The Massachusetts Algae and Aquatic Plant Management Guide (Mass APM Guide) is intended to provide an update to the 2004 Generic Environmental Impact Report on Eutrophication and Aquatic Plant Management in Massachusetts (GEIR) and the accompanying Practical Guide to Lake Management in Massachusetts.  The original GEIR was developed in the late 1990s and early 2000s.  Over the last two decades, much Massachusetts’ experience has been gained in algae and aquatic plant management, and these lessons have been incorporated into this guide.  Additionally, the guide incorporates relevant changes in regulations since 2004.  The Mass APM Guide incorporates updates to both the GEIR and Practical Guide into one hybrid document.  

​The draft Mass APM Guide was recently posted for initial public review and comment for 30 days in spring 2025. There were over 100 comments, questions, edits and suggestions received for the draft. Replies to comments, questions, edits and suggestions are now available and linked below in Appendix E of the Mass APM Guide that was submitted to the Massachusetts Environmental Policy Act (MEPA) Office for public comment and final review.  Please click the document below to download it for further review during the MEPA process until July 14, 2026.