AWWA JAW69707

Total coliform monitoring in the distributionsystem is perhaps the most expensive and intensivesampling mandated by law, with thenational cost of sampling required by the TotalColiform Rule (TCR) calculated as being inexcess of $100 million annually. For all but thelargest utilities, however, the sampling mandatedunder the TCR is inadequate to measurewith any confidence the real differences in totalcoliform occurrence between months. Becauseof the low number of samples taken by all but afew large facilities, most sample sizes are toosmall for systems to be able to verify the effectivenessof any mitigative action following aTCR violation.This article explains the statistical limitationsof current TCR practices and argues thatcurrent monitoring of total coliform does notmeet the stated objectives of the rule. In addition,the authors suggest strategies to enhanceinformation recovery from total coliformobservations. Includes 7 references, tables, figures.

Product Details

Edition:

Vol. 101 - No. 3

Published:

03/01/2009

Number of Pages:

14

File Size:

1 file , 870 KB