The Wastewater generated from the post-fire response clean-up activities, containing a hard-to-treat mixture of water, firefighting foam, and transformer oils, was pumped to more than 90 frac tanks staged on-site. Additionally, stormwater flowing through the fire response area was captured and pumped to a cement-lined basin to prevent off-site migration of contaminated water to nearby waterways.
The level of total PFAS exceeded 3600 ppt initially and increased to above 5000 ppt during operation, with 6:2 FTS, PFPeA & PFHxA having the highest concentrations of the 28 PFAS analytes measured.
The water required pretreatment due to the elevated TOC concentrations which would have impacted the performance of the ion exchange resin in the PFAS treatment system. Additionally, other contaminants were observed, such as oils & greases, that presented another treatment challenge.
Not only did the solution need to meet the PFAS discharge limit of less than 70 ppt for each individual PFAS compound, it also needed to be robust enough to treat the other assumed contaminants in the water.