Eriksson Lilja, Emmie2025-06-272025-06-272025-06-27https://hdl.handle.net/2077/88449PFAS (per- and polyfluorinated alkyl substances) are a collective name for over 10,000 synthetic chemicals. They are characterized by their persistence, bioaccumulation, and high mobility in aquatic environments, and their hydrophobic and lipophobic properties make them useful in firefighting foam. On December 16, 2013, extremely high levels of PFAS were found in the drinking water from the Brantafors waterworks. The source could be traced back to a fire training site at Blekinge air base (F17), where the Swedish Armed Forces had used firefighting foam containing PFAS since the 1980s. The study shows that international knowledge of PFAS risks existed long before 2013. Even early indications of similar contamination cases in Sweden, such as in Tullinge (2011) and Halmstad (2009), did not lead to coordinated national measures or changed guidelines. The Ronneby case identifies several actors who had the opportunity and, in some cases, the obligation to act preventively, but where lack of communication, insufficient regulatory compliance, or limited mandates contributed to passivity. These actors include manufacturers (who knew the risks but withheld information), the Swedish Armed Forces (which failed to conduct self-control and risk assessment despite internal knowledge), Ronneby Miljö & Teknik AB (which was responsible for the drinking water supply but relied on limited government directives), and national authorities such as the Swedish Chemicals Agency, the Swedish Environmental Protection Agency and the Swedish Food Agency, whose knowledge was not effectively communicated to the municipal level. The precautionary principle and Ch 26 § 19 in the Swedish environmental code were not followed through, and the fragmented chemicals regulation under the REACH Regulation has proven insufficient, mainly since PFAS regulation was carried out on a substance-by-substance basis for a long time. The late introduction of limit values for PFAS in the EU Drinking Water Directive also contributed to delayed action. The PFAS contamination in Ronneby illustrates a systematic failure characterized by unclear mandates, fragmented responsibilities, poor communication, and regulatory weaknesses. Actors who acted independently of each other, and several warning signs were ignored. The Ronneby case is, therefore, not an isolated exception but follows a recurring pattern from previous environmental toxics crises, such as with DDT and PCB, and underlines the need for better knowledge transfer between authorities and the local level, a more proactive risk assessment and better regulatory framework for the management of persistent chemicals.engText