A waste treatment system for separating contaminants including per-fluoroalkyl and poly-fluoroalkyl substances (PFAS) from bulk solid waste (12). A preparation module (9) having a bulk material separator separates oversize material (14) from bulk solid waste (12). A physical separation module (13), located down-stream of the preparation module (9), separates the bulk solid waste (12) based on particle size using physical and/or hydrodynamic and/or density separation techniques. An extraction/chemical separation module (19), located downstream of the physical separation module (13), adds leachate and/or extractant to separate the contaminants from a slurry output from the physical separation module (13), into a fines output and a contaminated water solution. A water circulation system (21) supplies water to the physical separation module (13) and the extraction/chemical separation module (19), the water circulation system including at least one water treatment process, the treated water being recycled and recirculated within the waste treatment system.