To assess the state of knowledge regarding the effectiveness
of distribution system disinfectant residuals
during accidental microbial intrusions, the authors
reviewed laboratory-, pilot-, and full-scale experimental
studies. The persistence of microorganisms in the
biofilms of simulated mains at the laboratory scale was
much longer than in pilot-scale settings, under the typical
disinfectant residual concentrations used in distribution
systems. Most of the studies reviewed used culture-based
methods for the enumeration of microorganisms,
which are known to underestimate the number and
diversity of microorganisms.
Because the distribution system is the last barrier
between the treatment plant and the consumer, intrusion
is of concern to utility managers. Conditions experienced
during some repairs, zero- or low-flow conditions
and/or delay in reinstatement of disinfection, are
likely to be critical for the persistence of intruded
microorganisms in the biofilm, a fact that underscores
the importance of adequate chlorination and flushing
procedures. For the research community, this review
highlights the need for additional studies using methods
(e.g., molecular tools) that allow the detection of viable
but nonculturable microorganisms. Includes 62 references, tables.
| Edition : | Vol. 100 - No. 10 |
| File Size : | 1
file
, 400 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 10/01/2008 |
