In December 2025, the South Ostrobothnia ELY Centre published a guide titled Guide to the Planning and Implementation of Drainage on Acid Sulfate Soils. The guide was prepared to support the planning and implementation of drainage projects in areas where acid sulfate soils occur. It addresses an identified need for information among drainage associations, planners, and authorities. The guide presents various methods for identifying acid sulfate soils and for assessing the risks associated with them.
Acid sulfate soils are sulfur-containing soils that, as a result of the oxidation of sulfur compounds, release harmful amounts of acidity and soluble metals into the soil and water systems. This causes damage to waterways and aquatic ecosystems that is difficult to remedy. In construction and infrastructure projects, such soils may also corrode metal and concrete structures.
The guide was prepared at the South Ostrobothnia ELY Centre by Heli Kentala together with a working group consisting of Eeva Nuotio, Krister Dalhem, Anna Bonde, Anna-Kaisa Prinkkilä, and Heidi Smart. The guide has been published in both Finnish and Swedish.
The guide is available through the search function in the digital publication service Doria, www.doria.fi. At the beginning of 2026, the ELY Centres ceased to exist, and their responsibilities were distributed among the Centres for Economic Development, the Licensing and Supervisory Authorities, and Traficom. The guide was prepared in cooperation with the Interreg Aurora funded project Developing Acid Sulfate Soil Management for Improved Water Status (MASSIW). For matters related to the guide, inquiries can be made by email (firstname.lastname@elinvoimakeskus.fi) to Heidi Smart, Project Coordinator at the South Ostrobothnia Centre for Economic Development, or to Eeva Nuotio, Lead Water Management Specialist at the Southwest Finland Centre for Economic Development.
Link to the guide (Finnish): https://www.doria.fi/handle/10024/193691
Link to the guide (Swedish): https://www.doria.fi/handle/10024/193722
YouTube video about the MASSIW project (Finnish): MASSIW – Developing Acid Sulfate Soil Management for Improved Water Status, FI
Link to the the project’s own website: MASSIW.
Learn more about the Interreg Aurora project MASSIW – Developing acid sulfate soil management for improved water status.
