Predicting that the Supreme Court of Illinois “is likely to recognize” a claim for medical monitoring, a federal judge in Philadelphia has refused to dismiss a class action suit brought by residents of a small northern Illinois town who claim that groundwater contamination has caused a cluster of brain cancer cases.

“Given the apparent trend of the federal and appellate courts in Illinois, the cost of diagnostic testing, even if periodic or ongoing, likely is a compensable injury under Illinois law,” U.S. District Judge Gene E.K. Pratter wrote in her 12-page opinion in Gates v. Rohm & Haas.