### MEMORANDUM

TO: Mr. Brian D’Amico, USEPA/EAD

FROM: Ms. Mary Wille tt and Cal Franz, ERG

DATE: January 23, 2012

SUBJECT: NSPS Feasibility – ADF Collection and Treatment Requirements

Background

Under the New Source Performance Standards (NSPS) for the Airport Deicing Category, EPA is establishing a standard of 60 pe rcent collection of available ai rcraft deicing fluid (ADF) and treating that waste to a numeric limit for the collected ADF. Available ADF is defined by EPA as 75 percent of the sprayed de icing fluid and 10 percent of the sprayed anti-icing fluid, excluding sprayed fluids used fo r defrosting or deicing for safe taxiing. EPA based the NSPS collection requirement on the use of centralized deicing pads (CDPs) and the numeric limit on anaerobic fluidized bed (AFB) tr eatment. CDPs are defined by EPA as a facility on an airfield designed for aircraft deicing opera tions, constructed with a drainage system separate (or one that can be made separate) from the airport main stor m drain system, and where the separate drainage system is connected to a wast ewater storage facility.

This memorandum summarizes EPA’s assessment that the NSPS requirements for ADF collection and treatment, while they may not be technologically available nationwide for some existing airports based on current information, are nevertheless availabl e and feasible for new airports.

CDP Comments

The focus of the comments received on CDPs rela ted to their use at ex isting airports. While these comments primarily related to the proposed BAT and not NSPS, EPA similarly considered

each of these concerns with respect to new airports.

Commenters raised multiple concerns about the technology basis for the proposed 60 percent collection requirement at existing airports: centralized deicing pads . First, they raised concerns that centralized deicing pads ar e not feasible at all locations because of lack of space. Second,

commenters raised concerns that using CDPs would cause traffi c and/or safety problems and would lead to delays. Finally, they raised co ncerns about the EPA’s proposal to require all deicing to be performed at CDPs. In particular, they noted that deicing applied for safe taxiing should not be subject to this requirement.

FAA also provided EPA with comments, which reiterated some of the issues raised by public commenters regarding the installa tion of centralized de icing facilities at existing airports.Memorandum 23 January 2012 Page 2

Further, FAA is concerned that for those land-co nstrained airports, construction and operation of centralized deicing pads would not be able to meet FAA design st andards. FAA raised concern about safety and efficiency with a provision that would exclusivel y require deicing pads to be used, noting that delays are extremely costly to the nation's productivity, economy, businesses, and the traveling public.

After considering these comments and review ing the information in its record, EPA has

concluded that while some exis ting airports can and do employ CD Ps safely and efficiently for deicing of some of their aircraft , the lack of available land, coupl ed with their existing layouts, has left some other existing airports in a position where installation of an airport-wide system of centralized deicing pads, intende d for all deicing activities, an d conforming to FAA’s Advisory Circulars on deicing pad design, (e.g., in a loca tion that aircraft can travel to safely and efficiently to conduct deicing operations) may be infeasible, see section V.B.2 in the preamble

for further discussion. These concerns are associ ated with the technologi es used for spent ADF collection, as these technologies must be deploye d in areas with aircraft activity. EPA is not aware of such constraints regarding treatment sy stems and storage/equali zation associated with meeting the numeric discharge limit. These may be situated anywhere on the airport grounds as there is no need for constructing storage/equali zation and treatment facilities near the deicing

areas.

EPA also made modifications to the definition of availabl e ADF which addresses these comments. In order to ensure safe aircraft opera tions, the final rule excludes ADF that is applied for safe taxiing. Therefore, the deicing that an airport may perform for this purpose is not subject to the NSPS collection or treatment require ments of this rule. Moreover, EPA received comments that defrosting activities, in many in stances, will not result in any ADF that is

available for collection. Therefore EPA is also exempting ADF sprayed for defrosting operations from the final rule requirements.

NSPS Feasibility

Having excluded ADF applied for safe taxiing an d defrosting, EPA in consultation with FAA,

finds that the concerns raised about safety, space, a nd operational constraints for CDPs that may be present at existing airports would not similarly apply to new airports. When designing a new airport, an airport authority ha s the ability to purc hase enough land and design the airport layout

in a fashion that would be able to avoid the logistical issues that arise when retrofitting a CDP, and no data was provided to indi cate otherwise. Furthermore, as described above, EPA has made allowances in the final rule for deicing perfor med for safe taxiing and defrosting which resolve the potential safety issues associated with th e 100 percent CDP requirement for all deicing

activities.

Many existing airports utilize CD Ps. Based on airport questionnair e responses, deicing pads are used at 34 airports for at leas t a portion of their flights, rangi ng from large to non-hub airports. One of the airports is Denver In ternational (DIA). Denver, the only new airport to open in the last 25 years that meets the applicability of the ELG, installed and uses deicing pads for all ofMemorandum 23 January 2012 Page 3

their flights 1 . During EPA’s site visit to DIA on N ovember 8, 2005, airport personnel indicated that all deicing is done on thei r CDPs, with the exception of lo w-level gate deicing (up to 25 undiluted gallons of ADF) to allow for safe plane movement. In 2011, EPA was told that, for a while, United Airlines discontinued the use of pads in favor of gate deicing. During this time, Denver experienced a whole host of complaints. Denver cited the mess at the gates and odor problems in gate areas and basements. As a re sult of these complaints, all deicing (except low level) is once again done on CDPs. In additi on, Denver indicated that when fully staffed, it processes planes through the deicing pad more quickly than the availa ble capacity at their

runways.

Finally, FAA concurs with EPA’s conclusion that new airports can be designed to minimize space and logistical constraints that may be identif ied for retrofits at existing airports. Further, they also noted that when desi gned appropriately, pad usage actually improves traffic flow and reduces delays.

Summary

EPA has concluded that CDP technology is techno logically available and demonstrated at new source airports for the collection of ADF-contaminated wastewater and that succe ssful siting and sizing of deicing pads is achie vable when planners take thes e CDPs into account during the design phase of new airport construction. In add ition, the only available evidence indicates that rather than leading to delays, use of such CDPs in fact improves traffic flow and reduces delays.

References

USEPA. 2008. Airline Detailed Ques tionnaire Database. U.S. Environmental Protection Agency/Office of Water. Wa shington, D.C. DCN AD00938.

USEPA. 2008. Airport Questionnaire Database. U.S. Environmental Protection Agency/Office of Water. Washington, D.C. DCN AD00927.

USEPA. 2007. Final Engineering Site Visit Report for Denver International Airport . U.S. Environmental Protection Agen cy/Office of Water. Washington, D.C. (November 4). DCN

AD00779.

Denver International Airport: Information on Se lected Financial Issues. General Accounting Office. (Letter Report, 09/18/95, GAO/AIMD-95-230). www.colorado.edu/libraries/govpub/dia.htm

1 DIA is operated by the City and C ounty of Denver Department of Aviati on and is a municipal airport facility serving the Denver, Colorado metropolitan area. The airpor t opened on February 28, 1995 and includes 4 northsouth and 2 east-west runways, for a total of 6 runways. The airport has 89 gates and associated taxiways, aircraft parking aprons; three airside concourses; and passenger and cargo terminals. The airport was designed with a centralized deicing system comprised of four CDPs that are used for passenger aircraft, and the airport has since added a fifth pad. The airport also has general aviati on and cargo ramps and a CDP whic h is occasionally used by cargo aircraft. Each of the passenger aircraft CDPs feed high concentration ADF stormwat er (greater than 1 percent glycol) to on-site storage tanks located at the airport’s glycol recycling plant.