HomeMy WebLinkAbout1 - Original Submission_ 2022 Kitsap Lake project summary for committeesKitsap Lake Algae Control and Aquatic Vegetation Control, 3/7/2022
Proposed scope of work with 2022 contract services from AquaTechnex LLC. include:
• $80,000 - Phoslock application to entire lake with possible second application in August
• $40,000 - Harvesting of excess aquatic vegetation
• $2,500 - Reapply herbicide to invasive shoreline vegetation and aquatic species
• $750 - Reapply for NPDES Permit
• $2,000 – Water quality sampling
• $35,000 Second Phoslock application in deep water portions of the lake
• Tax: $14,422.50
• Total contract - $175,000
Kitsap Lake Cleanup Background
Kitsap Lake water quality and aquatic vegetation have been studied for the past two decades. The lake is
fed by streams, springs, and stormwater runoff which carries nutrients into the lake. The lake has a very
limited exchange of water, so pollutants tend to “hangout” in the lake and settle to the bottom.
Accumulated sediment nutrients support aggressive aquatic vegetation growth and feeds potentially
toxic cyanobacteria (Blue-green algae) blooms. Further, the lake attracts waterfowl whose waste
contains bacteria including E-coli that further impairs water quality. Historically, these elevated bacteria
levels and cyanobacteria algae blooms prompted lake contact recreation advisories and closures each
year.
Mayor Wheeler and City Council identified Kitsap Lake as a priority concern and dedicated resources to
improve lake quality and restore recreational opportunities to the community. In late 2018, the City met
with lakefront property owners to discuss lake water quality and developed a partnership committed to
lake cleanup. Baseline water quality and lake sediment testing were completed in 2019, which defined
corrective actions needed. City staff complete seasonal water testing to track improvements or issues
associated treatment. Kitsap Public Health tests lake water to ensure it is safe for direct contact during
recreational use and fishing.
Water quality has improved significantly with no closures reported during the high use months of June
through August over the past two years. This is the third year of the project using Phoslock® (an
environmentally safe product) to control cyanobacteria growth in the lake. Algae blooms have occurred
outside of the high use periods. By comparison with pre-project blooms, these have been smaller and
shorter in duration. Continued project support will be needed over the coming years to maintain water
quality and control free reactive phosphorus in the lake.
The 2022 contract modification funds continued services from AquaTechnex LLC. that included:
DocuSign Envelope ID: 78ABC8F8-0C14-4743-A8D6-4D59E1FC1138
• Phoslock application to sequester free reactive phosphorus in the water column and lock
phosphorus in the bottom sediments.
• Harvest excess aquatic vegetation in the shoreline area (littoral zone).
• Elimination of invasive shoreline vegetation species with application of Clearcast herbicide.
Case study completed with data collected by City staff showed 90% reduction of available phosphorus
and increased water clarity by 3 times baseline equal to 15 feet of depth.
Project manager:
Chance Berthiaume, CPMSM, Stormwater Permit Coordinator
Email: Chance.berthiaume@ci.bremerton.wa.us
Phone: (360) 473-5929
DocuSign Envelope ID: 78ABC8F8-0C14-4743-A8D6-4D59E1FC1138