Information and consulting services to protect health and life by reducing the risk of Legionella and other waterborne pathogens.
Would you like to be notified about outbreaks, new publications, seminars, and new technology? Sign up for our free e-newsletter!
Visit riverpower.org!
Legionella E-news -- 28 May 2003**IN
THIS ISSUE** ================================================================== "As
discussed in this document, treatment requirements for disinfection of a
municipal water supply are thought to provide at least a 3 log reduction
of Legionella bacteria (see Section 3.2.2). However, some
recontamination may occur in the distribution system due to cross
connections and during installation and repair of water mains. It has
been hypothesized that the low concentrations of Legionella entering
buildings due to these sources may colonize and regrow in hot water
systems (USEPA, 1985). Although all of the criteria required for
colonization are not known, large institutions, such as hospitals,
hotels, and public buildings with recirculating hot water systems seem
to be the most susceptible. The control of Legionella in health care
institutions, such as hospitals, is particularly important due to the
increased susceptibility of many of the patients. The colonization and
growth of Legionella in drinking water primarily occurs within the
consumer's plumbing systems after the water leaves the distribution
system. Therefore, the control of these organisms must be the consumer's
responsibility. This appendix is intended to provide guidance to these
institutions for the detection and control of the Legionella bacteria. "It
is suggested that hospitals, and other institutions with potential for
the growth of Legionella, conduct routine monitoring of their hot water
systems at least quarterly. The analytical procedures for the detection
of these organisms can be found in Section 912.I 'legionellosis' of the
16th edition of Standard Methods. Samples should be taken at, or closely
following, the hot water storage reservoir and from a number of
showerheads. It is recommended that showers with the least frequent
usage be included in the sampling program. Follow-up testing is
suggested for all positive indications prior to the initiation of any
remedial measures. If the presence of Legionella is confirmed, then
remedial measures should be taken. Although the regrowth of Legionella
is commonly associated with hot water systems, hot and cold water
interconnections may provide a pathway for cross contamination. For this
reason, systems detecting Legionella in hot water systems should also
monitor their cold water systems." ================================================================== HSE
has also released a revised video, "An Introduction to the Control
of Legionella Bacteria in Water Systems." The video, accompanied by
a series of checklists, tells how to manage and control Legionella in
cooling towers and domestic water systems. It covers risk assessments,
treatment, control, monitoring, cleaning, and disinfection. For more
information, go to http://www.hse.gov.uk/press/2003/e03080.htm. ==================================================================
******************************************************************* THANK
YOU! Matt
Freije, Editor |