Full Description

Over the past 7 years, the Massachusetts Water Resource Authority (MWRA) has been monitoring their receiving waters for indicator bacteria, coliphages and anthropogenic viruses to evaluate the impact of Boston's Deer Island Sewage Treatment Plant discharge. Coliphages, enteric viruses, and indicator bacteria were originally assayed using traditional single agar overlay assay (SAL), cell culture MPN method, and membrane filtration techniques respectively. However, by using recent advances in viral detection, a two step enrichment procedure proposed for the Groundwater Rule phage detection, and the use of an integrated cell culture-nested polymerase chain reaction (ICC-nPCR) for the detection of enteric viruses (poliovirus, coxsackie virus, echovirus, rotavirus, adenovirus 40/41 and astrovirus), has permitted increased sensitivity and specificity for detection of both coliphages and enteric viruses. In the last 2 years, data has been collected on the presence of coliphages and enteric viruses using only these new techniques and the original samples collected 3 years prior were reanalyzed by ICC-nPCR. In the original analysis, 8.20 percent of the samples were positive for male-specific phage and 9.84 percent were positive for somatic phage. When samples taken from these same areas were evaluated by the enrichment procedure, 58 percent were positive for male specific phage and 55 percent were positive for somatic phage. Twenty three percent of the original samples were positive for virus by the MPN method. Reanalysis of these samples by ICC-nPCR demonstrated that 45.9 percent of the samples were positive for at least one virus. Several samples originally negative by the MPN method now demonstrated the presence of one or more viruses and several samples that were originally positive were negative when reanalyzed by ICC-nPCR. Preliminary comparative results demonstrate that effective and efficient monitoring of anthropogenic contamination can be achieved using these more sensitive techniques. Correlations between the presence of coliphages, enteric viruses and indicator bacteria were based on proximity to the treatment plant and seasonal variations. Levels of male specific coliphages and enteric viruses were highest in the fall, whereas somatic coliphages were highest in the spring and winter. Proximity related prevalence of coliphages was highest at the shore sites and enteric viruses at the sites closest to the diffuser. Includes 9 references, figures.

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Edition: Vol. - No. Published: 11/01/2002 Number of Pages: 11File Size: 1 file , 280 KB