Stormwater Management

Use of high flow rate absorbing filters an alternative for hydrocarbon recapturing

Airport fueling facilities at mid-sized and large airports typically have secondary containment for above ground fuel tanks and truck loading/unloading racks. Many such airports do not have secondary containment for refueler staging areas or aircraft refueling areas. The use of high flow rate hydrocarbon absorbing filter media has wide application in passive stormwater pre-treatment systems and also in spill containment of water-borne fuel spills. This filter media is gaining acceptance in municipal, industrial, and aviation environments.

The primary function of secondary containment areas is to capture and contain fuel spilled during incidents, thereby preventing its release to the environment. Since these secondary containment areas are normally exposed to the elements, they also collect stormwater during storm events. This stormwater is potentially contaminated due to residual fuel in the containment areas, and therefore it must be processed on site prior to discharge.

Secondary containment is an environmental asset in terms of preventing infrequent fuel spills from reaching the environment, but an environmental liability in that it can generate contaminated stormwater, which causes disposal issues.

The sizing of storage tank containment areas is defined by the National Fire Prevention Association (NFPA) Standard 30 (Flammable and Combustible Liquids Code). The sizing of loading/unloading racks and refueler staging areas is addressed in 40 CFR 112, which covers the requirements for Spill Prevention, Control, and Countermeasure (SPCC) plans for facilities with more than 1,320 gallons of above ground oil storage, and the potential to discharge oil to the surface waters.

Once a site is under SPCC jurisdiction, the entire facility — including receipt of fuels, storage of fuels, transport within the facility, and dispensing within the facility — must be included. For an airport fuel facility, the fuel is within a regulated facility from the time it reaches the storage facility via pipeline receiving station or truck unloading rack until it is loaded into aircraft.

‘Sized’ containment
Refueling ramps are typically flat, impervious areas without secondary containment, except for that provided by undulations in the pavement and the inherent storage in the base of stormwater catch basins and piping between the fueling area and the point of stormwater discharge (if storm sewers exist).

Under 40 CFR 112, aircraft fueling is a regulated activity and “general” rather than “sized” secondary containment is allowed. This means that the SPCC plan certifier can determine the size of the most probable spill, rather than meet pre-determined worst case spill containment volumes stated within the code.

With regard to tanker truck unloading and aircraft refueler loading activities, 40 CFR 112 makes a distinction between “truck loading/unloading areas” and “truck loading/unloading racks”. The former is defined as an area where there are only unloading pumps and hoses associated with storage tanks; the latter is an area with a physical loading rack structure with loading or unloading arms and platforms to access the trucks. A truck loading/unloading area must meet the “general” secondary containment requirements, whereas a truck loading/unloading rack must meet “sized” secondary containment requirements. The sized secondary containment for loading racks requires that it be equal to largest compartment on any truck using the rack, plus an allowance for stormwater.

Under 40 CFR 122.26(b)(14), airports which have the potential to discharge contaminated stormwater to the surface waters of the U.S. are a stormwater regulated industry. Under this regulation the secondary containment area surfaces which contact fuel are considered to be “industrial surfaces” because of their frequent exposure to small amounts of fuel. The photo below indicates typical staining from minor jet fuel spills on a concrete truck transfer pad, which can lead to the discharge of contaminated stormwater.

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