A federal judge in Philadelphia has granted preliminary approval of a $2 million partial settlement by Modine Manufacturing Co. in a class action medical monitoring suit brought by residents of a small Northern Illinois town who claim that groundwater contamination has caused a cluster of brain cancer cases.

In her 30-page opinion in Gates v. Rohm and Haas, U.S. District Judge Gene E.K. Pratter rejected the argument of the nonsettling defendants, who said it would be unfair to grant preliminary approval of a class settlement before ruling on whether the ongoing claims satisfy the requirements for class certification.