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Avian Influenza and Public Water Systems
Department of Environmental Conservation,
Division of Environmental Health, Drinking Water
Program, State of Alaska
http://www.state.ak.us/dec/eh/
April 7, 2006
This fact sheet is for public water systems that
have concerns about their ability to ensure water
they provide does not contain Avian Influenza
viruses.
This information is based on the state of scientific
knowledge as of March 2006 and may need to be
revised as our understanding of avian influenza
develops.
Avian influenza (bird flu) is an infectious disease
of birds caused by type A strains of the influenza
virus. Avian influenza, especially the H5N1 strain,
has become a worldwide concern. Wild birds carry
avian influenza in their intestinal tract and
can shed the virus in their feces. Avian influenza
has been detected in Asia, Africa and Europe and
is expected to make its way to North America,
possibly as early as this Spring. Alaska is expected
to be a primary entry point for the virus due
to the migration pattern of wild birds from Asia
and Europe. State and federal agencies are creating
response plans to be implemented if H5N1 avian
influenza is detected in Alaska.
Avian influenza is not expected to pose a major
threat to drinking water supplies in Alaska. However,
certain water birds can act as hosts for avian
influenza by carrying the virus in their intestinal
tracts and shedding it in their feces. There is
a potential that infected birds could land in
surface water sources that are used to supply
drinking water, such as lakes, rivers, tundra
ponds and reservoirs. Avian influenza is a fragile
virus but it can survive in contaminated surface
water for months in colder climates. If your drinking
water comes from a surface water source, it will
be important to make sure your current treatment
processes are optimized so that the virus is inactivated
if it enters your treatment system.
Current drinking water regulations, 18 AAC 80.600,
require that all surface water sources be filtered
and disinfected before being distributed to the
public. There are a few public water systems in
Alaska that currently avoid filtration under the
criteria listed in 18 AAC 80.620, but these systems
do disinfect their drinking water to inactivate
bacteria, viruses and other pathogens. Public
water systems that use a source that has been
determined to be Groundwater Under the Direct
Influence of Surface Water (GWUDISW) are required
to provide the same level of filtration and disinfection
treatment as surface water sources. (18 AAC 80.605)
Filtration and disinfection are very effective
in removing and inactivating the avian influenza
virus. Normal disinfection contact times will
provide adequate protection against the avian
influenza virus. It is also important to remove
as much organic material (turbidity) from the
raw water as possible. Organic material present
in the water can interfere with the disinfection
process. Filtration processes, which precede the
disinfection process, are utilized to remove turbidity
from raw water. Optimization of the filtration
process will reduce turbidity so that the disinfection
process is effective in inactivating bacteria,
viruses and other pathogens.
People should not drink untreated water from any
surface water source. Hunters, hikers, and other
outdoors persons should be sure to treat any water
used for drinking water or cooking by either boiling
the water for at least 3 minutes or disinfecting
with chlorine or Ultraviolet (UV) radiation. Portable
filtration units alone are not effective in removing
or inactivating viruses. It is important to read
the manufacturer’s information provided with
any portable filtration or disinfection device.
The information will explain the percentage of
virus inactivation that can be achieved with the
device.
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