NOWPAP Common Procedure 2013 Revised Edition 2025/5/22 2025/6/17 “Procedures for assessment of eutrophication status including evaluation of land-based sources of nutrients for the NOWPAP region (the NOWPAP Common Procedure 2013 Revised Edition)” was published. Based on the lessons learned from the case studies conducted in the 2010-2011 biennium, the NOWPAP Common Procedure (2009) was revised.