On June 20, 2012, Governor Snyder signed into law Michigan’s Senate Bill No. 1090 amending MCL 324.20120(e) of Michigan’s Part 201. As we discussed in an earlier blog entry on April 23, 2012, many owners and operators that undertake remediation have had difficulty demonstrating compliance with Michigan’s statutory requirements associated with meeting Groundwater Surface Water Interface (“GSI”) criteria.

Central to the amendments is support for self-implementation by liable parties of a GSI assessment. This flexibility in methodology, assessment and remedial design is coupled with some duties to give notice to the MDEQ. This amendment allows parties greater flexibility in demonstrating that response activities undertaken have appropriately addressed the risk of venting to groundwater. Parties can demonstrate compliance with Part 201 through ecological demonstration and modeling.

The amendment sets forth factors a party can rely upon to demonstrate that the GSI pathway is not relevant or the effect is de minimis. The amendments also allow parties to demonstrate that the venting of groundwater has no effect on a surfacewater body. The party can submit a request for a technical intractability waiver from the Michigan Department of Environmental Quality (“MDEQ”) if it can demonstrate that compliance with GSI criteria is not achievable. Parties that have concluded that venting groundwater has no or de minimis effect must give notice of its conclusion to the MDEQ. The MDEQ must disprove this conclusion within 90 days or it is deemed approved.

Parties have the flexibility to demonstrate that natural attenuation of hazardous substances present in groundwater is an acceptable form of remediation. Parties can now model the risk posed by groundwater contamination plume that has entered a sewer and define the remediation obligation even if the sewer discharges to a surfacewater body.

These amendments apply retroactively and allow parties to revise judgments, orders, consent judgments and other agreements that address the issue of GSI remediation.

In conjunction with this amendment, Administrative Rule 299.5716 entitled “Cleanup Criteria for Groundwater Based on Protection of Surfacewater Resources from Hazardous Substances in Venting Groundwater” was rescinded. This administrative rule had set forth the previous methodology for demonstrating compliance with GSI criteria.

The amendment to GSI provisions is the first step in many more amendments that are being considered over the next six months. Many of these other amendments under consideration will reflect a move away from an emphasis on only using complex prescriptive administrative rules to allow for self-implementation opportunities. These anticipated amendments will also provide clarifications in methods and flexibility in demonstrating environmental compliance in light of actual site conditions and anticipated use, along with consideration of all applicable risks scenarios.

We will continue to track these changes and provide updates on the status of revisions to Part 201.