Spill of AFFF Concentrate at Military Base

CHALLENGES

BACKGROUND

In November 2001, a leak was detected in the underground piping system responsible for transferring an Aqueous Film-Forming Foam (AFFF) solution* at a heliport located on a Canadian military base. This incident resulted in the loss of 14,550 liters (3,840 US gallons) of AFFF liquid, which seeped into the sandy soils and eventually reached the groundwater at a depth of 5.4 meters below ground surface (bgs). The AFFF solution consisted of traditional firefighting surfactants, primarily propylene glycol butyl ether, and also contained per- and polyfluoroalkyl substances (PFAS), particularly perfluorooctane sulfonate (PFOS).

Given the characteristics of the aquifer present, immediate action was necessary to address the situation. Defence Construction Canada, in collaboration with Environment Canada, implemented emergency measures to effectively respond to the incident. Remediation efforts were initiated in the months following the spill, aiming to mitigate the environmental impact and restore the affected area.

*Aqueous Film Forming Foam (AFFF) is a fire suppressant used to extinguish flammable liquid fires such as fuel fires

SOLUTION

• Work performed on the basis of an emergency response with a fixed monetary amount.
• Hydraulic containment using upstream wells to slow down the dispersion of the plume in the aquifer
• Groundwater pumping and treatment using a foaming column followed by filter column
• Sequence including sand, UltrasorptionTM and activated carbon medias
• Controlled in situ soil washing of the vadose zone by re-injection treated water

PROJECT HIGHLIGHTS

• Over 15,000 litres (3,960 US gallons) @ 10% of AFFF product lost
• 175 m³ of soil treated using in situ washing
• Water treatment at 50 litres per minute with over 4,500,000 litres (1,190,000 US gallons) of water treated
• Overall water treatment efficiency at over 95%
• Approximately 377 kilograms of concentrate product recovered and 30 m³ of waste disposed at authorized facility
• Reduction of AFFF concentrations in water below acute toxicity criteria for daphnia magna and rainbow trout.