EPA Scrutinizes Deicing

Environmental attorney reviews EPA's initiative.


The Environmental Protection Agency recently surveyed U.S. airports regarding their deicing activities as the agency looks to reevaluate its policies related to groundwater runofff and remediation. Here, an environmental attorney explores EPA's initiative as well as considerations for airports regarding compliance. He suggests that some airports (and tenants) may be caught off guard by the agency’s initiative.

The Environmental Protection Agency is continuing its effort to more tightly regulate air carriers and airports that use deicing chemicals which are exposed to stormwater runoff or discharge. EPA recently sent questionnaires to 153 airports using its authority under Clean Water Act § 308, and sent screening questionnaires to 94 air carriers, which will also receive follow-up questionnaires.

The process is designed to identify deicing controls and measures that will be imposed on airports and air carriers by federal regulation, potentially causing significant increase in the cost, infrastructure, and regulatory scrutiny associated with deicing and anti-icing. Any airport or air carrier conducting deicing operations without a state or federal Clean Water Act discharge permit that specifically covers deicing chemicals will also be identified through this process.

The primary purpose is to develop new Clean Water Act standards; a collateral regulatory impact will probably be that facilities operating without a Clean Water Act permit will have to obtain one. Depending on the standards set in the Effluent Limitation Guidelines (ELG) process, facilities with existing permits could face major modifications of permit limits and other restrictions.

A Bit of History

Airports and air carriers are required by FAA regulations to apply deicing and anti-icing chemicals to airplanes and runway surfaces under certain conditions for safety. Chemicals used for deicing and anti-icing vary, but they share the common problem of contributing, when discharged to a water body with stormwater runoff, to water quality degradation. The environmental issue is primarily one of depleting oxygen in the water that would otherwise be available to fish, for example.

For aircraft deicing, the most commonly used substances are ethylene glycol or propylene glycol. The most common pavement deicers are potassium acetate, sodium acetate, sodium formate, or urea. The means used to apply deicing materials vary from airport to airport, as do those employed to prevent, capture, or otherwise control the residue or excess deicing chemicals which mingle with rain and snow and eventually with stormwater runoff to the airport's storm drains. Some facilities discharge all or part of that runoff to a public sanitary sewer system; in many other cases, the runoff simply washes untreated into a nearby water body, albeit usually in a much diluted condition.

Federal law requires that deicing runoff that does reach so-called waters of the U.S. (streams, creeks, wetlands, sloughs, bays, sounds, etc.) must be covered by a state or federal National Pollution Discharge Elimination System (NPDES) permit. However, both the federal government and the many states which are delegated Clean Water Act regulatory authority have been inconsistent in enforcing that requirement.

Some ten years ago, that inconsistency precipitated a class-action lawsuit, which in turn caused some large airports to spend millions of dollars to obtain and comply with a NPDES permit for deicing. Unfortunately, due to the complexities of airport operations, weather, and technical challenges in designing control methods, some airports have expended a great deal of money — only to discover they are still unable to consistently comply with permit limitations.

Local conditions in which airports operate vary so widely with respect to airport layout, weather, and the nature of the water that receives deicing runoff that it's impossible to identify a single control plan, or even a suite of measures, that will work in every situation. However, there are common themes that EPA hopes will be further defined through the process now underway: the Effluent Limitation Guideline process.

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