AWWA WQTC52747

A better understanding of Cryptosporidium and other pathogen occurrence insource water is needed to help assess the adequacy of treatment under existing regulations. The Information Collection Rule (ICR) and Supplemental Surveys were designed to provide such occurrence data but measurement quality and low detection frequencies make interpretation difficult. This paper describes the analysis of ICR Cryptosporidium data. Raw measurement data are used to produce point estimates of occurrence for plant influents that were sampled in the ICR surveys. Bayesian statistical methods are used to assess the national occurrence distribution for mean Cryptosporidium concentration. Includes 3 references, tables, figures.