Quality of waterways in the Amsterdam Forest.

additional water bottom investigation

An additional water bottom investigation was conducted in the Amsterdam Forest due to management and maintenance activities and suspected PFAS contamination from a fire at Schiphol Airport in 2008. Silt was found in all watercourses investigated, with varying thicknesses between 0.04 and 0.8 meters, with no visual indications of contamination or presence of asbestos. The quality of the sludge falls into class A or B, but in some locations (such as fish pit 6 and parts of the swimming pond) the sludge is not dispersible in surface water. Elevated PFOS levels were measured in all samples, which limits the application of the sludge to the shore according to the PFAS policies of Amsterdam and Amstelveen. In many cases, the limit value of 3.2 µg/kg ds is exceeded, as a result of which it is recommended that the dredged material be removed to an approved processor. The fire at Schiphol Airport is considered the most likely source of PFOS contamination.