In the late morning Monday, Rick Jaspers glided over the still waters of Lake Sacajawea in his kayak. The experience, though, was tainted by islands of gooey green algae floating on the surface. Like icebergs, most of the mass of green goo lurked under water.
Algae is thriving early and abundantly this year, even though Longview is flushing the lake as usual with 4 million gallons fresh water drawn from the Cowlitz River daily.
“I walk around there a lot, but you really have a different perspective when you’re out in the middle of it,” Jaspers said.
There’s no odor yet, but the problem likely will get worse later this summer. In August, the city will shut down the flushing operation entirely to modify pipes, screens and water intakes at the old Fisher’s Lane water plant, which the city will modify to continue drawing water from the river to flush the lake.
Work on the $1.7 million project began in June and is expected to wrap up by Oct. 31. The improvements will conform to federal standards meant to protect smelt and other endangered species, particularly salmon, and make the operation more efficient. The city considered other options for keeping the lake fresh but rejected them as far too costly.
Amy Blain, the city’s project engineer, said hot weather can cause more algae to bloom. Longview has experienced early record-breaking heat waves starting in April, which likely is a factor in this year’s outbreak.
“You will get algae when you get high temperatures,” Blain said. “We’ve seen that happen in the past.”
Blain said she hasn’t received any citizen complaints this summer, and there’s a limit to what the city can do if algae becomes a problem. The city can drop the water levels down and try to wash some growth out at the south end of the lake, she said.
“There may be small clusters of algae here and there ... and those are likely to persist throughout the year regardless of our flushing efforts,” Blain said by email. “A large bloom in the middle or north lobes would not be so easily dealt with.”
Plenty of slime already has badly tainted the north end of the lake between Louisiana Street and Ocean Beach Highway, and the section south of Louisiana Street also is teeming with the green goo.
Chris Bischoff, environmental health manager at the Cowlitz County Health Department, said possibly other factors contributing to large algae blooms are nutrients washing into the lake. Nutrients could be coming from urban stormwater and perhaps the Cowlitz itself.
Blain said she hasn’t received any citizen complaints lately. She said before the flushing began in May, stormwater staff noticed algae blooms north of the Washington Way bridge on the west side and in the south by Kessler Elementary School. Water quality improved there after flushing began, she said.
But even pouring 4 million gallons of fresh river water into the lake daily can only have so much impact: At that rate, it takes a month to flush the entire lake, which holds about 130 million gallons of water.
Jaspers said the algae doesn’t deter him from kayaking in the lake because he is training for a triathlon. But that might change if algae starts to smell, he said.
The city is not allowed to flush the lake before May 15 or after Oct. 31 due to federal concerns of flushing protected smelt.