confidence: 87%

The Prevalence of Freshwater Flocculation in Cold Regions: A Case Study from the Mackenzie River Delta, Northwest Territories, Canada

Droppo¹,

Jeffries²,

Jaskot³

et al. 1998

ARCTIC

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ABSTRACT. The Mackenzie River Delta (MRD) is used as a case study for evaluating the extent to which flocculation may play an important role in the transport of sediment and associated contaminants in arctic regions. Samples were collected for nondestructive analysis of particle/floc size, major ions, particulate organic carbon (POC), dissolved organic carbon (DOC), bacterial counts, and suspended solid (SS) concentrations. On-site measurements were made for pH, conductivity, and temperature. Results indicate that the dominant form of sediment transport to and within the MRD is flocs, and not traditionally sized primary particles. It is shown that the flocs of the Mackenzie Delta are at times larger in size than those in southern Ontario rivers that have been studied. The sediment distributions were bimodal in nature; the particle-deficient zone potentially represented a preferential particle size for flocculation. Spatial and temporal trends in the grain-size distributions suggest sitespecific controlling factors of flocculation, such as source area and sediment characteristics. It is hypothesized that water temperature, suspended solid concentration, and bacteria are the important factors in controlling flocculation within the Delta.Key words: flocculation, suspended sediment, grain-size distribution, bacteria, transport RÉSUMÉ. Le delta du Mackenzie (DM) sert d'étude de cas pour déterminer l'importance du rôle que peut jouer la floculation dans le transport des sédiments et contaminants connexes dans les régions arctiques. On a recueilli des échantillons pour analyse non destructive de la taille des particules/flocons, des ions majeurs, du carbone organique particulaire (COP), du carbone organique dissous (COD), de la numération bactérienne et des concentrations solides en suspension. Les mesures du pH, de la conductivité et de la température ont été faites sur le terrain. Les résultats indiquent que le transport solide en amont et à l'intérieur du DM s'opère principalement sous forme de flocons et non sous forme de particules élémentaires calibrées de façon traditionnelle. On montre que les flocons du delta sont parfois plus gros que ceux des cours d'eau du sud de l'Ontario qui ont déjà fait l'objet d'une étude. La distribution des sédiments était de nature bimodale: la zone déficitaire en particules représentait potentiellement une grosseur de particules propice à la floculation. Des tendances spatiales et temporelles dans la distribution granulométrique suggèrent l'existence de facteurs de contrôle de la floculation qui sont spécifiques à certains sites, tels que la source d'origine et les caractéristiques des sédiments. On émet l'hypothèse que la température de l'eau, la concentration des matières solides en suspension et les bactéries sont les principaux facteurs qui contrôlent la floculation dans le delta.

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Section: Resultssupporting

confidence: 87%

The Prevalence of Freshwater Flocculation in Cold Regions: A Case Study from the Mackenzie River Delta, Northwest Territories, Canada

Droppo¹,

Jeffries²,

Jaskot³

et al. 1998

ARCTIC

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“…Municipal sewage and stormwater runoff become the conduits for the passage of pathogens into surface waters (10,21). In this study, high levels of Salmonella strains were recorded in river and wastewater samples.…”

Section: Discussionmentioning

confidence: 68%

“…Nevertheless, the highest diversity of strains was found during flood events, and some serotypes were detected only in these samples. Although wastewater discharge into the river represents a permanent source of pollution, flood events may mobilize a wide variety of Salmonella reservoirs located within the watershed and contribute to the dissemination of a large diversity of species which are transmitted to surface waters (5,8,10,21). Some of the serotypes found only during storm events may correspond to species whose habitat is specific to particular animals and who are not disseminated from the permanent discharge of wastewaters.…”

Section: Discussionmentioning

confidence: 99%

Diversity of Salmonella Strains Isolated from the Aquatic Environment as Determined by Serotyping and Amplification of the Ribosomal DNA Spacer Regions

Baudart

Lemarchand

Brisabois³

et al. 2000

Appl Environ Microbiol

157

142

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Salmonella species are pathogenic bacteria often detected in sewage, freshwater, marine coastal water, and groundwater. Salmonella spp. can survive for long periods in natural waters, and the persistence of specific and epidemic strains is of great concern in public health. However, the diversity of species found in the natural environment remains unknown. The aim of this study was to investigate the diversity of Salmonella strains isolated from different natural aquatic systems within a Mediterranean coastal watershed (river, wastewater, and marine coastal areas). A total of 574 strains isolated from these natural environments were identified by both conventional serotyping and the ribosomal spacer-heteroduplex polymorphism (RS-HP) method (M. A. Jensen and N. Straus, PCR Methods Appl. 3:186-194, 1993). More than 40 different serotypes were found, and some serotypes probably mobilized from widespread animal-rearing activities were detected only during storm events. These serotypes may be good indicators of specific contamination sources. Furthermore, the RS-HP method based on the PCR amplification of the intergenic spacer region between the 16S and 23S rRNA genes can produce amplicon profiles allowing the discrimination of species at both serotype and intraserotype levels. This method represents a powerful tool that could be used for rapid typing of Salmonella isolates.

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“…[19][20][21][22][23] Usually, sediment fecal coliform are much higher than the water column fecal coliform concentration. Irvine [24] suggested incorporating sediment impact to fecal coliform modeling.…”

Section: Sediment Storage Of Fecal Coliformmentioning

confidence: 99%

Three-Dimensional Modeling of Fecal Coliform in the Tidal Basin and Washington Channel, Washington, DC

Bai

Lung

2006

Journal of Environmental Science and Health, Part A

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Fecal coliform are widely used as bacterial indicator in the United States and around the world. Fecal coliform impaired water is highly possible to be polluted by pathogenic bacteria. The Tidal Basin and Washington Channel in Washington, DC are on the Total Maximum Daily Load (TMDL) list due to the high fecal coliform level. To support TMDL development, a three-dimensional numerical model of fecal coliform was developed using the EFDC framework. The model calculates the transport of fecal coliform under the influences of flap gate operations and tidal elevation. The original EFDC code was modified to calculate the die-off of fecal coliform under the impact of temperature and solar radiation intensity. The watershed contribution is expressed as storm water inflow and the load carried by the runoff. Model results show that fecal coliform vary strongly in space in both the Tidal Basin and Washington Channel. The storm water only impacts a small area around the storm water outfall in the Tidal Basin and the impacts are negligible in the Washington Channel due to dilution. The water from the Potomac River may affect the fecal coliform level in the area close to the flap gate in the Tidal Basin. The fecal coliform level in the Washington Channel is mainly controlled by the fecal coliform level in the Anacostia River, which is located at the open boundary of the Washington Channel. The potential sediment layer storage of fecal coliform was analyzed and it was found that the sediment layer fecal coliform level could be much higher than the water column fecal coliform level and becomes a secondary source under high bottom shear stress condition. The developed model built solid connection of fecal coliform source and concentration in the water column and has been used to develop TMDL.

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Indicator Bacteria-Sediment Relationships: Implications for Water Quality Modeling and Monitoring

Cited by 9 publications

References 35 publications

The Prevalence of Freshwater Flocculation in Cold Regions: A Case Study from the Mackenzie River Delta, Northwest Territories, Canada

The Prevalence of Freshwater Flocculation in Cold Regions: A Case Study from the Mackenzie River Delta, Northwest Territories, Canada

Diversity of Salmonella Strains Isolated from the Aquatic Environment as Determined by Serotyping and Amplification of the Ribosomal DNA Spacer Regions

Three-Dimensional Modeling of Fecal Coliform in the Tidal Basin and Washington Channel, Washington, DC

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