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pdfDEVELOPING A LEGIONELLA WATER MANAGEMENT PROGRAM
Decide Where Control Measures
Should Be Applied
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Control measures and limits should be established for each control point. See the diagram on the next
page for the types of monitoring that could occur in Building A. You will need to monitor to ensure your
control measures are performing as designed. Control limits, in which a chemical or physical parameter
must be maintained, should include a minimum and a maximum value.
Examples of chemical and physical control measures and limits to reduce the risk of Legionella growth:
6 Water quality should be measured throughout the system to ensure that changes that may lead to
Legionella growth (such as a drop in chlorine levels) are not occurring.
6 Water heaters should be maintained at appropriate temperatures.
6 Decorative fountains should be kept free of debris and visible biofilm.
6 Disinfectant and other chemical levels in cooling towers and hot tubs should be continuously
maintained and regularly monitored. Surfaces with any visible biofilm (i.e., slime) should be cleaned.
Healthcare Facilities
Clinicians should test patients with healthcare-associated pneumonia for Legionnaires’ disease.
This is especially important among patients at increased risk for developing Legionnaires’ disease
(see Appendix A), among patients with severe pneumonia (in particular those requiring intensive
care), or if any of the following are identified in your facility:
Patients with Legionnaires’ disease, no matter where they acquired the infection
Positive environmental tests for Legionella
Changes in water quality that may lead to Legionella growth (such as low chlorine levels)
The preferred diagnostic tests for Legionnaires’ disease are culture of lower respiratory secretions on
selective media and the Legionella urinary antigen test.
Additionally, certain commonly-encountered changes
in building water system design or management
might require increasing increasing the extent and
frequency of monitoring. It’s a good idea to anticipate
additional hazardous conditions that could be
associated with scheduled or unanticipated changes
in water quality, such as:
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Anti-scald Regulation
You should follow local and state
anti-scald regulations. However,
maximum temperatures allowed by your
state may be too low to limit Legionella
growth. Engineering controls that mix hot
and cold water together at the source can
reduce the risk of scalding while allowing
water in pipes to remain hot enough to
limit Legionella growth.
System start up
System shut down
Regularly scheduled maintenance
Renovations, construction, and installation of new equipment on your property
Equipment failure
Water main break or other service interruptions
Reference: ASHRAE 188: Legionellosis: Risk Management for Building Water Systems June 26, 2015. ASHRAE: Atlanta. www.ashrae.org
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DEVELOPING A LEGIONELLA WATER MANAGEMENT PROGRAM
Make Sure the Program Is Running
as Designed & Is Effective
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Verification: Are we doing what we said we would do?
Your program team should establish procedures to confirm, both initially and on an ongoing
basis, that the water management program is being implemented as designed. This step is called
“verification.” For example, if you said you would test the hot tub daily for chlorine and record and
communicate those results, have you been doing that? If you found a problem, did you take the
action included in your program?
People should not verify the program activity for which they
are responsible. For example, if one person is responsible
for maintaining the hot tub and another is responsible for the
cooling tower, they could verify each other’s work, not their own.
Validation: Is our program actually working?
Now that you have a water management program, you need to
be sure that it is effective. Your program team should establish
procedures to confirm, both initially and on an ongoing basis,
that the water management program effectively controls the
hazardous conditions throughout the building water systems.
This step is called “validation.”
Healthcare Facilities
Water management program
teams that include infection
control staff may also choose
to use their facility’s routine
surveillance for healthcareassociated Legionnaires’ disease
to validate their program. To look
for healthcare-associated cases,
histories for all patients with
diagnosed Legionnaires’ disease
should be reviewed for possible
healthcare exposures and
certain patients with healthcareassociated pneumonia (see gray
box on page 13) should be tested
for Legionnaires’ disease.
Environmental testing for Legionella is useful to validate the
effectiveness of control measures. The program team should
determine if environmental testing for Legionella should be
performed and, if so, how test results will be used to validate
the program. Factors that might make testing for Legionella more important include:
6 Having difficulty maintaining the building water systems within control limits
6 Having a prior history of Legionnaires’ disease associated with the building water systems
6 Being a healthcare facility that provides inpatient services to people who are at increased risk for
Legionnaires’ disease (see Appendix A)
If the program team decides to test for Legionella, then the testing protocol should be specified
and documented in advance. You should also be familiar with and adhere to local and state
regulations and accreditation standards for this testing.
Reference: ASHRAE 188: Legionellosis: Risk Management for Building Water Systems June 26, 2015. ASHRAE: Atlanta. www.ashrae.org
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File Type | application/pdf |
Author | avb8 |
File Modified | 2016-08-05 |
File Created | 2016-08-02 |