Download Notkin`s Legionella Risk Management Roadmap

WHAT YOU NEED
TO KNOW ABOUT
LEGIONELLA AND
ASHRAE’S NEW
STANDARD 188.
Legionella & ASHRAE 188
ASHRAE standard 188 was approved and adopted in June 2015 and sets out guidelines for the
prevention of Legionella in any facility with a centralized water system.
Simply put, the new standard establishes a comprehensive and annually updated management
plan as a best practice and industry standard for protecting against Legionella in your water
system.
With the adoption of this standard, it is likely that we will see cities and states incorporate this
language in their building codes. In addition, many experts believe that the standard will be
held as a legal imperative in cases of legionellosis outbreaks, possibly increasing liabilities for
facilities that do not have a risk management plan in place.
What is Legionella?
Contracting Legionellosis
Legionella is a naturally occurring bacteria that
can be found in water supplies and can cause
Legionnaires disease and Pontiac fever, both of
which are often referred to as Legionellosis.
Legionellosis exposure occurs through the microaspiration of Legionella bacteria in drinking water
and ice, and through the inhalation of bacteria in
water spray or mists.
Legionellosis Symptoms
Common sources for contracting the disease
include ice machines, hot tubs, showers, decorative
fountains, and other amenities that produce water
spray, mist, or vapor.
Legionellosis is a form of pneumonia and comes
with all of the various symptoms you would expect:
•
Fever;
•
Headache;
•
Chills;
•
Tiredness; and
•
Cough;
•
Loss of appetite.
Most people exposed to the bacteria do not
become ill. Those most at risk for contracting the
disease include the elderly, small children, and
individuals with suppressed immune systems.
Legionellosis is very treatable when diagnosed early,
although mortality rates are commonly around
5-10%, if treatment is delayed they sky rocket to
nearly 50%.
Annual Legionellosis Cases in US, Australia, & Europe (~13,552)
1
<50 Years Old
(3,388)
25%
35%
Female (4,743)
50+ Years Old
(10,164)
75%
65%
Male (8,809)
Patient Age
Patient Gender
Based on WHO fact sheet No 285
158° F +
Legionella dies instantly
140°-158° F
90% die in 2 minutes
122°-140° F
90% die in 80-124 minutes
Legionella
Propagation
Legionella bacteria is found
naturally in our water and will
typically be found in small
quantities at the water source.
108°-122° F
Survives but does not multiply.
Large plumbing systems are often
a perfect breeding ground allowing
these bacteria to multiply and
become a problem.
The bacteria thrives in temperatures
from 68 to 122 degrees Fahrenheit,
but can be present in anything
68°-108° F
Legionella’s ideal growth range.
under 158 degrees.
Most often, facilities find the
highest concentrations of Legionella
where there is stagnation in their
water systems. This might include
cooling towers, tanks, lesser used
plumbing lines, and piping runs
that terminate in dead ends.
Abandoned piping that is capped
but not disconnected from the
Below 68° F
system after a remodel can often be
a culprit.
Legionella survives but is
dormant (even at below freezing
temperatures).
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Assessing Your Risk
Detecting Legionella
Does your facility have a centralized domestic water system, cooling tower, or water
features? If you answered yes, then ASHRAE’s new standard 188 applies to you.
Regardless of the water source, incoming water will always carry
ASHRAE 188 requires a Hazard Analysis and Critical Control Point (HACCP) risk
managment plan. The following is a brief guide, walking you through what it takes to
perform an HACCP.
As a general rule, keeping the level of Legionella in your water
some low level of the Legionella organism.
system at or below the level of your water source should be
sufficient to protect against your customers, patients, tenants
and/or employees contracting the disease.
Laboratory testing is the only way to be certain whether your
current system has acceptable levels of Legionella bacteria;
however, it isn’t necessarily advisable to test your water without
going through a Legionella risk assessment first.
PUT TOGETHER A TEAM
DIAGRAM YOUR
CONDUCT A HAZARD
Your team should
include:
WATER SYSTEM
ANALYSIS
Many facilities
do not have a
simplified water
diagram of their
water system.
Hazards include
unique piping
arrangements,
water fountains,
cooling towers and
storage tanks.
• the owner;
• your infection
control staff;
• the facility
manager;
• a domestic water
system design
professional; and
• an industrial
Diagrams can
be a vital tool in
assessing risks
and determining
required controls.
They also include
any locations that
are frequented by
at risk occupants
and staff.
hygienist
(optional).
Most importantly, ensure that all of your HACCP Risk
Management Plan team members are working in the
best interest of your facility and its owners. During risk
assessment and management planning, steer clear of
relying on companies who sell either chemical treatment
options or physical treatment/management systems.
3
ESTABLISH A
IDENTIFY CORRECTIVE
CONTROL POINTS
MONITORING SYSTEM
M
ACTIONS
Control points are
those points within
your water system
where you can
measure potential
problems or
introduce solutions.
The monitoring
system may be
as simple as
measuring or
confirming the
domestic hot water
temperatures or as
complex as water
sampling and lab
b
testing.
Corrective actions
include those that
you may need to
take immediately,
ongoing
maintenance plans
that effect daily
operations, and
establishment of
protocols for future
system revisions.
DETERMINE CRITICAL
Control points
can include the
incoming water
source, water
heaters, storage
tanks, or distal
outlets at the
extreme ends of
your system.
Corrective actions
can include
changes in water
temperatures,
installation of
chemical treatment
systems, or piping
modifications
to limit growth
locations among
many others.
CREATE CONFIRMATION
DEFINE RECORD
SCHEDULE AN
PROCEDURES
KEEPING NEEDS
ANNUAL UPDATE
As part of the
HACCP, you must
be able to confirm
that it is working as
expected. This will
typically include
testing water
samples to confirm
chemical and
bacteria levels.
A number of
processes and
check points
will need to be
documented during
implementation to
show compliance
and provide
guidance for future
decision making.
The annual update
confirms that
critical control
points are within
reasonable
parameters,
systems are
functional and
occupant and staff
risks are limited.
4
Protecting Against Legionella
As you go through your water system risk assessment, you will likely encounter a number
of areas that can be improved to eliminate Legionella growth and decrease the risk of
someone contracting the disease.
Many new systems are
on the market that tout
the ability to control
Legionella. Most of
these systems have
had limited testing and
their effectiveness is
unknown.
The solutions presented
here are well-tested
and industry standard.
When these strategies
are implemented
correctly, you can be
sure that they will
provide the intended
results.
Domestic Hot Water Storage
Some of the most commonly identified improvements are to
the system’s hot water tanks. Typically, facilities will store
water in these tanks at a low enough temperature to prevent
scalding; however, those lower temperatures provide a perfect
environment for Legionella growth.
The easiest remedy for this condition is to flush your tanks
periodically and store your hot water at 140ºF, mixing it with
cold water to deliver lower temperatures at the point of use.
Cooling Towers
Cooling towers have long been a source of legionella, the recent
outbreak in New York City is a prime example of what can
happen when they are not maintained correctly.
Preventive measures for ensuring that legionella doesn’t
contaminate the system are imperative and include startup
procedures, ongoing water treatment, monitoring, and
corrective actions plans. Additionally, a contingency response
and emergency disinfection plan should be in place in case a
suspected correlated legionellosis case(s) arises.
Piping System
When pipes aren’t used, the water stagnates and Legionella is
able to colonize and grow. You will find these types of problems
where renovations have abandoned sections of piping without
disconnecting them from the system, creating a “dead leg”.
Your risk management plan should address remediation of any
existing dead legs and provide guidelines for future system
modifications to limit the amount of dead-end piping.
Point of Use Filtration
5
Equipping fixtures with point of use filtration is a proven and
effective way to limit risk for at-risk occupants.
There is no standardized
“right solution” for
every facility.
Secondary Treatment Systems
A secondary treatment system is a likely recommendation where
there are at-risk occupants and there is no reasonable way to
limit the system’s dead-end piping. These systems do come with
some drawbacks; however, there are cases where secondary
treatment is your only, or most affordable option. In those cases
you may consider any one of the following systems.
Chemical Chlorine Injection
Chlorine injection has limited kill rates and is the least effective
of the secondary treatment systems available and there is a high
cost associated with the chemicals. However, these systems
do have the ability to provide electronic feedback, clearly
demonstrating the chemical concentration levels. Chlorine
injection is often used to shock a system if there has been a spike
in Legionella.
Your unique needs,
operations, and systems
will require tailored
recommendations to
provide the best value
and a management plan
that is actionable and
easy to maintain.
Notkin or other
specialized design
professionals can help
to organize and guide
your facility assessment
team.
Chemical Chlorine Dioxide Injection
Chlorine dioxide systems have the same electronic feedback
capabilities as chlorine injection systems with the added
benefit of being less corrosive and more effective in managing
legionella. Chlorine dioxide is costly and the chemical is toxic so
safe handling and managing concentration levels in your water
system is imperative.
Copper Silver Ion System
Copper Silver Ion systems disperse positively charged ions into
the water system and over time the ions destroy the biofilm
that harbors Legionella. These systems are highly effective and
have a lower maintenance cost than chemical systems, but they
do require regular lab testing to measure the level of ions in
your system and regular cleaning of the nodes to ensure proper
function.
6
If you have questions about ASHRAE Standard 188 or would
like more information about your options for controlling the
risk of Legionella at your facility, give us a call.
(206) 448-1911
www.notkin.com