AWWA WQTC58875

EPA Method 1623 for the recovery, detection and enumeration of Cryptosporidium and Giardiafrom water represents significant advances over earlier methods. However, protozoa recoveryefficiency remains variable, depending upon water matrices and other factors, yieldingpotentially misleading results. This problem is exacerbated as modified versions of the methodare increasingly applied to non-routine matrices, in part due to the focus on reclaimed water.To assess the effect of a particular matrix on recovery efficiency of protozoa, Method 1623requires that a matrix spike (MS) sample be collected along with the field sample within every20 samples from a particular source. While better than no recovery data, the validity of thisapproach for assessing matrix effect within a given sample set and across a set of 20 samples,depends upon:the homogeneity of the field sample and the MS sample in terms of indigenous protozoaconcentration and potential interferences, within the given sampling event; and,the temporal consistency of the water matrix over the 19 sample interval betweensuccessive MS samples. Includes extended abstract only.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

2

File Size:

1 file , 210 KB