AWWA WQTC55140

USEPA Methods 1622 and 1623 have demonstrated that Cryptosporidium oocysts and/or Giardia cysts can be recovered reproducibly from small volumes (10 L) of source water. The original components of these methods included Gelman Envirochek filters for sample collection, Dynal immunomagnetic separation (IMS) kits for sample clarification and detection using fluorescein isothiocyanate conjugated monoclonal antibodies (FITC-mAbs). Two other filters (Whatman Cryptest and IDEXX Filta-Max filters) and a FITC-mAb (Waterborne, Inc.) have also demonstrated performance equivalency to USEPA Method 1623 by undergoing multi-laboratory round-robin validation under the USEPA performance based measurements system (PBMS) program. In this study, we present an new technique for the recovery of Cryptosporidium oocysts from high volume finished water samples, and develop and test an alternate technique for elution of cysts and oocysts from 50L source water samples collected on Filta-Max filters. These are examples of the USEPA PBMS approach to method development and testing that allows method improvements to be easily incorporated into existing methods. Includes 10 references, tables.