CASE STUDIES
Kitsap Lake
A targeted phosphorus management strategy dramatically improved water quality and reduced the conditions that drive harmful algal blooms.
THE CHALLENGE
Decades of Harmful Algal Blooms Impact Recreation and Public Safety
Kitsap Lake is a 246-acre recreational lake in Bremerton, Washington, supporting boating, water skiing, fishing, and other community activities. For decades, the lake experienced recurring harmful algal blooms (HABs) and cyanobacteria outbreaks that resulted in repeated lake closures and ongoing public health concerns.
A 2011 phosphorus reduction study identified internal phosphorus recycling from lake sediments during low-oxygen conditions as the primary driver of bloom development. The need for action became especially apparent in September 2019 when a severe HAB event forced another lake closure after a police K-9 required treatment for potential toxin exposure following an enforcement activity in the water.
A 2011 phosphorus reduction study identified internal phosphorus recycling from lake sediments during low-oxygen conditions as the primary driver of bloom development. The need for action became especially apparent in September 2019 when a severe HAB event forced another lake closure after a police K-9 required treatment for potential toxin exposure following an enforcement activity in the water.
THE APPROACH
Targeting Phosphorus at Its Source
In late 2019, AquaTechnex evaluated lake conditions through historical data review and field sampling, including water and sediment monitoring at five locations throughout the lake. Working with EutroPHIX, the team developed a restoration plan for the City of Bremerton and project stakeholders.
Restoration efforts began in June 2020 using EutroSORB G to bind phosphorus in lake sediments and reduce nutrient availability in the water column. Since implementation, two treatment applications have been completed each summer to support long-term lake restoration goals.
Restoration efforts began in June 2020 using EutroSORB G to bind phosphorus in lake sediments and reduce nutrient availability in the water column. Since implementation, two treatment applications have been completed each summer to support long-term lake restoration goals.
Significant Water Quality Improvements
Phosphorus management treatments improved water clarity, reduced nutrient availability, and established a sustainable path toward long-term restoration.
90
%
PHOSPHORUS REDUCTION
35
%
INCREASE IN WATER CLARITY
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