(March 20, 2018, 12:02 PM EDT) -- PHILADELPHIA — A group of chemical companies on March 16 filed a brief in Pennsylvania federal court arguing that it should not reconsider a stay it issued last month in a groundwater contamination lawsuit involving allegations that individuals were exposed to toxic chemicals from aqueous film forming foam (AFFF) (Hanah Bates, et al. v. 3M Company, et al., No. 16-4961, E.D. Pa.)....