Building trust in target groups for ALUM treatment – an effective, yet misunderstood method for water quality improvement (TRUST ALUM)

In August 2023, LIAE launches a new Interreg BSR project – TRUST ALUM – as lead partner.

The project addresses one of the biggest water management challenges in the Baltic Sea region – eutrophication, and more specifically the historical phosphorus load in lakes. Excessive algal blooms due to elevated phosphorus loads in lakes reduce the value of ecosystem services and have negative impacts on human health. Eutrophication can be limited by the ALUM method, which essentially uses aluminium sulphate to convert phosphorus in sediments into insoluble compounds. The project will build trust in the ALUM method of lake treatment. It is widely used in water treatment in Sweden, for example, and has been applied there for more than 60 years. There are around 250 positive examples of application of this method in Sweden.

However, the ALUM method has never been used in the Baltic countries due to these identified barriers: lack of knowledge, belief that it is too expensive and fear of aluminium as a chemical element. ALUM is a safe method that is often thought of as a chemical treatment, when in fact it involves the addition of a phosphorus-binding mineral. Aluminium sulphate is commonly found on Earth to trap phosphorus permanently.

Project aim: To reduce eutrophication by building trust among target groups and thus spread the use of ALUM method more widely.

Project partners

Project lead partner: Latvian Institute of Aquatic Ecology (LIAE)

Project partners:

Stockholm Environment Institute Tallinn Centre
Ministry of Environmental Protection and Regional Development (Latvia)
SwedishUniversity of Agricultural Sciences
State Environmental Service(Latvia)
Lake Restoration Sweden Incorporated
Riga City Council
Vattenresurs Sverige AB
Environmental Centre for Administration and Technology (ECAT)