During the late summer months, when the temperature rises, many people flock to the shores of Green Lake to swim. However, swimmers may face another lake closure for a third straight year because of a toxic algae bloom.
"We're facing another summer where the lake may close," said Ref Lindmark, vice president of the Green Lake Community Council. "Everybody who lives in Green Lake - whether they walk around it or bring their kids - wants the water quality addressed."
The Lake Restoration Committee, formed this spring, created a petition to Seattle Mayor Greg Nickels and Seattle Parks and Recreation Superintendent Ken Bounds to try to get the city to fund a treatment for the lake.
"We want to be able to keep the lake open for recreation, and the lake has to have better water quality," said Karen Schurr, chairperson of the committee.
"We think that the city seems to have a lot of reasons not to take care of the lake," Lindmark said. "The expectation of the city and residents is that the city will take care of it."
Green Lake, called the "jewel within the city" by Lindmark, is one of the most popular recreational lakes in Seattle.
"It definitely hurt us last year," said Kris Enkap, of Green Lake Boat Rentals. "Business definitely slows down about 50 percent. The problem is it's a man-made lake, and there's not much filtration." Enkap said that when the algae bloom is in effect, the lake omits a smelly odor and changes color to a more blue-greenish tone.
The committee obtained 240 signatures at the Seafair Milk Carton Derby at Green Lake on July 8. They plan to circulate the petition to gain more signatures on a daily basis and set up A-frame boards. The petition is urging that immediate action be taken to protect lake users from toxic algae blooms and to maintain aquatic recreation.
Kevin Stoops, of the Seattle parks department, stated that part of the problem is that Green Lake is a shallow, warm-water lake. According to Stoops, the toxic bacterial bloom called cyanobacteria, also referred to as "blue-green algae," is caused from an increase of phosphorus or nutrient-enriched waters stimulating the growth of the algae.
"We basically did a quick study in the past few months," Stoops said.
According to Stoops, consultants recommend an alum (aluminum sulfate) treatment. The last alum treatment, in 1991, lasted for four to five years.
"People were shocked that nothing had been done in 12 years," Schurr said.
"By 1996 or 1997, they should have done something," said Doug Martin, a fisheries biologist and a member of the Lake Restoration Committee.
There is no money in the capital budget for an alum treatment, said Dewey Potter, a spokesperson for the Seattle parks department.
The treatment will cost approximately $1.5 million.
"In 2004, we do have the plans to start going through the permit process to start the treatment," Potter assured. "We hope to begin treating [Green Lake] in 2005. We're very eager to get this done." The city's next projected alum treatment, the most cost-effective plan, will be a stronger treatment that will be effective for at least 10 to 12 years, according to Stoops.
Martin attributes the algae problem to too much nutrient enrichment as a result of goose-droppings, surface run-off of fertilizers and from an accumulation from more than 100 years of city development.
Exposure to the toxins produced by cyanobacteria causes acute or chronic illnesses, such as gastroenteritis, respiratory and neurologic effects, skin irritation, allergic responses and liver damage. Exposure can be from inhalation, skin contact and water consumption, which are dangerous for both humans and animals. Symptoms of illnesses caused by the liver toxins that the bloom releases are flu-like and include abdominal pain, diarrhea and vomiting.
According to a study by Seattle University professor Jean Jacoby, cyanobacterial blooms may cause a variety of water-quality problems, including aesthetic nuisances such as odors, scum, fish tainting and unsightliness.
Martin also stated that milfoil (an exotic, thick and leafy plant) is prolific in Green Lake, and its stem pulls nutrients out of the sediment. When the plant dies, it releases those nutrients, which stimulate more algae growth and subsequently an algal bloom in August. The bloom lasts for a month to two months, and the toxins released linger for about a week after the bloom is over.
Milfoil was accidentally imported into the lake.
"In the future, we want to seek out alternative solutions that will be permanent," Martin said.
Alternative solutions Martin would like to see include piping clean water from Lake Washington to dilute the water and maintain the nutrients at a lower level; dredging a large portion of the lake material and removing it, which would reduce the overall load and remove some milfoil; or building a filtration plant.
Green Lake has had algae problems since the 1930s, according to Stoops. He stated that the city poisoned the algae with copper sulfate as a remedy.
In the '60s, the city began pushing fresh drinking water through Green Lake to dilute the nutrient enriched waters. They cycled 8 million to 10 million gallons of water.
When the city couldn't use drinking water anymore to dilute the lake, the city started extensive studies in 1980. A Green Lake water quality improvement program was developed in 1990 and found that the alum treatment, using a chemical that binds phosphorus and makes it unavailable to the algae for growth, would be the cheapest and most effective plan.
The Lake Restoration Committee is working toward a bond issue that can do a more major restoration. The petition is to grab the attention of the City Council and the mayor, said Schurr.
"The letter is to urge them to seek funding to treat the lake," said Schurr, who hopes to secure funding in time for this winter. "Most people are very anxious to do something for the lake."
Martin stated that the best time to treat the lake is in the winter, when all the nutrients are in the water.
"The committee really wants to see this through, and we definitely need everyone's support," Martin said.