AWWA WQTC71655

This powerpoint presentation begins by providing a brief overview of outbreaks caused by distribution system deficiencies and epidemiological studies by Payment et al., in 1991 and 1997. The impact of Payment's studies is presented, along with applying the QMRA model to distribution systems. Presentation conclusions: the first step of QMRA intrusion modeling is to establish the duration, frequency and intensity of ingress to determine realistic ingress distributions; must address this first task before any mechanistic modeling; still considerable amount of work to be done; unsolved issues about base QMRA modeling; significant limitations in predicting intrusion volumes; and, non-mechanistic modeling is not hindered by these issues but has other limitations such as pathogen/indicator relationships. Includes figures.