Many lakes in the Baltic region suffer from eutrophication, a process that leads to excessive algal blooms, which harms both ecosystem and human health. The main drivers of eutrophication are currently high loads of historical phosphorus, which continue to pollute our waterbodies. Aluminium treatment is our solution to historical phosphorus loading and effective reduction of eutrophication in heavily polluted lakes.
The aluminium treatment method involves adding a phosphorus-binding salt (such as polyaluminium chloride) to permanently capture phosphorus in lake’s sediments. The salts are added to the lake water or injected into the sediment using a specialized treatment boat that ensures precise dosing which is carefully designed based on monitoring data and modelling. Proper monitoring and data analysis ensures that the treatment is safe, cost-effective and provides long-lasting benefits.
Aluminium treatment has been successfully applied in lakes worldwide for over 60 years, with numerous positive examples, but was only introduced to the Baltic region in 2024. Members of the Blue Siren Solutions team led the successful restoration of Lake Velnezers in Riga – the first aluminium treatment project carried out in the Baltic states. The intervention used the EKOBENTIX method, a Swedish technology that enables the direct injection of phosphorus-binding salts into lake sediments, effectively targeting pollution at its source.
Under the EU Water Framework Directive (WFD), Member States are required to achieve good status for all waterbodies. However, many lakes continue to fall short due to phosphorus pollution. Where conditions are suitable, aluminium treatment is one of the most effective ways to achieve WFD goals in eutrophic lakes.
If you have an eutrophic lake and consider aluminium treatment as a restoration option, Blue Siren Solutions can support the entire process, covering the following steps:
01
Initial survey
A one-time survey to determine if the lake is appropriate for aluminium treatment.
02
Detailed survey
A year-long, monthly monitoring carried out to collect data required for lake modeling and treatment design.
03
Lake modeling
Development of a lake model to evaluate the phosphorus balance in the lake system and perform later treatment design.
04
Treatment design
Calculation of the optimal dose and dosing scheme to ensure an effective and cost-efficient outcome, including cost estimation.
05
Permit acquisition
Preparation and submission of the permit acquisition application to the relevant Institution in your country.
06
Lake treatment
A special treatment vessel, treatment chemicals and other necessary equipment are transported to your lake, where phosphorus-binding salts are precisely applied to the water column or injected directly into the sediment, depending on the treatment design.
07
Post-treatment monitoring
At least a full year of seasonal monitoring is required to assess the effects of the treatment, with more prolonged monitoring highly advised.