The U.S. Geological Survey, in cooperation with the Maryland Department of the Environment and the Wisconsin State Laboratory of Hygiene, conducted a study to characterize the occurrence and distribution of viral contamination in small public water-supply wells in the surficial aquifer in Worcester and Wicomico Counties, Maryland. Two hundred seventy-eight well sites were evaluated with regard to simulated ground-water flow paths, land use, soils groups, and well characteristics. On the basis on this evaluation, the 27 sites considered to be most vulnerable were selected for sampling. Samples were collected by pumping 400 gallons of untreated well water through an electropositive filter. In addition to analysis for culturable viruses and virus groups by use of gene-probe techniques, samples were analyzed for somatic and male-specific coliphage, Bacteroides fragilis, Clostridium perfringens, Enterococci, Escherichia coli, total coliform, total oxidized nitrogen, dissolved organic carbon, organic nitrogen, total phosphate, orthophosphate, acid-neutralizing capacity, pH, specific conductance, temperature, and dissolved oxygen. Eleven percent of the samples analized tested positive for either culturable viruses or the presence of viral ribonucleic acid. About 15 percent of the samples analyzed had bacterial contamination. A principal component analysis indicates that a water-quality component and a pathogen component account for nearly 75 percent of the variance in the data set. This analysis also indicates that the presence of pathogens is not strongly correlated to physical or chemical characteristics in the sampled wells. See water.usgs.gov/owq/dwi
Learning Objectives: At the conclusion of the session, the participant will be able to describe the distribution of viral contamination in ground water in certain Maryland counties.
Keywords: Drinking Water Quality, Pathogens
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: U.S. Geological Survey
I have a significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.
Relationship: Employment