Some Lake Anna residents may have noticed two specialized pontoon boats on the water just after Labor Day spreading something in the upper reaches of the North Anna River branch. This is the start of the 2025 Phosphorus Mitigation Program funded by the Virginia General Assembly and administered by the Lake Anna Advisory Committee (LAAC). The North Anna River treatment was concluded the week after Labor Day. Long-awaited treatment in the Pamunkey Branch is scheduled for the week of September 8.
For two years LAAC has spearheaded a phosphorus mitigation project to start addressing Lake Anna’s phosphorus issues that cause algal blooms and harmful algal blooms. EutroPHIX, a division of SePRO Corporation, and SOLitude Lake Management have been selected through a proposal process to undertake this project, which is currently in its second year of implementation.
In 2025, the project will include lake treatments to significantly reduce phosphorus sources in the sediments of the North Anna and Pamunkey Creek tributaries, and a treatment system on the North Anna River to mitigate phosphorus inputs. These activities will improve water quality in Lake Anna and help mitigate the source of harmful algae blooms.
The 2025 activities are Phase 2 of a multi-year restoration plan for the northern end of Lake Anna. What residents saw was the start of the treatment of 600 acres of the North Anna Arm and 470 acres of the Pamunkey Branch with a material known as EutroSORB® G to mitigate available sediment phosphorus. The treatments will take place during the month of September, 2025.
Additionally, a treatment system will inject EutroSORB® WC into the North Anna River to permanently bind soluble phosphorus before the water enters Lake Anna. This injection will take place from September through November, 2025.
EutroSORB G is a 10% lanthanum modified bentonite and EutroSORB WC is a liquid phosphorus binder. EutroSORB G is applied to a waterbody and settles to the lake sediment where it continues binding phosphorus to capacity. EutroSORB WC rapidly and permanently binds phosphorus from water. Both formulations are effective phosphorus binders with a wide margin of safety for aquatic organisms, fish, birds, mammals, and humans. The treatments have been reviewed and approved by Dominion Energy and the Virginia Department of Wildlife Resources.
This project will be meticulously monitored to determine the amount of improvement in water quality and the effectiveness of these treatments. There will be monthly water sampling in both treatment areas as well as ongoing monitoring of the North Anna River. Results from this project will be used to inform future lake management actions taken at Lake Anna.
This project will provide immediate water quality benefits to northern Lake Anna, and the LAAC is currently seeking funding for implementation in future years. This project provides a tremendous benefit to the local community from improving recreation, supporting growth of the local economy, and protecting this valuable resource and downstream uses of water. Please reach out to the LAAC for additional information.
Contacts: Harry Looney Environmental & Water Quality Subcommittee Chair Lake Anna Advisory Committee (571) 393-7920 Hlooney.laac@gmail.com Shannon Junior Eastern Water Quality Technical Specialist EutroPHIX (540)830-6547 Shannon.junior@eutrophix.com
