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Surface Water Management Division
Sunday Lake Toxic Algae Bloom Alert
Last updated 3/1/2013
ADVISED CAUTION LIFTED FOR SUNDAY LAKE - JANUARY 2013
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Sunday Lake experienced a bloom of potentially toxic blue-green algae in the fall and early winter of 2012/2013. The inlet channel and the area around the Community club's dock, in particular, had thick scum ranging from bright great to milky-blue (see picture).
The most recent samples were taken on Dec. 11th, 2012. Results show that the liver toxin, microcystin, was present at less than 1 part per billion (ppb) which is below the WA State Department of Health's recreational standard of 6 parts per billion. Results for anatoxin a, a neurotoxin, showed that this toxin was not detected in the lake. |
Scum of blue-green algae at Sunday Lake |
Snohomish County removed the Caution signs at the public access sites in January, since the bloom had cleared. Residents had been advised to exercise caution when recreating in the lake especially in areas of scum. Pets who may drink water are at particular risk and should be kept away from the lake. More information is provided below. If scum is seen these precautions should still be taken.
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CAUTION sign posted at Sunday Lake - click to enlarge |
The "CAUTION" signs recommend:
- Do not swim in areas of scum.
- Do Not Drink Lake Water
- Keep pets and livestock away from the lake
- Clean fish well and discard guts
- Avoid areas of scum when boating
For more information refer to our Toxic Algae page or visit the State Department of Health website. For health related inquiries you may also call the Snohomish Health District at 425-339-5250. To sign up for toxic algae email alerts email Marisa Burghdoff. |
Should I be concerned?
Yes. Toxic algae can cause serious illness in humans and animals who play in or ingest affected waters. Toxic algae exposure can kill pets, waterfowl, and other animals. Pets who drink lake water, especially dogs, are at particular risk.
How should I respond?
- Follow the "CAUTION" sign advisory to not swim in areas of scum or ingest water, keep pets away from the lake, clean fish well and discard guts, and avoid areas of scum
- Contact your healthcare provider if you or your pets are ill after exposure*
- Return to this site to find out the latest testing results
- Sign up to receive toxic algae email alerts by emailing Marisa Burghdoff
* For additional information on health risks or to report exposures contact the WA Department of Health at (360) 236-2251.
Is it safe to drink water from Lake Howard if it has been filtered?
The Snohomish Health District advises that lake water never be used as a drinking water source. In addition, studies have shown that conventional water treatments such as coagulation, sedimentation, filtration, and chlorination are ineffective for removal of liver toxins associated with the toxic algae bloom at Sunday Lake. For additional information contact the Snohomish Health District at 425-339-5250.
How does the bloom impact wildlife?
Residents have noted that Sunday Lake has wildlife that might be at risk from the bloom, including waterfowl and otters . Unfortunately, wildlife are also susceptible to the toxins - particularly if they are consuming water with high concentrations of algal scum. Please report any incidents where you suspect wildlife may have been injured from the conditions.
What is causing this problem at Sunday Lake?
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With the help of citizen volunteers, Snohomish County has been monitoring the water quality of Sunday Lake for 19 years. Monitoring at Sunday Lake show the lake has high nutrient levels - especially phosphorus. Toxic algae blooms are one symptom of the high levels. The phosphorus comes from runoff flowing into the lake from fertilizers, failing septic systems, runoff from roofs and driveways, and pet and animal wastes.
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Example of of typical blue-green algae bloom
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Where did the toxic algae come from?
The term "toxic algae" refers to a handful of blue-green algae species that sometimes produce toxins. These algae are a normal part of the lake system and are always there in low numbers. However, when high levels of phosphorus are present, the algae can sometimes grow rapidly - causing blooms. As the algae die, the green scum forms on the lake surface.
What can I do to help?
Unfortunately, there is no simple lake treatment for toxic algae. The best way to help Sunday Lake and prevent future blooms is to reduce nutrients coming into the lake. You can start acting today to protect your lake - find out more on our LakeWise page.
For more information
| Test Date |
Microcystin* ppb |
Anatoxin a** ppb |
Above Recreational Standard |
| 11/6/2012 |
0.70 |
Not Detected |
NO |
| 11/13/2012 |
4.8 |
Not Detected |
NO |
| 12/06/2012 |
Less than 1 |
Not Tested |
NO |
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*Microcystin is a liver toxin and the WA State recreational standard is 6 parts per billion (ppb)
**Anatoxin a is a neurotoxin and the WA State recreational standard is 1 part per billion. |
Contact
Gene Williams, Senior Planner, 425-388-3464 extension 4563
Marisa Burghdoff, Water Quality Specialist, 425-388-3464 extension 4639
Jen Oden, Water Quality Specialist, 425-388-3464 extension 4352
Some of these documents are in pdf format. To read these files you'll need to have Adobe Acrobat Reader installed on your computer.
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