PFAS have been found in surface waters surrounding the Willow Grove site. Exposure to PFAS from non-drinking water sources would add to the potential risk. However, swallowing small amounts of PFAS during recreational activities in the nearby creek would not result in a significant exposure. Absorption of PFAS through the skin is not a major exposure route due to the physical characteristics of PFAS. These same characteristics cause most PFAS to remain in the water column and not separate into sediment or become volatilized into the air, thereby reducing the likelihood of exposures via contact with creek sediment or breathing while swimming. Currently, ATSDR, EPA and the Pennsylvania Fish and Boat Commission (PFBC) do not have screening values for PFAS in surface water. In addition, swimming or wading in natural bathing waters can put public health at risk due to an assumed presence of fecal coliform bacteria from natural sources. Care should be taken to prevent young children from swallowing any recreational water, and for any swimmers to wash afterward with an approved water source.