STANWOOD — Miriam Lancaster paddled her kayak over the surface of Lake Ketchum. The water was still, a wisp of fog caressing the surface.
At the splash of her paddle, a flock of cormorants launched from a nearby dock, while others swam, looking for fish.
Lancaster, 70, doesn’t get out on the water every day, especially in winter, but when the weather is warmer, she loves to take her kayak out for a paddle across the 25-acre lake.
But with summer comes algae, and Lake Ketchum, ringed by homes in a rural corner of north-Snohomish County, is more susceptible to algae than most because of a high level of phosphorus, a nutrient that is used in agricultural fertilizer.
This has been a problem on Lake Ketchum going back decades. In the early 1990s, residents on the lake contacted the county’s then-new lake management program to investigate it.
Now, more than 20 years later, Snohomish County is going to start an approximately $450,000 multiyear treatment program to reduce the phosphorus concentration in the lake and restore it to something closer to its natural state.
How bad is it?
Lancaster thinks that toxic algae are partly responsible for her autoimmune disease.
One of her neighbors, Norma Arnold, believes toxins in the algae are responsible for the deaths two years ago of her two black Labradors.
Roy VanWinkle, a real estate agent who lives on the lake, said that when he sold his mother-in-law’s house next door, it stayed on the market for nine months and sold between 10 percent to 15 percent below market price because of the algae problem.
Most polluted lake
But numbers, rather than perceptions, tell a more complete story. Snohomish County has been testing Lake Ketchum since the 1990s. While a phosphorous concentration of 25 micrograms per liter is considered “eutrophic,” or nutrient-rich enough to promote algae growth, 15 years of testing revealed the lake’s summertime average is 277 micrograms per liter.
That’s in the surface water. In the sediments at the bottom, the level is much higher: 1,746 micrograms per liter.
Based on those levels, Lake Ketchum is the most polluted lake in Snohomish County, if not the state.
All lakes go through a eutrophic period as part of their natural evolution, said Gene Williams, a senior planner in Snohomish County’s Surface Water Management program.
That natural process takes thousands of years, however. Lake Ketchum got this way in relatively recent decades.
“At one time Lake Ketchum was the drinking water source for Stanwood,” Williams said. “That indicates it wasn’t always green and slimy.”
Not all algae blooms are created equal.
Cyanobacteria — commonly called blue-green algae because of the slimy soup it forms on the surface of area lakes — is fairly common during the warm summer months. Most of it is nontoxic, if unpleasant to look at or smell.
In Washington state, the most common toxins in algae are microcystins (liver toxins) and anatoxins (nerve toxins). Toxic blooms are hard to predict, however, because some algae blooms produce both toxic and nontoxic strains, and nontoxic blooms can turn toxic without warning.
Timing of symptoms
Lancaster believes her own condition involved just such an unpredictable outbreak.
She moved to her house on the lake in 2000, and would take her kayak out every day, even when algae was visible.
In 2008-2009 a new inexpensive test for toxicity became available, and the county began posting warning signs on the shore to keep people and animals out of the water during toxic blooms. Risk extended to people involved in boating and kayaking.
“I stopped that when the county started posting, but I was already starting to get sick,” Lancaster said.
One day in 2009, she lost vision in one eye.
Her symptoms worsened rapidly, affecting her back, lungs, intestines, heart and urinary tract. She required oxygen and home care, and was forced to retire from a career as a nurse with the U.S. Public Health Service. She needed home health care herself.
“I couldn’t get out of bed for six months, really,” she said.
Her diagnosis was Reiter’s syndrome, a form of arthritis that primarily affects the spine but can affect other areas of the body, and ankylosing spondylitis, another inflammatory condition that could lead to the vertebrae fusing together.
Her doctor couldn’t pinpoint the cause, but the timing of the onset of symptoms corresponds to when Snohomish County began posting warnings about the water quality in Lake Ketchum, she said.
Her treatment was an aggressive steroid regimen that now has her in remission and mostly symptom-free, but which will cost her $2,000 a month most likely for the rest of her life.
Norma Arnold has the same suspicions about what killed her dogs. Her Labs, Cate and Biff, were about 14 years old, so perhaps had weakened constitutions.
Both still weighed more than 100 pounds each.
Arnold knew about the toxic algae, and had kept her dogs restrained. They nevertheless managed to get loose and into the lake one night, she said.
“The next morning they couldn’t stand up,” she said.
The dogs were put down later that day.
Arnold said she didn’t have the bodies tested, but she believes her two otherwise healthy dogs wouldn’t both simultaneously have become so ill as to require euthanizing if they hadn’t been poisoned.
Treating the lake
The key ingredient in treating algae in lakes is alum, or aluminum sulfate. The aluminum bonds with phosphorous in the water, then settles to the bottom as a particulate, where it forms a “cap” on the lake bed, preventing more nutrients from being released from the sediment in the summer.
That’s important, because right now 73 percent of all the phosphorus released into the water of Lake Ketchum during the summer months is coming from the lake bed itself.
How it got there in the first place is another matter. Testing in the 1990s identified the primary source as a dairy farm south of the lake.
The northern field of the farm was used for pasturing cattle, and the farmer had been accepting chicken manure and putting it in the fields as fertilizer.
That pasture drained into the creek that feeds the wetlands on the southern shore the lake.
After tests confirmed the farm as the source of the pollution, the owner took a few steps to mitigate it, including moving cattle off the northern field and turning the land over to hay production. However, a dispute over further actions and a lawsuit filed by the newly founded Ketchum Shores Improvement Club against the farm led to years of animosity between the farm owner and lakefront residents.
Ideally, a cleanup program for the lake would have involved removing contaminated soils from the former pasture, Williams said, because farm runoff still contributes about 23 percent of the lake’s annual phosphorous load.
Calls to the farm were not returned.
In the long term
The treatment for the lake will begin in May, most likely, Williams said. A single large injection of alum will, he hopes, remove about 85 percent of the phosphorus from the water.
Smaller alum treatments will follow in the years 2015-2018 to bind up remaining phosphorous in the lake bed and to offset the continuing runoff. All told, the modeling is expected to bring the phosphorus down to a more manageable concentration of 40 micrograms per liter. That’s still considered eutrophic, and there will still be algae in the lake, but the blooms will be nowhere near as common or as severe as in past years, Williams said, adding that the lake should be fine to use recreationally.
The cost for the four-year treatment plan is estimated to be $446,000, with the money coming from a variety of sources, including a state Department of Ecology grant, the Stillaguamish River Clean Water District’s discretionary fund, the county Surface Water Management’s funds, and the people living on the lake.
In particular, the residents of Lake Ketchum will kick in $36,000 from their Local Improvement District reserve fund, plus another $4,440 per year from LID assessments going forward. In 2013 the residents won approval from the County Council to raise an additional $13,560 per year from their own water fees.
While the model projection for the alum treatments says one thing, it’s possible that future annual treatments will be needed, and possibly another major infusion of alum seven or eight years in the future, Williams said.
There is no funding identified for alum treatment beyond 2018, Williams said.
Roy VanWinkle, president of the Ketchum Shores Improvement Club, said the lakefront owners have taken an active role in the lake’s cleanup, to the point of taxing themselves at a higher level, and are now just looking forward to seeing improvement.
“It’s one of those situations where you really can’t ignore it. It won’t go away on its own,” VanWinkle said.
For Miriam Lancaster, restoring the lake is personally important. With her illness in remission, she would enjoy taking out her kayak more often, which was her primary source of exercise before she got sick.
It’s also a source of personal enjoyment, which is apparent even in mid-winter.
“It’s a beautiful lake and it really should be cleaned up,” she said.
Chris Winters: 425-374-4165; firstname.lastname@example.org.