22 BUILDINGS 03.16
have either 10-plus stories or a centralized domestic hot water
system, and 5 that don’t have any risk factors. If you establish a
WMP for the 15 but not for the other 5, you should still implement control measures in the 5 that are consistent with the 15
for like-kind equipment. For example, if the WMPs for the 15
buildings outline control measures for cold water storage tanks,
implement those same measures for cold water storage tanks
in the other 5. If the WMP for the 15 buildings has flushing
procedures for infrequently used faucets, make sure the other 5
buildings use the same. Otherwise, if a case of Legionnaires’ disease occurs, how will you explain why you implemented control
measures in buildings 1-15 but not for the same equipment in
buildings 16-20? Saying ASHRAE 188 did not require a WMP is
not a good enough answer – your program must be defensible.
A smart approach might be to establish comprehensive
WMPs for buildings with risk factors and then decide how to
keep the other buildings consistent with that plan. For some
facilities, it may make sense to establish a full WMP even if
ASHRAE 188 does not require it. In others, you might create a
simple list of maintenance measures without all the elements of
a full-blown WMP such as team meetings and validation.
3) Define the Assessment Scope
A WMP should be established based on types of building
water systems rather than on Legionella test results or the
condition of equipment. This means that the objective of the
assessment is not to assess risk to determine whether a WMP
is needed; the point is simply to identify the types of water
A list of water management plan team members. Teams
typically consist of 10 or fewer facility employees who oversee the program and make decisions about it. Many others, including vendors, will
be needed to implement the WMP.
A brief description of the building water systems with
flow diagrams. Salient information must be included for all building
water systems, not just ones requiring Legionella control measures. Simple line flow diagrams should show where water is received, processed
Hazard analysis of the water systems. If you define the hazard
as just Legionella, the analysis will note which water systems present a
significant potential for Legionella growth and transmission and whether
Legionella control measures can be effectively applied there.
Control measures. The team must come up with a specific list of
control measures for each building water system. ASHRAE 188 offers a
framework for the team to fill in, stating that procedures must be included
for new construction, equipment siting, start-up and shutdown, inspec-
tions, maintenance, cleaning, disinfection, monitoring for factors like
temperatures and disinfectant levels, and water treatment.
systems on the site, note key system components and construct
diagrams showing how the systems flow to one another. Taking
pictures can be helpful to the team but is optional. Testing
water systems for Legionella can provide valuable information
for validating the effectiveness of a WMP, but is not necessary
for the assessment.
Your assessment also doesn’t need to report conditions con-
ducive to Legionella growth or transmission. A comprehensive
WMP will include control measures to correct any problems a
surveyor would find. That is why the water management plan
model provides better risk reduction than periodic expert assess-
ments. Instead of getting a risk assessment report card once a
year, the WMP leads the facilities personnel down a path of con-
tinuously uncovering and correcting potential problems.
Because the primary objective is to identify water systems
rather than assess risk, it is actually more accurate to call it a site
survey or water systems survey rather than an assessment.
4) Define a Specific Hazard
How your WMP defines water systems hazards will affect
the complexity and validation of the WMP. There isn’t a right or
wrong definition; just be aware of the impact of your decision.
For instance, a very broad definition would be “all building-related
hazards,” which includes indoor air as well as water. Narrowing
the definition to just water-related hazards covers chemical and
physical hazards as well as biological. You could reduce it further
to waterborne pathogens or even just Legionella. The broader the
definition, the more complex the WMP.
WHAT BELONGS IN A WATER MANAGEMENT PLAN?
The team must also write out
steps for responding to Legionnaires’ disease if a case occurs
despite the prevention efforts. Each
control measure must be monitored to
determine whether it is performed to a
team-defined standard (called the “control
limit”). If it isn’t, then corrective action must
be implemented. The monitoring procedure, control limit and corrective action must be listed for each
Documentation procedures. You need to document all control
measures and other water management activities. A number of methods
will likely be needed, including logs, vendor reports and maintenance
Verification procedures. A designated verification person must
review the documentation to ensure the WMP is being implemented.
Validation. The effectiveness of the WMP in controlling Legionella must
MAKE SURE YOU ACCOUNT FOR THESE SEVEN AREAS WHEN
DEVELOPING YOUR PLANS TO REDUCE LEGIONELLA RISK.