contamination of pfsc in downstream groundwater from leaking of landfill leachate were shown that c6s was most abundance in the groundwater from Chachoengsao province, c6a was most abundance in the groundwater from Nakhon Pathom province and c8s was most abundance in the groundwater from Sumut Prakan province. Each PFCs contaminant may leach from those products which were use the PFCs as surface treatment or as a part of product.That evidence had shown the failure of secure landfill management. The contaminated groundwater may effect to human health risk when they has consume those groundwater.