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Feb 2014
February 10, 2014

MDEQ Poised to Modify Air Toxics Rules

An early initiative of Governor Rick Snyder was to undertake a comprehensive review of state administrative rules which were redundant of federal requirements, antiquated, or substantially impaired Michigan’s business competitiveness without tangible benefit to the public. One set of rules reviewed was MDEQ-Air Quality Divisions “air toxics rules.” Following nearly 15 months of stakeholder discussion regarding whether and how these state rules should be revised, the MDEQ is close to proposing amendments which will somewhat streamline their application while also broadening public participation regarding what should be considered an “air toxic” and how stringent any emission standards should be for individual “toxic air pollutant” or “TAC.”

While the federal law regulates 183 potentially toxic air pollutants as “Hazardous Air Pollutants” or “HAPs” under Section 112 of the Clean Air Act, some state programs regulate a far greater number of substances solely under state law. The current MDEQ rules regulate more than 1200 substances as TACs. In contrast, other states have no program independent of the federal program for regulating potentially toxic pollutants. Other Midwestern states’ air toxics programs seek to regulate less than half the number of air toxics that Michigan regulates.

Based on a report developed through a stakeholder process1, the MDEQ in 2014 is expected to propose amendments that will reduce by one-third the number of TACs routinely regulated by the MDEQ under Michigan’s air law, Part 55 of NREPA. The MDEQ will propose to amend the definition of TAC under its Part 1 air rules to eliminate regulation of non-carcinogenic substances considered to have low toxicity potential in the ambient environment.  Additionally, the MDEQ will no longer regulate as TACs substances where it has inadequate information for establishing acceptable ambient levels.  In effect, the MDEQ will no longer deem a substance a TAC by default.

The amendments will greatly enhance public participation in the process of identifying new TACs and in establishing or revising the ambient concentrations deemed protective of the public health.  For the first time, the rules will provide, through internet based tools, public notice of proposed additions to the TAC list and the associated ambient air concentrations deemed acceptable for each pollutant. The MDEQ will provide references to the information used to identify TACs, and acceptable ambient levels. The public will have the opportunity to comment on the MDEQ’s proposal and supplement the information available.

Critically, the amendments contain refinements to the MDEQ’s “back-stop” authority.  This authority will allow the MDEQ to impose, under special circumstances, more stringent requirements for TACs than its rules might otherwise provide. It would also allow the agency to regulate substances not included under the revised definition of TACs where it is clear such authority must be exercised to assure protection of the public health.

While the anticipated amendments will not fully level the playing field between Michigan and other Midwestern states – such as Ohio, Indiana and Wisconsin - the amendments will lessen the regulatory burden on businesses needing air permits in Michigan to establish or modify their operations.

If you have questions or desire further information regarding this issue, please contact Steven Kohl at 248.784.5141, or, or any other member of the Resource, Energy and Environment Practice Group.


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