Civil procedure: statute of limitations; accrual of cause of action for groundwater contamination cases; revise. Amends 1961 PA 236 (MCL 600.101 & 600.9947) by adding sec. 5830.

HB 4639 modifies Michigan's statute of limitations for groundwater contamination cases involving hazardous substances. It specifies that legal claims for damages accrue when a plaintiff discovers the contamination or should have discovered it, rather than when the contamination initially occurred. This change directly affects individuals or communities suing over groundwater pollution from sources like industrial leaks or spills. The provision aims to give plaintiffs more time to pursue claims once they become aware of the harm, aligning the timeline with actual discovery of the issue.