Regulatory Update   |   Jan 24th, 2019 Michigan Amends Law Governing Clean Up of Contaminated Sites

Trc Michigan Part 201

Outgoing Michigan Gov. Rick Snyder signed a bill (SB 1244) in December that updated the state’s contaminated site clean-up standards under Part 201 of Michigan’s Natural Resources & Environmental Protection Act (NREPA).

The bill – signed despite opposition from a group of employees from Michigan’s Department of Environmental Quality (DEQ) – broke a longstanding impasse in negotiations with the DEQ over promulgating appropriate clean up criteria for contaminated sites.

Senate Bill 1244 amends Part 201 (Environmental Remediation) of NREPA to modify the circumstances and requirements according to which the DEQ may carry out environmental remedial actions. A summary of key points is provided below.

NFA Reports

The revised law allows a person to file a No Further Action (NFA) report before completing the remedial actions as long as the person has documented the basis for concluding that these remedial actions are sufficient to address the threat to public health and the environment posed by the environmental contamination.

Indoor Air Inhalation Exposure

The revised law allows a person to manage potential contamination of the quality of indoor air by a hazardous substance using any of the following methods:

  • The cleanup methods outlined in Section 20120a(18) of NREPA.
    • (18) A person demonstrates compliance with indoor air inhalation criteria for a hazardous substance at a facility under this part if all of the following conditions are met:
      • The facility is an establishment covered by the classifications provided by sector 31-33 – manufacturing, of the North American industry classification system, United States, 2012, published by the office of management and budget.
      • The person complies with the Michigan occupational safety and health act, 1974 PA 154, MCL 408.1001 to 408.1094, and the rules promulgated under that act applicable to the exposure to the hazardous substance, including, but not limited to, the occupational health standards for air contaminants, R 325.51101 to R 325.51108 of the Michigan administrative code.
      • The hazardous substance is included in the facility's hazard communication program under section 14a of the Michigan occupational safety and health act, 1974 PA 154, MCL 408.1014a, and the hazard communication rules, R 325.77001 to R 325.77004 of the Michigan administrative code, except that unless the hazardous substance is in use in the facility, the requirement to have a material safety data sheet in the workplace requires only a generic material safety data sheet for the hazardous substance and the labeling requirements do not apply.
  • For petroleum releases, the process outlined in the Interstate Technology Regulatory Council (ITRC) Petroleum Vapor Intrusion Guidance Document.
    • An approach, using multiple lines of evidence, demonstrating that the potential contamination does not pose an unacceptable risk to the public health, safety, or welfare, or the environment as consistent with EPA OSWER guidance, Johnson & Ettinger modeling, or ITRC guidance.
    • Indoor air sampling that accounts for actual conditions and demonstrates acceptable indoor air concentrations resulting from vapor intrusion compared to criteria outlined further in the law.
    • A method or model allowed in a promulgated rule.
    • An alternative method or model that utilizes only site-specific variables or a combination of site-specific or building-specific variables, as long as the method or model is scientifically sound and supported by adequate site information. Alternative methods or models would have to be approved by the DEQ for contamination that has migrated beyond the boundaries of the property.

The indoor air inhalation pathway is not considered a reasonable and relevant pathway in need of response activity if there is no occupied building or planned occupied building within lateral and vertical separation distances under the ITRC guidance for petroleum contamination or within 100 feet (vertical and lateral) for any other volatile hazardous substance contamination.

Development of Cleanup Criteria

DEQ is now prohibited from unilaterally adopting clean-up criteria, like it did in setting PFAS criteria. Another bill tied into this that also passed in December – HB4205, nicknamed “No Stricter Than Federal” – that bars all Michigan agencies from adopting rules that are stricter than those of their federal counterparts without “clear and convincing” evidence to support them. This is likely to hamstring DEQ somewhat and add conflict for the studies such as the recent Michigan PFAS Action Team Report from December, which recommends more stringent regulation on PFAS. 

This change does provide more opportunities for stakeholder input before DEQ establishes new or modified criteria. Essentially the law sets the standards for how cleanup criteria can be developed using established values from the Environmental Protection Agency.  The new law also provides exceptions on how the DEQ can use alternative values if they are justified.

Furthermore, the revised law addresses how the DEQ can address single-event exposure scenarios for sensitive receptors, such as pregnant women. Limits are also provided on the daily exposure times for inhalation that is equal to the average number of hours that such workers would work during a five-day week (not exceeding 10 hours) according to government data.

Promulgation of Generic Cleanup Criteria

The revised law requires the DEQ to promulgate all generic cleanup criteria, target detection limits, etc. as rules to ensure they are legally enforceable. This will help close the gap for instances where DEQ in the past has lowered criteria for certain compounds without officially going through the rules process and then tried to enforce a costly cleanup.

New hazardous substances that did not already have generic cleanup criteria, can be calculated by the DEQ using toxicity values. However, within 30 days the DEQ would have to initiate rulemaking to promulgate the new criteria into rules by filing a rule-making request under the Administrative Procedures Act. If the DEQ did so, the criteria would have legal effect when published. 

Work plans, remediation plans, post-closure plans or similar documents submitted prior to the effective date of revised criteria can continue to use the older criteria unless:

  • The person making the submittal voluntarily elected to apply the revised cleanup criteria.
  • The DEQ department director makes a site-specific demonstration, based on clear and convincing evidence, that the prior cleanup criteria are no longer protective and meets other detailed exemptions outlined in the law.

If DEQ previously approved site-specific criteria, changes to the generic criteria for that hazardous substance would not invalidate the site-specific criteria. This could be a good way to “lock-in” your cleanup criteria.

Calculation of Toxic Equivalency Quotients

The new law establishes the following:

  • The toxic equivalency factors must only be those adopted by the World Health Organization.
  • When multiple parties contribute to the hazardous substances measured by the quotients, the harm is considered divisible and liability is subject to apportionment as laid out in the NREPA.
  • To assess human health risks, the toxic equivalency quotient must be compared to generic or site-specific criteria for the reference hazardous substance.

Polychlorinated Dibenzodioxin and Dibenzofuran Congeners

Reiterates that these compounds will not likely leach from soil to groundwater or volatilize from soil or groundwater into air. Therefore, those pathways are not considered applicable or relevant when performing assessments for these congeners.


The law clarifies the definition of disputes as: “Dispute means any disagreement over a technical, scientific, or administrative issues, including, but not limited to…” and then goes on to list typical submittals under Part 201 and Part 213.

It's still too early to tell how the DEQ will adapt to these changes, so keep an eye out for more to come as we wade through the muddy waters. And check out our website to see how TRC can assist with your environmental remediation needs.