(November 23, 2015, 10:10 AM EST) -- PITTSBURGH — The Pennsylvania federal judge presiding over a lawsuit brought by environmental groups against PPG Industries Inc. for allegedly contaminating groundwater on Nov. 19 ruled that PPG is permitted to file a third-party complaint against the operator of a landfill where the company disposed of waste, which is the subject of the lawsuit (PennEnvironment, et al. v, PPG Industries Inc., et al., No. 12-342, W.D. Pa.; 2015 U.S. Dist. LEXIS 156521)....