LEGIONELLA - World Health Organization

• descriptions of any significant incidents, their investigation, action plans for necessary
work, and changes arising from them.
Records should be retained for several years. These documents should be checked and audited
regularly by a competent person, according to the risk assessment.
8.4.2 Monitor control measures
This step involves defining the limits of acceptable performance and how these are monitored.
The pH should be measured continuously in public pools, and adjusted automatically. For hot
tubs, monitoring should be conducted several times a day during operating hours (WHO, 2006).
Visual inspection of pool water should accompany other monitoring, such as monitoring of pH
and disinfectant residuals. Facilities should be free of visible physical contamination, such as
hair, sticking plasters, etc.
Strainers should be inspected and cleared regularly. Where filters are installed, they should be
backwashed, either automatically or manually.
8.5 Management communication
8.5.1 Establish documentation and communication procedures
Table 8.3 gives an example of a routine monitoring and corrective action loop.
Table . Example of documentat on for mon tor ng and correct ve act on
Process
step Ind cator Mon tor ng
Filtration Particulates What Visual contamination
(e.g.
matted hair)
LEGIONELLA AND THE PREVENTION OF LEGIONELLOSIS
Operat onal
l m t Correct ve act on
Absence
of gross
particulates
What Physical
removal of gross
particulates
How Visually How Clean strainers
and flush filters
When Daily When Immediately
Where At the facility Who Spa manager
Who Spa manager