AWWA JAW60490

Drinking water produced by conventional surfacewater treatment plants with typical levels of Cryptosporidiumoocysts in source waters might putpublic health at risk. This study proves that oocysts thatbreak through the treatment barriers could be alive andinfectious under in vitro human cell culture conditions.Studies have shown that surface source waters andfinished drinking water might be contaminated withCryptosporidium oocysts. However none of the methodsused in these studies, nor the currently approved USEnvironmental Protection Agency diagnostic techniquesfor compliance testing, are able to determine the publichealth significance of the results because those methodsdo not measure the infectivity of C. parvum.The study presented in this article showed that90% of the finished water samples positive for Cryptosporidiumoccurred in filtered drinking water sampleswith low turbidities and that microbial indicatorssuch as Bacillus, Clostridium, and phage werenot associated with Cryptosporidium occurrence.Because none of the parameters analyzed couldaccount for the occurrence of infectiousCryptosporidium in the treated water, it was concludedthat conventional treatment plants are at riskfor breakthrough of infectious oocysts. As a result ofthis study, the authors recommend that treatmentshould be improved using alternative disinfectiontechniques to preserve public health. Includes 36 references, tables, figures.

Product Details

Edition:

Vol. 96 - No. 9

Published:

09/01/2004

Number of Pages:

11

File Size:

1 file , 250 KB