OWML: Current Projects

Project Title: Testing of analytical methods for pathogens in finished drinking-water supplies.

Project chief:  Donna Francy

Project support:  Rebecca Bushon, Chris Kephart, Amie Brady, Christina Likirdopolus, Erin Bertke, Erin Stelzer

Cooperators:  U.S. Environmental Protection Agency, National Homeland Security Research Center (USEPA NHSRC), Cincinnati, OH

Project duration:  January 2006 – September 2008

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Introduction and problem: 
Certain microbiological pathogens are considered potential biological warfare agents and cause homeland security concerns, especially for drinking-water supplies.  Traditional cultural and microscopic methods allow detection of these pathogens; however, the methods take days before any confirmatory answer is available.  A quantitative polymerase chain reaction (QPCR) method can be used to obtain rapid analysis of pathogens from water samples by targeting the DNA of the pathogens.  Little is known, however, about the ability of QPCR to detect pathogens in treated drinking water and the reliability of QPCR as compared to traditional methods.

Goals and objectives:
The goal of the proposed project is to collect data to assess the utility and performance of analytical methods for determination of pathogens in finished drinking waters. Specific objectives are the following:

1. Test, optimize, and finalize protocols for analytical methods for six pathogens.
    

2. Determine the efficiency and variability of recoveries of analytical methods for pathogens in drinking-water samples collected from public utilities. 
    

3. Compare the performance of molecular detection methods to that of traditional methods.
    

4. Document the effects of physical properties of water and concentrations of organic carbon in drinking-water supplies on the detection of six pathogens.

 Approach: 
The USGS will collect finished drinking-water samples at eight drinking-water plants within a 4-hour drive of Columbus, Ohio—four supplied by ground water (GW) and four by surface water (SW). Each SW site will be sampled twice; each GW site will be sampled once, but a duplicate will be collected during each GW sampling event.  Thus, a total of 16 samples will be collected.  Two subsamples will be collected at each location during each sampling event—one to be seeded with target pathogens or surrogates (in the laboratory) and the second to determine the natural incidence of these pathogens and serve as a negative control. In the unlikely event that one of these pathogens is detected in an unseeded sample, the local health department will be contacted.  Samples will be analyzed for five bacterial pathogens (Bacillus anthracis, Burkholderia pseudomallei, Salmonella typhi, Vibrio cholerae, and Francisella tularensis) and one protozoan pathogen (Cryptospordium parvum).  The following samples will be collected:

• For pathogens—220 L from SW plants or 320 L from GW plants

• For total coliforms and E. coli—1 L

• For specific conductance, temperature, dissolved oxygen, and pH—measured on site or in the lab van

For alkalinity, turbidity, dissolved organic carbon, and total hardness—1 L