Swimming Beach Program Frequently Asked Questions
How often are the swimming beaches sampled?
Swimming beaches are sampled once a week from May through September. Generally, samples are collected every Monday.
Who does the water quality sampling at swimming beaches?
Environmental Specialists from the King County Department of Natural Resources and Parks sample the swimming beaches.
How are samples collected?
Samples are collected in swimming areas where the water depths are approximately 1 meter (approximately 3 feet).
All samples are collected in sterile 1 Liter wide mouth high-density polyethylene bottles, labeled for each sampling
location. Care is taken to prevent contaminating the sample by washing hands before sampling, keeping fingers out of
the inside of sample bottle, and inverting the sample bottle while scooping away from the person collecting the sample.
Samples are preserved on ice in coolers during transport to the environmental laboratory.
What swimming beaches are tested?
The swimming beaches selected for this survey are public swimming beaches with officially designated swimming areas.
These beaches were selected to provide a wide geographic coverage of beaches in lakes Sammamish and Washington, with
Green Lake providing a small lake comparison. In addition, some cities contract with King County to participate in
the program, or send King County their data to post on the website. To see what beaches are currently part of the
program, please check out the list on the
Swimming Beach Home Page.
Who analyzes the water quality samples from swimming beaches?
Samples are analyzed at the King County Environmental Laboratory. Microbiologists analyze the samples within hours
of sample collection and can determine fecal coliform results in 24 hours.
If a beach is closed, can my dog swim in the area?
Photo courtesy of Jonathan Frodge
Dogs should not be taken to public swimming beaches. There is a $500 fine for having dogs on public swimming beaches
in Seattle. Pets are more likely to go into various types of water to swim and drink than people. This can increase
their risk of getting sick because of exposure bacteria and algal toxins, particularly at closed beaches. The best
thing to do as soon as the animal leaves the water is to wash the animal thoroughly with soap and rinse it very well.
If your animal develops diarrhea you can initially treat it by withholding food. At this stage it would be wise to
consult with your veterinarian about what to do next. Be aware that if your animal is quite young or old, it could be
at higher risk. If the animal seems unusually ill, call your vet immediately.
What are fecal coliforms?
Fecal coliforms are intestinal bacteria that are routinely used as an indicator of sewage pollution in water, and as
an indicator of the human health risk. Fecal coliform bacteria always occur at very high counts (several thousand CFU's)
when sewage is present in the water; an example is when a sewer line breaks. However, high bacteria counts in water
do not necessarily indicate human sewage pollution because many other mammals and birds also contribute to this type of
bacteria. Low counts of fecal coliform bacteria, less than 50 CFU’s, are routinely found in high quality water. Typical
fecal coliform bacteria counts from the middle of lakes Washington and Sammamish during the summer are less than 20 CFU's.
What is a CFU/100mL?
CFU’s are a unit of measure and stand for Colony Forming Units. After incubation, bluish colonies of bacteria should
appear on the sample dish. It is then necessary to count all of the colonies that are in each dish. A calculation must be
performed to determine the number of colony forming units per 100 milliliters of sample.
What is the method being used to determine fecal coliform?
The method used by the King County can be found in:
American Public Health Association. 1998. Method 9222 D. Fecal Coliform Membrane Filter Procedure. Clesceri, L.S.,
A.D. Eaton, and A.E, Greenberg (ed). Standard Methods for the Examination of Water and Wastewater. 20th Edition.
American Public Health Association, Washington DC.
Why don't we use the RNA test for routine sampling of the beaches?
A technique that has been used to identify the source of the fecal bacteria is to use the genetic material RNA
(ribonucleic acid) from the bacteria. This provides information on the species of animal that added the bacteria to
the water. A 1993 study using this RNA method conducted in Piper's Creek in Seattle's Carkeek Park identified domestic cats
as the major source of bacteria. Studies conducted at Juanita Beach in 1998, identified ducks and geese as the major source
of fecal coliform pollution, with seagulls and dogs as secondary sources. The RNA tests are expensive and time consuming,
taking weeks to obtain the data. While the results are valuable in designing our long-term water quality protection programs,
the results are not available fast enough to use this technique for routine monitoring of the beaches or the sewer system.
The fecal coliform testing (without RNA analysis) takes less than 48 hours, allowing a much faster response to a potential
problem. King County has been investigating new testing techniques that can identify the specific hosts of intestinal
bacteria more cheaply than RNA testing. Currently. we are testing a few different methods, which we hope will identify
bacteria sources so that we can better understand if there are risks to swimmers getting sick when fecal coliform counts
are high.
What is the standard used by King County to determine if a swimming beach should be closed?
King County uses the Ten State Standard, which is a geometric mean of 200 fecal coliforms with no single sample exceeding 1000.
What is the cause for high bacteria counts?
There may be multiple bacterial sources for high fecal coliform counts. Potential sewage spills are the highest concern
because of the increased risk of transferring disease from a human source. Fecal contamination from waterfowl, dogs and cats,
surface run-off from poorly drained grassy areas adjacent to the beach, high concentrations from nearby creeks, and poor water
circulation in the swimming area may contribute to the high bacterial counts.
Who determines if a beach should be closed for swimming?
Municipal and King County Park Departments determine if their respective swimming beach facility should be closed.
Public Health - Seattle and King County advises local park departments on swimming beach closures related to health and safety concerns.
What are the symptoms if I swim in an area contaminated with bacteria?
Ingestion - If a person incidentally or accidentally swallows water contaminated with fecal bacteria water, your risk of
becoming sick would probably increase slightly over swallowing water outside the area of contamination. The degree of risk would
depend on 1) the amount of water swallowed, and 2) general health of the person (healthy, sick, immuno-suppressed).
Gastrointestinal distress is a common symptom.
Dermal - Your risk of becoming ill or getting infection from skin contact is likely very low. The skin provides a very good
barrier against most common bacteria and viruses. Your risk would increase slightly if contaminated water comes in contact
with the inner ear, eyes or cuts/abrasions. Any infections resulting from this type of exposure would likely be treatable.
What are the symptoms if I swim in an area contaminated with algal toxins?
For more information about risks associated with algal toxins please check out the State Department of Health website:
http://www.doh.wa.gov/ehp/algae/faqs.htm
Who is responsible for cleaning up the goose poop in the park?
The parks department staff is responsible for cleaning the walkways, piers and floats.
Why are there so many geese at these county parks?
In recent years, non-migratory ducks and geese have been living the good life, protected and encouraged by human development
in King County. These waterfowl love to feed on the succulent grasses of well-kept lawns; particularly the new growth shoots
that sprout after mowing. With few natural enemies to keep their numbers in balance, geese and ducks can overpopulate and
become a nuisance. Large flocks can compete with other species of waterfowl, overgraze lawns, and litter yards and docks with
droppings and molted feathers. Their droppings pollute lakes with nutrients, and, to make matters worse, their intestines may
contain a tiny parasite that can cause a condition known as "swimmer's itch."
Canada geese are protected by the International Migratory Bird Treaty Act and should not be harmed. However, these and other
waterfowl can be discouraged by deterrents such as two-foot-high fences, large helium balloons, scarecrows, streamers or
reflectors. Because geese and ducks are attracted to lawns or domestic grass growing along shorelines, a buffer of native
vegetation between the water's edge and a home-owner's lawn will deter them. Most importantly, do not feed waterfowl-and
discourage others from feeding them as well.
What is the role of Public Health - Seattle and King County?
Public Health - Seattle and King County determines the public health implications of the bacteria and algal toxin data
collected from this program and conveys this information to elected officials, local park departments and the public.
What is the role of local Parks Departments?
The parks departments are responsible for the operation and maintenance of park facilities.
What is the Water Quality Standard for Fecal Coliform in Streams?
According to the Washington Water Quality Standards WAC 173-201A-030, freshwaters rated AA (extraordinary) shall not
have fecal coliform levels exceeding 50-colonies/100 ml and not have more than 10% of all samples exceeding
100-colonies/100 ml (for Class A excellent - 100 colonies/100 ml and less than 10% of all samples exceeding 200
colonies/100 ml). These concentrations are often exceeded in urban streams in King County.
What are some best management practices (BMP’s) that King County is implementing to help keep swim beaches open this year?
If fewer geese spend less time at the parks, there will be fewer feces and the bacterial load will decrease. Goose control
using trained dogs is occurring at some parks outside of the King County park system.
Park personnel and the King County Marine Patrol have replaced the practice of washing duck and geese feces off of the
walkways and into the swimming area.
An option would be to spray geese feces with dilute hydrogen peroxide would kill bacteria and would photo-oxidize, posing
little or no water quality threat.
Comparison data indicate lower bacterial counts at beaches on open shorelines and in areas where there is greater exchange
of water. Beaches in more enclosed bays, or with streams from an urbanized watershed discharging into them tend to have
higher bacterial counts.