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    Ohio EPA proposes new TMDL rules

    This week, Ohio Environmental Protection Agency (EPA) proposed amendments to three rules pertaining to modeling and total maximum daily loads (TMDLs) in Ohio Administrative Code Chapter 3745-2. The proposed amendments follow an interested party review and comment period previously held from June 20, 2018, through July 20, 2018. The proposed amendments are part of Ohio EPA’s five-year rule review consistent with R.C. 106.03 and also seek to incorporate the requirements of House Bill 49 of the 132nd General Assembly. H.B. 49 required Ohio EPA to adopt rules governing the agency’s development of TMDLs, specifically with establishing procedures for providing notice to stakeholders and criteria for determining significant public interest. 

    The rules under review include:

    • 3745-2-04:  Determinations preliminary to development of water quality-based effluent limitations
    • 3745-2-10:  Wasteload allocation for ammonia-nitrogen toxicity
    • 3745-2-12:  Total maximum daily loads

    Ohio EPA’s proposed changes to OAC 3745-2-04 and -10 involve mostly grammatical and stylistic edits. The more substantive changes incorporating the requirements of H.B. 49 fall within OAC 3745-2-12. Ohio EPA is proposing to adopt new requirements for stakeholder involvement in the TMDL development process at four additional steps: (1) the project assessment study plan; (2) the biological and water quality report; (3) the loading analysis plan; and (4) the preliminary modeling results. The rule additionally adds two factors for Ohio EPA to use when determining the assessment area for a TMDL. Several proposed changes were also made in response to comments received during the interested party comment period.

    Ohio EPA’s public comment period on the proposed rules will run until December 18, 2018, and Ohio EPA will hold a public hearing on December 18, 2018, at 10:30 am in Conference Room A at Ohio EPA’s Central Office, located at 50 West Town Street, Suite 700, Columbus, Ohio.  

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