The analysis of PFAS by EPA 1633A and ASTM D8421 is part of the U.S. EPA’s Methods Update Rule (MUR) Rule 22. The action will promulgate EPA into 40 CFR Part 136. Also part of this action, PFAS method ASTM D8421 is proposed to be codified.
Because of Michigan’s complex geology, the groundwater-surface water interface (GSI) plays an important role in the state’s environmental cleanup program. Last month, we shared with you information about recent updates made by the MDEQ to the Generic Cleanup Criteria Tables. But what exactly is a GSI Pathway and how is GSI Pathway relevancy determined?
The MDEQ published updates on June 25th to the Generic Cleanup Criteria Tables to reflect recent changes to the GSI (Groundwater-Surface Water) Criteria. The GSI tables are based upon the water quality standards developed under Michigan Part 31, Rule 57 of (Water Resources of the Natural Resources and Environmental Protection Act). Water quality standards were updated in March 2018, which served as a precursor to the GSI Criteria table updates.
