Alison Wakelin

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Mar 22, 2022

Observed each year on March 22, World Water Day is an opportunity for us to recognize the essential role water plays in our lives and think about ways we can safeguard our water supply. This year, the focus is on protecting groundwater and using it sustainably.

Groundwater supplies a significant proportion of the water we use for drinking, food production, sanitation, and industrial processes and is critically important to the healthy functioning of ecosystems. Some 2.5 billion people depend solely on it to satisfy their daily drinking and other domestic water needs. Yet, our groundwater supply is threatened by various sources of pollution including agricultural and manufacturing chemicals, and other human activities.

Groundwater Health Hazards: AFFF Firefighting Foams

One source of groundwater pollution is the group of chemicals referred to as per- and polyfluoroalkyl substances (PFAS). Known as “forever chemicals,” PFAS can persist indefinitely in the groundwater and have been associated with serious environmental and human health hazards. Research suggests that exposure to high levels of certain PFAS may increase the prevalence of certain cancers as well as cause organ damage and developmental issues in fetuses and infants.

Aqueous Film-Forming Foam (AFFF), a Class-B fluorinated firefighting foam, contains varying amounts and mixtures of PFAS and is used to both fight and prevent flammable liquid fires. AFFF is widely used at military installations and in commercial aviation as well as shipyards, firefighting training facilities, chemical plants, and refineries. The primary health hazard of AFFF is its level of persistence and treatability in wastewater treatment plants (WWTPs). The use of AFFF also has the potential to contaminate a community drinking water supply or local waterways (e.g., rivers, lakes).

Aircraft Hangar AFFF Tanks + Containment Solutions Protect Our Groundwater

Because AFFF is highly effective at combatting fuel spill fires, many aircraft hangar fire suppression systems use AFFF. When the hangar fire protection system is activated, a solution of water and AFFF is released forming a film over the spill that prevents air from reaching the surface, thereby extinguishing or preventing any fire.

Containing and disposing of AFFF effluent following a fire, however, poses a unique challenge since AFFF cannot be discharged directly into municipal WWTPs. Conventional WWTP treatment does not effectively remove the PFAS in water and may result in the chemical being passed through to lakes, streams, and groundwater. It also affects the microbes of wastewater treatment plants and may interfere with management of solids from the treatment process.

Preventing AFFF effluent from entering WWTPs is the best way to avoid PFAS from being released into the environment. In aircraft hangars with AFFF fire suppression systems, alternate drainage and containment systems are designed to take the AFFF effluent from the building during system activation, remove it from the building, and store it in underground AFFF containment tanks.

These drainage and containment systems can be quite large due to the significant volumes of water released by fire protection systems. An aircraft hangar fire protection system can release 0.1 gallons per minute (gpm) per square foot over the entire floor area of a hangar bay. For a 20,000-square-foot hangar bay, this amounts to approximately 2,000 gpm of water that must be contained.

Furthermore, these systems typically consist of a diverter valve that sends fire protection effluent draining from the building away from the sanitary system into the containment system, drainage piping and an underground containment tank. The effluent is then pumped from these tanks to tanker trucks and removed from the site for disposal.

AFFF tanks and containment systems are essential to prevent hazardous groundwater chemicals like PFAS from being released into our environment and water supply. Click here to learn more about how Jensen Hughes experts can assist with designing AFFF drainage and containment systems and other sustainable solutions for your facility.