Long Lake Management District conducted its annual treatment last week to mitigate harmful algal blooms ahead of the coming summer.
The lake management district contracted with AquaTechnex to perform the treatment alongside EutroPHIX last Wednesday and Thursday, May 15-16.
Algal blooms occur due to excess nutrients. Ryan Van Goethem from EutroPHIX explained to The JOLT that Long Lake has had a decades-long history of excess phosphorus in the lake due to the natural buildup of sediment.
Stored sediment releases phosphorus during summer which contributes to algal blooms. Van Goethem said that one pound of phosphorus can enable the growth of 500 pounds of algae, so managing the amount of phosphorus in the lake is important before algal blooms appear.
The lake management district has done some previous pest management work to address the issue, but Van Goethem said that algal blooms have developed more aggressively in the past years, urging the lake management district to reengage in such efforts.
To perform the treatment, Eutrophix used a granular product which when applied to the lake, binds to phosphorus, and prevents its release during summer. The product is a bentonite formulation modified with lanthanum.
A map of where the treatment is being applied is available on the lake management district’s website.
“This is a proven strategy that's utilized across the country,” Van Goethem said adding, “There's a couple other local projects and local water bodies that are utilizing the same strategy such as Kitsap Lake in Kitsap County [and] Lacamas Lake down in, I believe, Clark County by Vancouver.”
Van Goethem said that the general target for lakes in western Washington is to keep the phosphorus amount to 20-25 micrograms per liter. He added that a more important goal is to ensure that nearby homeowners can continue to use the lake and prevent the lake’s closure during the summer.
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Esther
There is phosphorus in the sediments, but much of that excess phosphorus came from nutrients entering the lake over years -from faulty septic systems, many of which are old and below current standards around Long Lake. From quick release fertilizers from lawns. From stormwater runoff from all the paved surfaces that have increased dramatically as we build more houses. Algal blooms are a serious problem worldwide. There are common sense solutions we can do to prevent algal blooms, instead of treating them with more chemicals that add to the toxic burden in the long term and do not contribute to the health of the lake. Nutrients can be intercepted before they enter the lake. Floating wetlands absorb phosphorus through the roots of plants growing on them. And everyone should be using organic fertilizers that don’t create polluted runoff. Clean Black Lake Alliance advocates for these ecosystem-based methods.
The contaminants in Long Lake and others in the area have been found in our groundwater aquifers. It’s time we thought of restoration, instead of expensive short term solutions that do not protect the drinking water we all rely on.
Monday, May 20 Report this