An airport in the northern United States routinely used propylene glycol for de-icing activities, which were performed by several FBOs at multiple locations. Long term use of the de-icing agent resulted in offsite discharges including impacts to an adjacent wetland. Further, the local regulatory authority reduced the stormwater discharge limits for parameters such as the biological oxygen demand (BOD), which resulted in routine exceedances. The airport considered a centralized de-icing area, but due to the physical constraints of the airport, this was deemed impractical and expensive. Faced with significant fines and a potential consent order, the airport was forced to take action so flight operations were not impacted.
AXA XL’s environmental claims counsel and a technical consultant worked with the FBOs and airport to prepare a plan for smaller de-icing areas with an improved collection system. Discharges were routed to a central engineered wetland to provide passive treatment of the propylene glycol and meet storm water permit requirements. Construction of the engineered wetland and storm water conveyance systems cost under $2 million and saved the airport from over $13 million in non-compliance costs and fines. This was accomplished with limited disruption to airport operations and no impact to flight schedules. The FBOs incurred some legal defense expense and a portion of the construction expense.