Facility Managers' Responsibilities for Legionella Prevention Under ASHRAE 188
Determining responsibility for water safety in
buildings has historically been murky. It typically falls somewhere among the
building owner, the facility manager and a water treatment company. ASHRAE 188
lays the responsibility for water safety squarely at the feet of those
responsible for the water systems. That means everyone associated with design,
construction, installation, ownership, operation, management, and maintenance
are required to ensure building water systems are designed, maintained and
operated in a manner that minimizes the risk of Legionellosis. There is no
question that the new standard puts facility managers on the front line of
Legionellosis prevention.
ASHRAE Standard 188 applies to water systems in
human-occupied buildings new and existing. Single-family residential homes
are exempt. To comply with the
standard, facility owners and managers will be required to do an annual survey
of their buildings, on a building-by-building basis, to determine risk
characterization. If a building possesses one or more of the risk
characteristics set out in the standard, it will be necessary to develop a risk
management plan for Legionella control.
This includes conducting an evaluation using Hazard Analysis Critical Control
Point (HACCP) methodology, documenting water system operation and maintenance,
and verifying monitoring and control.
ASHRAE Standard 188 also requires validating that Legionella is under control in all water
systems. These include: potable and
utility water systems for water used for drinking, cooking, washing, bathing,
and also water emitted from plumbing fixtures, cooling towers, boilers and
other HVAC-related equipment.
Annual
Survey to Determine Risk Characteristics
There are specific building characteristics that
allow Legionella to colonize building
water systems. Facilities at high risk for Legionella
include healthcare facilities, such as hospitals and nursing homes. An
increasing number of cases have been reported from assisted-living and
long-term care facilities.
Under the new standard, facility managers are charged with conducting
an annual survey to determine what risk is present in their buildings. Specific
risk factors called out in the standard are:
-
multiple
housing units with one or more centralized water heaters
-
more than 10
stories (including levels below grade)
-
cooling tower
or evaporative condenser
-
one or more
whirlpools or spas within or adjacent to building
-
devices that
release aerosols (e.g., ornamental fountains, misters, air washers or
humidifiers)
-
incoming
potable water containing less than 0.5 ppm residual halogen such as chlorine
-
inpatient
health care facility
-
occupants
primarily older than age 65
-
occupants
receiving chemotherapy for cancer or bone marrow transplantation.
If a facility manager identifies the presence of
one or more risk factors after conducting the survey, then a risk management
team must be assembled to prepare and implement a HACCP plan to prevent the
threat posed by Legionella bacteria.
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