PFAS and stormwater, 2023

Four sub-projects to evaluate the occurrence and distribution of fluorinated substances (PFASs) in stormwater, sediment and stormwater biofilters have been funded by the Swedish Environmental Protection Agency. The total budget for these projects is 1.590.000 SEK.

Subproject 1: PFASs will be analysed in stormwater samples taken in Östersund where we previously analysed metals, nutrients and indicator bacteria. The data will shed light on the contribution of stormwater PFASs from urban catchment areas with different land use to the receiving waters. The sampling covers several seasons and all samples are taken with flow proportional sampling.

Subproject 2: In a previous project funded by the Swedish Environmental Protection Agency, the impact of urban stormwater on receiving waters in Uppsala, Norrköping and Söderköping is investigated. Sampling is now supplemented with analysis of bottom sediments from the recipients for the analysis of PFASs, PAHs, metals, and other substances, which will enable a more detailed mapping of sources and transport routes.

Subproject 3: At a test facility in Växjö, stormwater biofilters with and without biochar have been installed in pairs to evaluate the effect of biochar added to the filter substrate. In a previous project, the effect on treatment efficiency of metals and nutrients has been investigated. Since biochar has a high adsorption capacity, it can probably have a greater impact on the treatment efficiency of organic substances. Through additional sampling, we will analyse PFASs, PAHs, nonyl/octyl phenols, bisphenol A, phthalates and organotins.

Subproject 4: In a previous project, the presence of metals, organic substances and microplastics in the filter material of 12 older stormwater biofilters has been investigated. In this subproject, the existing dataset will be supplemented with analyses of PFASs. The results will contribute to an understanding of whether PFASs are present in biofilter material and whether/how this affects the long-term function and disposal of used filter material.

Heléne Österlund, Godecke-Tobias Blecken, Maria Viklander,Suna Ekin Kali and Ali Beryani