me-2026-P185: 06-096 C.M.R. Ch. 579, Classification Attainment Evaluation Using Biological Criteria for Fresh Surface Waters.

Department of Environmental Protection CHAPTER NUMBER AND RULE TITLE: 06-096 C.M.R. Ch. 579, Classification Attainment Evaluation Using Biological Criteria for Fresh Surface Waters. TYPE OF RULE: Routine Technical PROPOSAL FILING NUMBER: 2026-P185 (Second Notice) BRIEF SUMMARY: The proposed rulemaking would amend existing rule Chapter 579: Classification Attainment Evaluation Using Biological Criteria for Rivers and Streams. The existing rule establishes numeric aquatic life criteria and statistical models for rivers and streams based on the benthic macroinvertebrate community. No changes to those criteria are proposed. The amendment will establish new numeric criteria and statistical models for the following waterbody and biological community types: Benthic macroinvertebrate communities in soft-bottom streams, marshes and shallow lakes and ponds; epilithic algal communities (algae growing on hard surfaces such as rocks and logs) in eroded, mineral-bottom streams and rivers; epiphytic algal communities (algae growing on aquatic plant stems) in soft-bottom streams, marshes and shallow lakes and ponds. The proposed amendment will formalize the Department’s current practice of assessing these waterbody and community types. Assessing both macroinvertebrate and algal communities enhances the potential to identify environmental stressors and better target management strategies to protect and improve water quality for the future. PUBLIC HEARING: None scheduled. There is a 30-day written comment period. A public hearing will be held if the Department receives 5 or more requests before the end of the comment period. COMMENT DEADLINE: Monday November 2, 2026, 11:59 pm CONTACT PERSON FOR THIS FILING: Matthew Hight 17 SHS, Augusta, ME 04333-0017 (207) 719-0703 TTY: (207) 287-7688 ext. 711 Matt.hight@maine.gov CONTACT PERSON FOR SMALL BUSINESS IMPACT STATEMENT (if different): Same FINANCIAL IMPACT ON MUNICIPALITIES OR COUNTIES (if any): None. STATUTORY AUTHORITY FOR THIS RULE: 38 M.R.S. §§ 341-H; 464-470 SUBSTANTIVE STATE OR FEDERAL LAW BEING IMPLEMENTED (if different): Same. AGENCY WEBSITE: https://www.maine.gov/dep/index.html EMAIL ADDRESS FOR OVERALL AGENCY RULEMAKING LIAISON: Tom.Graham@maine.gov