Opportunity for Comment
Chapter 579: Classification Attainment Evaluation Using Biological Criteria for Rivers and Streams
Comment deadline: April 13, 2026
The Maine Department of Environmental Protection is considering updating Chapter 579: Classification Attainment Evaluation Using Biological Criteria for Rivers and Streams and replacing it with Chapter 579: Classification Attainment Evaluation Using Biological Criteria for Fresh Surface Waters. The concept is to expand the scope of the rule to include additional criteria applicable to more waterbody and biological community types. Existing criteria for stream macroinvertebrates would be retained and remain unchanged.
Additional biological criteria would enable Department staff to assess a greater diversity of waterbodies, document their level of ecological health, and determine if state water quality standards are attained. Assessing more than one type of biological community (i.e., macroinvertebrates and algae) will also enhance our ability to identify different environmental stressors (toxic substances, nutrient enrichment, altered habitat, etc.) that may cause harm to aquatic organisms. Understanding the causes and sources of biological impairment helps target management strategies to protect and improve water quality for the future. The Department estimates that 28 waters would be listed as impaired based on the concept criteria, no permitted discharges would be affected.
Matthew R. Hight, Environmental Specialist
Office of the Commissioner
Maine Department of Environmental Protection
(207) 719-0703