Environmental protection: cleanups; cleanup standards; require. Amends secs. 20101, 20107a, 20112a, 20114, 20114b, 20114c, 20114d, 20114e, 20119, 20126, 20126a, 20137 & 20139 of 1994 PA 451 (MCL 324.20101 et seq.); adds secs. 20113a & 20139a & repeals secs. 20114a & 20114g of 1994 PA 451 (MCL 324.20114a & 324.20114g). TIE BAR WITH: HB 4638'25, HB 4636'25

HB 4640 updates Michigan's environmental cleanup rules by clarifying how background levels of contaminants in soil are determined. It requires property buyers to conduct an "all appropriate inquiry" before purchase to establish baseline contamination levels, preventing unnecessary cleanup costs for naturally occurring pollutants. The bill amends cleanup standards to use scientific data from the Michigan Background Soil Survey, directly affecting property developers, real estate transactions, and environmental agencies managing contaminated sites. This change ensures cleanup efforts focus only on pollution caused by human activity, not natural soil conditions.