Chapter outline: Water Sampling and Processing Techniques

Proposed title:  Water Sampling and Processing Techniques for Public Health-Related Microbes
Chapter no.: ____

Author(s):       Vincent Hill (PhD)

                        Waterborne Disease Prevention Branch

                        Centers for Disease Control and Prevention

                        1600 Clifton Road, NE, Mailstop D-66

                        Atlanta, GA 30329

                        Phone: (404) 718-4151

Fax: (404) 718-4197              

                        E-mail: vhill@cdc.gov

Notes:

·          Material in this chapter may overlap with other chapters focused on detection of health-related microbes in water 

·          Techniques covered include large-volume sampling techniques for pathogens, smaller-volume sampling techniques for indicator microbes, and secondary processing techniques for concentration and separation of target microbes

·          Techniques relevant to viruses, bacteria, and parasites will be covered

·          Focus is on techniques for freshwater (surface water, ground water) and treated water sampling (tap water, aquatic venue water), not marine water

Proposed topics

1)     Introduction: How investigation goals and conditions drive selection of sampling techniques (e.g., target microbes, analytical methods, acceptable detection limits/sample volume size, grab sample vs. composite sampling, anticipated water quality)

2)     Grab sampling and composite sampling from surface water (including storm water), ground water, drinking water systems, swimming pools, and cooling towers

3)     Physical separation filtration techniques (membrane filtration, use of pre-screens, microfilter cartridges, ultrafiltration)

4)     Adsorption-elution filtration techniques [positively-charged membranes (e.g., 1MDS, NanoCeram, glass wool), negatively-charged (e.g., MgCl_2, AlCl₃ methods), and celite for secondary concentration

5)     Centrifugation techniques (conventional static centrifugation, continuous-flow centrifugation, precipitation-based methods (e.g., polyethylene glycol, organic flocculation, aluminum hydroxide), and microconcentrators (e.g., Centricons)

6)     Capture techniques (immunomagnetic separation and “NextGen” techniques such as aptamers and dielectrophoresis)

7)     Sample handling issues (holding times, temperature, dechlorination, sample bottle head space)

8)     Sustainability issues affecting water sampling and testing choices in resource-limited environments (capital costs associated with pumps, consumables costs and potential reuse, streamlining techniques, use of low-tech methods, unreliable infrastructure)

Chapter Highlights

The following concepts will be conveyed in this chapter:

1.  Impact of water quality characteristics on effectiveness of sampling methods, method selection

2.  Utility of methods for simultaneous concentration of diverse microbe types

3.  Field-deployability of sampling methods and issues affecting sampling implementation in developing countries