Use of aqueous film forming foam (AFFF) in the military, aviation, oil and gas, and a myriad of other industries from the 1970’s until recently has resulted in impacts to soil and groundwater in many locations. AFFF contains per- and polyfluoroalkyl substances (PFAS), which have been identified as compounds of interest and are considered emerging contaminants. Recent studies indicate that these compounds are relatively common in association not only with fire training areas, as would be expected, but in proximity to aviation hangars, municipal fire stations, wastewater treatment plants, landfills, and aircraft or rail crash sites. The widespread usage and occurrence also has the potential to impact Brownfields and province-led clean-up projects. Increasing regulatory scrutiny and public awareness has resulted in numerous jurisdictions issuing screening levels, guidance levels, or in rare cases, mandated clean-up standards in soil or groundwater. In Canada, there are human-health based screening levels for PFOA (0.85 mg/Kg) and PFOS (2.1 mg/Kg) which are similar to values in some bordering states such as Alaska, New Hampshire, and Minnesota. Given risk-based guidance values established for water, states such as Michigan and Alaska have adopted soil-screening levels for groundwater protection which are orders of magnitude lower (0.0017 to 0.075 mg/Kg). As such, as the regulations continue to be established, groundwater protection could drive soil values in Canada even lower. Some of these groundwater-protection values are extremely low and result in almost universal exceedances where samples are collected at facilities where AFFF was used. Because these compounds have only recently been discovered, the overall understanding of their nature and extent is limited, especially when compared to our knowledge of the behaviour of petroleum constituents, chlorinated solvents and metals. However, the state of knowledge is growing as more sites are investigated. Construction projects frequently involve soil removals, demolition of fire stations, hangars, and associated buildings where AFFF was used, runway extension and replacement, and demolition or construction of wastewater treatment facilities. These projects involve large-scale earthworks and often some form of construction dewatering to enable construction of foundations and drain systems below the static water table. Additionally, construction projects often include stormwater management addressing large quantities of surface water. Handling these potentially-impacted media under emerging regulatory programs is an increasing challenge. Given the likelihood of encountering PFAS-impacted soil, surface water or groundwater, having a complete understanding of the conceptual site model (CSM) is critical in the early planning stages of construction projects. The CSM must consider the storage, usage and release of AFFF through time, as well as the fate and transport characteristics of PFAS. Considering the CSM in pre-design and planning activities could allow project teams to incorporate design elements which could reduce treatment or disposal of impacted materials. Recent literature indicates PFAS presence in concrete from fire training areas and fire station building materials, requiring careful scrutiny of disposal practices for construction debris. This presentation will discuss PFAS sources, CSM issues affecting mobility and occurrence, and disposal, treatment, and management options for this emerging group of contaminants.