[Federal Register Volume 77, Number 95 (Wednesday, May 16, 2012)]
[Rules and Regulations]
[Pages 29168-29205]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-10633]



[[Page 29167]]

Vol. 77

Wednesday,

No. 95

May 16, 2012

Part VII





Environmental Protection Agency





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40 CFR Parts 9 and 449





 Effluent Limitations Guidelines and New Source Performance Standards 
for the Airport Deicing Category; Final Rule

  Federal Register / Vol. 77 , No. 95 / Wednesday, May 16, 2012 / Rules 
and Regulations  

[[Page 29168]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9 and 449

[EPA-HQ-OW-2004-0038. FRL-9667-6]
RIN 2040-AE69


Effluent Limitations Guidelines and New Source Performance 
Standards for the Airport Deicing Category

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: EPA is promulgating technology-based effluent limitations 
guidelines (ELGs) and new source performance standards (NSPS) under the 
Clean Water Act (CWA) for discharges from airport deicing operations. 
The requirements generally apply to wastewater associated with the 
deicing of airfield pavement at primary airports. The rule requires all 
such airports to comply with requirements based on substitution of less 
toxic pavement deicers that do not contain urea. The rule also 
establishes NSPS for wastewater discharges associated with aircraft 
deicing for a subset of new airports. These airports must also meet 
requirements based on collection of deicing fluid and treatment of the 
collected fluid. The ELGs and NSPS will be incorporated into National 
Pollutant Discharge Elimination System (NPDES) permits issued by the 
permitting authority. EPA expects compliance with this regulation to 
reduce the discharge of deicing-related pollutants by 16 million pounds 
per year. EPA estimates the annual cost of the rule at $3.5 million.

DATES: This final rule is effective on June 15, 2012.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OW-2004-0038. All documents in the docket are listed on the 
Web site at http://www.regulations.gov. Although listed in the index, 
some information is not publicly available, e.g., Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. Certain other material, such as copyrighted material, is 
not placed on the Internet and will be publicly available only in hard 
copy form. Publicly available docket materials are available either 
through the docket Web site or in hard copy at the Office of Water 
Docket, EPA West Building Room 3334, 1301 Constitution Ave. NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is 202-566-1744, and the telephone 
number for the Office of Water Docket is 202-566-1752.

FOR FURTHER INFORMATION CONTACT: For further information, contact Eric 
Strassler, Engineering and Analysis Division, telephone: 202-566-1026; 
email: [email protected].

SUPPLEMENTARY INFORMATION: 

Regulated Entities

    Entities regulated by this action may include:

------------------------------------------------------------------------
                                                        North American
                                      Example of           Industry
            Category               regulated entity     Classification
                                                          System code
------------------------------------------------------------------------
Industry........................  Primary airports..           481, 4881
                                  Airlines..........                4811
------------------------------------------------------------------------

    This section is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities that are likely to be regulated 
by this action. Other types of entities that do not meet the above 
criteria could also be regulated. To determine whether your facility is 
regulated by this action, you should carefully examine the 
applicability criteria listed in Sec.  449.1 and the definitions in 
Sec.  449.2 of the rule and detailed further in Section V of this 
preamble. If you still have questions regarding the applicability of 
this action to a particular entity, consult one of the persons listed 
for technical information in the preceding FOR FURTHER INFORMATION 
CONTACT section.

Supporting Documentation

    Today's final rule is supported by a number of documents, 
including:
     Technical Development Document for Final Effluent 
Limitation Guidelines and Standards for the Airport Deicing Category 
(TDD), Document No. EPA-821-R-12-005.
     Economic Analysis for Final Effluent Limitation Guidelines 
and Standards for the Airport Deicing Category (EA), Document No. EPA-
821-R-12-004.
     Environmental Impact and Benefit Assessment for Final 
Effluent Limitation Guidelines and Standards for the Airport Deicing 
Category (EIB), Document No. EPA-821-R-12-003.

These documents are available in the public record for this rule and on 
EPA's Web site at http://epa.gov/guide/airport.

Overview

    The preamble describes the terms, acronyms, and abbreviations used 
in this notice; the background documents that support the regulations; 
the legal authority of these rules; a summary of the final rule; 
background information; and the technical and economic methodologies 
used by the Agency to develop these regulations.

Table of Contents

I. Legal Authority
II. Purpose and Summary of the Final Rule
III. Background
    A. Clean Water Act
    B. NPDES Permits
    1. General Permits
    2. Individual Permits
    C. Effluent Guidelines and Standards Program
    1. Best Practicable Control Technology Currently Available (BPT)
    2. Best Conventional Pollutant Control Technology (BCT)
    3. Best Available Technology Economically Achievable (BAT)
    4. New Source Performance Standards (NSPS)
    5. Pretreatment Standards for Existing Sources (PSES)
    6. Pretreatment Standards for New Sources (PSNS)
    D. Proposed Rule
    1. ADF Collection
    2. Numeric Limit for Collected ADF
    3. Airfield Pavement Deicers
    4. Other Technology Basis Considered
IV. Scope and Applicability of Final Rule
    A. Subcategorization
    B. Industry Description
    C. Wastewater Sources and Wastewater Characteristics
    1. Aircraft Deicing
    2. Airfield Pavement Deicing
    D. Control and Treatment Technologies for the Aviation Industry
    1. ADF Collection Technologies
    2. ADF-Contaminated Wastewater Treatment Technologies
    3. Pollution Prevention Technologies
    4. Airfield Pavement Deicing Control Technologies
    E. Regulated Pollutants
V. Final Regulation
    A. BPT and BCT
    B. BAT
    1. Airfield Deicing

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    2. Aircraft Deicing
    3. Options Considered for Today's Final Rule
    4. BAT Options Selection
    C. NSPS
    1. New Source Definition
    2. NSPS Applicability
    3. NSPS Option Selection
    D. PSES and PSNS
VI. Technology Costs and Pollutant Reductions
    A. Compliance Costs
    1. Overview
    2. Approach for Estimating Airfield Pavement Deicing Costs
    3. Approach for Developing Aircraft Deicing Costs
    4. Calculation of National Costs
    B. Approach to Estimating Pollutant Reductions
    1. Overview
    2. Sources and Use of Available Data
    C. Approach to Determining Long-Term Averages, Variability 
Factors, and Effluent Limitation Guidelines and Standards
    1. Criteria Used To Select Data as the Basis of the Limitations
    2. Data Used as Basis of the Effluent Limitations
    3. Statistical Percentile Basis for Limitations
    4. Rationale for Establishing Limitation on Weekly Averages 
Instead of Monthly Averages for COD in Effluent Discharges
    5. Rationale for Promulgating a Limitation Only for Daily 
Discharges of Ammonia in Effluent Discharges
    6. Calculation of Limitations for COD and Ammonia
    7. Derivation of Long-Term Average for COD and Ammonia: Target 
Level for Treatment
    8. Engineering Review of Effluent Limitations
VII. Economic Analysis
    A. Introduction
    B. Annualized Compliance Cost Estimates
    C. Economic Impact Methodologies
    1. Cost Annualization
    2. Airport Impact Methodology
    3. Co-Permittee Airline Impact Methodology
    D. Results of Impact Analysis
    1. Results of Airport Impact Analysis
    2. Results of Co-Permittee Airline Impact Analysis
    3. Economic Achievability
    E. Economic Impacts for New Sources
    F. Cost and Pollutant Reduction Comparison
    G. Small Business Analysis
VIII. Environmental Assessment
    A. Environmental Impacts
    B. Environmental Benefits
IX. Non-Water Quality Environmental Impacts
    A. Energy Requirements
    B. Air Emissions
    C. Solid Waste Generation
X. Regulatory Implementation
    A. Relation of ELGs and Standards to NPDES Permits
    B. Effective Date
    C. Compliance With the NSPS Requirement
    1. Applicability
    2. Demonstrating Compliance With the NSPS Collection Requirement
    3. P2 Approaches
    D. Alternative Compliance Option for Pavement Deicers Containing 
Urea
    E. COD Effluent Monitoring for New Source Direct Dischargers
    F. Best Management Practices
    G. Upset and Bypass Provisions
    H. Variances and Modifications
    1. Fundamentally Different Factors (FDF) Variance
    2. Economic Variances
    3. Water Quality Variances
    I. Information Resources
XI. Statutory and Executive Order (EO) Reviews
    A. EO 12866: Regulatory Planning and Review and EO 13563: 
Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act (UMRA)
    E. EO 13132: Federalism
    F. EO 13175: Consultation and Coordination With Indian Tribal 
Governments
    G. EO 13045: Protection of Children From Environmental Health 
and Safety Risks
    H. EO 13211: Energy Effects
    I. National Technology Transfer Advancement Act (NTTAA)
    J. EO 12898: Federal Actions To Address Environmental Justice in 
Minority Populations and Low-Income Populations
    K. Congressional Review Act
Appendix A to the Preamble: Abbreviations and Definitions Used in 
This Document

I. Legal Authority

    EPA is promulgating this regulation under the authorities of 
sections 101, 301, 304, 306, 308, 402, and 501 of the CWA, 33 United 
States Code (U.S.C.) 1251, 1311, 1314, 1316, 1318, 1342, and 1361 and 
pursuant to the Pollution Prevention Act of 1990, 42 U.S.C. 13101 et 
seq.

II. Purpose and Summary of the Final Rule

    Commercial airports and air carriers conduct deicing operations as 
required by the Federal Aviation Administration (FAA). Airport 
discharges from deicing operations may affect water quality in 
surrounding communities, including reductions in dissolved oxygen, fish 
kills, reduced organism abundance and species diversity, contamination 
of drinking water sources (both surface and groundwater), creation of 
noxious odors and discolored water in residential areas and parkland, 
and other effects.
    Today, EPA is promulgating effluent limitations guidelines (ELGs) 
and new source performance standards (NSPS) for the Airport Deicing 
Point Source Category. The regulations address control of the 
wastewater discharges from deicing operations based on product 
substitution, wastewater collection practices used by airports, and 
treatment practices for the collected wastewater. New source airports 
within the scope of this rule are required to collect spent aircraft 
deicing fluid (ADF) and meet numerical discharge limits. Those airports 
and certain existing airports performing airfield pavement deicing are 
to use non-urea-containing deicers, or alternatively, meet a numeric 
effluent limitation for ammonia. The requirements are implemented in 
CWA discharge permits.
    The rule requirements and the technologies that serve as the basis 
for the ELGs and standards are explained in Sections IV, V, and VI of 
this preamble.

III. Background

A. Clean Water Act

    Congress passed the Federal Water Pollution Control Act Amendments 
of 1972, also known as the CWA, to ``restore and maintain the chemical, 
physical, and biological integrity of the nation's waters.'' (33 U.S.C. 
1251(a)). The CWA establishes a comprehensive program for protecting 
our nation's waters. Among its core provisions, the CWA prohibits the 
discharge of pollutants from a point source to waters of the United 
States, except as authorized under the CWA. Under section 402 of the 
CWA, EPA and delegated state permitting authorities authorize 
discharges by a NPDES permit. The CWA also authorizes EPA to establish 
national technology-based effluent limitation guidelines and standards 
(effluent guidelines or ELGs) for discharges from different categories 
of point sources, such as industrial, commercial, and public sources.
    In addition, the CWA authorizes EPA to promulgate nationally 
applicable pretreatment standards that restrict pollutant discharges 
from facilities that discharge wastewater indirectly through sewers 
flowing to publicly owned treatment works (POTWs), as outlined in 
section 307(b) and (c), 33 U.S.C. 1317(b) and (c). EPA establishes 
national pretreatment standards for those pollutants in wastewater from 
indirect dischargers that may pass through, interfere with, or are 
otherwise incompatible with POTW operations. Generally, pretreatment 
standards are designed to ensure that wastewaters from direct and 
indirect industrial dischargers are subject to similar levels of 
treatment. In addition, POTWs are required to implement local treatment 
limits applicable to their industrial

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indirect dischargers to satisfy any local requirements. See 40 CFR 
403.5.
    Direct dischargers must comply with effluent limitations in NPDES 
permits. Indirect dischargers, who discharge through POTWs, must comply 
with pretreatment standards. Technology-based effluent limitations in 
NPDES permits are derived from effluent limitations guidelines (CWA 
sections 301 and 304, 33 U.S.C. 1311 and 1314) and new source 
performance standards (section 306) promulgated by EPA, or based on 
best professional judgment where EPA has not promulgated an applicable 
effluent guideline or new source performance standard (CWA section 
402(a)(1)(B), 33 U.S.C. 1342(a)(1)(B)). Additional limitations based on 
water quality standards (CWA section 301(b)(1)(C), 33 U.S.C. 
1311(b)(1)(C)) are also required to be included in the permit in 
certain circumstances. The ELGs are established by regulation for 
categories of industrial dischargers and are based on the degree of 
control that can be achieved using various levels of pollution control 
technology.
    EPA promulgates national ELGs and standards of performance for 
major industrial categories for three classes of pollutants: (1) 
Conventional pollutants (i.e., total suspended solids, oil and grease, 
BOD5, fecal coliform, and pH), as outlined in section 
304(a)(4) and 40 CFR 401.16; (2) toxic pollutants (e.g., toxic metals 
such as chromium, lead, nickel, and zinc; toxic organic pollutants such 
as benzene, benzo-a-pyrene, phenol, and naphthalene), as outlined in 
section 307(a) of the Act, 40 CFR 401.15 and 40 CFR part 423 appendix 
A; and (3) non-conventional pollutants, pollutants that are neither 
conventional nor toxic (e.g., ammonia-N, formaldehyde, and phosphorus).

B. NPDES Permits

    Section 402 of the CWA requires permits for point source discharges 
of pollutants to waters of the United States. In most states, the 
permits are issued by a state agency that has been authorized by EPA. 
Currently, 46 states and one U.S. territory are authorized to issue 
NPDES permits. In the other states and territories, EPA issues the 
permits.
    Section 402(p) of the Act, added by the Water Quality Act of 1987 
(Pub. L. 100-4, February 4, 1987), requires stormwater dischargers 
``associated with industrial activity'' to be covered under an NPDES 
permit. In its initial stormwater permit regulations, called the 
``Phase I'' stormwater regulations (55 FR 47990, November 16, 1990), 
EPA designated air transportation facilities, including both airlines 
and airports, that have vehicle maintenance shops (including vehicle 
rehabilitation, mechanical repairs, painting, fueling, and 
lubrication), equipment cleaning operations, or airport deicing 
operations as subject to NPDES stormwater permitting requirements. See 
40 CFR 122.26(b)(14)(viii).
    Airport stormwater discharges may be controlled under a general 
NPDES permit, which covers multiple facilities with similar types of 
operations and/or wastestreams, or by an individual permit. An airport 
may have additional NPDES permits for non-stormwater discharges, such 
as from equipment repair and maintenance facilities. The following 
discussion pertains only to airport stormwater permits.
1. General Permits
    Currently, most airport deicing discharges are covered by a general 
permit issued by either EPA or an NPDES-authorized state agency. In 
most areas where EPA is the permit authority, the Multi-Sector General 
Permit (MSGP) covers airport deicing discharges (73 FR 56572, September 
29, 2008). Many NPDES-authorized state agencies have issued general 
permits in their respective jurisdictions with requirements similar to 
the MSGP. An airport seeking coverage under a general permit submits a 
Notice of Intent (NOI) to the permit authority rather than a detailed 
permit application. By submitting an NOI, the permittee is agreeing to 
comply with the conditions in the final general permit.
    For airports, the major requirements of the current MSGP, include 
the following:
     Develop a stormwater pollution prevention plan, including 
a drainage area site map, documentation of measures used for management 
of deicing contaminated stormwater, an evaluation of runway and 
aircraft deicing operations, and implementation of a program to control 
or manage deicing contaminated stormwater, including consideration of 
various listed control practices.
     Implement deicing source reduction measures, including 
minimizing or eliminating the use of urea and glycol-containing deicing 
chemicals; minimizing contamination of deicing contaminated stormwater 
from runway and aircraft deicing operations; evaluating whether over-
application of deicing chemicals occurs; and consider use of various 
listed source control measures.
     For airports using more than 100,000 gallons of glycol-
based deicing chemicals and/or 100 tons or more of urea containing 
deicers annually, monitor discharges quarterly for the first four 
quarters of the permit cycle, for the following pollutants: biochemical 
oxygen demand (BOD 5), chemical oxygen demand (COD), 
ammonia, and pH.
     If the average of the four monitoring values for any 
parameter exceeds its benchmark, implement additional control measures 
where feasible, and continue monitoring.
     Conduct an annual site inspection during the deicing 
season, and during periods of actual deicing operations if possible, as 
well as routine facility inspections at least monthly during the 
deicing season.
    EPA expects to modify the MSGP when the next permit is issued, to 
conform it to today's final Airport Deicing rule.
2. Individual Permits
    Some EPA and state NPDES-permitting authorities have required 
certain airports to obtain individual permits. In these situations, an 
airport must submit a detailed application and the permit authority 
develops specific requirements for the facility.
    Some individual permits contain specialized requirements for 
monitoring and/or best management practices (BMPs). Some of these 
permits also contain numeric water quality-based effluent limitations. 
Information on water quality-based permitting is available on EPA's Web 
site at http://cfpub.epa.gov/npdes/generalissues/watertechnology.cfm.

C. Effluent Guidelines and Standards Program

    Effluent guidelines and NSPS are technology-based regulations that 
are developed by EPA for a category of dischargers. These regulations 
are based on the performance of control and treatment technologies. The 
legislative history of CWA section 304(b), which is the heart of the 
effluent guidelines program, describes the need to press toward higher 
levels of control through research and development of new processes, 
modifications, replacement of obsolete plans and processes, and other 
improvements in technology, taking into account the cost of controls. 
Congress has also stated that EPA need not consider water quality 
impacts on individual water bodies as the guidelines are developed; see 
Statement of Senator Muskie (October 4, 1972), reprinted in Legislative 
History of the Water Pollution Control Act Amendments of 1972, at 170. 
(U.S. Senate, Committee on Public Works, Serial No. 93-1, January 
1973.)

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    There are four types of standards applicable to direct dischargers 
(dischargers to surface waters), and two standards applicable to 
indirect dischargers (discharges to POTWs).
1. Best Practicable Control Technology Currently Available (BPT)
    Traditionally, EPA establishes BPT effluent limitations based on 
the average of the best performances of facilities within the industry, 
grouped to reflect various ages, sizes, processes, or other common 
characteristics. EPA may promulgate BPT effluent limits for 
conventional, toxic, and non-conventional pollutants. In specifying 
BPT, EPA looks at a number of factors. EPA first considers the cost of 
achieving effluent reductions in relation to the effluent reduction 
benefits. The Agency also considers the age of the equipment and 
facilities, the processes employed, engineering aspects of the control 
technologies, any required process changes, non-water quality 
environmental impacts (including energy requirements), and such other 
factors as the Administrator deems appropriate. See CWA section 
304(b)(1)(B). If, however, existing performance is uniformly 
inadequate, EPA may establish limitations based on higher levels of 
control than what is currently in place in an industrial category, when 
based on an Agency determination that the technology is available in 
another category or subcategory, and can be practically applied.
2. Best Conventional Pollutant Control Technology (BCT)
    The 1977 amendments to the CWA required EPA to identify additional 
levels of effluent reduction for conventional pollutants associated 
with BCT technology for discharges from existing industrial point 
sources. In addition to other factors specified in section 
304(b)(4)(B), the CWA requires that EPA establish BCT limitations after 
consideration of a two part ``cost-reasonableness'' test. EPA explained 
its methodology for the development of BCT limitations in July 1986 (51 
FR 24974). Section 304(a)(4) designates the following as conventional 
pollutants: BOD 5 measured over five days, total suspended 
solids, fecal coliform, pH, and any additional pollutants defined by 
the Administrator as conventional. The Administrator designated oil and 
grease as an additional conventional pollutant on July 30, 1979 (44 FR 
44501; 40 CFR 401.16).
3. Best Available Technology Economically Achievable (BAT)
    BAT represents the second level of stringency for controlling 
direct discharge of toxic and nonconventional pollutants. In general, 
BAT ELGs represent the best economically achievable performance of 
facilities in the industrial subcategory or category. The factors 
considered in assessing BAT include the cost of achieving BAT effluent 
reductions, the age of equipment and facilities involved, the process 
employed, potential process changes, and non-water quality 
environmental impacts, including energy requirements and such other 
factors as the Administrator deems appropriate. The Agency retains 
considerable discretion in assigning the weight to be accorded these 
factors. Economic achievability is an additional statutory factor 
considered in setting BAT. Generally, EPA determines economic 
achievability on the basis of total costs to the industry and the 
effect of compliance with BAT limitations on overall industry and 
subcategory financial conditions. As with BPT, where existing 
performance is uniformly inadequate, BAT may reflect a higher level of 
performance than is currently being achieved based on technology 
transferred from a different subcategory or category. BAT may be based 
upon process changes or internal controls, even when these technologies 
are not common industry practice.
4. New Source Performance Standards (NSPS)
    NSPS reflect effluent reductions that are achievable based on the 
best available demonstrated control technology (BADCT). Owners of new 
facilities have the opportunity to install the best and most efficient 
production processes and wastewater treatment technologies. As a 
result, NSPS should represent the most stringent controls attainable 
through the application of the BADCT for all pollutants (that is, 
conventional, nonconventional, and priority pollutants). In 
establishing NSPS, EPA is directed to take into consideration the cost 
of achieving the effluent reduction and any non-water quality 
environmental impacts and energy requirements.
5. Pretreatment Standards for Existing Sources (PSES)
    Section 307(b) calls for EPA to issue pretreatment standards for 
discharges of pollutants to POTWs. PSES are designed to prevent the 
discharge of pollutants that pass through, interfere with, or are 
otherwise incompatible with the operation of POTWs. Categorical 
pretreatment standards are technology-based and are analogous to BPT 
and BAT effluent limitation guidelines. See CWA sections 301((b)(1)(B) 
and 301(b)(2)(A)), 33 U.S.C. 1311(b)(1)(B) and 1311(b)(2)(A). The 
General Pretreatment Regulations, which set forth the framework for the 
implementation of categorical pretreatment standards, are found at 40 
CFR part 403. These regulations establish pretreatment standards that 
apply to all non-domestic dischargers. See 52 FR 1586 (January14, 
1987).
6. Pretreatment Standards for New Sources (PSNS)
    Section 307(c) of the Act calls for EPA to promulgate PSNS. Such 
pretreatment standards must prevent the discharge of any pollutant into 
a POTW that may interfere with, pass through, or may otherwise be 
incompatible with the POTW. EPA promulgates PSNS based on best 
available demonstrated technology for new sources. New indirect 
dischargers have the opportunity to incorporate into their facilities 
the best available demonstrated technologies. The Agency typically 
considers the same factors in promulgating PSNS as it considers in 
promulgating NSPS.

D. Proposed Rule

    EPA published a proposed rule for the Airport Deicing Category on 
August 28, 2009 (74 FR 44676). The proposed rule covered primary 
commercial airports that conduct deicing operations and have 1,000 or 
more annual jet departures. An existing airport in the scope of the 
proposal would have been required to certify that it uses airfield 
pavement deicers that do not contain urea, or alternatively, meet an 
effluent limitation for ammonia. Additionally, in-scope airports with 
10,000 or more annual departures would have been required to:
     Collect at least a specified proportion (either 20 or 60 
percent, based on size) of available ADF after it is sprayed on 
aircraft; and
     Meet a specified numeric effluent limit for ADF wastewater 
collected and discharged directly.
    As proposed, all in-scope new source dischargers had the same 
airfield pavement deicing requirements as existing sources and were 
required to collect 60 percent of available ADF and meet the specified 
numeric limit for direct discharges of the collected fluid. EPA 
estimated that the proposed rule would apply to 218 existing airports; 
110 airports for both the pavement deicer and ADF collection and

[[Page 29172]]

discharge requirements, and another 108 airports for the pavement 
deicer requirement only. Of those 218 airports, the Agency estimated 
that 148 airports were already in compliance with the proposed 
requirements.
1. ADF Collection
    The proposed rule would have required all existing primary airports 
that have 10,000 or more annual departures to collect at least 20 
percent of available ADF. The 20 percent collection requirement was 
based on the estimated performance of glycol collection vehicles 
(GCVs). Those primary airports that use 460,000 or more gallons of 
normalized ADF annually, which make up a small subset of this group, 
would have been required to collect at least 60 percent of all 
available ADF. (As defined in proposed Sec.  449.2, normalized ADF is 
ADF less any water added by the manufacturer or customer before ADF 
application.) This collection requirement was based on the estimated 
performance of centralized deicing pads (CDPs). In-scope primary 
airports with less than 10,000 annual departures would not have been 
required to meet the national ELG requirements to collect their 
available deicing fluid or meet associated discharge limitations and 
would have continued to be subject to case-by-case Best Professional 
Judgment (BPJ) permitting requirements for ADF collection and 
treatment.
2. Numeric Limit for Collected ADF
    For airports discharging collected ADF directly to surface waters, 
the proposal would have required these airports to meet numeric 
effluent limitations for COD. The limits were based on anaerobic 
fluidized bed (AFB) treatment technology.
3. Airfield Pavement Deicers
    EPA proposed BAT for direct dischargers associated with airfield 
pavement deicing based on product substitution. Specifically, EPA based 
BAT on the substitution of pavement deicers containing urea with 
alternative, less toxic products that are also effective and not 
harmful to aircraft.
4. Other Technology Basis Considered
    In the proposed rule, in addition to CDPs and GCVs, EPA described 
plug-and-pump technology with GCVs as a possible BAT basis for an ADF 
collection requirement, and calculated the cost of this technology. 
This technology, when used in combination with GCVs, is estimated to 
collect at least 40 percent of available ADF.

IV. Scope and Applicability of Final Rule

    This final rule applies to primary airports. Existing airports with 
greater than or equal to 1,000 annual departures by non propeller 
driven aircraft must meet BAT requirements at Sec.  449.10, as 
applicable.
    A new airport with deicing discharges and located in specified 
geographic locations (see section V.C.2), that is operating less than 
1,000 non-propeller aircraft departures annually is not required to 
meet the NSPS provisions in Sec.  449.11. However, if the number of 
departures later increases above that threshold, then the substantive 
requirements in Sec.  449.11 apply. This means that a new airport that 
expects to eventually exceed the 1,000 departure threshold must plan to 
install and operate facilities that will comply with the requirements 
of that section once it reaches the threshold of 1,000 non-propeller 
departures annually.

A. Subcategorization

    EPA may divide a point source category into groupings called 
``subcategories'' to provide a method for addressing variations among 
products, processes, and other factors, which result in distinctly 
different effluent characteristics. See Texas Oil & Gas Ass'n. v. US 
EPA, 161 F.3d 923, 939-40 (5th Cir. 1998). Regulation of a category by 
subcategories provides that each subcategory has a uniform set of 
effluent limitations that takes into account technological 
achievability and economic impacts unique to that subcategory. In some 
cases, effluent limitations within a subcategory may be different based 
on consideration of these same factors, which are identified in CWA 
section 304(b)(2)(B). The CWA requires that EPA, in developing effluent 
guidelines, consider a number of different factors, which are also 
relevant for subcategorization. The CWA also authorizes EPA to take 
into account other factors that the Agency deems appropriate.
    In developing today's rule, EPA considered whether subcategorizing 
the aviation industry was warranted. In addition to those factors 
specified in the CWA, EPA evaluated a number of factors and potential 
subcategorization approaches, including the presence of an onsite 
glycol reclamation facility, amount of ADF applied, number of 
departures, availability of land to install collection systems, and FAA 
airport classifications. EPA concluded that establishing formal 
subcategories is not necessary for the Airport Deicing category. EPA 
structured the applicability and requirements of the final rule to 
account for the relevant factors (e.g., amount of ADF applied) and has 
established a set of requirements appropriate for the range of 
situations that an airport may encounter during deicing operations.

B. Industry Description

    The Airport and Airway Improvement Act (AAIA), 49 U.S.C. Chapter 
471, defines airports by categories of airport activities, including 
Commercial Service (Primary and Non-Primary), Cargo Service, and 
Reliever. These categories are not mutually exclusive; an airport may 
be classified in more than one of these categories. Another group of 
generally smaller airports, not specifically defined by AAIA, is 
commonly known as ``general aviation'' airports. EPA estimates that 
there are approximately 500 commercial service airports.
    Commercial service airports are publicly owned airports that have 
at least 2,500 passenger boardings each calendar year and receive 
scheduled passenger service. Passenger boardings refer to revenue 
passenger boardings on an aircraft in service in air commerce, whether 
or not in scheduled service. The definition also includes passengers 
who continue on an aircraft in international flight that stops at an 
airport in any of the 50 states for a non-traffic purpose, such as 
refueling or aircraft maintenance rather than passenger activity. 
Passenger boardings at airports that receive scheduled passenger 
service are also referred to as ``enplanements.''
    Primary commercial service airports (primary airports) have more 
than 10,000 passenger boardings each year. Primary airports are further 
subdivided into Large Hub, Medium Hub, Small Hub and Non-Hub 
classifications, based on the percentage of total passenger boardings 
within the United States in the most recent calendar year ending before 
the start of the current fiscal year.
    Early in the regulatory development process, EPA focused on deicing 
activities at primary airports, particularly those with extensive non-
propeller traffic. Operators of general aviation aircraft, as well as 
smaller commercial non-jet aircraft, typically suspend flights during 
icing conditions, whereas commercial airlines operating at primary 
airports are much more likely to deice their jets in order to meet 
customer demands.
    Based on the results of industry surveys that EPA conducted prior 
to the proposed rule, the Agency estimated that 320 primary airports 
conduct deicing operations. EPA reviewed the

[[Page 29173]]

relative sizes of various airports (based on annual departures), the 
levels of deicing activity, traffic characteristics (i.e., passenger 
versus cargo operations), the extent of pollution controls and 
treatment in place, and the costs of various technologies for these 
airports. EPA further classified airports based on the number of annual 
non-propeller departures. EPA found that there were some primary 
airports, typically smaller airports, with high percentages of 
propeller aircraft, and therefore excluded airports with fewer than 
1,000 annual non-propeller departures from the scope of the proposed 
rule. These airports have a higher proportion of propeller-aircraft 
flights, which are typically delayed or cancelled during icing 
conditions (i.e., far less deicing takes place at these airports and 
far less deicing fluid is used, than at airports serving more jets).

C. Wastewater Sources and Wastewater Characteristics

1. Aircraft Deicing
    Airlines apply most ADF to aircraft through pressurized spraying 
systems, mounted either on trucks that move around an aircraft, or on 
large fixed boom devices located at a pad dedicated to deicing.
    Most of the ADF sprayed is Type I fluid, which is designed for 
minimal adhesion to aircraft surfaces. Consequently, the majority of 
Type I ADF is available for discharge due to dripping, over-spraying, 
tires rolling through or sprayed with fluid, and shearing during 
takeoff. Once the ADF has reached the ground, it will then mix with 
precipitation, as well as other chemicals found on airport surfaces; 
these chemicals typically include aircraft fuel, lubricants and 
solvents, and metals from aircraft, ground support and utility 
vehicles. Water containing these substances enters an airport's storm 
drain system. At many airports, the storm drains discharge directly to 
U.S. waters with no treatment.
    Type IV fluid, an anti-icing chemical, is designed to adhere to the 
aircraft. Because of this adherence characteristic, EPA estimated that 
the majority of Type IV fluid is not available for collection.
    For the purposes of this rule, the pollutant loadings are discussed 
in terms of applied ADF and how much of that ADF is expected to be 
discharged. A more detailed discussion of loadings estimates is 
presented in Section VI.B. Given the highly variable nature of storm 
events, it is difficult to estimate flows or concentrations of ADF-
contaminated stormwater generated at an airport. Those factors are 
greatly dependent on site-specific factors, such as the size of the 
storm event associated with the discharge, drainage characteristics, 
ADF collection systems (if present), and airport operations. 
Additionally, due to the design of drainage systems at some airports, 
discharges may occur well after a storm event has completed.
2. Airfield Pavement Deicing
    Most solid airfield deicing chemical products are composed of an 
active deicing ingredient (e.g., potassium acetate, sodium acetate) and 
a small amount of additives (e.g., corrosion inhibitors). Liquid 
airfield deicing chemical products are composed of an active ingredient 
(e.g., potassium acetate, propylene glycol), water, and minimal 
additives. The airfield deicing products that include salts (i.e., 
potassium acetate, sodium acetate, and sodium formate) will all ionize 
in water, creating positive salt ions (K\+\, Na\+\), BOD5, 
and COD load as the acetate or formate ion degrades into carbon dioxide 
(CO2) and water. Pavement deicers containing urea will 
degrade to ammonia, as well as generate BOD5 and COD load.
    Most of EPA's deicing characterization data does not reflect 
airfield pavement deicers. However, EPA collected samples from a few 
locations at Detroit Metro Airport that contain airfield deicing 
stormwater. Detroit Metro and Pittsburgh, both large hub airports, 
provided sampling data associated with stormwater contaminated by 
airfield pavement deicers. More information on these sampling 
activities is provided in the TDD. As with the aircraft deicers, the 
variability of storm events and drainage systems makes it difficult to 
estimate flows or concentrations of pavement deicing waste streams 
generated at an airport.

D. Control and Treatment Technologies for the Aviation Industry

    The ADF application process has presented a challenge for those 
airports attempting to manage their contaminated stormwater streams. 
The process of applying ADF to aircraft through high pressure spraying, 
combined with the typical practices of spraying the aircraft outdoors 
in multiple, large unconfined (but usually designated) spaces, results 
in pollutants being dispersed over a wide area and entering storm 
drains at multiple locations. This process contrasts sharply with many 
other industries where pollutants are generated in confined areas, 
managed through a piping system, and not commingled with precipitation.
    EPA has identified several technologies that are available to 
collect and manage portions of the ADF wastestream. Some of these 
collection technologies are more effective than others. EPA has also 
identified several pollution prevention (P2) approaches that may be 
used to minimize the amount of ADF applied. However, no single 
technology or P2 approach is capable of collecting or eliminating all 
applied ADF, as a portion of the fluid is designed to adhere to the 
aircraft until after takeoff, in order to ensure safe operations. 
Furthermore, with few exceptions, tracking by aircraft tires, wind 
dispersion, and dripping during taxiing and takeoff ensures that some 
amount of sprayed ADF, even if performed in a contained area, will end 
up in the drainage system of the airport. For these reasons, EPA 
concludes that all airports that perform aircraft deicing operations 
are direct dischargers. There are limited instances where an airport in 
a warm climate that performs only defrosting and gets little to no 
precipitation may, in fact, not discharge any deicing materials.
    Once the available ADF wastestream is collected, it can be treated, 
and this process is similar to many other industries that generate 
wastewater. In a similar manner, airfield deicing has presented a 
challenge for airports attempting to manage their contaminated 
stormwater streams. Airfield deicing is typically conducted over a 
large area, including areas with frequent aircraft traffic, such as 
runways, where active collection technologies (i.e., GCVs) are 
impractical to implement. At this time, EPA has not identified any 
available economically achievable technologies for the collection of 
pavement deicing stormwater. As a result, EPA also examined P2 
technologies, which can reduce or eliminate the use of ADF chemicals 
and urea containing deicers for pavement deicing in today's final rule.
    The following section discusses the technologies EPA considered for 
ADF collection and treatment and for addressing airfield deicing.
1. ADF Collection Technologies
a. GCV
    A GCV is a truck that utilizes a vacuum mechanism to gather 
stormwater contaminated with ADF, resulting from deicing operations. 
GCVs are typically stationed near the ADF spraying trucks and are 
deployed either during aircraft deicing activities or after the 
aircraft deicing activity has been completed. The GCV then transports 
the

[[Page 29174]]

ADF-contaminated stormwater to an onsite storage and/or equalization 
facility, after which the material is either treated at the airport or 
sent offsite for treatment. EPA estimates that GCVs typically collect 
at least 20 percent of the available ADF when properly operated and 
maintained.
b. Plug and Pump
    The plug and pump collection system utilizes an airport's existing 
stormwater collection system infrastructure to contain and collect ADF 
contaminated stormwater. Plug and pump systems also commonly utilize 
GCVs for ancillary ADF collection. Typical GCV deployment may include 
collecting ADF that has been sprayed beyond the plug and pump 
containment area or as an additional collection measure at the gate, 
ramp, and/or apron area after deicing operations and active plug and 
pump collection have ceased. The plug and pump system operates by 
placing either temporary inflatable balloons or storm sewer shutoff 
valves in the existing storm sewer system. During deicing events, the 
balloons are inflated and storm sewer shutoff valves are closed, 
trapping the ADF-contaminated stormwater in the collection system. 
Vacuum trucks pump the trapped contaminated stormwater from the storm 
sewer system and transport the liquid to onsite storage and/or 
equalization. In addition, catch basin inserts can be placed into 
manholes to collect ADF-contaminated stormwater.
c. CDPs
    A CDP is a paved area on an airfield built specifically for 
aircraft deicing operations. It is typically located adjacent to a gate 
area, taxiway, or runway, and constructed with a drainage system 
separate from the airport's main storm drain system. A CDP is usually 
constructed of concrete with sealed joints to prevent the loss of 
sprayed ADF through the joints. The pad's collection system is 
typically connected to a wastewater storage facility, which then may 
send the wastewater to an onsite or offsite treatment facility.
    Some airports use GCVs in combination with CDPs to collect ADF that 
lands outside the pad collection area in order to maximize collection 
and containment of ADF-contaminated stormwater. Airports typically 
locate the pads near the gate areas or at the threshold of a runway to 
minimize delays in aircraft takeoff and to enhance the effectiveness of 
the ADF applied by limiting time between application and takeoff.
    CDPs reduce the volume of deicing wastewater by restricting deicing 
to small areas, and managing the collected wastewater through a 
dedicated drain system. EPA estimates that CDPs allow airports to 
collect at least 60 percent of the available ADF.
d. Summary of ADF Collection Technology Usage
    EPA estimates the number of airports that use each of the above 
collection technologies in Table IV-1. Some airports use more than one 
technology, and some of the airports in the estimate use the technology 
for only a portion of their ADF-contaminated stormwater.

   Table IV-1--Estimated Totals of ADF Collection Technologies Used by
                                Airports
------------------------------------------------------------------------
                                                             Number of
                  Collection technology                      airports
------------------------------------------------------------------------
Glycol Collection Vehicle...............................              53
Plug and Pump...........................................              29
Centralized Deicing Pad.................................              66
------------------------------------------------------------------------

See Section 8.2 of the TDD for further explanation of EPA's estimates 
of the ADF collection rates for the fluid collection technologies.
2. ADF-Contaminated Wastewater Treatment Technologies
    In the proposed rule, EPA identified four technologies for treating 
ADF-contaminated wastewater: AFB, Ultrafiltration/Reverse Osmosis, 
Mechanical Vapor Recompression and Distillation, and Aerated Pond. The 
Agency selected AFB for further consideration and rejected the other 
technologies. See 74 FR 44687 and the TDD.
    An AFB treatment system uses a vertical, cylindrical tank in which 
the ADF-contaminated stormwater is pumped upwards through a bed of 
granular activated carbon at a velocity sufficient to fluidize, or 
suspend, the media. A thin film of microorganisms grows on and coats 
each granular activated carbon particle, providing a vast surface area 
for biological growth. These microorganisms provide treatment of the 
ADF-contaminated stormwater. Byproducts from the AFB treatment system 
include methane, CO2, and new biomass (animal material, 
bacteria). The AFB treatment system includes storage as an initial step 
to equalize flows and pollutant concentrations that feed into the 
biological treatment unit.
    Treating wastes using an anaerobic biological system as compared to 
an aerobic system offers several advantages. The anaerobic system 
requires much less energy since aeration is not required and the 
anaerobic system produces less than 10 percent of the sludge of an 
aerobic process. In addition, because the biological process is 
contained in a sealed reactor, odors are eliminated. Based on EPA 
sampling results, the AFB treatment system successfully removes over 98 
percent of BOD5, over 97 percent of COD, and over 99 percent 
of propylene glycol from deicing wastestreams. This treatment reduces 
the BOD5 and COD loads discharged to receiving waters by 
over 98 and 97 percent, respectively. Two airports in the United States 
use the AFB technology: Albany International Airport in Albany, New 
York, and Akron-Canton Regional Airport, in Akron, Ohio. Additionally, 
Portland International Airport in Oregon recently installed an AFB 
system and T.F. Green Airport in Providence, Rhode Island is planning 
the installation of this technology.
 3. Pollution Prevention Technologies
    EPA has identified several technologies currently in use at 
airports across the United States that may reduce ADF usage. The 
following section describes the major P2 approaches EPA identified 
during this rulemaking. EPA notes that it did not identify these ADF P2 
approaches as a technology basis for BAT or NSPS in today's final rule 
due to a lack of available quantitative data on the actual pollutant 
reductions that these technologies may achieve and, moreover, because 
of a lack of data correlating minimized ADF application with safe 
deicing practices. However, EPA is aware that many airports use these 
technologies successfully and EPA encourages additional use. 
Furthermore, EPA notes that the collection technologies evaluated for 
today's rule are only capable of collecting a portion of the applied 
ADF. Therefore, to the extent that P2 technologies are proven to be 
effective, they have the ability to considerably reduce or eliminate 
ADF discharges. The ability to reduce the amount of applied deicing 
chemicals will not only have a positive environmental effect, but may 
also be cost-effective, as the decreases in costs of purchased deicing 
chemicals may offset the cost of the technology itself.
    EPA applauds all efforts to develop deicing chemicals and 
approaches that reduce or eliminate pollutant discharges. In order to 
ensure that this rule doesn't prevent such approaches as they become 
proven, feasible, and available, today's final rule includes a 
provision to apply a P2 credit against the standard ADF collection

[[Page 29175]]

requirement. See Section X.C., ``Compliance with the NSPS 
Requirement,'' in this preamble.
    In addition EPA notes that in discussions with the major airline 
and airport industry associations, ATA and ACI-NA, they stressed their 
commitment to pollution prevention approaches to reduce aircraft 
deicing discharges, while ensuring safety at all times, and the great 
strides they had made on pollution prevention approaches in addition to 
employing ADF collection technologies (see DCN AD01333). As a follow-up 
to these conversations, industry associations submitted a description 
of a voluntary pollution reduction program designed to further spur the 
industry towards safely reducing ADF discharges to the environment. 
Under the program, these associations intend to work together to:
     Conduct outreach and facilitate information exchange on 
the program and available pollution reduction technologies;
     Encourage the development, testing, and commercially 
appropriate deployment of pollution reduction technologies;
     Provide information characterizing the qualitative and 
quantitative performance and environmental benefits of appropriate 
pollution reduction technologies;
     Develop a quantitative goal for environmental benefits to 
be achieved through this program;
     Inventory pollution reduction technologies adopted during 
this program;
     Develop a comparison of the environmental benefits of 
pollution reduction technologies adopted during the program with the 
quantitative goal; and
     Report the results of the above components to EPA.

EPA supports this pollution prevention program and believes it has the 
potential to significantly reduce aircraft deicing discharges in a safe 
manner. See DCN AD01334 for more details on industry's pollution 
prevention program.
a. Infrared (IR) Deicing Systems
    A few U.S. airports have used IR heating systems for several years 
and these systems have been demonstrated to deice aircraft effectively. 
One type of IR system consists of an open-ended hangar-type structure 
with IR generators mounted inside, suspended from the ceiling. The IR 
equipment is designed to use specific wavelengths that heat ice and 
snow, and minimize heating of aircraft components. The IR energy level 
and wavelength may be adjusted to suit the type of aircraft. Although 
the system can deice an aircraft, it cannot provide aircraft with anti-
icing protection. Consequently, when the ambient temperature is below 
freezing, anti-icing fluid is typically applied to the aircraft after 
it leaves the hangar. In addition, a small amount of deicing fluid may 
be required for deicing areas of the aircraft not reached by the IR 
radiation, such as the flap tracks and elevators. The system, 
therefore, does not completely replace glycol-based fluids, but may 
greatly reduce the volume required.
    Vendors claim use of an IR system reduces the amount of Type I ADF 
required by up to 90 percent. John F. Kennedy International Airport, in 
New York, uses an IR system for a small percentage of its flights.
b. Forced Air/Hot Air Deicing Systems
    Forced air/hot air deicing systems are currently in operation at a 
few U.S. airports. These systems use forced air to blow snow and ice 
from aircraft surfaces. Some systems allow deicing fluids to be added 
to the forced air stream at different flow settings (e.g., 9 and 20 
gallons/minute), while other systems require separate application of 
deicing fluid. Several vendors are currently developing self-contained, 
truck-mounted versions of these forced-air systems, and most systems 
can be retrofitted onto existing deicing trucks.
    The double gantry forced-air spray system is a similar method to 
truck-mounted forced-air systems. The gantries support a set of high- 
and low-pressure nozzles, which blast the aircraft surfaces with heated 
air at a pressure of 40 to 500 pounds per square inch. When weather 
conditions are severe, a small volume of water and glycol may be added 
to the air stream to remove dense coverings of snow and ice. Airfield 
use of the gantry system has been limited, perhaps because it is a 
permanently mounted system that has been known to cause delays in 
aircraft departures.
c. Product Substitution
    Another solution to environmental problems associated with deicing 
chemicals is to replace chemical deicers with more environment-friendly 
products. In the ADF products category, initially the predominant 
deicers were based on ethylene glycol, whereas in recent years, 
propylene glycol-based deicers, which are less toxic to mammals, have 
become more widely used. Chemical manufacturers, the aviation industry, 
and the U.S. Air Force are continuing to explore development of deicers 
that could generate lower levels of pollutants compared to the glycol-
based products.
4. Airfield Pavement Deicing Control Technologies
    EPA identified product substitution as an available control 
technology for airfield pavement deicing chemicals. The Agency did not 
identify an available economically achievable technology to collect and 
treat wastewater containing pavement deicing pollutants.
    Several types of products, such as potassium acetate, sodium 
formate, and sodium acetate, are available as alternatives to pavement 
deicers containing urea. The results from EPA's airport questionnaire 
reported that 83 percent of primary airports use airfield pavement 
deicers that do not contain urea. The most widely used substitute 
product, potassium acetate, accounts for 63 percent (by weight) of the 
annual airfield pavement deicer usage in the United States.

E. Regulated Pollutants

    EPA identified 31 pollutants of concern that stem directly from 
airport deicing operations. For today's final rule, EPA identified COD 
as a pollutant of concern to be controlled for discharges of collected 
ADF contaminated stormwater and urea and ammonia as pollutants of 
concern to be controlled in discharges of airfield deicing contaminated 
stormwater. See Section 6 of the TDD for a full discussion of 
pollutants of concern and for EPA's rationale for selecting regulated 
pollutants.

V. Final Regulation

A. BPT and BCT

    EPA considered whether, in this rule, it was necessary to establish 
BPT limits, given that pavement deicers will be controlled at the BAT 
level, which is no less stringent than the BPT limit. Because the same 
wastestream that would be controlled by BPT is also controlled by BAT, 
it is not necessary for EPA to promulgate BPT effluent limitations 
guidelines for the Airport Deicing Category, given that the BAT 
collection and treatment requirements on that wastestream would be at 
least as stringent as BPT requirements. Similarly, EPA is not 
establishing BCT limitations for this industry because the same 
wastestream that would be controlled by BCT is being controlled by BAT.

[[Page 29176]]

B. BAT

1. Airfield Deicing
a. Applicability/Scope of Airfield Deicing Discharge Requirements
    EPA did not receive significant comments regarding the scope of the 
requirements for controlling airfield deicing discharges. EPA has 
retained the scope as described in the proposal: primary airports with 
departures of 1,000 or more non-propeller aircraft departures.
b. Candidate BAT Airfield Deicing Technologies: Product Substitution of 
Pavement Deicers Containing Urea
    In general, airports discharge airfield pavement deicing chemicals 
without treatment, due to the difficulty and expense of collecting and 
treating the large volumes of contaminated stormwater generated on 
paved airfield surfaces. EPA is not aware of an available means to 
control these pollutants through collection and use of a conventional, 
end-of-pipe treatment system. It is possible, however, to reduce or 
eliminate certain pollutants by modifying deicing practices, such as 
using alternative chemical deicing products. In particular, EPA has 
identified ammonia and COD from airfield deicing as pollutants of 
concern, and both of these pollutants are a byproduct of pavement 
deicers containing urea. Accordingly, to address discharges of ammonia 
from airfield pavement, EPA identified one candidate for best available 
technology, namely, product substitution, or discontinuing the use of 
pavement deicers containing urea and using alternative pavement deicers 
instead. EPA found that the use of deicers without urea is the best 
available technology for reducing discharges of ammonia from pavement 
deicing, because it is safe, technologically feasible, and available 
across the industry. The technology does not produce discharges of 
ammonia as produced by deicers containing urea. Currently, only about 
10 percent of chemical pavement deicers applied nationwide contain 
urea. The most widely used pavement deicer is potassium acetate, which 
represents 63 percent of all chemical pavement deicers applied 
nationwide.
2. Aircraft Deicing
    For today's final rule, based on comments to the proposed rule, EPA 
revised the requirements related to the collection and discharge of 
ADF.
a. Applicability/Scope of Aircraft Deicing Discharge Requirements
    Commenters raised multiple concerns with EPA's proposed approach of 
using departures as a proxy for ADF use. First, commenters explained 
that an airport in the very southern portion of the United States could 
have significant departures but use little ADF. Second, commenters 
requested that EPA consider a de minimis cut-off to account for 
defrosting (i.e. ADF application in the absence of active 
precipitation). Under the proposal, defrosting would be counted towards 
the volume of ADF required to be collected, yet commenters claim that 
it evaporates and is unable to be collected. Finally, airports with low 
overall ADF usage also requested EPA consider a de minimis cut-off. 
They cited concerns that the costs of the collection and treatment for 
ADF at these airports are disproportionally high in relation to the 
amount of pollutants generated. For example, one commenter, a non-hub 
primary airport, explained that it typically receives little snow and 
conducts occasional defrosting of aircraft, and generates no ADF-
contaminated water, yet it would effectively be required to purchase a 
GCV if subject to the 20 percent collection requirement.
    EPA reviewed its data with respect to each of these comments. On 
further review of the data and comments, EPA agrees that ADF usage in 
general is not closely related solely to the number of departures at 
airports. As such, in considering options for today's final rule, EPA 
did not base ADF collection and associated discharge options on the 
number of departures. Instead, EPA considered options based directly on 
estimates of the overall volume of ADF use, which EPA indicated in the 
proposal was another possible threshold criterion for the rule (74 FR 
44714).
    EPA reevaluated ADF usage data for all existing airports. This 
evaluation showed that airports with less than 30,000 gallons of 
available ADF may conduct a significant amount of defrosting, rather 
than deicing. See DCN AD01335. Defrosting results in limited amounts of 
ADF available for collection--effectively rendering collection 
technologies infeasible. Additionally, EPA found that the costs and 
economic impacts of ADF collection and treatment technologies for 
airports using less than 60,000 gallons of normalized ADF annually were 
disproportionally higher than those with greater ADF use.\1\ See DCN 
AD01338 for additional details. As a result, in today's final rule, EPA 
evaluated options based on a cut-off of greater than or equal to 60,000 
gallons of normalized ADF per deicing season. Under this option, 
airports at or above this threshold would be subject to these 
requirements, but airports below this threshold would have the 
technology-based limitations for aircraft deicing discharges in their 
NPDES permits determined by the permitting authority on a case-by-case, 
best professional judgment basis.
---------------------------------------------------------------------------

    \1\ EPA notes, however, that many existing airports with 
annualized normalized ADF usage below 60,000 currently employ 
deicing collection technologies including centralized deicing pads.
---------------------------------------------------------------------------

b. Exempted Wastewater (Those Associated With Deicing for Safe Taxiing)
    EPA also altered its consideration of exempting wastewaters 
associated with deicing for safe taxiing. The proposed rule included a 
provision that would have exempted ADF-contaminated wastewater 
associated with deicing for safe taxiing from the proposed collection 
and treatment requirement. EPA proposed to limit deicing for safe 
taxiing to 25 gallons of ADF, based on an allowance at Denver 
International Airport (DIA), as the maximum amount that could be 
applied to an aircraft for the purposes of safe taxiing. This 
definition was intended to apply to airports with CDPs, and to prohibit 
conducting complete deicing of an aircraft at a terminal area without a 
collection system, instead of using the deicing pad. However, 
commenters expressed concern that climatic conditions at airports in 
the Midwest, Alaska, and on the East Coast differ greatly from those at 
DIA: commenters claimed that any ``deicing for safe taxiing'' 
allowances established at DIA cannot form a reasonable basis for 
application to airports in other regions of the country. In addition, 
cargo aircraft sometimes experience layovers in excess of 24 hours, 
potentially increasing the amount of snow or ice that must be removed 
to achieve compliance with FAA regulations. EPA agrees with the 
commenters and therefore the final rule does not limit the amount of 
ADF sprayed for the purposes of safe taxiing, nor does EPA require an 
airport to collect and treat ADF applied for safe taxiing purposes.
c. Candidate BAT Technology Bases for Collection and Discharge 
Requirements
    EPA is not aware of an available and economically achievable 
technology that is capable of capturing 100 percent of the sprayed ADF. 
Section IV.D.1 details the available technologies for

[[Page 29177]]

collecting ADF, which include GCVs, plug and pump equipment, and CDPs. 
EPA estimates that these technologies collect 20 percent, 40 percent, 
and 60 percent of available ADF, respectively.
    Commenters raised multiple concerns about CDPs, the technology that 
EPA proposed to identify as the basis for the 60 percent collection 
requirement. First, commenters raised concerns that CDPs are not 
feasible at all locations because of lack of space. Some of these 
commenters provided detailed engineering plans and analyses 
demonstrating their specific space constraints. Second, commenters 
raised concerns that using CDPs for all deicing operations would cause 
traffic and/or safety problems. Third, commenters asserted that the use 
of CDPs would lead to flight delays and that EPA had not included costs 
associated with such delays in its analyses. In addition, FAA indicated 
that it had similar concerns to those raised by industry commenters, 
regarding the identification of centralized deicing facilities as BAT. 
FAA indicated that the 60 percent collection requirement based on the 
exclusive use of CDPs might adversely affect the operational efficiency 
of some of the nation's largest and busiest airports. Further, FAA was 
concerned that for those land-constrained airports, construction and 
operation of CDPs for all deicing operations would not be able to meet 
FAA design standards. In explaining its concerns, FAA noted that delays 
associated with the use of CDPs would be extremely costly to the 
nation's productivity, economy, businesses, and the traveling public.
    After considering these comments and reviewing the information in 
its record, EPA is not establishing a 60 percent ADF collection 
requirement based on CDPs for BAT. First, in response to FAA's concerns 
about the exclusive use of deicing pads for aircraft deicing, EPA 
contacted a number of large hub airports that currently use CDPs. EPA 
found the current percentage of flights for which these airports use 
the CDPs ranges from 50 to 95 percent. The airports explained that 
various operational or weather-related issues may make deicing pad use 
for all flights cumbersome if not impossible, (i.e., severe system-wide 
delays), and require them to deice at the gate in some circumstances. 
EPA shares the commenters' and FAA's concerns that moving to exclusive 
use of CDPs for all deicing might lead to operational issues and 
delays. EPA, in discussions with FAA, attempted to craft regulatory 
provisions to allow an airport limited ability to bypass the use of a 
centralized pad in order to avoid these circumstances. However, limited 
data on the site-specific nature of this industry left EPA unable to 
develop regulatory provisions that would give airports the flexibility 
they need to avoid significant operational issues and delays. Second, 
based on public comments and information from FAA, EPA is concerned 
that some large airports critical to efficient air traffic operations 
in this country are space (land) constrained, and that building well-
located CDPs for all deicing operations at these airports is likely not 
feasible for that reason. At the time of the proposal, EPA estimated 
that 14 airports would be subject to the 60 percent collection 
requirement. Because the data in EPA's record indicate that many of 
these airports currently meet this requirement, EPA estimated 
approximately seven airports would likely need to install pads as a 
result of the proposed requirement. Of these seven airports, four are 
large hubs, which, over years of expansions and other improvements, 
have already built out the majority of the land available to them. EPA 
has concluded that the lack of remaining available land, coupled with 
their existing layouts, has left these airports in a position where a 
CDP conforming to FAA's Advisory Circulars on deicing pad design, 
(e.g., in a location that aircraft can travel to safely and efficiently 
to conduct deicing operations) cannot be constructed.
    Therefore, for today's final rule, EPA has not established a 60 
percent ADF collection requirement, which would have been based on 
identification of centralized deicing facilities as BAT for 100 percent 
of aircraft departures. This technology is not available at a number of 
existing airports due to land constraints, and therefore is not 
technologically feasible on a nationwide basis. For this and the other 
reasons discussed above, EPA finds that centralized deicing facilities 
should not be identified as BAT for this nationwide rulemaking. See CWA 
304(b)(2)(B)--factors relating to the assessment of BAT include ``the 
process employed, the engineering aspects of the application of various 
types of control techniques, * * * and such other factors as the 
Administrator deems appropriate.'' EPA then considered the other two 
technologies described in the proposal as a possible basis of BAT for 
aircraft deicing discharges for today's final rule: 40 percent ADF 
collection requirement based on plug and pump with GCVs and 20 percent 
ADF collection requirement based on GCVs. With either of these 
collection technologies, as was the case in the proposed rule, EPA also 
included numeric COD limitations for direct discharges of collected ADF 
based on anaerobic treatment. For a discussion of other technologies 
examined but not selected as candidates for the basis of the COD 
limitations, see Section VII.E.2 in the proposed rule preamble (74 FR 
44692) and Section 7 of the TDD.
3. Options Considered for Today's Final Rule
    Using the technology bases identified above for airfield and 
aircraft deicing discharges, EPA developed three primary options for 
today's final rule. All three of these options have the same airfield 
pavement deicing discharge requirements based on product substitution 
of deicers that do not contain urea, but would vary the approach to 
control aircraft deicing discharges:
     Option 1: 40 percent ADF collection requirement for large 
and medium ADF users (based on plug and pump with GCVs); numeric COD 
limitations for direct discharges of collected ADF (based on anaerobic 
treatment).
     Option 2: 40 percent ADF collection requirement for the 
large ADF users (based on plug and pump with GCVs) and 20 percent ADF 
collection requirement for medium ADF users (based on GCVs); numeric 
COD limitations for direct discharges of collected ADF (based on 
anaerobic treatment).
     Option 3: Site-Specific Aircraft Deicing Discharge 
Controls: Do not establish effluent limitation guidelines in the final 
rule for aircraft deicing discharges, but instead, leave the 
determination of BAT requirements for each airport to the discretion of 
the permit writer on a case-by-case, ``best professional judgment'' 
basis based on site-specific conditions.
    Under the first option, in addition to the airfield pavement 
requirements, all airports that use greater than or equal to 60,000 
gallons of normalized ADF annually would be required to collect 40 
percent of available ADF based on plug and pump with GCV technologies. 
In the proposed rule, EPA considered but did not identify this as its 
lead option because it found its costs to be comparable to those of 
CDPs, while CDPs achieved greater ADF collection. In the proposal, EPA 
therefore identified CDPs as BAT. EPA subsequently determined that CDPs 
are not achievable nationwide for existing airports and dropped it as 
an option for consideration in the final rule. This left the plug and 
pump with GCV option as the technology, among those that remained under 
consideration for today's rule, that would achieve the greatest 
collection of ADF.

[[Page 29178]]

    Under the second option, in addition to the airfield pavement 
requirements, all airports that use greater than or equal to 60,000 
gallons of normalized ADF annually but less than 460,000 gallons of 
normalized ADF (``medium ADF users,'' estimated to be 42 airports) 
would be required to collect 20 percent of available ADF based on GCVs, 
and airports that use more than 460,000 gallons of normalized ADF 
(``large ADF users,'' estimated to be 14 airports) would be required to 
collect 40 percent of available ADF based on the use of plug and pump 
with GCV technology.
    Under both Options 1 and 2, the requirement to meet numeric 
effluent limits for COD for the collected ADF would need to be met 
prior to commingling with other wastestreams prior to discharge. For a 
discussion of other technologies examined but not selected as 
candidates for the basis of the nationwide COD limitations, see Section 
VII.E.2 in the proposed rule preamble (74 FR 44692) and Section 7 of 
the TDD.
    Under the third option, EPA would establish national deicing 
discharge controls for airfield pavement deicing only. BAT limitations 
for aircraft deicing discharge would continue to be established by the 
permitting authority on a case-by-case basis.
    Table V-1 provides the estimated national cost of each option along 
with the estimated national removals.

                  Table V-1--Cost of Final Rule Options
------------------------------------------------------------------------
                                               Total           Total
                                             pollutant      annualized
                 Option                      removals       costs (2006
                                           (million lb)      $million)
------------------------------------------------------------------------
1.......................................            33.0           $78.4
2.......................................            30.2            49.4
3.......................................            16.4             3.5
------------------------------------------------------------------------

4. BAT Options Selection
    EPA is selecting Option 3 as best available technology for 
controlling airport deicing discharges. EPA has determined the best 
available technology for controlling airfield pavement discharges is 
product substitution. The record shows that products without urea are 
widely available in the industry, and in fact are already in use at a 
majority of airports across the country.
    With respect to aircraft deicing discharge controls, EPA's record 
demonstrates that ADF collection and associated treatment technologies 
are technically feasible for many airports. Data supplied from the 
industry through EPA's nationally representative survey of airports 
indicates that dozens of airports currently use GCVs and plug and pump 
collection systems, in addition to a myriad of P2 technologies and 
practices, ranging from alternative means of applying ADF such as 
forced air nozzles, to alternate deicing technologies such as IR 
deicing. In addition, many airports also employ a variety of treatment 
technologies to treat collected ADF prior to discharge. Thus, EPA 
concludes this industry has several technology options potentially 
available for mitigating the pollutants associated with aircraft 
deicing activities. See the TDD for more information about collection 
and P2 technologies.
    However, EPA has determined that none of the ADF collection 
technologies considered for today's final rule represents the best 
available technology for the entire category. Rather, EPA concludes 
that best available technology determinations should continue to be 
made on a site-specific basis because such determinations appropriately 
consider localized operational constraints (e.g., traffic patterns), 
land availability, safety considerations, and potential impacts to 
flight schedules. Based on the information in its record, EPA cannot 
identify with precision the extent to which such limitations may 
preclude, at any particular airport, the use of the technologies that 
it considered for BAT control of aircraft deicing discharges for 
today's final rule. However, the record demonstrates that such 
limitations exist and are not isolated or insignificant. In light of 
this finding, EPA decided that it should not establish national ADF 
collection (and associated discharge requirements) based on any one or 
more of the ADF collection technologies as the presumptive BAT-level 
control technology. Rather, site-specific proceedings are the 
appropriate forum for weighing all relevant considerations in 
establishing aircraft deicing discharge controls.
    More specifically, commenters provided by airport and airline 
industry on the proposed regulation raised concerns about the impacts 
that ADF collection technologies may have on safety and operations at 
airports across the country. They also commented on the lack of 
available space at many land constrained airports for ADF collection 
and treatment technologies. EPA reviewed the information submitted in 
comments, subsequent information provided by industry, and information 
obtained from site visits to thoroughly evaluate these concerns. After 
reviewing this information, EPA agrees with commenters that while many 
airports likely have the ability to implement some form of collection 
or P2 technologies in order to mitigate pollutant discharges associated 
with aircraft deicing, space, safety and operational considerations may 
limit the selection of the specific technologies and the extent to 
which they can be implemented at any particular airport. This finding 
became particularly apparent after reviewing questionnaire responses 
for some of the airports at which EPA also conducted site visits. EPA 
found that its ``model facility'' approach was not a suitable 
substitute for a detailed analysis of the site constraints at each 
airport. For example, a permit authority may need to evaluate existing 
traffic patterns at an airport, not only of the aircraft, but also of 
the service vehicles to determine if additional collection vehicles 
would lead to unacceptable safety concerns. With respect to land 
constraints, in the absence of detailed airport schematics, or without 
conducting a detailed site visit at each airport, EPA cannot determine 
if adequate space exists to incorporate the specific treatment and 
collection technologies evaluated as the basis for today's final rule.
    Additionally, industry and FAA, in particular, have expressed 
overarching concerns about possible delays and economic impact that 
could result from the use of plug and pump and GCVs, both at specific 
airports and nationwide. EPA agrees that delays must be a factor in 
considering today's possible requirements and recognizes that such 
delays fundamentally affect U.S and

[[Page 29179]]

international business and recreational interests.
    Airplane deicing activities, by their very nature, occur during 
freezing precipitation events. For some airports, even small amounts of 
precipitation can lead to delayed aircraft departures--even without 
deicing activity and/or ADF collection and treatment. As such, when 
delays occur at an airport during inclement weather, it is difficult to 
determine whether the delays are associated with the weather, the ADF 
collection and treatment technologies, or both. Further, even small 
delays at certain hub airports have a ripple effect that can affect the 
entire national air traffic schedule.
    Some airports have identified procedures to mitigate or prevent 
delays associated with aircraft deicing discharge controls. These 
airports can handle large amounts of precipitation and/or operate ADF 
collection and treatment technologies with little or no delay, but 
these approaches may not be applicable nationwide. Further, the extent 
of delays deemed acceptable is likely to vary by airport. As was the 
case with land constraints, the confounding factors that need to be 
considered to evaluate possible delays that may be associated with the 
technology bases do not lend themselves to a national determination 
using a model facility approach. Further, EPA does not have detailed 
site-specific information to evaluate delays on an airport-by-airport 
basis.
    While the facts stated above do not necessarily preclude the 
ability of an airport to collect and treat spent ADF, they do 
illustrate why EPA did not select any of the technologies considered as 
BAT for today's final rule, and why a site-specific BAT determination 
for ADF collection and treatment requirements is the proper approach 
for today's final rule.
    Therefore, for the reasons identified above, EPA determined Option 
3 is the only technologically feasible and available option considered 
for today's final BAT requirements. Option 3 would remove 4.4 million 
pounds of ammonia and 12 million pounds of COD, with a projected annual 
cost of $3.5 million. The costs of Option 3 are reasonable in terms of 
the pollutant reductions achieved ($0.21/lb). Further, as discussed in 
more detail in Section VII, EPA finds Option 3 is economically 
achievable. In addition, EPA examined the non-water quality impacts 
anticipated from compliance with Option 3 requirements and found none 
or only very minor impacts in comparison to typical industry energy 
use, emissions generation and sludge generation. See Section IX, ``Non-
Water Quality Environmental Impacts.'' Therefore, based on all the 
factors above, EPA is identifying Option 3 as BAT and has based today's 
final rule on the Option 3 BAT requirements.

C. NSPS

1. New Source Definition
    In the proposed rule, ``new source'' would have included both new 
airports and new runways constructed at existing airports. Commenters 
objected to the inclusion of new runways at existing airports in the 
new source definition. They noted that a new runway is not a source of 
pollutant discharges from aircraft deicing activity and that a new 
runway is not ``substantially independent'' of an existing source as 
required under the regulatory definition of ``new source.'' See 40 CFR 
122.2 and 40 CFR 122.29(b)(1). Commenters acknowledge that a new runway 
may lead to additional discharges associated with airfield deicing, but 
noted that the requirements for airfield deicing discharges are the 
same for new and existing discharges. With respect to the requirements 
associated with discharges from aircraft deicing, they explained that a 
new runway is not a source of new discharges because aircraft deicing 
is performed at locations away from airport runways. Moreover, they 
explained that unlike a plant or factory from which a new source of 
discharge associated with a new process, production line, or piece of 
equipment can be clearly distinguished as a new source of discharge 
associated with an existing source, a new runway is not operated 
independently from other runways at an airport. Rather, a new runway 
and associated deicing operations are part of a wholly integrated 
airport system. After carefully considering these comments, EPA agrees 
that new runways should not be treated as new sources because new 
runways are generally too integral to the operations of an existing 
airport to be considered ``substantially independent'' of the existing 
airport.
2. NSPS Applicability
    For today's final rule, the applicability of the NSPS provisions is 
effectively the same as that in the proposed rule. New primary airports 
with greater than or equal to 1,000 annual departures by non-propeller-
driven aircraft are subject to the provisions of Sec.  449.11(a) and 
(b).
    In the proposed rule, Sec.  449.1 defined the applicability of the 
overall category as covering primary airports with at least 1,000 
annual scheduled commercial air carrier jet departures. In the final 
rule, the language in Sec.  449.1 has been simplified to just ``primary 
airports,'' and the 1,000-departure threshold criteria are included in 
the provisions at Sec. Sec.  449.10 and 449.11. This arrangement 
results in the same requirements for new source airports that EPA had 
intended in the proposed rule, with a clarification: A new primary 
airport with initially less than 1,000 departures is a new source, but 
not subject to the requirements of Sec.  449.11. If the airport 
eventually exceeds 1,000 departures, then the provisions of Sec.  
449.11 apply.
    The proposed rule defined the threshold for the new source ADF 
collection and associated discharge requirements as any new source with 
10,000 or more annual departures. As was the case with existing 
sources, commenters explained that the number of departures is not a 
good analog for the amount of ADF usage, citing, for example, airports 
in the South that may have significant numbers of departures but 
typically need to deice their aircraft only once a year. After 
reviewing these comments and the information in its record, EPA agrees 
that departures alone are not the most appropriate indicator of ADF 
usage.
    Therefore, for today's final rule, in addition to the proposed 
departure threshold, EPA is adding a geographical component to define 
which new sources are subject to the ADF collection and discharge 
requirements. As explained in Section V.B, EPA determined that, on a 
national basis, ADF collection may be infeasible at airports with 
annual ADF usage below 30,000 gallons. ADF usage below 30,000 gallons 
may reflect significant volumes of defrosting activity, which does not 
leave ADF available for collection.
    Unlike existing sources, however, new sources do not have past ADF 
usage data available for establishing a threshold for being subject to 
ADF collection requirements. Therefore, in combination with the 
proposed departure threshold, in today's final rule, the Agency is 
incorporating a geographically based component that is closely aligned 
with a 30,000 gallon annual ADF usage threshold. In addition to 
applying the proposed departure threshold, EPA is making NSPS 
collection requirements for ADF applicable based on whether the airport 
is located within specific colder climatic zones (called a ``heating 
degree day [HDD] category'') as documented by the National Oceanic and 
Atmospheric Administration (NOAA). For airports within the scope of 
today's rule,

[[Page 29180]]

location in a warmer climate zone is generally associated with the use 
of smaller volumes of ADF.
    HDD means the number of degrees per day the daily average 
temperature is below 65 degrees Fahrenheit. The daily average 
temperature is the mean of the maximum and minimum temperature for a 
24-hour period. The annual HDD value is derived by summing the daily 
HDDs over a calendar year period. HDDs are computed using data from the 
U.S. National 1961-1990 Climate Normals, published by the National 
Climatic Data Center of NOAA. The original data are in whole degrees 
Fahrenheit. HDD values range from 0 to more than 9,000. NOAA presents 
this information in 1,000-HDD increment groups. EPA used the NOAA 
information to create HDD groups. These groups range from A to I, with 
group A being the lowest HDD values (less than 1,000 HDD) and group I 
being the highest (greater than 9,000 HDD).
    EPA identified the corresponding HDD groups for existing airports 
and then compared the HDD group to ADF usage at each airport. In 
general, airports with greater than 10,000 departures in HDD groups A 
through C (3,000 HDD or less) used less than 30,000 gallons of ADF 
while those in HDD groups D through I used more than 30,000 gallons of 
ADF. As a result, these HDD groups in combination with the departure 
cut-off provide a dividing line nationwide that corresponds well with 
the ADF usage dividing line that EPA determined makes ADF collection 
feasible. EPA concludes that this approach best captures those new 
airports that will conduct more frequent deicing operations, as opposed 
to defrosting operations, and excludes those new airports that will 
likely conduct infrequent deicing. See DCN AD01267 for EPA's analysis 
of HDD categories.
    In addition, EPA received comments questioning the feasibility of 
ADF collection technologies for airports located in Alaska. These 
commenters stated that deicing wastewater generation at Alaskan 
airports is substantially different from airports in the lower 48 
states. First, often airports in Alaska will suspend air traffic as 
opposed to conducting deicing operations. Second, commenters stated 
that long periods of below freezing temperatures result in runoff 
characteristics that are substantially different from those is the 
lower 48 states and, as such, deicing materials are not available for 
collection (due to lack of runoff) making collection technologies 
infeasible. The data provided in the survey responses from Alaskan 
airports show that airports in this climactic zone use widely varying 
amounts of ADF per departure. Based on this data, EPA is unable to 
conclude that Alaskan airports conduct significant deicing, rather than 
defrosting, and as such, today's final new source ADF collection and 
discharge requirements do not apply to new airports in Alaska.
    For the airports that are excluded from the NSPS requirements in 
today's final rule, permit authorities would determine an applicable 
new source performance standard on a case-by-case, best professional 
judgment basis.
3. NSPS Option Selection
    For today's final rule, EPA evaluated ``best available demonstrated 
control technologies'' for purposes of setting NSPS under CWA section 
306. Section 306 directs EPA to promulgate NSPS ``for the control of 
the discharge of pollutants which reflects the greatest degree of 
effluent reduction which the Administrator determines to be achievable 
through application of the BADCT, processes, operating methods, or 
other alternatives, including, where practicable, a standard permitting 
no discharge of pollutants.'' Congress envisioned that new treatment 
systems could meet tighter controls than existing sources because of 
the opportunity to incorporate the most efficient processes and 
treatment systems into the facility design. As a result, NSPS should 
represent the most stringent controls attainable through the 
application of the BADCT for all pollutants (that is, conventional, 
nonconventional, and priority pollutants).
    After careful consideration of the information in its record, EPA 
is today promulgating the same NSPS requirements for both airfield 
pavement deicing discharges and airplane deicing discharges as it 
proposed; however, the applicability of the NSPS requirements has 
changed. Clearly, product substitution, the technology basis for the 
airfield deicing discharge requirements promulgated today for existing 
airports, is fully applicable to new airports. EPA determined that, 
just as with existing sources, all new sources would be capable of 
using airfield deicing products without urea. Furthermore, product 
substitution represents the greatest level of reduction in ammonia 
among the available technologies considered. Accordingly, EPA 
identifies product substitution of non-urea-containing airfield deicers 
as the best demonstrated available control technology for all new 
sources. As with BAT, there would be two alternatives for meeting this 
effluent limitation: either a certification requirement or a numeric 
limit on ammonia for all direct discharges of the stormwater from the 
airfields.
    With respect to aircraft deicing discharge controls, EPA, in 
consultation with FAA, finds that its determination about safety, 
space, and operational constraints that may be present at existing 
airports for all the collection and treatment technologies discussed in 
today's final rule (CDPs, plug and pump with GCVs, GCVs alone and AFB 
treatment) would not similarly apply to new airports. This finding is 
supported because new airports can be designed to minimize space and 
logistical constraints that have been identified for retrofits at 
existing airports (see DCN AD01285). Further, among the ADF collection 
technologies that EPA considered, CDPs collect the greatest level of 
available ADF and are available to new sources in this category. With 
respect to new airports, the use of CDPs does not present the space/
land, safety, or operational issues that would be raised in connection 
with the use of deicing pads at existing sources. In addition, CDPs in 
combination with AFBs for treatment of collected ADF are not so costly 
in comparison to the cost of a new airport \2\ that they would be 
considered a ``barrier to entry.'' Moreover, according to FAA, when 
designed properly, CDPs often improve traffic flow and reduce delays 
associated with aircraft deicing. When designing a new airport, the 
local operating agency plans the site for all needed facilities, such 
as runways, taxiways, terminal(s) and other components needed to comply 
with safety and environmental requirements, which includes deicing 
facilities. See DCN AD01285. The new airport must be designed and built 
on enough land, in total, to accommodate a deicing pad and AFB 
treatment system (or other technology that meets the 60 percent 
collection requirement and the discharge requirements), to be installed 
either during initial construction or at a later time when it exceeds 
the 10,000 departure threshold. The airport sponsor would design its 
layout of runway(s), taxiways, location of terminal(s) and other 
buildings with sufficient space so that deicing facilities can be 
installed later without the need to acquire additional land. Therefore, 
EPA is promulgating the same NSPS requirements for airfield pavement 
deicing discharges as for existing sources, but in contrast to existing 
sources, EPA is promulgating NSPS requirements for ADF collection and 
discharge requirements at new airports

[[Page 29181]]

based on the use of CDPs and anaerobic biological treatment. Meeting 
this combination of new source requirements for both airfield pavement 
deicing discharges and aircraft deicing discharges would not be an 
economic barrier to entry for new airports, as the cost of new airport 
construction, even at small airports, is significantly greater than the 
costs associated with product substitution and collection and/or 
treatment of spent deicing fluids. See Section VII.E.
---------------------------------------------------------------------------

    \2\ Includes total costs for controls both for airfield pavement 
and aircraft deicing discharges.
---------------------------------------------------------------------------

    As a point of clarification, EPA is promulgating the same numeric 
COD limitations for collected ADF that is discharged directly for new 
sources as was proposed. The technology basis, AFB system, is available 
to new airports. In addition, AFB achieves the greatest level of 
pollutant removals of those technologies considered during the 
development of this regulation, and the installation and use of this 
technology is not economically a barrier to entry for new airports.
    Additionally, although EPA did not identify pollution prevention 
approaches and technologies as a basis for NSPS, these technologies may 
be effective at reducing available ADF. Moreover, future pollution 
prevention technologies may become available to aid in meeting the NSPS 
requirements. As such, the final rule includes a provision that allows 
dischargers to request a credit to be applied to the NSPS ADF 
requirement. See Section X.C.3 for additional information and examples.

D. PSES and PSNS

    EPA is not promulgating PSES and PSNS for the Airport Deicing 
Category. Although some airports in the United States discharge ADF-
contaminated stormwater to POTWs, EPA received no comments or other 
information indicating that POTWs currently have problems of pollutant 
pass-through, interference, or sludge contamination stemming from these 
discharges that would necessitate the promulgation of national 
categorical pretreatment standards.
    Like the biological treatment system that forms the basis for 
today's COD new source performance standard, POTWs typically employ 
biological treatment systems and are similarly designed to remove 
organic pollutants that contribute to COD and/or BOD5. In 
general, POTWs have the capability to achieve comparable removals to 
the NSPS technology basis. However, some airports and POTWs may need to 
make operational adjustments in order to process the wastewater 
effectively while avoiding POTW upset. EPA received a comment about the 
Downriver Treatment Facility in Detroit, Michigan, which accepts ADF 
wastewater from the Detroit Metropolitan Wayne County Airport. The 
treatment plant experienced viscous bulking due to a nutrient imbalance 
that occurred during the months that ADF was accepted. The issue was 
resolved by removing phosphorus at a later stage in the treatment plant 
system, rather than from the raw wastewater. The airport also made 
significant changes in order to segregate the deicing wastewater, 
collect and recycle the most concentrated ADF wastewater, and control 
the amount and concentration of wastewater discharged to the POTW.
    EPA is aware that high concentration or ``slug'' discharges of 
deicing wastewater can create POTW upset. The national pretreatment 
program regulations specifically prohibit industrial users from 
discharging high concentrations of oxygen-demanding pollutants to POTWs 
if they cause interference to the POTW. See 40 CFR 403.5(b)(4). Under 
40 CFR 403.5(c), control authorities may set and enforce ``local 
limits'' for airport discharges to POTWs to implement the prohibitions 
listed in Sec.  403.5(b)(4). This provision ensures that any potential 
limits would protect against POTW interference by the oxygen-demanding 
pollutants in airport deicing discharges. See ``Local Limits 
Development Guidance,'' document no. EPA 833-R-04-002A, July 2004, 
available on EPA's Web site at http://cfpub.epa.gov/npdes/pretreatment/pstandards.cfm. As a result, many airports that discharge to POTWs have 
airport-specific requirements on allowable BOD5 or COD 
discharge loading per day. These limits on daily pollutant loadings are 
specific to the receiving POTW. Airports usually meet this requirement 
by storing deicing stormwater in ponds or tanks and metering the 
discharge to meet the POTW permit loading requirements.

VI. Technology Costs and Pollutant Reductions

A. Compliance Costs

1. Overview
    EPA estimated industry-wide compliance costs for the three options 
considered for today's rule. This section summarizes EPA's approach for 
estimating compliance costs, while the TDD provides detailed 
information on these estimates. All final cost estimates are expressed 
in terms of 2006 dollars and represent the cost of purchasing and 
installing equipment and control technologies, annual operating and 
maintenance costs, and associated monitoring and reporting 
requirements. In general, this approach is the same as the approach 
used in the proposal. However, some modifications were made for costing 
specific technology pieces in the costing models, including the numbers 
of GCVs per airport and the manner in which airports would store 
collected ADF containing wastewater.
    EPA estimated compliance costs associated with the three options 
considered for today's rule using data collected through survey 
responses, site visits, sampling episodes, specific airport requests, 
and information supplied by vendors. Under the options considered, 
certain airports would have limitations based on the substitution of 
non-urea-containing pavement deicers and also would be required to 
collect a percentage of their available ADF that was applied to 
aircraft and treat the collected wastewater to comply with numeric 
limitations if discharged directly. EPA estimated costs for an airport 
to install technology to comply with the options, as well as to 
annually operate and maintain equipment and perform required monitoring 
or other activities to demonstrate ongoing compliance. EPA's cost 
estimates represent the incremental costs for a facility when its 
existing practices would not lead to compliance with the option being 
evaluated.
    EPA calculated costs based on a computerized design and cost model 
developed for each of the technology options considered. EPA developed 
facility-specific costs for each of the airport industry questionnaire 
respondents (149 facilities), where each facility was treated as a 
``model'' airport. Because the questionnaire respondents represent a 
subset of the industry, EPA subsequently modeled the national 
population by adjusting the costs upward to estimate the entire 
affected airport population.
    The questionnaire responses provided EPA with information on three 
consecutive deicing seasons (2002 to 2005) for each of the model 
facilities. Some portions of EPA's costing effort reflect the airports' 
operations as reported for the three seasons. For example, estimates of 
applied deicing chemicals were taken as an average of the years for 
which the information was reported. In instances where aspects of an 
airport's operation changed over the three-year period, EPA used the 
most recent information.
    EPA first established existing conditions (i.e., baseline) for each 
model airport based on information and site plans submitted as part of 
the airport questionnaire. EPA then determined what upgrades or 
changes, if any, would

[[Page 29182]]

be required to comply with the option being considered for today's 
final rule. For example, in general, when an airport lacked a 
comparable collection system to the one used as the basis for an 
option, EPA included costs for installation/operation and maintenance 
of the option technology basis (e.g., plug and pump systems in 
conjunction with GCVs).
2. Approach for Estimating Airfield Pavement Deicing Costs
    Today's rule sets requirements for an airport to certify it uses 
non-urea-containing airfield deicers (unless it chooses to meet a 
numeric limit for ammonia). Through the airport questionnaire 
responses, EPA estimates that 198 airports will be subject to today's 
requirements. Of these 198 airports, 37 airports use deicers containing 
urea for airfield pavement deicing. As detailed in Section IV.D.4, EPA 
based its airfield pavement deicing requirement on product 
substitution. EPA calculated the cost for facilities to substitute the 
deicers containing urea with another widely available pavement deicer 
that does not produce ammonia in the wastewater. EPA chose to model the 
substitution costs on what it would cost to switch to potassium 
acetate, specifically because that product accounts for 63 percent of 
the applied chemical airfield deicer usage (by weight) in the United 
States. These incremental costs include capital costs associated with 
application equipment and storage, as appropriate, as well as the 
differential chemical costs. EPA assumed that those airports that 
currently do not use urea-containing deicers as a means of pavement 
deicing would experience no cost associated with this portion of 
today's regulation.
    Using the facility area usage data as provided in the airport 
questionnaire, and available literature on typical urea-containing 
pavement deicer application rates, EPA estimated the airfield area that 
was annually deiced at each model facility. Using the estimated model 
facility deicing area in conjunction with the estimated $2.92/1,000 
square feet cost of potassium acetate, EPA was able to calculate the 
cost per model facility to perform airfield deicing with potassium 
acetate. This cost was compared to the questionnaire-reported urea-
containing deicer costs to determine the incremental costs of switching 
chemical airfield deicers. See the TDD for additional details on 
costing for airfield deicing product substitution.
3. Approach for Developing Aircraft Deicing Costs
    Under two of the options considered for this rule, certain existing 
airports would be required to collect a percentage of their available 
ADF, and treat the collected wastewater to comply with numeric effluent 
limitations if it discharges directly. EPA estimated the costs for an 
airport to comply with collection and treatment requirements, as 
applicable, as well as perform required monitoring to demonstrate 
compliance. Of the 198 airports within the scope of the aircraft 
deicing controls considered for BAT, EPA expects that 55 airports would 
exceed the threshold for ADF use that would trigger the collection/
discharge requirement. Costing for ADF collection is not relative to 
baseline practices in all instances, as an airport's existing 
collection technology may not be incrementally upgradeable to achieve 
the required collection efficiency. As such, EPA assessed all costs to 
comply with the options based on ADF collection and treatment with the 
assumption that any airport required to make upgrades to its collection 
and/or treatment system to meet the option would be starting from a 
baseline of zero collection and treatment. Note that this assumption 
does not carry through to pollutant removals, as baseline removals are 
accounted for when assessing pollutant removals associated with today's 
options. See section VI.B for more detail on the pollutant removal 
calculations.
    EPA first established existing conditions for each model airport 
based on information and site plans submitted as part of the airport 
questionnaire. EPA then determined what upgrades, if any, would be 
required to comply with an option. As explained above, in general, when 
an airport lacked a comparable collection system to the one used as the 
basis for the option, EPA included costs for installation/
implementation of the option technology basis such as plug and pump 
systems in conjunction with GCVs and an AFB treatment system for Option 
1.
    For those airports that would be required to collect additional ADF 
and meet associated discharge requirements to comply with the option, 
EPA estimated costs for storage/equalization (and associated piping to 
transfer collected ADF to storage) as part of the costs of the 
treatment technology. The option would not require, nor is it based on, 
collecting the full volume of wastewater generated in a deicing season. 
Rather, storage is included as part of the technology basis for flow 
and/or pollutant equalization to support the AFB treatment system. 
Where EPA estimates an airport would incur capital costs associated 
with ADF collection and discharge requirements, the Agency included 
costs for above-ground storage tanks, since above-ground storage tanks 
will have less of an impact on subsurface utilities, for which EPA does 
not have site-specific information. If airports needed to install 
below-ground storage tanks for operational reasons, this would likely 
be more expensive.
    For the 15 airports that EPA anticipates would need to collect 
additional quantities of ADF-contaminated stormwater to comply with 
Option 1 or 2, EPA assumed these additional quantities would be 
discharged directly, thus requiring treatment to comply with the COD 
limitations. For example, for Option 1, this includes all airports that 
EPA estimates collect less than 40 percent of available ADF. 
Specifically, this includes those facilities that currently collect 
some portion of ADF-contaminated stormwater and subsequently discharge 
indirectly to a POTW or a centralized waste treatment (CWT) facility. 
EPA recognizes that an airport may decide to discharge to a POTW or CWT 
facility rather than directly discharge its wastewater. While this is 
likely a lower cost alternative in some cases, EPA did not assume that 
airports could discharge to a POTW or CWT, because the Agency does not 
have enough information about the capacity or willingness of a specific 
POTWs to receive these volumes of wastewater. To the extent that an 
airport selects this alternative, EPA may have over-costed the option.
    Additionally, airports may have costs associated with permit 
application requirements or demonstrating compliance with Option 1 or 
2, including assessing yearly ADF usage, determining ADF stormwater 
collection, system inspections, and COD monitoring. Monitoring 
requirements will continue to be determined by the permitting 
authority. However, for purposes of estimating monitoring costs 
associated with today's options, EPA assumed that airports that 
directly discharge collected ADF would take a 24-hour composite sample 
and analyze that for COD, and perform that analysis seven times per 
week for the duration the treated discharge occurs. EPA made a similar 
assumption for purposes of computing the weekly average effluent 
limitation (see the TDD for additional details). As a conservative 
estimate, EPA assumed a six-month discharge duration season for all 
modeled facilities.

[[Page 29183]]

4. Calculation of National Costs
    EPA categorized all of the costs as either capital costs (one-time 
costs associated with planning or installation of technologies), or as 
operations and maintenance (O&M) costs (costs that occur on a regular 
ongoing basis such as monitoring or annual purchases of deicing 
materials). EPA amortized these capital costs over the lifespan of the 
capital improvement. For additional information on amortization, see 
the EA. Finally, EPA combined the amortized capital costs with the 
annual O&M costs to calculate the total annual cost of the option for 
that model facility.
    EPA then utilized statistical weights assigned to each of the 149 
model facilities to calculate a national estimated cost of complying 
with the option. Further discussion of all of the calculations 
discussed can be found in the TDD and in the EA.

B. Approach to Estimating Pollutant Reductions

1. Overview
    The pollutants of concern associated with airfield and aircraft 
deicing and anti-icing chemicals are discussed in Section 6 of the TDD. 
These chemicals commingle with stormwater and may be discharged to the 
environment. These discharges are of environmental concern because the 
biodegradation of deicing chemicals results in oxygen depletion in the 
receiving water body. Moreover, some of these pollutants, such as 
ammonia, have toxic properties.
    Pollutant loadings from airport deicing operations are challenging 
to estimate because they are highly variable and airport-specific. 
Because the use of deicing and anti-icing chemicals is weather 
dependent, the pollutant loadings at each airport vary based on weather 
conditions. The pollutant loadings also vary from airport to airport 
based on each airport's climate. In addition, the amount of applied 
chemical that is discharged to surface water is airport-specific, based 
on the existing stormwater separation, collection, and/or containment 
equipment present at each airport.
    Due to the variable nature of these pollutant loads, EPA developed 
a baseline (or current) pollutant loading methodology based on the 
usage of ADF and airfield chemicals at the airports responding to the 
survey questionnaires. The methodology takes into account EPA's 
existing data sources and provides a better estimate of the loadings 
than those based on sporadic monitoring data alone. Similar to the 
costing methodology, EPA developed facility-specific baseline loads for 
a subset of the industry (i.e., model facilities). For those model 
airports where existing practices would not lead to compliance with 
today's options, EPA then calculated the incremental pollutant removals 
associated with compliance. EPA subsequently adjusted the incremental 
pollutant removals upward to estimate the entire affected airport 
population. This approach is the same as the approach taken in the 
proposal.
2. Sources and Use of Available Data
    While developing the pollutant loading models, EPA considered the 
following data sources:
     Pavement deicing chemical usage/purchase information for 
the 2002/2003, 2003/2004, and 2004/2005 deicing seasons, as reported by 
airport authorities in the Airport Deicing Questionnaire.
     ADF purchase information for the 2002/2003, 2003/2004, and 
2004/2005 deicing seasons, as reported by air carriers in the Airline 
Deicing Questionnaire.
     Standard airport information available from the FAA and 
the Bureau of Transportation Statistics, including the number of 
operations and departures by airport,
     Weather information for each airport from NOAA, including 
temperature, freezing precipitation, and snowfall data.
     Existing airport stormwater collection and containment 
systems, as reported by airport authorities in the Airport Deicing 
Questionnaire.
     Standard chemical information about ADF and pavement 
deicing chemicals, including molecular formulas and densities.
     Analytical data from EPA sampling episodes of airport 
deicing operations.
a. Baseline Loading Calculations
    The Agency estimated the total amount of pavement deicing chemicals 
and ADF used based on data collected in the Airport and Airline 
Questionnaires. The Airport Questionnaire respondents reported the 
purchase/usage amount, concentration, and brand name of pavement 
deicing materials. Using the Airline Questionnaire, EPA collected ADF 
purchase data from airlines with 1,000 or more departures operating at 
selected airports. During questionnaire development, airports indicated 
they did not have information on ADF usage and that EPA should direct 
this question to airlines. Purchase data were collected because the 
airlines stated that purchase data were most readily available, while 
usage data was not. For the purposes of these loading calculations, EPA 
estimated that the annual amount purchased was equal to the amount used 
for a deicing season. For instances in which EPA did not have ADF 
purchase data for every airline operating at a particular model 
airport, EPA extrapolated the amount of ADF used by the reporting 
airlines to estimate the total amount of ADF used by the entire 
airport. This was done based on the number of airport operations 
(departures) at the reporting airlines versus the total number of 
airport operations. In addition to the 56 airports for which EPA 
collected ADF purchase/usage data from the airline tenants, 10 airports 
reported the total volume of their ADF usage to EPA in their comment 
section of the Airport Deicing Questionnaire, resulting in estimates of 
total ADF usage for 66 model airports.
    Using the airline and airport ADF purchase and usage data obtained 
from the questionnaire, airport departure data, and climate data, EPA 
developed a relationship between the amount of ADF used, and the 
climate and size of each model airport. EPA then used this equation to 
estimate the total gallons of ADF used at model airports that did not 
have ADF usage data in the Airport or Airline Questionnaires. EPA is 
aware that part of the methodology for developing today's regulation 
involved estimating airport-specific ADF usage. However, in order to 
prevent mandatory survey responses marked as CBI from being released, 
EPA is not revealing the exact methodology for modeling this ADF usage 
due to the potential for the deduction of CBI data through back 
calculation.
    Once the amount of ADF used at each model airport had been 
determined, EPA needed to determine the amount of ADF available for 
direct discharge to the waters. EPA assumed that 75 percent of applied 
Type I ADF falls onto the pavement at the deicing area and is available 
for discharge. EPA assumed that 10 percent of Type IV ADF falls to the 
pavement in the deicing area and is available for discharge; the 
remaining 90 percent adheres to the plane. See the TDD for more 
information on these estimates. EPA then multiplied the total amount of 
applied ADF for each model airport by the appropriate percent available 
for discharge to determine the amount of ADF available for discharge. 
Note that collection requirements in the options are specified as 
percentages of ADF available for discharge, not percentages of total 
ADF applied. Evaluating the amount of ADF available for discharge, 
coupled with the estimated baseline collection rate, results in the 
total amount of discharged

[[Page 29184]]

available ADF. EPA then calculated the amount of COD loading associated 
with these discharges, described as follows.
    Airfield pavement deicing chemicals are applied at various airside 
locations such as runways, taxiways and ramps. Theoretically, the 
amount of pavement deicers being discharged could range from 
approximately 0 percent, for chemicals that infiltrate highly permeable 
soils in unpaved areas during a thaw, to virtually 100 percent for 
paved areas near storm drains. In general, soil in unpaved areas is 
frozen during deicing season and is impermeable, promoting the overland 
flow of stormwater and pollutants to surface waters. Estimating the 
amount or proportion of pavement deicers discharged at a particular 
airport is difficult without performing a detailed study at the 
airport. EPA has not received any such detailed studies, nor other 
information from airports indicating that pavement deicers are absorbed 
into soil during the deicing season. Therefore, the Agency assumed for 
this rulemaking that 100 percent of the pavement deicers used could be 
discharged to surface waters.\3\ This means the estimates of baseline 
pollutant loadings and removals associated with pavement de-icing are 
upper bound estimates. EPA then calculated the amount of COD loading 
associated with airfield chemical use and discharge as described below.
---------------------------------------------------------------------------

    \3\ As a point of clarification, in contrast to the NSPS 
requirements for aircraft deicing where an airport is only required 
to meet the standards for a portion of the applied deicing chemical, 
this means that an airport that elects to comply with today's BAT or 
NSPS requirements by meeting the ammonia limitation must meet this 
limitation for all airfield deicer that is discharged.
---------------------------------------------------------------------------

    To calculate the COD loading associated with either ADF or airfield 
chemical discharge, EPA determined the theoretical oxygen demand (ThOD) 
associated with the degradation of each of the deicing chemicals. EPA 
based the ThOD estimate on the molecular formula of the chemical and 
the stoichiometric equation of the breakdown of the chemical to the end 
products of CO2 and water. EPA assumed that the chemical 
would completely degrade in the environment over time and, therefore, 
the calculated ThOD load would be equivalent to the COD load. EPA 
estimated the COD load associated with each reported chemical based on 
the calculated mass of the chemical discharged, the molecular weight of 
the chemical, the ThOD, and the molecular weight of oxygen. EPA 
estimated the ammonia load associated with deicers containing urea 
based on the chemical equation for the breakdown of urea to ammonia, 
the mass of urea use, and the molecular weights of urea and ammonia. 
See Section 9 of the TDD for more information and example calculations 
of baseline loadings associated with ADF and airfield deicers.
b. Calculation of Pollutant Removals
    After determining baseline loadings, EPA calculated total 
reductions of COD and ammonia associated with a national implementation 
of today's options.
i. Aircraft Deicing Related Pollutant Removals
    EPA estimated the amounts of COD that would be reduced by Option 1 
and 2, by estimating the existing baseline loadings associated with 
aircraft deicing at model airports and comparing that to the COD load 
that would be discharged after complying with the option (e.g., for 
Option 1, COD load discharged if 40 percent of available ADF were 
collected and treated to meet the required discharge limitation). If a 
particular airport would be subject to a collection requirement of 40 
percent under this option and is currently estimated to collect a 
greater proportion of available ADF, then no load removals were 
estimated for that airport.
ii. Airfield Deicing Related Pollutant Removals
    EPA calculated ammonia and COD baseline loads for those model 
facilities using deicers containing urea. The Agency then calculated 
ammonia and COD loads for those same model facilities if they replaced 
their deicers containing urea with the substitute product, potassium 
acetate (which does not form ammonia and exerts a lower COD than urea). 
EPA computed the total load reduction by subtracting the ammonia and 
COD loadings between the baseline and the regulatory compliance 
conditions.
iii. National Extrapolation
    These calculated loading reductions, summed for both airfield and 
aircraft deicing chemicals, as applicable, were then extrapolated by 
multiplying the pollutant removals for each model facility by the 
airport survey weighting factors to determine national loads for the 
entire industry for each regulatory option considered for today's rule.

C. Approach to Determining Long-Term Averages, Variability Factors, and 
Effluent Limitation Guidelines and Standards

    This section describes the statistical methodology used to develop 
the daily maximum and the maximum for weekly average NSPS representing 
the BADCT levels of control for COD. EPA also used the same statistical 
methodology to develop the daily maximum limitation/standard for 
ammonia that is a compliance alternative when deicers containing urea 
are applied to runways. The following discussion uses the term 
``limitation'' to collectively refer to effluent limitations guidelines 
and NSPS.
    The following sections describe the data selection criteria, the 
statistical percentile basis of the effluent limitations, rationales 
for certain limitations, the calculations, the recommended long-term 
average value for treatment operations, and the engineering evaluation 
of the model technology's ability to achieve the levels required by the 
limitations.
1. Criteria Used To Select Data as the Basis of the Limitations
    Typically, in developing effluent limitations for any industry, EPA 
qualitatively reviews all the data before selecting the appropriate 
data to use for calculating the limitations. EPA typically uses four 
criteria to assess the data. One criterion generally requires that the 
influent and effluent represent only wastewater from the regulated 
operations (e.g., deicing), and do not include wastewater from other 
sources (e.g., sanitary wastes). A second criterion typically ensures 
that the pollutants were present in the influent at sufficient 
concentrations to evaluate treatment effectiveness. A third criterion 
generally requires that the facility must have the technology and 
demonstrate proper operation of the technology. A fourth criterion 
typically requires that the data cannot represent periods of treatment 
upsets or shutdown and start-up periods. Shutdown periods can result 
from upset conditions, maintenance, and other atypical operations.
    EPA has adapted the application of the fourth general criterion for 
data corresponding to start-up periods to reflect some unique 
characteristics of treating discharges from aircraft deicing 
operations. Most industries incur start-up conditions only during the 
adjustment period associated with installing new treatment systems. 
During this acclimation and optimization process, the concentration 
values tend to be highly variable with occasional extreme values (high 
and low). After this initial adjustment period, the systems should 
operate at steady state for years with relatively low variability 
around a long-term average. Because start-up conditions reflect one-
time operating conditions, EPA

[[Page 29185]]

generally excludes such data in developing the limitations. In 
contrast, EPA expects airports to encounter start-up operations at the 
beginning of every deicing season because they probably will cease 
treatment operations during warmer months. Because this adjustment 
period will occur every year for the Airport Deicing Category, EPA has 
included start-up data in the data set used as the basis of the 
limitations. However, through its application of the other three 
criteria, EPA excluded extreme conditions that do not demonstrate the 
level of control possible with proper operation and control even during 
start-up periods. For detailed information on these exclusions, see 
Section 14 of the TDD.
    In part, by retaining start-up data for the limitation's 
development, the limitations will be achievable because EPA based these 
limits on typical treatment during the entire season. As a point of 
clarification, once acclimated, EPA expects a typically well-designed 
and operated system for the collected deicing fluid to run continuously 
until the end of the deicing season, as facilities utilize storage/
equalization prior to the AFB to manage a steady flow rate.
2. Data Used as Basis of the Effluent Limitations
    As explained in Section 8 of the TDD, the technology basis for the 
COD numerical limitations associated with discharges of collected ADF 
wastewater is AFB biological treatment. Of the effluent data available 
to EPA, 2,562 concentration values for COD met the requirements in the 
criteria described above and are the basis of the COD final NSPS. The 
concentration values are measurements of filtered effluent collected 
from Albany Airport's two-unit anaerobic treatment system. The 2,562 
COD values were collected by the airport during its daily monitoring of 
COD over ten deicing seasons (December 1, 1999 through April 10, 2009).
    Product substitution is the basis for today's effluent limitation 
regarding airfield deicing chemicals. EPA also established ammonia 
discharge limitations as a compliance alternative. Ammonia naturally 
occurs in airport discharges as a result of excretions from wildlife 
that enter the stormwater; therefore, EPA determined it would not be 
appropriate to set this limitation at the non-detect level. Moreover, 
depending on a specific airports' drainage system, a portion of 
airfield deicing stormwater may be routed to the treatment system 
utilized in treating the collected ADF. Further, the AFB that has been 
identified as the basis for the NSPS requirement for treating collected 
ADF will itself produce ammonia discharges as a byproduct of treatment. 
Therefore, where airfield deicing stormwater that is free of urea 
contamination is routed through the AFB treatment system, the discharge 
after treatment may have ammonia concentrations higher than the non-
detect level (see DCN AD00842). Consequently, EPA used ammonia effluent 
discharge data from the same AFB system it used to establish NSPS 
discharge requirements for ADF, located at Albany, to establish today's 
ammonia compliance alternative. Five ammonia concentration values 
available from Albany met the limitations criteria described above. The 
five ammonia values were collected by EPA during its sampling episode 
(February 5 through February 9, 2006).
3. Statistical Percentile Basis for Limitations
    EPA uses a statistical framework to establish limitations that 
well-operated facilities are capable of complying with at all times. 
According to EPA, well-operated facilities are those that represent the 
BAT/BADCT level of control. Statistical methods are appropriate for 
dealing with effluent data because the quality of effluent, even in 
well-operated systems, is subject to a certain amount of variability or 
uncertainty. Statistics is the science of dealing with uncertainty in a 
logical and consistent manner. Statistical methods, together with 
engineering analysis of operating conditions, therefore, provide a 
logical and consistent framework for analyzing a set of effluent data 
and determining values from the data that form a reasonable basis for 
effluent limitations. Using statistical methods, EPA has derived 
numerical values for its daily maximum limitations and weekly average 
limitations.
    The statistical percentiles upon which the limitations are based 
are intended to be high enough to accommodate reasonably anticipated 
variability within control of the facility. The limitations also 
reflect a level of performance consistent with the CWA requirement that 
these limitations be based on the best available technologies (or BADCT 
for new sources), including proper operation and maintenance of these 
technologies.
    In establishing daily maximum limitations, EPA's objective is to 
restrict the discharges on a daily basis at a level that is achievable 
for an airport that targets its treatment system design and operation 
at the long-term average while allowing for the variability around the 
long-term average that results from a well-operated system. This 
variability means that at certain times airports may discharge at a 
level that is greater than the long-term average. This variability also 
means that airports may at other times discharge at a level that is 
lower than the long-term average. To allow for possibly higher daily 
discharges, EPA has established the daily maximum limitation at a 
relatively high level (i.e., the 99th percentile). EPA has consistently 
used the 99th percentile as the basis of the daily maximum limitation 
in establishing limitations for numerous industries for many years; 
numerous courts have upheld EPA's approach. EPA typically establishes 
limitations based upon statistical percentile estimates and has done so 
for the weekly average limitation in today's final rule. In its 
derivation of the weekly average NSPS for COD, EPA used an estimate of 
the 97th percentile of the weekly averages of the daily measurements. 
This percentile basis is the midpoint of the percentiles used for the 
daily maximum limitation (i.e., 99th percentile of the distribution of 
daily values) and the monthly average limitation (i.e., 95th percentile 
of the distribution of monthly average values). Courts have upheld 
EPA's use of these percentiles, and the selection of the 97th 
percentile of a weekly average of the daily measurements is a logical 
extension of this practice. Compliance with the daily maximum 
limitation is determined by a single daily value; therefore, EPA 
considers the 99th percentile to provide a reasonable basis for the 
daily maximum limitation by providing an allowance for an occasional 
extreme discharge. Because compliance with the monthly average 
limitation is based upon more than one daily measurement and averages 
are less variable than daily discharges, EPA has determined that 
facilities should be capable of controlling the average of daily 
discharges to avoid extreme monthly averages above the 95th percentile. 
In a similar manner to the monthly average limitation, compliance with 
the weekly average limitation also would be based upon more than one 
daily measurement. However, the airport would monitor for a shorter 
time and thus would have fewer opportunities to counterbalance highly 
concentrated daily discharges with lower ones. Consequently, EPA has 
determined that the 97th percentile is an appropriate basis for 
limiting average discharges on a weekly basis. EPA considers the use of 
the 97th percentile for the weekly average limitation a level

[[Page 29186]]

that is achievable for airports using the model technology. EPA also 
considers this level of control in avoiding extreme weekly average 
discharges to be possible for airports using the model technology.
4. Rationale for Establishing Limitation on Weekly Averages Instead of 
Monthly Averages for COD in Effluent Discharges
    From a monitoring perspective, EPA considers the weekly average 
standard to be a better fit than the monthly average standards for the 
deicing discharges. In this situation, the weekly average standard 
would apply to every week that the treatment system operates during the 
deicing season. A weekly average standard preserves EPA's intention for 
an additional restriction beyond the daily maximum standard that 
supports its objective of having airports control their average 
discharges at the long-term average level.
    When EPA establishes monthly average standards, EPA's objective is 
to provide an additional restriction to help ensure that facilities 
target their treatment systems to achieve the long-term average. The 
monthly average standard requires facilities to provide ongoing control 
that complements controls imposed by the daily maximum standard. To 
meet the monthly average standard, a facility must counterbalance a 
value near the daily maximum standard with one or more values well 
below the daily maximum standard. To achieve compliance, these values 
must result in a monthly average value at or below the monthly average 
standard.
    The deicing season is unlikely to start at the beginning of a 
calendar month and close exactly at the end of a calendar month. This 
means that the facility would be monitoring at a reduced frequency 
during those two months. Increasing or decreasing monitoring frequency 
does not affect the statistical properties of the underlying 
distribution of the data used to derive the standard. However, 
monitoring less frequently theoretically results in average values that 
are more variable. For example, monthly average values based on 10 
monitoring samples per month would be (statistically) expected to 
include some averages that are numerically larger (as well as some that 
are numerically smaller) than monthly average values based upon 20 
monitoring samples. Because of this reduced monitoring, an airport 
might have trouble in complying with the monthly average standard even 
with an otherwise well-operated and controlled system. In other words, 
because it was not monitoring as frequently, the airport would have 
fewer opportunities to counterbalance high concentrations with lower 
values.
5. Rationale for Promulgating a Limitation Only for Daily Discharges of 
Ammonia in Effluent Discharges
    Unlike the COD limitations, EPA believes that it is appropriate to 
rely only on a daily maximum limitation to ensure that airports 
appropriately control ammonia levels. As explained above, the 
technology basis for the COD effluent standards is a well operated and 
controlled AFB system whereas the technology basis for the ammonia 
limitation is product substitution. It is well documented that during 
start up, biological treatment systems, such as AFB, may require 
several days to acclimate the microorganisms. Once acclimated, well-
operated and controlled AFB systems operate continuously (typically by 
managing a steady flow from their equalization tank). If the system 
only operated during storm events, it would have difficulties 
stabilizing and achieving the performance levels necessary to comply 
with the COD standards.
    In contrast, with product substitution, the operator could consider 
the conditions associated with each storm event, and then decide 
whether to use urea. If the operator chose to use urea rather than 
product substitution, the operator would have to determine its approach 
for meeting the ammonia limitation. Anaerobic systems, such as AFB 
systems, would not be a good candidate because they generate, rather 
than treat, ammonia. However, depending on a specific airport's 
drainage system, a portion of airfield deicing stormwater may be routed 
to the treatment system utilized in treating the collected ADF. For 
this reason, by using the ammonia data from the AFB system which was 
preceded by product substitution for urea, EPA created an allowance for 
such situations. Because the choice to use urea or product substitution 
can vary on a daily basis, EPA has established only the daily maximum 
limitation for ammonia. Additionally, EPA expects airports to select 
product substitution (i.e., non-urea deicers) rather than the 
compliance alternative that requires collection and treatment of runway 
deicing contaminated stormwater. Thus, it is possible that no airports 
will be subject to any limitation on ammonia discharges.
6. Calculation of Limitations for COD and Ammonia
    For COD, EPA used nonparametric statistical methods to estimate the 
percentiles used as the basis of the daily maximum and weekly average 
standards. A simple nonparametric estimate of a particular percentile 
(e.g., 99th) of an effluent concentration data set is the observed 
value that exceeds that percent (e.g., 99 percent) of the observed data 
points.
    For the daily maximum standard for COD, EPA used the nonparametric 
method to derive a 99th percentile of the more than 1,200 daily 
measurements for each unit, and then set the standard equal to the 
median of the two 99th percentile estimates, or 271 milligrams per 
liter (mg/L). The median is, by definition, the midpoint of all 
available data values ordered (i.e., ranked) from smallest to largest. 
In this particular case, because there are two units, the median is 
equal to the arithmetic average (or mean).
    For the weekly average standard of COD, EPA first calculated, for 
each unit, the arithmetic average of the measurements observed during 
each week, excluding weekends. EPA then used the nonparametric method 
to derive a 97th percentile of the more than 200 weekly averages for 
each unit, and set the standard equal to the median of the two 97th 
percentile estimates, or 154 mg/L.
    For ammonia, EPA used a parametric approach in estimating the 99th 
percentile based upon the data collected during EPA's five-day sampling 
episode. The calculations assume the ammonia concentrations can be 
modeled by a lognormal distribution. EPA's selection of parametric 
methods, such as a model based on the lognormal distribution, used in 
developing limitations for other industries is well documented (e.g., 
Iron and Steel [40 CFR part 420], Pulp, Paper and Paperboard [40 CFR 
part 430], and Metal Products and Machinery [40 CFR part 438] 
categories). Variance estimates based upon parametric methods can be 
adjusted for possible biases in the data. The limitation of 14.7 mg/L 
includes such an adjustment for possible bias from positive 
autocorrelation. When data are positively autocorrelated, it means that 
measurements taken close together in time (such as one or two days 
apart) are more similar than measurements taken further apart in time, 
such as a week or month apart. The adjusted variance then better 
reflects the underlying variability that would be present if the data 
were collected over a longer period.
7. Derivation of Long-Term Average for COD and Ammonia: Target Level 
for Treatment
    Due to routine variability in treated effluent, an airport that 
discharges consistently at a level near the values of

[[Page 29187]]

the daily maximum standard or the weekly average standard, instead of 
the long-term average, may experience frequent values exceeding the 
standards. For this reason and as noted previously in this section, EPA 
recommends that airports design and operate the treatment system to 
achieve the long-term average for the model technology. Thus, a system 
that is designed to represent the BADCT level of control will be 
capable of complying with the promulgated standards.
    For COD, EPA recommends that airports target treatment systems to 
achieve the long-term average value of 52.8 mg/L, which is the median 
of the two averages, of 52.28 mg/L and 53.40 mg/L, of the daily values 
from the two units. The daily allowance for variability, or the ratio 
of the standard to the long-term average, is 5.13. EPA usually refers 
to this allowance as the ``variability factor.'' In other words, the 
daily maximum standard of 271 mg/L is about five times greater than the 
long-term average achievable by the model technology. The weekly 
variability factor is 2.92.
    For ammonia, EPA derived its recommended long-term average value of 
5.24 mg/L from the statistical expected value of the lognormal 
distribution. The daily maximum limitation of 14.7 mg/L is about three 
times greater than the long-term average, of 5.24 mg/L, achievable by 
the ADF treatment model technology. Ammonia is generated as a byproduct 
of the model technology, and EPA expects the concentrations of ammonia 
to have similar variability to what is being treated (i.e., COD).
8. Engineering Review of Effluent Limitations
    In conjunction with the statistical methods, EPA performs an 
engineering review to verify that the limitations are reasonable based 
upon the design and expected operation of the control technologies and 
the facility conditions. During the site visit and sampling trip at the 
Albany treatment plant, EPA confirmed that the airport used the model 
technologies, specifically AFB. EPA subsequently contacted the plant 
personnel to obtain more information about the installation and 
operation of the model technologies. EPA used this engineering 
information to select the subset of data from which to develop the 
effluent limitations.
    As part of this engineering review, EPA concluded that the values 
of the limitations were consistent with the levels that are achievable 
by the model technologies. Next, EPA compared the value of the effluent 
limitations to the data values used to calculate the limitations. None 
of the data selected for ammonia were greater than its daily maximum 
limitation, which supports the engineering and statistical conclusions 
that the limitation value is appropriate. Because of the statistical 
methodology used for the COD standards (i.e., use of percentiles), some 
values were appropriately greater than the standards. See Section 
VI.C.3. Even though EPA would expect this statistically, EPA looked at 
the values that exceed the standards from an engineering perspective. 
EPA wanted to ensure there were no underlying conditions contributing 
to such exceedances. In particular, EPA looked at deicing season, 
influent concentrations, and start-up operations. In evaluating the 
impact of the deicing seasons, EPA concluded that the higher values did 
not seem to be predominant in any one season. In particular, the higher 
values occurred one to seven times in each of eight seasons. In 
evaluating influent concentrations, EPA found that influent 
concentrations were generally well controlled into the treatment plant. 
In general, the treatment system adequately treated even the extreme 
influent values, and the high effluent values did not appear to be the 
result of high influent discharges. In considering start-up operations, 
EPA noted that the higher values occurred in every month from December 
through May, except in April, and, thus, the standards appear to 
provide adequate allowance for start-up operations.

VII. Economic Analysis

A. Introduction

    EPA's EA assesses the costs and impacts of the regulatory options 
considered today on the regulated industry. This section explains EPA's 
methodology and the results of its EA. With one exception, all costs, 
airport counts and other results in this section are presented using 
sample weights to expand results from the surveyed airports to 
represent the entire population of airports potentially affected by the 
rule. The single exception, the results of the debt service coverage 
analysis, is clearly marked as ``unweighted.'' In addition, all cost 
figures are presented in 2006 dollars.

B. Annualized Compliance Cost Estimates

    EPA considered three regulatory options for today's final rule. 
Under all of these options, airports subject to BAT or NSPS would have 
requirements with respect to airfield deicing stormwater (certify no 
use of airfield deicing products that contain urea, or airfield 
pavement discharges must achieve a numeric limit for ammonia). EPA 
estimates that 198 existing airports--those that perform deicing 
operations with at least 1,000 annual non-propeller aircraft 
departures--are subject to the airfield deicing requirements.\4\ In 
addition, for two of the options, a subset of those airports--airports 
with annual normalized ADF usage equal to or exceeding 60,000 gallons 
per year (55 airports)--would also need to meet requirements related to 
wastewater from aircraft deicing (ADF collection and COD discharge 
limitations). The regulatory options that EPA considered differ in the 
level of ADF collection required for aircraft deicing at existing 
airports. Option 1 would require 40 percent collection and treatment 
for all airports with at least 60,000 gallons of annual normalized ADF 
usage. Option 2 would set a two-tier requirement: 20 percent collection 
and treatment for airports with at least 60,000, but less than 460,000 
gallons of annual normalized ADF usage, and 40 percent collection and 
treatment for airports with at least 460,000 gallons of annual ADF 
usage. Under Option 3, aircraft deicing discharge BAT limitations would 
continue to be established by the permitting authority on a case-by-
case basis. Under all three options, new airports with at least 10,000 
annual departures and located in an area with at least 3000 HDDs would 
also have to collect 60% of ADF available for discharge and store and 
treat this effluent to meet a COD effluent limit. For both new and 
existing airports with deicing discharges that do not meet the NSPS 
airfield or aircraft pavement applicability requirements, limitations 
would continue to be set by the permitting authority on a case-by-case 
basis using BPJ.
---------------------------------------------------------------------------

    \4\ Because many airports do not meet the applicability 
criteria, EPA estimates that approximately 184 primary airports, 135 
non-primary airports, and almost 3,000 general aviation airports are 
not required to meet the BAT effluent limitations guidelines and 
NSPS, but rather would be subject to site-specific BAT and NSPS 
requirements set on a best professional judgment basis.
---------------------------------------------------------------------------

    EPA selected Option 3 for promulgation in this final rule. EPA 
estimates the technologies identified in this notice to comply with the 
BAT limitations will cost existing airports $3.5 million annually. EPA 
has not estimated the cost for compliance with the NSPS, but separately 
discusses the potential for the NSPS to pose a barrier entry in section 
VII.E below.

[[Page 29188]]

    In estimating costs associated with Option 1 and Option 2, EPA 
projects the effective service life of GCVs and block-and-pump 
technologies to be 10 years; all other components necessary to meet the 
options have an effective service life of 20 years. Therefore, EPA 
selected a 20-year analytic period and incorporated replacement capital 
expenditures in year 10, in addition to the initial capital 
expenditure. For example, EPA estimated total capital costs to include 
all initial and replacement capital expenditures for GCV and plug-and-
pump for Option 1. However, because the replacement capital 
expenditures occur 10 years after promulgation, the discounted present 
value (PV) of those expenditures is less than their current value.
    EPA uses 3 percent and 7 percent interest rates for two purposes. 
First, the interest rates are used to discount future capital 
replacement costs required when the 20-year analytic period exceeds the 
effective service life of a technology. Second, the interest rates 
represent the opportunity cost of capital to industry, and, thus, 
essentially the interest rate the industry may be charged if the 
industry borrows money.
    EPA discounted and annualized the stream of capital costs projected 
to be incurred by industry over 20 years using two different discount 
rates, 3 percent and 7 percent, in accordance with EPA and OMB guidance 
(``Economic Analysis of Federal Regulations under Executive Order 
12866,'' January 11, 1996). The PV of capital costs under the final 
rule over the 20-year analytic period is $6.02 million based on the 
discount rate of 3 percent, and $5.27 million using the 7 percent rate.
    The annual cost of operating and maintaining the technologies 
identified as BAT for deicing for this final rule is estimated at $3.04 
million. Adding this O&M cost to the annualized capital costs, the rule 
has aggregate national costs of $3.43 million per year using a 3 
percent discount rate and annualized costs to industry of $3.5 million 
using a 7 percent rate (in 2006 dollars). Table VII-1 presents 
projected costs for the final rule, as well as the other option 
examined.

                Table VII-1--Costs to Existing Airports That Deice Aircraft and Airfield Pavement
                                    [2006 $million--198 airports (weighted)]
----------------------------------------------------------------------------------------------------------------
                                                                                                       Total
                                   Total capital   Present value    Annualized      Annual O&M      annualized
             Option                    costs        of capital     capital costs       costs        compliance
                                                       costs                                           costs
----------------------------------------------------------------------------------------------------------------
                                          3 Percent Real Discount Rate
----------------------------------------------------------------------------------------------------------------
1...............................         $319.9          $309.0           $20.2           $52.0           $72.1
2...............................          250.3           243.7            15.9            28.4            44.3
3 \a\...........................            6.83            6.02            0.39            3.04            3.43
----------------------------------------------------------------------------------------------------------------
                                          7 Percent Real Discount Rate
----------------------------------------------------------------------------------------------------------------
1...............................          319.9           299.0            26.4            52.0            78.4
2...............................          250.3           237.6            21.0            28.4            49.4
3 \a\...........................            6.83            5.27            0.46            3.04            3.50
----------------------------------------------------------------------------------------------------------------
\a\ Selected option.

C. Economic Impact Methodologies

    For the purposes of the economic impact analysis, the 
distinguishing feature of airports that makes the analysis different 
from more traditional analyses EPA would perform for a for-profit 
manufacturing industry, is that all potentially affected airports are 
publicly owned and operated by local, county, or state governments, or 
by quasi-governmental authorities created to operate the airport. As 
governmental or quasi-governmental entities, airports do not earn a 
profit or loss in the traditional financial sense; in fact, many 
airports have been operated with the expectation that they will break 
even financially, with the airlines that use the airport legally 
required to cover expenditures in excess of budgeted costs.
    Airlines may also be impacted by today's rulemaking. In the vast 
majority of cases, airlines are not directly subject to today's 
requirements. In such cases, impacts to airlines are considered 
secondary impacts. Historically, EPA determines economic achievability 
based on primary or direct impacts only (i.e., impacts to NPDES permit 
holders directly subject to ELG requirements) and does not evaluate 
secondary impacts. At the time of the proposal, EPA elected to evaluate 
secondary impacts to airlines because of the unique contractual 
relationship between airports and airlines, because airlines are the 
entities that use ADF, and because airlines are occasionally co-
permittees (but never the principal permittee) at an airport.
    In a revision from the proposal and consistent with past effluent 
guideline economic achievability analyses, for today's final rule, EPA 
determined economic achievability based on primary or direct impacts 
only. EPA returned to its historical approach of evaluating economic 
achievability based on only primary impacts (here, impacts on airports 
and airline co-permittees) for today's final rule because the Agency 
concluded that ultimately these entities will be responsible for 
incurring the costs and associated impact of any additional regulation.
    In the analyses described below, EPA first evaluates the economic 
achievability of the options assuming all costs are borne by airports, 
and the summaries of impacts to airports are based on that assumption. 
EPA also presents an analysis that shares compliance costs between 
affected airports and their co-permittee airlines, as applicable. 
Therefore, impacts to co-permittee airlines presented as follows are 
not in addition to the impacts to airports. To the extent that airports 
share costs with co-permittee airlines according to EPA assumptions, 
the costs and impacts to airports are reduced. This analysis is 
described in detail in the rulemaking record DCN AD01280. The following 
text describes the methodology and the results EPA used to evaluate 
economic impact associated with the three regulatory options considered 
for today's final rule, both under the assumption that airports incur 
100 percent of compliance costs, and

[[Page 29189]]

the assumption that airports share compliance costs with co-permittee 
airlines.
1. Cost Annualization
    Cost annualization is the first step in projecting the economic and 
financial impacts of the regulatory options rule. EPA projected the 
capital and operating and maintenance costs of the three regulatory 
options for each airport, then annualized those costs over 20 years. 
The method for estimating each airport's capital and operating costs is 
described in Section VI.A.
    EPA used airport-specific interest rates based on recent General 
Airport Revenue Bonds (GARBs) issued to annualize compliance costs for 
the proposed rule. Based on public comments arguing that EPA 
underestimated the cost of capital to airports, EPA used a higher real 
interest rate of 7 percent to annualize airport capital costs for the 
final rule. However, EPA believes many airports will issue tax-exempt 
GARBs to fund capital expenditures. To the extent that airports use 
GARBs, the use of GARBs will lower the cost of capital, and reduce 
impacts to the financial health of the airports. EPA does not assume 
that airports will be able to fund capital expenditures using Airport 
Improvement Program (AIP) grants or Passenger Facility Charges (PFCs) 
because such funds are likely to already be committed to airport 
projects into the foreseeable future. However, to the extent that 
airports might use AIP or PFC funds for capital expenditures associated 
with this rule, it will also lower the cost of capital, and reduce 
impacts to the financial health of the airports relative to what EPA 
has projected in its analysis.
2. Airport Impact Methodology
    Because all in-scope airports are nonprofit government or quasi-
government entities (e.g., port authorities), the effect of an effluent 
guideline on airport income statements and balance sheets is not best 
measured by a traditional closure analysis. Therefore, EPA chose to 
examine the financial impacts of the regulatory options using two 
measures. First, EPA compared total annualized compliance costs with 
airport revenues. Second, because many airports fund capital 
expenditures using debt financing, EPA examined the impact of 
additional debt on each airport's debt service coverage ratio (DSCR).
a. Revenue Test
    EPA's ``Guidelines for Preparing Economic Analyses'' (2010) 
recommends the ``revenue test'' as a measure for impacts of programs 
that directly affect government and not-for-profit entities. EPA finds 
that the revenue test is appropriate in this case. The revenue test 
compares the total annualized compliance costs of each regulatory 
option with the revenues of the governmental entities. Although the 
current Guidelines do not specify the use of one and three percent for 
the revenue test, EPA's 2000 Guidelines did specify that use, and the 
Agency's analysis for the proposed rule followed that guidance; EPA 
applied the same test here.
    The 2000 Guidelines suggest evaluating the affordability of a 
regulatory option as follows:
     If total annualized compliance costs are less than 1 
percent of revenues, the option is generally considered affordable for 
the entity.
     If total annualized compliance costs are greater than 3 
percent of revenues, the option is generally considered not affordable 
for the entity.
    EPA used operating revenue as reported on Form 127 of the FAA's 
Airport Financial Reporting Program as the denominator for the revenue 
test ratio, and total annualized compliance costs as described under 
Cost Annualization as the numerator for the ratio.
    Industry commenters on the proposed rule objected that the revenue 
test is too simplistic. EPA disagrees, and moreover, industry 
commenters were unable to provide any alternative test that would more 
accurately project economic impacts on the industry. Some industry 
commenters suggested that EPA examine different, more narrowly defined 
ratios, such as the ratio of compliance costs to aeronautical revenues, 
or the incremental cost per enplaned passenger. EPA did not choose to 
replace the revenue test with one of these variants because EPA 
determined that total operating revenues are the appropriate 
denominator for the test; the sole purpose of the airport is to support 
air transportation services. Landside revenues raised through parking, 
retail, and food concessions, for example, are not designed to provide 
a revenue stream to support the provision of a different service or 
product, but to allow airports to accumulate revenue from non-airline 
sources. Thus, the intent of these revenue streams is also to support 
the provision of air transportation services and is therefore a 
component of an airport's resources relevant to its implementation of 
these effluent limitation guidelines. Furthermore, industry commenters 
offered no suggestions for alternative thresholds for finding airport 
impacts, and, in fact, acknowledged that such thresholds do not exist 
in the case of their recommended incremental cost per enplaned 
passenger test. EPA did, however, perform several of these alternative 
tests as sensitivity analyses and determined that the resulting 
projections of economic impacts to the industry did not differ 
qualitatively from those under the revenue test analysis.
b. Debt Service Coverage Ratio
    When creating quasi-governmental agencies such as port authorities, 
the legislation that created the agency typically includes a lower 
limit on the authority's DSCR. Airports owned and operated directly by 
a state or local government might also have direct limits on airport 
debt (if the airport has authority independent of the city or county 
government to incur debt). The authority will be in default on its debt 
if the DSCR falls below the relevant benchmark. A review of 
Comprehensive Annual Financial Reports for affected airports shows that 
generally the ratio of net revenues to debt service for any given year 
cannot fall below 1.25. Therefore, EPA estimated the impact debt 
financing will have on the post-regulatory DSCR for each airport 
incurring capital expenditures under each regulatory option.
    Using the Airport Questionnaire responses, EPA collected each 
airport's current DSCR, and the net revenues and debt service used to 
calculate that ratio. For airports that belonged to multi-airport 
systems under the same ownership, DSCR was reported at the level of the 
entire system. Therefore, for each regulatory option, EPA aggregated 
compliance costs for all affected airports in the system, and performed 
a single calculation for the post-regulatory DSCR.
    Some evidence suggests airports will pass on less than 100 percent 
of costs, at least in the short run, if there is concern an airline 
might withdraw service if the airport increases fees too much. This 
might occur if the airport has nearby competitors, or if airline 
finances are fragile. EPA wanted to determine if an airport would be in 
danger of default on its debt even if it was unable to pass through 
compliance costs to its airline customers. Thus, the Agency calculated 
post-regulatory DSCR in two ways: (1) Assuming costs are passed through 
to airlines in the form of higher landing fees, and (2) assuming no 
costs are passed through.
    In the baseline, the DSCR is calculated by dividing airport net 
revenues by airport debt service. Assuming 100 percent cost pass-
through

[[Page 29190]]

from airports to airlines, EPA estimated the post-regulatory DSCR of 
each regulatory option by: (1) Assuming zero change in airport net 
revenues in the numerator (more precisely, EPA assumes that annual 
increase in landing fees are exactly equal to incremental annual 
deicing costs, thus leaving net revenues unchanged), and (2) adding the 
annualized value of capital compliance costs to debt service in the 
denominator. The DSCR decreases even when assuming 100 percent cost 
pass-through; although the value of the numerator is unchanged, the 
denominator increases by the amount equal to annualized capital cost, 
decreasing the value of the ratio.
    Assuming no cost pass-through from airports to airlines, EPA 
estimated the post-regulatory DSCR by for each regulatory option by: 
(1) Subtracting incremental annual deicing operating and maintenance 
costs from pre-regulatory airport net revenues in the numerator, and 
(2) adding the annualized value of capital compliance costs to debt 
service in the denominator. With zero cost pass-through, the numerator 
in the ratio decreases because incremental O&M costs are subtracted 
from existing revenues, while the denominator increases because 
incremental debt service is added to existing debt service; thus, the 
DSCR clearly falls.
    All additional analyses, their methodologies, justifications, and 
results, are presented in the Economic Analysis (EA).
3. Co-Permittee Airline Impact Methodology
    In response to public comment, EPA examined potential economic 
impacts to airlines that are directly subject to today's final 
regulation: those that are co-permittees on NPDES permits. EPA 
conducted analyses of impacts to airlines that are co-permittees at 
certain airports, under the assumption that co-permittee airlines would 
directly pay a share of the airport's compliance costs. EPA identified 
airline co-permittees through EPA's Airport Deicing Questionnaire, 
where airports had been asked to identify all co-permittees. While the 
questionnaire responses identified co-permittees, they did not provide 
any data or insight into how permit-related compliance costs are 
currently distributed to, and among, co-permittees, if at all. Although 
the general outlines of standard contractual relations between airports 
and airlines can be characterized (see section 2.8 of the EA), the 
inclusion of an airline on the airport's NPDES permit is not a common 
practice. In addition to reviewing information supplied in the 
questionnaires, EPA searched publicly available information, reviewed 
comment responses, and inquired of airline representatives on such 
relationships. Industry representatives did not provide EPA with 
information on these contractual relationships in the questionnaires or 
their comments on the proposed rule, nor did they provide this 
information to the Agency in pre-proposal meetings that were arranged 
to discuss the economic methodology of the rule. EPA was unable to 
gather any specific insight into these relationships or the 
distribution of compliance costs among the principal NPDES permit 
holder and its co-permittees. Thus, for purposes of this analysis, EPA 
assumed compliance costs would be distributed equally among the 
principal permittee (i.e., airport) and its co-permittee airlines. EPA 
recognizes that some individual airports may incur a higher percentage 
of the compliance costs relative to their co-permittees and others may 
incur a lower percentage. However, for purposes of a national analysis, 
and with a lack of informative data, EPA finds a 50 percent 
distribution assumption to be reasonable.
    EPA does not separately assign capital costs to airlines and 
annualize those costs using airline-specific costs of capital; it seems 
more likely that with responsibility for the physical site, the airport 
would take the lead and have those costs reimbursed by the co-
permittees. Thus, EPA assigned 50 percent of the total annualized 
compliance costs collectively to the co-permittee airlines. For each 
model airport with co-permittees, EPA needed to determine how to 
apportion the co-permittee portion of the compliance costs to the 
individual co-permittees. As explained in previous text, EPA does not 
have data to determine if co-permittees currently incur any permit 
compliance-related costs, nor, if they do incur those costs, how they 
are distributed among co-permittees at individual airport locations. In 
the absence of specific information, EPA chose to attribute airport-
specific compliance costs to each co-permittee based on its share of 
total landed weight at the airport. EPA chose this method because ADF 
usage should be roughly proportionate to the number and type of 
aircraft an airline typically uses at the airport, and therefore 
proportionate to the costs of collecting and treating that ADF. Share 
of landed weight can be considered a simple summary measure that 
reflects both relative usage and aircraft size. This approach is also 
consistent with how airports typically attribute airside operational 
costs to airlines. EPA then calculated an airline's total compliance 
costs by summing its airport-specific compliance costs over all 
airports at which the airline is a co-permittee. Finally, each 
airline's compliance costs were compared to its system-wide operating 
revenue, operating profit, and net income.
    The comparison of one year's average annualized compliance costs 
with operating profit and net income is consistent with a typical 
economic impact analysis. In a typical economic impact analysis, EPA 
would project the affected entities' discounted compliance costs and 
cash flow over the period of analysis. If an entity's pre-regulatory 
discounted cash flow is positive, and its post-regulatory discounted 
cash flow is negative (i.e., projected pre-regulatory discounted cash 
flow less discounted compliance costs), the entity would be projected 
to close as a result of the effluent guideline. EPA then typically 
examines economic achievability by looking at the total number of 
closures relative to the total number of in-scope companies. In this 
case, if average compliance costs in one year exceed average operating 
profit or net income for that year (i.e., the ratio of compliance costs 
to operating profit or net income is greater than 100 percent), the 
airline can be projected to ``close'' as a result of the effluent 
guideline.
    However, such an analysis is problematic for airlines for a number 
of reasons. First, a baseline closure, an entity with negative income 
prior to the promulgation of the effluent guideline, cannot be 
evaluated on the basis described above because the logic of that 
analysis requires that the entity's pre-regulatory income be greater 
than zero. As amply documented in the EA (and updated in DCN AD01285), 
the last decade has been financially difficult for the airline 
industry, and approximately half the U.S.-flag airlines incurring 
compliance costs as co-permittees under normal circumstances would be 
categorized as baseline closures and could not be analyzed by this 
standard.
    Second, airlines have many options they can undertake in response 
to increased costs, short of going out of business. For example, 
airlines have the option to change service to a particular airport by 
increasing fares, decreasing service frequency, using different 
(typically smaller) aircraft, eliminating destinations flown to 
directly from that airport, or even eliminating service altogether to 
that airport.
    To address the baseline closure issue, EPA included airline 
operating revenue as a third measure against which

[[Page 29191]]

compliance costs can be compared, along with operating profit and net 
income. The purpose of using operating revenue is solely because such a 
large proportion of the airline industry cannot be evaluated due to 
negative baseline operating profit and/or net income: 23 of 46 co-
permittee airlines with financial data available have negative baseline 
operating profit, and 25 of 46 have negative baseline net income. 
Furthermore, classifying an entity as a baseline closure does not mean 
it will necessarily close; a business entity might earn negative 
operating profit or net income at some point in its financial history 
without closing permanently, and this appears to be particularly 
prevalent in the airline industry (see, for example, the Industry 
Profile in the EA). Rather than ignore roughly half of all co-permittee 
airlines, EPA chose to evaluate them using the ratio of compliance 
costs to operating profit to determine if the rule imposes costs that 
can be characterized as ``relatively small.'' The primary drawback of 
using operating revenue to measure economic impacts is that, unlike 
with operating profit or net income, there is no obvious threshold that 
determines what is economically achievable.
    To respond to the issue of changing service levels at an airport, 
it would also be informative to perform, if possible, a closure 
analysis at the route level for each airline's routes associated with 
airports. However, EPA does not have airline financial data available, 
nor could it reasonably obtain airline financial data at either the 
route level or the airport level. Therefore, EPA must evaluate impacts 
to co-permittee airlines based on the only level at which airline 
financial data are available: their system-wide operations.

D. Results of Impact Analysis

1. Results of Airport Impact Analysis
a. Revenue Test Impact Results
    Table VII-2 shows the projected financial impact of the regulatory 
options considered for today's rule based on the revenue test. Under 
Option 1, airports would incur $78.4 million in annualized costs (7 
percent real interest rate), and 9 of the 198 airports (4.5 percent) 
are projected to incur costs exceeding 3 percent of operating revenue. 
Of the 198 BAT airports, 172 airports (87 percent) are projected to 
incur annualized compliance costs composing less than 1 percent of 
operating revenue. Under Option 2, airports would incur $49.4 million 
in annualized costs (7 percent real interest rate), and 5 of the 198 
airports (2.5 percent) are projected to incur costs exceeding 3 percent 
of operating revenue. Of the 198 airports subject to BAT, 176 airports 
(89 percent) are projected to incur annualized compliance costs 
composing less than 1 percent of operating revenue. Under both Option 1 
and Option 2, five airports incur costs but do not have airport-
specific financial data because they are part of Alaska's Rural 
Aviation System (RAS), and therefore could not be analyzed. Under 
Option 3, airports would incur $3.5 million in annualized costs (7 
percent real interest rate), and one of the 198 airports (0.5 percent) 
are projected to incur costs exceeding 3 percent of operating revenue. 
Of the 198 BAT airports, 190 airports (96 percent) are projected to 
incur annualized compliance costs composing less than 1 percent of 
operating revenue. Under Option 3, two airports incur costs but do not 
have airport-specific financial data because they are part of Alaska's 
RAS, and therefore could not be analyzed.

                      Table VII-2--Financial Impacts of BAT Options on Airports That Deice
                                    [2006 $million--198 airports (weighted)]
----------------------------------------------------------------------------------------------------------------
                                                   Number of airports with ratio of annualized compliance costs
                                       Total                         to operating revenue of:
             Option                 annualized   ---------------------------------------------------------------
                                       costs                      Between 1% and   Greater than    Not analyzed
                                                   Less than 1%         3%              3%              \a\
----------------------------------------------------------------------------------------------------------------
1...............................           $78.4             172              13               9               5
2...............................            49.4             176              13               5               5
3 \b\...........................            3.50             190               6               1               2
----------------------------------------------------------------------------------------------------------------
a Airports incurred compliance costs but are owned by the state of Alaska; financial impacts could not be
  analyzed because Alaska does not track revenue data for these airports.
b Selected option.

b. DSCR Impact Results
    For multi-airport systems, the DSCR must be evaluated at the level 
of the owner, aggregating compliance costs incurred by all system 
airports. Thus, EPA analyzes entities owning single airports separately 
from multi-airport systems. Under today's final rule, among owners of 
single airports, none are projected to be in danger of default on its 
debt even if 0 percent of compliance costs are assumed to be passed 
through to airlines (see Table VII-3). EPA identified three multi-
airport systems owning four airports projected to incur costs under the 
final rule (note these owners also owned other airports not projected 
to incur costs); the results presented in Table VII-4 show that today's 
final rule is projected to have no impact on the ability of multi-
airport authorities to finance debt. EPA did not analyze impacts to the 
DSCR for the Alaska RAS (one system owning two BAT airports) because 
Alaska does not use debt financing to fund this system.

[[Page 29192]]



   Table VII-3--Impact of Financing BAT Options on Airport Debt Service Coverage Ratio--Single Airport Owners
                                            [172 Airports (weighted)]
----------------------------------------------------------------------------------------------------------------
                                                                                    Owners with pre-regulatory
                                                                                       DSCR > 1.25 and post-
                                                    Incur costs    Not  analyzed      regulatory DSCR < 1.25
                     Option                             \a\             \a\      -------------------------------
                                                                                  100% cost pass   0% cost  pass
                                                                                      through         through
----------------------------------------------------------------------------------------------------------------
1...............................................             172              59               2               3
2...............................................             172              59               1               2
3 \b\...........................................              29               3               0               0
----------------------------------------------------------------------------------------------------------------
\a\ Of 198 airports (weighted), each of the 172 airports was estimated to be both subject to BAT under Option 1
  and Option 2 and the only airport controlled by its ownership. These columns represent the number of those 172
  airports projected to incur costs under each option, and of those airports incurring costs, the number that
  cannot be analyzed due to lack of sufficient data. Under Option 3, 29 airports incur costs under BAT; three of
  which cannot be analyzed due to lack of sufficient data.
\b\ Selected option.


                        Table VII-4--Impact of Financing BAT Options on Airport Debt Service Coverage Ratio--Multi Airport Owners
                                         [Nine airport authorities owning 21 in-scope airports (unweighted) \a\]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Incur costs \b\                Not analyzed \b\           Owners with pre-regulatory
                                                         ----------------------------------------------------------------      DSCR > 1.25 and post-
                                                                                                                              regulatory DSCR < 1.25
                         Option                                                                                          -------------------------------
                                                              Owners         Airports         Owners         Airports     100% cost pass   0% cost pass
                                                                                                                              through         through
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.......................................................               9              21               1               5               0               0
2.......................................................               9              21               1               5               0               0
3 \c\...................................................               3               4               0               0               0               0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Some airports that are part of a multi-airport system have a sample weight greater than one; because airports were not sampled based on ownership
  patterns, it is not appropriate to use the sample weight in this analysis. The results cannot be extrapolated to represent any airports and their
  ownership patterns other than themselves.
\b\ EPA found nine distinct airport authorities owning 21 airports that were determined to be subject to BAT under Options 1 and 2. These columns
  represent the number of airport owners and the number of airports they owned that are projected to incur costs under each option, and of those owners
  and airports incurring costs, the number that cannot be analyzed due to lack of sufficient data. Four airports owned by three airport systems incur
  costs under Option 3.
\c\ Selected option.

    For the selected option, the DSCR analysis was performed on 26 
airports owned by single airport authorities and 4 airports owned by 3 
multi-airport authorities expected to incur costs under BAT (3 airports 
owned by single airport authorities cannot be analyzed). EPA projects 
that none of these airports are at risk for default on their debt.
c. Impacts to Alaska's RAS
    Five airports operated by Alaska could not be analyzed using the 
revenue test or the DSCR as presented above; all five airports are 
projected to incur costs under Option 1 and Option 2, while only two of 
these five airports are projected to incur costs under Option 3. These 
airports are part of Alaska's RAS, which is not a self-supporting 
system; Alaska has determined these airports must remain open despite 
financial loses to provide access to otherwise isolated rural 
communities. EPA evaluated economic impacts to these airports 
separately, which is described as follows.
    Alaska operates two airport systems. The Alaska International 
Airport System (Ted Stevens Anchorage International Airport and 
Fairbanks International Airport) is a major enterprise fund of the 
state of Alaska, and considered to be self-sufficient; in short, the 
Alaska International Airport System operates in the same manner as most 
other multi-airport authorities in the United States. Alaska's second 
system, the RAS, which consists of 256 rural airports, is not a self-
sufficient government unit and loses money every year. EPA determined 
that five RAS airports (Bethel, Ketchikan International, Sitka Rocky 
Gutierrez, Nome, and Ralph Wien Memorial) would be subject to BAT 
requirements. Due to the nature of transportation in Alaska, it is 
vital that these airports remain in operation despite not being 
profitable; approximately 82 percent of Alaskan communities are not 
served by roads, and these communities rarely have a practical 
alternative to air transportation for access (see DCN AD01336). 
According to the Alaska Department of Transportation and Public 
Facilities, RAS airports ``are funded through a combination of user 
fees, state, local, or tribal funds, and federal funds.'' However, the 
rural airports have very limited opportunities for generating revenue; 
in 2004 revenues from airport users, concessions, and leasing of 
airport property comprised less than 17 percent of the cost of 
operating the system (DCN AD05081). The system is largely reliant on 
state subsidies to pay O&M costs at these airports. Therefore, EPA 
evaluated impacts to the RAS separately.
    EPA estimated compliance costs for the five RAS airports subject to 
BAT. EPA used the estimated yearly contribution of $23 to $24 million 
by the state of Alaska to cover the operating costs of the RAS (DCN 
AD05081) as a proxy for RAS operating revenues for the purpose of 
measuring economic impacts; this is an underestimate of RAS revenues 
because it does not account for the unknown revenue stream from other 
sources. Under the selected BAT option in the final rule, projected 
compliance

[[Page 29193]]

costs for the five RAS airports together total $61,000, which compose 
0.26 percent of the state's contribution to airport operations. EPA 
therefore determined that because compliance costs to the RAS compose 
less than 3 percent of the system's revenues, the rule is economically 
achievable to the RAS.
2. Results of Co-Permittee Airline Impact Analysis
    Under Options 1 and 2, EPA determined that 27 airports subject to 
BAT and incurring costs listed 75 individual airlines as co-permittees. 
However, under the selected Option 3, six airports subject to BAT and 
incurring costs listed 28 individual airlines as co-permittees. Twenty-
seven of these co-permittee airlines were U.S.-flagged, and one was 
foreign-owned under Option 3. On average, each of the 27 U.S.-flagged 
air carriers was a co-permittee at two airports, with a range of co-
permitting of between one to four airports. Under an assumption of a 
50:50 split of compliance costs between airports and co-permittee 
airlines, these 27 carriers would incur $180,000 in annualized 
compliance costs, and the foreign-flag carrier would incur less than 
$150 in annualized compliance costs.
    Twenty-five of the 27 U.S. co-permittee airlines have available 
financial data. Ten co-permittees have positive baseline operating 
profits, while nine have positive baseline net income, and therefore 
are eligible to be analyzed using these metrics. EPA projected that 
none of these airlines will incur costs exceeding 3 percent of 
operating profit or net income under Option 3, which is well short of 
the 100 percent threshold that would indicate a definitive closure. 
Furthermore, none of the 25 airlines were projected to incur compliance 
costs exceeding 1 percent of operating revenues under Option 3.
    Finally, to the extent that 50 percent of airport compliance costs 
are shared with co-permittee airlines, impacts to airports are reduced 
as measured by the ratio of compliance costs to operating revenue. EPA 
projects that no airports incur costs exceeding 3 percent of revenues 
under the promulgated option using the assumptions of the co-permittee 
airline analysis. Assuming no costs are shared with co-permittee 
airlines, EPA projected that one airport incurs costs exceeding 3 
percent of revenues under this option.
3. Economic Achievability
    Based on the analyses presented above, EPA has determined that the 
selected option is economically achievable. EPA finds that the 
promulgated option is economically achievable both when airports are 
assumed to incur 100 percent of compliance costs, and when airports and 
their applicable airline co-permittees are assumed to share compliance 
costs.
    Under previous rulemaking efforts that directly impose compliance 
costs on government agencies, EPA used the revenue test to evaluate 
impacts to these agencies; when projected compliance costs exceed 3 
percent of operating revenues, the rule is judged to be unaffordable 
for a facility. As shown in Table VII-2, only one airport, which 
represents 0.5 percent of the airports subject to BAT, is projected to 
incur costs exceeding 3 percent of operating revenue when airports are 
assumed to incur 100 percent of compliance costs. EPA used several 
conservative assumptions in evaluating impacts to airports; costs were 
annualized using a real 7 percent interest rate, which is significantly 
higher than airports typically pay for debt financing. At the 7 percent 
real interest rate, EPA demonstrated that airports' ability to service 
debt would not, in general, be negatively affected by the rule. EPA 
also did not take into account airports' ability to access other 
funding for capital expenditure, such as AIP grants or PFCs. Also, EPA 
performed its analysis of airport impacts without distributing any 
costs to co-permittee airlines. As such, the estimates of impacts at 
airports with co-permittees may be overstated.
    As noted in the previous section, EPA examined a number of 
alternative measures of economic impacts for airports in response to 
public comments on the proposed rule. However, EPA found none of these 
alternative approaches to be preferable to the revenue test method. 
None of the approaches provided a clear dividing line for determining 
what impacts might or might not be economically achievable for 
airports. That is, even if EPA selected one of industry's alternative 
measures, EPA would still have to determine some threshold that 
distinguishes impacts that are economically achievable from those that 
are not; industry did not provide such thresholds with their preferred 
measures, and for one measure specifically stated they did not know the 
appropriate threshold. Nevertheless, EPA did perform sensitivity 
analyses to determine what affect the use of these alternative measures 
might have on its conclusions on economic achievability of the final 
rule. EPA's sensitivity analyses found that using these alternative 
measures would not substantively change the overall results on the 
final rule's economic achievability. The results of these alternative 
analyses are not presented in this preamble, but are included in the EA 
as sensitivity analyses.
    With respect to airlines that are NPDES co-permittees, none of 
these airlines are shown to incur a demonstrable impact under the 
selected option on three airline income measures: operating revenue, 
operating profit, or net income. Therefore, EPA finds the costs to be 
economically achievable for co-permittee airlines for today's final 
rule.
    Finally, EPA also assumed compliance costs would not be passed 
through to airlines and/or their passengers in the form of higher rates 
and charges. As previously explained, EPA did assume costs would be 
shared by co-permittee airlines. The no-pass-through assumption is 
conservative and EPA believes that airports and, ultimately, airlines 
will likely pass through costs to reduce the cost and impact of the 
rule, which is further support for EPA's conclusion that today's final 
rule is economically achievable.

E. Economic Impacts for New Sources

    EPA has determined that the NSPS in the final rule would not impose 
a barrier to entry for new sources. DIA is the only ``greenfield'' 
airport, or an airport built on undeveloped land or land not previously 
used for aviation, that definitely meets the scope of this rulemaking, 
and was built in the past 25 years.\5\ DIA was developed with deicing 
pads and an extensive treatment system for collected ADF; information 
from DIA demonstrates that the CDPs, along with the extensive treatment 
system, comprised 3.6 percent of the cost of building a new airport, 
and did not pose a barrier to entry (DCN AD01260).
---------------------------------------------------------------------------

    \5\ DIA opened in 1995, but new, major airports built prior to 
Denver predate it by 20 or more years: Dallas-Fort Worth, which 
opened in 1973, George Bush International in Houston, Texas, and 
Washington Dulles, which opened in the 1960s.
---------------------------------------------------------------------------

    As previously indicated, the building of major greenfield airports 
has become a relatively rare occurrence. Conversion of ex-military 
airports (e.g., Orlando International) appears to be a much more common 
source of sites for cities seeking to increase air transportation 
access. Such conversions would not be considered ``new sources'' under 
today's rule. EPA reviewed FAA's National Plan of Integrated Airport 
Systems (NPIAS) reports published between 2002 and 2010, and found that 
the development of any new commercial service airports

[[Page 29194]]

is relatively rare, but a smaller commercial service greenfield airport 
is more likely to be built, as compared to a major airport. In 2002, 
FAA expected 125 airports, none of which were commercial service 
airports, to open within the next five years. Furthermore, when queried 
in 2011, FAA indicated that they had no applications for any new 
airports that would be subject to NSPS in today's rule, nor were they 
aware of any expected applications. However, two new primary airports 
recently opened in Panama City, Florida (May 2010), and St. George, 
Utah (January 2011). A new, smaller commercial airport is more likely 
than a large airport such as DIA, EPA wanted to examine the possible 
barrier to entry for new smaller commercial airports that might be 
subject to new source requirements.
    Based on incomplete data published in the NPIAS, EPA assumes that 
the St. George airport, with a planned service level of 55,000 annual 
enplanements, cost $159 million (approximately $145 million in 2006 
dollars). The Panama City airport, with a planned service level of 
225,000 annual enplanements, appears to have cost $318 million 
(approximately $289 in 2006 dollars) in the same period. Because 
eligibility for the ELG is partly based on non-propeller driven 
aircraft departures, EPA estimated departures for these two airports 
based on expected annual enplanements. Among the 198 existing airports 
subject to BAT requirements, only 14 airports in the lower 48 states 
have fewer than 100,000 annual enplanements, and only six airports have 
fewer than 60,000 annual enplanements. Thus, EPA believes an airport 
like St. George might be too small to be subject to the requirements of 
this new source performance standard.
    EPA then looked to Panama City as a model for a barrier to entry 
analysis for small, commercial facilities. Clearly, due to its 
location, an airport such as Panama City airport will not be subject to 
NSPS requirements. However, this airport is the only airport EPA found 
with data available on construction costs, and is of sufficient size 
that it might be subject to the ELG were it located further north. 
Therefore, EPA used Panama City's cost data to represent a new, 
relatively small airport that could be subject to NSPS.
    Based on the costs of constructing CDPs and related ADF wastewater 
treatment system at Denver, EPA estimated the average capital cost per 
departure of constructing a CDP and treatment system of appropriate 
size to meet the Denver airport's operating requirements as total 
capital cost of the deicing pad and treatment system divided by average 
annual departures. Thus, the average capital cost of a CDP and related 
ADF wastewater treatment system is approximately $897 per average 
annual departure at Denver. In addition, EPA estimated annual 
departures at Panama City; existing commercial service airports with 
annual enplanements between 200,000 and 300,000 have, on average, about 
32.3 passengers per departure, so EPA expects Panama City will average 
somewhat less than 6,959 departures per year \6\. Therefore, EPA 
estimates that should an airport the size of Panama City need to build 
a CDP and ADF wastewater treatment system, the capital cost of that pad 
will be about $6.2 million, or about 2.2 percent of the initial cost of 
the airport.
---------------------------------------------------------------------------

    \6\ EPA notes that NSPS for ADF collection and treatment only 
applies to airports that have at least 10,000 annual departures. 
Because Panama City is the only airport of its size for which EPA 
has data and because it is close to, but does not exceed, the size 
cut-off for NSPS applicability, EPA concludes that new airports with 
greater than 10,000 annual departures would similarly not experience 
a barrier to entry.
---------------------------------------------------------------------------

    Therefore, after comparing costs for CDPs and associated treatment 
systems at small and large airports in comparison to overall airport 
construction costs and finding that such pads and treatment systems 
cost from 2.2 percent to 3.3 percent of the cost of building a new 
airport, EPA has determined that the NSPS in the final rule would not 
impose a barrier to entry to new sources (DCN AD01260).

F. Cost and Pollutant Reduction Comparison

    Today's final rule is expected to reduce COD and ammonia loads by 
16.4 million pounds at an annualized cost of $3.5 million, for a cost 
of $0.21 per pound of pollutant removed.

Table VII-5--Pollutant Removals, Costs and Cost-Reasonableness of BAT Options for Airports That Deice (Weighted)
----------------------------------------------------------------------------------------------------------------
                                                       Total           Total                        Incremental
                                                     pollutant      annualized        Cost/lb         cost/lb
                     Option                          removals      costs (2006 $     pollutant       pollutant
                                                   (million lb)      million)         removed         removed
----------------------------------------------------------------------------------------------------------------
1...............................................            33.0          $78.4            $2.37          $10.4
2...............................................            30.2           49.4             1.64            3.3
3 \a\...........................................            16.4            3.50            0.21            0.21
----------------------------------------------------------------------------------------------------------------
\a\ Selected option.

    EPA has reviewed the relative cost per pound of pollutants removed 
in previous effluent guidelines and has found that the cost per pound 
presented in today's final airport deicing rule is similar to or less 
expensive than many guidelines promulgated to date including Aluminum 
Forming (40 CFR part 467), $2.42/lb; Landfills (40 CFR part 445), 
$15.00/lb; and Waste Combustors (40 CFR part 444), $38.83/lb. EPA notes 
that the selected option is eight times more cost effective than the 
next more stringent option based on average cost/lb removed, and 
sixteen times more cost effective than the next more stringent option 
based on incremental cost/lb removed.

G. Small Business Analysis

    The Regulatory Flexibility Act (RFA), as amended by the Small 
Business Regulatory Enforcement Fairness Act of 1996 (hereinafter 
referred to as RFA), acknowledges that small entities have limited 
resources, and makes it the responsibility of regulating federal 
agencies to avoid burdening such entities unnecessarily. The ultimate 
goal of RFA is to ensure that small entities do not incur 
disproportionate adverse economic impacts as a result of a regulation. 
The first step in this process is to determine the number and type of 
small entities potentially affected by the regulation.
    The RFA (5 U.S.C. 601) defines three types of small entities: Small 
business, small not-for-profit organization, and small governmental 
jurisdictions. Airport ownership is composed of states, county, city 
governments, and

[[Page 29195]]

single and multi-purpose port authorities. Single and multi-purpose 
port authorities are quasi-governmental agencies created by legislation 
to maintain and operate airports, shipping ports, and other government-
owned facilities such as bridges.
    The RFA defines a small government entity as governments of cities, 
counties, towns, townships, villages, school districts, or special 
districts, with a population of less than 50,000. After matching each 
airport-owning governmental entity with its population, EPA estimates 
that:
     72 airports are owned by small government entities.
     20 airports owned by small government entities are subject 
to BAT requirements in today's final rule.
     Three airports owned by small government entities and 
subject to BAT requirements incur costs under the promulgated option in 
today's final rule.

Although many Alaskan airports are relatively small when measured by 
service level, most of these airports are owned by the state of Alaska 
and therefore are not considered small for the purposes of the RFA; 10 
of the 11 surveyed Alaskan airports are not small by this standard.
    One of the 20 BAT airports owned by small government entities is 
expected to incur total annualized compliance costs exceeding three 
percent of airport operating revenues.

                 Table VII-6--Financial Impacts of BAT Options on Small Airports That Deice \a\
                                     [2006 $million--20 airports (weighted)]
----------------------------------------------------------------------------------------------------------------
                                                   Number of airports with ratio of annualized compliance costs
                                       Total                         to operating revenues of:
             Option                 annualized   ---------------------------------------------------------------
                                       costs                      Between 1% and   Greater than    Not  analyzed
                                                   Less than 1%         3%              3%              \b\
----------------------------------------------------------------------------------------------------------------
1...............................           $0.34              19               0               1               0
2...............................            0.34              19               0               1               0
3 \c\...........................            0.31              19               0               1               0
----------------------------------------------------------------------------------------------------------------
\a\ An airport is considered small if the governmental entity that owns the airport serves a region with less
  than 50,000 people.
\b\ Airports incurred compliance costs but financial impacts could not be analyzed due to lack of airport
  revenue data.
\c\ Selected option.

    EPA found that 18 airlines that are co-permittees at BAT airports 
are small by Small Business Administration (SBA) standards; 16 of these 
airlines had available financial data. Six airlines that are small by 
SBA standards are co-permittees at BAT airports that incur costs under 
the promulgated option, and five of these airlines have available 
financial data. None of the five small co-permittee airlines were 
projected to incur compliance costs exceeding 1 percent of operating 
revenues under Option 3. When comparing compliance costs with operating 
profits and net income, three small airlines had positive baseline 
operating profits and net income, and none are projected to incur costs 
exceeding 3 percent of either measure under Option 3. Again, these 
findings are well short of the 100 percent threshold that would 
indicate a definitive closure.
    One airport with airline co-permittees on its NPDES permit is small 
by SBA standards. This airport's projected compliance costs exceed 3 
percent of airport revenue if it does not share compliance costs with 
its co-permittee airlines. Its costs do not exceed 3 percent of revenue 
if it does share compliance costs with its co-permittee airlines.
    EPA concludes that small entities are not disproportionately 
affected by this effluent limitations guideline. Only a fraction of in-
scope airports are small by SBA standards, and only one of those 
airports is projected to incur costs exceeding 3 percent of operating 
revenues. Furthermore, this airport is not projected to exceed that 
threshold if 50 percent of its compliance costs are shared with co-
permittee airlines. EPA also concludes that small airlines are not 
disproportionately affected by the rule. Airlines are only subject to 
the rule if they are co-permittees on an airport's NPDES permit. Six 
co-permittee airlines are small by SBA standards; five of these 
airports have available financial data. As previously described, 
analysis of these airlines shows that under the assumption of 50:50 
costs sharing with affected airports, none come close to a threshold 
that indicates a significant impact of their financial situation.

VIII. Environmental Assessment

A. Environmental Impacts

    EPA has evaluated environmental impacts associated with the 
discharge of wastewater from airport deicing activities (Environmental 
Impact and Benefit Assessment [EIB]). As discussed in Section VI.B, 
deicing wastewater discharges can increase the loadings of multiple 
pollutants to receiving surface waters.
    The most widely recognized pollutant from deicing activity is 
oxygen-demanding material, measured as either COD or BOD5. 
All primary ingredients in both aircraft and airfield deicers exert 
oxygen demand. Propylene glycol and ethylene glycol are the primary 
ingredients in aircraft deicers. Acetate salts, formate salts, 
propylene glycol, ethylene glycol, and urea are the primary ingredients 
in airfield deicers. Propylene glycol and ethylene glycol, in 
particular, exert extremely high levels of oxygen demand when they 
decay in the environment. Acetates, formates, and urea exert lower, 
though still significant, levels of oxygen demand.
    Acetate or formate salts, the primary ingredients in many airfield 
deicers, also contain potassium or sodium. Potassium and sodium can 
raise overall salinity levels or cause ion imbalances in surface 
waters. Urea, another primary airfield deicer ingredient, decomposes in 
water to produce ammonia, a toxic compound, and nitrates, a nutrient 
pollutant that can increase the incidence of algal blooms in surface 
waters.
    Aircraft and airfield deicers also contain additives in addition to 
the primary ingredients. These additives serve a variety of purposes, 
such as reducing fluid surface tension, thickening, and fire and 
corrosion inhibition. Because deicer manufacturers consider the 
identity and quantity of additives in their formulations to be 
proprietary information, EPA was unable to obtain complete information 
on the nature and use of these additives.
    EPA was able to obtain some limited information through various 
public sources, and identified several additives with toxic properties. 
These additives include nonylphenol ethoxylates, alcohol ethoxylates, 
triazoles, and

[[Page 29196]]

polyacrylic acid, among others. Although toxic, these additives 
directly influence the effectiveness and safety of deicing and anti-
icing formulations and are therefore essential components. Because 
deicer formulations change periodically, some of the additives EPA 
identified may not be present in current formulations. Deicing fluid 
manufacturers are also investigating ways to formulate deicing and 
anti-icing compounds with the use of less toxic, or non-toxic, 
additives.
    Airports in the United States discharge deicing wastewater to a 
wide variety of water body types, including streams, rivers, lakes and 
estuaries. Many airports discharge deicing wastewater to small streams 
with limited waste dilution and assimilation capacities. Impacts from 
deicing wastewater discharges have been documented in a variety of 
surface waters adjacent to or downstream of a number of airports in the 
United States. Some locations experienced acute impact events, whereas 
other locations have experienced chronically degraded conditions. 
Observed impacts to surface waters include both physical and biological 
impacts. Some surface waters have been listed as impaired under section 
303(d) of the CWA because they do not meet applicable state water 
quality standards. Physical impacts include elevated levels of glycol, 
salinity, ammonia, and other pollutants; depressed oxygen levels; 
foaming; noxious odors; and discoloration. Biological impacts include 
reduced organism abundance, fish kills, modified community composition, 
and reduced species diversity.
    Deicing wastewater discharges have impaired both aquatic community 
health and human uses of water resources. Available documentation 
indicates multiple cases of hypoxic conditions and severe reduction in 
aquatic organism levels in surface waters downstream of deicing 
wastewater discharge locations. Documented human use impacts include 
contamination of surface drinking water sources, contamination of 
groundwater drinking water sources, degraded surface water aesthetics 
due to noxious odors and discolored water in residential areas and 
parklands, and degradation of fisheries.

B. Environmental Benefits

    EPA has evaluated environmental benefits associated with today's 
final rule to reduce the discharge of pollutants from airport deicing 
activities. This assessment is described in detail in the EIB. The 
final rule is expected to decrease COD discharges associated with 
airport runway deicing and anti-icing activities by approximately 12.0 
million pounds per year. The rule is also estimated to reduce ammonia 
discharges by 4.4 million pounds. Note these do not count benefits from 
the NSPS, which were not estimated quantitatively, due to the 
difficulty of predicting when and where in-scope new airports may be 
built. However, EPA projects qualifying new airport construction over 
the next decade to be minimal.
    The decline in pollutant loadings will reduce environmental impacts 
to surface waters adjacent to and downstream of these airports. A 
variety of surface waters have improved in quality after reductions in 
deicing pollutant loadings. Documented improvements have included 
abatement of noxious odors, decline in fish kill frequency, and partial 
recovery of community species diversity and organism abundance in small 
water bodies.
    Today's final rule will decrease pollutant loadings to multiple 
surface waters currently listed as impaired under CWA section 303(d). 
The rule will also reduce pollutant loadings to surface drinking water 
intakes, parks, and residential areas downstream of airports. 
Groundwater aquifers will also benefit. See the EIB for additional 
details.

IX. Non-Water Quality Environmental Impacts

    Sections 304(b) and 306 of the CWA require EPA to consider non-
water-quality environmental impacts (including energy requirements) 
associated with effluent limitations guidelines and standards. As 
explained in Section V, EPA evaluated three regulatory options for 
today's rule. The first two options are based on technologies to 
control aircraft and airfield deicing discharges and the third option 
is based on technology to control only airfield deicing discharges. 
Section V also explains that EPA selected Option 3 as the basis for the 
final requirements.
    To comply with the requirements to consider non-water quality 
environmental impacts, EPA first performed a formal analysis of the 
potential impact of the Option 1 technologies on energy consumption, 
air emissions, and solid waste generation. Because Option 2 is similar 
to Option 1, but would result in less operational changes at a subset 
of airports and therefore lead to less non-water quality impacts than 
Option 1, EPA did not perform a formal analysis of non-water quality 
impacts associated with Option 2. Instead, EPA concluded that the 
results for Option 2 will be similar to or less than Option 1. Because 
Option 3 is based only on technology to control airfield deicing 
discharges, EPA also analyzed impacts for Option 3. As described below, 
there are no non-water quality impacts associated with the regulatory 
option selected for the basis of the final regulation, Option 3. There 
are no increases in energy usage, air emissions, or solid waste 
generation associated with substituting one airfield deicing product 
with another. For a more in-depth discussion of EPA's formal analysis 
of non-water quality impacts, see the TDD.

A. Energy Requirements

1. Options 1 and 2
    Net energy consumption associated with Option 1 and Option 2 
considers electrical requirements for pumping ADF-contaminated 
stormwater from collection areas to storage, electrical requirements 
for operating AFB bioreactors, and fuel requirements for GCVs. There is 
no net energy consumption associated with product substitution, the 
technology basis for Option 3.
    EPA estimates that the total incremental electrical usage for 
Option 1 to pump ADF-contaminated stormwater into storage tanks would 
be approximately 1.2 million kilowatt hours per year (kWh/yr). EPA also 
developed a relationship between electrical use and COD removal by the 
AFB bioreactors based on information provided by Albany International 
(ALB) airport. Using the information from ALB, EPA estimated the 
electrical requirement for COD removal for Option 1 as approximately 
1.3 kWh/lb COD removed. Using this unit rate, EPA estimated total 
electrical requirements to remove COD for Option 1 to be a maximum 
additional 22 million kWh/yr.
    EPA also analyzed fuel use by GCVs collecting ADF-contaminated 
stormwater. EPA used Airport Questionnaire data for diesel fuel costs 
for GCVs, and then estimated an average diesel fuel use based on the 
unit cost for diesel fuel of $2.07/gallon.\7\ EPA then estimated annual 
fuel usage per gallon of applied ADF to be 0.08 gallons per gallon of 
ADF applied. Using this relationship, EPA estimated that the total 
incremental consumption of No. 2 diesel fuel, at all airports subject 
to BAT and installing additional collection

[[Page 29197]]

equipment, to be 354,500 gallons per year.
---------------------------------------------------------------------------

    \7\ This diesel fuel price was the average reported by the 
Energy Information Administration for the 2004 to 2005 winter 
season, the same period that EPA is analyzing for airport deicing 
activity.
---------------------------------------------------------------------------

    EPA compared incremental diesel fuel use by GCVs as a result of 
Option 1 to diesel fuel use on a national basis. Approximately 25.4 
million gallons of No. 2 diesel fuel was consumed per day in the United 
States in 2005. The diesel fuel requirement associated with Option 1 is 
less than 0.004 percent of the annual amount of diesel fuel consumed.
    EPA also considered qualitatively the potential for Options 1 and 2 
to cause flight delays and possibly greater jet fuel use as a result. 
EPA was not able to quantify this effect, because EPA was not able to 
project how many flights would be delayed for how long or how much 
extra fuel use this might entail. However, EPA's selection of Option 3 
will also ensure that there are no unacceptable energy impacts 
associated with increased jet fuel use.
2. Option 3
    EPA did not identify any additional energy consumption associated 
with the Option 3 technology. There is no change in energy consumption 
associated with substituting one airfield deicer with another.

B. Air Emissions

1. Options 1 and 2
    Additional air emissions as a result of Option 1 could be 
attributed to added diesel fuel combustion by GCVs collecting ADF-
contaminated stormwater and from anaerobic treatment of ADF. Emissions 
from these sources are discussed below. There could also be increases 
in emissions from aircraft operations associated with Option 1, but EPA 
was not able to quantify this effect.
a. Emissions From GCV Collection
    EPA estimated the air emissions from the Option 1 ADF collection 
requirement. As discussed in Section IX.A above, EPA conservatively 
estimated that GCVs collecting ADF-contaminated stormwater at airports 
will consume an additional 354,500 gallons of No. 2 diesel fuel per 
year. To estimate air emissions related to combustion of No. 2 diesel 
fuel in the internal combustion engines on GCVs, EPA used published 
emission factors for internal combustion engines. The Agency selected 
emission factors for gasoline and diesel industrial engines because EPA 
assumed this class to be a more representative population of engines. 
To estimate emissions from the GCVs, EPA first converted the additional 
354,500 gallons of diesel fuel to million British thermal units and 
then applied the appropriate emission factors. The calculated annual 
emissions indicate that an additional 4,070 tons per year of 
CO2 will be emitted from GCVs combusting additional diesel 
fuel to comply with the rule. CO2 is the primary greenhouse 
gas attributed to climate change, and the 4,070 additional tons per 
year that would be associated with the rule is very small, as relative 
to other sources. For example, in 2006, industrial facilities 
combusting fossil fuels emitted 948 million tons of CO2 
equivalents. An additional 4,070 tons per year from GCVs is less than a 
0.0004 percent increase in the overall CO2 emissions from 
all industrial sources.
b. Emissions From AFB Treatment Systems
    Anaerobic digestion of glycols found in ADF-contaminated stormwater 
generates biogas containing approximately 60 percent methane and 40 
percent CO2. Airports installing AFBs for treatment of ADF-
contaminated stormwater are expected to burn a portion of the gas in 
onsite boilers in order to maintain reactor temperature. The remainder 
of gas can be either combusted in a microturbine for electricity 
generation or flared. Regardless of the combustion technology, nearly 
all biogas generated by AFBs is converted to CO2, the 
primary greenhouse gas. EPA calculates a maximum 3,730 additional tons 
per year of CO2 generation for 40 percent ADF collection, 
which is very small relative to other sources. For example, in 2006, 
industrial facilities combusting fossil fuels emitted 948 million tons 
of CO2 equivalents. An additional 3,730 tons per year of 
CO2 from AFB treatment is less than 0.0004 percent of the 
annual industrial CO2 emissions nationwide.
2. Option 3
    EPA did not identify any additional air emissions associated with 
the Option 3 technology. There is no change in air emissions associated 
with substituting one airfield deicer with another.

C. Solid Waste Generation

1. Options 1 and 2
    AFB bioreactors will generate sludge that will require disposal, 
probably in an offsite landfill. To estimate annual sludge generation 
by the AFB bioreactors that may be installed at airports to treat ADF-
contaminated stormwater under Option 1, EPA first estimated the 
potential COD removal for the collection and treatment scenarios and 
then applied published anaerobic biomass yield information to estimate 
total sludge generation on a national basis. The biomass yield 
calculation, which simply multiplies the COD removal by the yield, is a 
rough method of estimating sludge generation and does not account for 
other factors such as degradation or inorganic material (e.g., AFB 
media) that may be entrained into the sludge. However, this method does 
provide an order of magnitude estimate of sludge generation that can be 
compared to other types of common biological treatment systems to 
determine if AFB sludge generation would be unusually high at airports 
treating ADF-contaminated stormwater.
    To provide some perspective on the potential total amount of 
biomass produced annually by the AFB biological reactors treating ADF-
contaminated stormwater, EPA compared the most conservative biomass 
generation estimate with its national biosolids estimates for all 
domestic wastewater treatment plants throughout the United States. 
Approximately 8.2 million dry tons of biosolids were produced in 2010. 
EPA estimates that AFB bioreactors treating ADF-contaminated stormwater 
will increase biosolids generation in the United States by 
approximately 271 dry tons/year or less than 0.003 percent of dry ton 
biosolids produced in the United States in 2010.
2. Option 3
    EPA did not identify any additional sludge generation associated 
with the Option 3 technology. There is no change in sludge generation 
associated with substituting one airfield deicer with another.

X. Regulatory Implementation

A. Relation of ELGs and Standards to NPDES Permits

    Effluent guidelines act as a primary mechanism to control the 
discharge of pollutants to waters of the United States. Today's final 
rule will be applied to airports through incorporation in individual or 
general NPDES permits issued by EPA or authorized states under section 
402 of the Act.
    The Agency has developed the limitations for this final rule to 
cover the discharge of pollutants from this point source category. 
Those permits issued after this rule is effective must incorporate the 
effluent limitations guidelines and NSPS in this rule. For airports 
below the regulatory thresholds in this rule, EPA intends to allow 
permitting authorities to apply technology-based requirements on a best 
professional judgment basis. Also, for any airport discharges, under 
section 510 of the CWA, states may require

[[Page 29198]]

effluent limitations under state law as long as they are no less 
stringent than the requirements of this rule. Finally, in addition to 
requiring application of the technology-based effluent limitations 
guidelines and standards in this rule, section 301(b)(1)(C) of CWA 
requires the permitting authority to impose more stringent effluent 
limitations on discharges as necessary to meet applicable water quality 
standards.
    For individual permits, ELG provisions are typically incorporated 
when those permits are renewed, although permit authorities may require 
modification upon promulgation upon consent of the permittee. EPA will 
revise its MSGP to include the airport deicing provisions when the 
permit is renewed, and authorized states will proceed likewise with 
their respective general permits.

B. Effective Date

    The effective date for today's final rule is June 15, 2012.

C. Compliance With the NSPS Requirement

1. Applicability
    The final rule establishes airfield pavement deicing effluent 
controls for new primary airports with 1,000 non-propeller aircraft 
departures annually. For a subset of these airports--certain airports 
located in cold climatic zones--it also establishes ADF effluent 
controls.
    A new airport that opens with less than 1,000 departures would not 
be subject to today's requirements. However, if the number of 
departures at this new airport later increases above the departure 
threshold, then Sec.  449.11 becomes applicable. For the ADF collection 
and treatment NSPS requirements, if a new airport located in an area 
that has more than 3,000 annual heating degree days and estimates that 
within five years of commencing operations it will exceed 10,000 annual 
departures, EPA expects it to plan during initial construction to be 
able to install facilities that comply with the ADF collection and 
treatment requirement should the departure threshold of the ADF 
collection and treatment threshold be exceeded. If the new airport 
elects not to do so, it must still meet all applicable ADF collection 
and discharge requirements in the event it exceeds the departure 
threshold within five years of construction. During the planning 
process for a new airport, FAA requires the airport sponsors to prepare 
long-range aviation forecasts, including estimates of passenger 
enplanement levels and use of jet aircraft. See FAA Advisory Circular 
150/5070-6B, Chapter 7, ``Aviation Forecasts.'' These forecasts will 
provide a sufficient basis for a new source airport to estimate if it 
will be likely to exceed the departure threshold.
2. Demonstrating Compliance With the NSPS Collection Requirement
    The NSPS ADF collection requirement differs from end-of-pipe 
effluent limitations with regard to demonstrating compliance. 
Compliance with the collection requirement may not always be determined 
through end-of-pipe sampling and analysis. Additionally, the amount of 
ADF available for collection can vary depending on the weather and 
icing conditions at the time of application. As in the proposed rule, 
today's final rule provides three procedures for selection by the 
permittee, for demonstrating compliance with the ADF collection 
requirement.
    To use the first procedure, at Sec.  449.20(b), a permittee 
certifies to the permitting authority that it is operating its 
collection system in accordance with specifications for the applicable 
technology. The specifications describe design and operating practices 
for the technologies. As long as these technologies are operated and 
maintained as required, the permittee will be deemed in compliance with 
the associated collection rate. The only reporting requirement for this 
procedure is for the permitted facilities to certify to the permit 
authority that it is operating according to the specifications.
    Since it is not practical for EPA to provide operating 
specifications for all potential collection technologies, the procedure 
at Sec.  449.20(b)(2) allows an airport with an individual permit to 
propose performing ADF collection with a technology other than those 
described in the regulations. The permit authority may allow, on a 
case-by-case basis, an alternative ADF collection technology as the 
manner in which the permittee must demonstrate compliance with its 
collection requirement. The Director may also allow alternate operating 
parameters for one of the technologies listed elsewhere in Sec.  
449.20, as requested and demonstrated by the permittee. For example, an 
airport may operate a CDP, and through more aggressive collection 
measures, have data to show that 60 percent of available ADF for its 
aircraft deicing operations as a whole is collected, without 
necessarily having all flights deiced in the designated collection 
area(s). Another example would be an airport that uses a technology 
other than CDPs, with clearly detailed technical specifications and 
data demonstrating it achieves 60 percent collection of the available 
ADF. A third example would be an airport that is unable or unwilling to 
use a standard set of collection technologies and operating procedures, 
and instead elects to demonstrate compliance with the ADF collection 
requirement by regular monitoring of applied and collected ADF. See 
Sec.  449.20(a)(3). EPA has not published a specific monitoring 
methodology for a permittee to demonstrate its compliance with the 
collection requirement, but expects that such a demonstration would 
involve some type of mass-balance analysis. This procedure would be 
developed by the permittee, prior to the permitting authority proposing 
the permit, so that the method would be subject to public comments 
prior to incorporation into the permit. As long as the permittee is 
able to demonstrate to the permit authority's satisfaction that the 
specified technology is designed to achieve the collection requirement 
as set forth in Sec.  449.11(a)(1), the only reporting requirement for 
this provision is for the permittee to certify that it is operating and 
maintaining its technology as required in its permit.
3. P2 Approaches
    Several P2 approaches and technologies are described above in 
Section IV.D.3. Although EPA did not identify any of these technologies 
as a basis for NSPS, these technologies may be effective at reducing 
available ADF. Moreover, future P2 technologies may become available to 
aid in meeting the NSPS requirements. Permittees using P2 technologies 
that reduce the volume of, or quantity of, pollutants in, available ADF 
may request a credit to be applied to the ADF collection requirement. 
Under Sec.  449.20 (b)(2)(ii), a permittee may request a credit by 
providing documentation of the volumes or loads associated with the 
available ADF that would be generated in the absence of the P2 approach 
and the volumes or loads associated with the available ADF reduced 
through the use of P2. Once the permit authority determines that the 
reduction values are demonstrated, it will adjust the ADF collection 
requirement by subtracting the P2-based available ADF reductions from 
the original ADF collection requirement. The following two examples 
show how an airport may use the P2 provisions to reduce the amount of 
ADF that is required for collection.
a. P2 Example 1
    On average, Airport X uses 600 gallons of Type I ADF and 500 
gallons of Type IV ADF per flight and has 1,000

[[Page 29199]]

flights during a deicing season. In order to meet the 60 percent 
collection requirement, the airport must demonstrate the collection and 
treatment (or equivalent source reduction of) 300,000 gallons of 
available ADF.
     600 gallons Type I x 75% available for collection + 500 
gallons x 10% available for collection = 500 gallons available ADF/
flight
     500 gallons available ADF/flight x 1,000 flights x 60 
percent collection = 300,000 gallons for collection.
    The airport decides to install an IR deicing system and wants to 
use it in combination with GCVs as the basis for its 60 percent 
collection requirement. The airport provides data to its permit 
authority that use of an IR deicing system reduces 90 percent of the 
available ADF per aircraft and that the new IR facility has the 
capability of comfortably handling 600 flights per deicing season. This 
reduction is equivalent to the collection of 270,000 gallons of 
available ADF as shown below:
     500 gallons available ADF/flight x 90 percent reduction in 
available ADF = 450 gallons ADF reduction per flight
     600 flights x 450 gallon reduced = 270,000 gallons ADF 
reduced.
    Therefore, the airport would need to collect an additional 30,000 
gallons of available ADF during the deicing season:
     300,000 gallons of ADF required for control -270,000 
gallons of ADF reduced = 30,000 gallons to collect.
    EPA's documentation shows that GCVs collect 20 percent of available 
ADF. In order to collect the remaining 30,000 gallons, the airport 
would need to use GCVs when deicing 300 flights during the deicing 
season.
     500 gallons of available ADF/flight x 20 percent 
collection = 100 gallons of ADF collected per flight.
     300 flights x 100 gallons collected per flights = 30,000 
gallons of ADF collected.
    In this example, for every 1,000 flights where deicing would be 
appropriate, the airport could use the IR for 600 flights, GCVs for 300 
flights, and may elect to collect nothing for 100 flights. More 
generically, for every one flight deiced with no collection, three 
flights must be deiced in an area with GCV collection and six flights 
must be sent through the IR system. The airport would have the 
flexibility to apply these technologies as appropriate for each event. 
For example, if the airport was experiencing exceptional delays for a 
particular event, the airport could forgo collection during that event 
as long as it had documentation to demonstrate that over the deicing 
season the combination of these technologies was applied in a manner to 
theoretically achieve the required percentage.
b. P2 Example 2
    On average, Airport Y uses 300 gallons of available ADF per flight 
and has 8,000 flights during the deicing season. In order to meet the 
60 percent collection requirement, the airport must demonstrate the 
collection and treatment (or equivalent source reduction of) 1,440,000 
gallons of available ADF.
     300 gallons available ADF/flight x 8,000 flights x 60 
percent collection = 1,440,000 gallons for collection.
    Airport Y has recently installed forced air nozzles and covered 
deicing booms, and has provided data to its permit authority that use 
of these technologies together reduces 65 percent of the available ADF 
per aircraft.
    Airport Y deices all of its aircraft using these forced air nozzles 
and covered deicing booms, resulting in a source reduction of 1,560,000 
gallons of ADF per deicing season.
     300 gallons of Available ADF/flight x 65 percent reduction 
= 195 gallons of ADF reduced per flight
     8000 flights x 195 gallons reduced per flights = 1,560,000 
gallons of ADF reduced.
    As a result, Airport Y is in compliance with the 60 percent 
collection requirement simply through the use of the P2 technologies.

D. Alternative Compliance Option for Pavement Deicers Containing Urea

    While EPA expects that most airports will choose product 
substitution to meet the pavement deicer requirement in Sec.  449.10(b) 
or Sec.  449.11(b), airports may continue to use pavement deicers 
containing urea if they meet the alternative effluent limitation. An 
airport that chooses this alternative is required to perform an 
analysis for ammonia in airfield pavement discharges at all locations 
where pavement deicing with deicers containing urea is occurring and 
must achieve the numeric limitations for ammonia prior to any dilution 
or commingling with other non-deicing discharges. The sampling 
frequency, analytical method, and reporting procedures are determined 
by the permit authority.

E. COD Effluent Monitoring for New Source Direct Dischargers

    New source direct dischargers subject to Sec.  449.11(a) are 
required to sample and analyze the discharges from their treatment 
system for COD prior to any dilution or commingling with other non-
deicing waters. The sampling frequency, analytical method, and 
reporting procedures are determined by the permit authority. Permittees 
must follow the sampling protocol specified in Appendix A of Part 449.

F. Best Management Practices

    Sections 304(e), 308(a), 402(a), and 501(a) of the CWA authorize 
the Administrator to prescribe best management practices (BMPs) as part 
of effluent guidelines and standards or as part of a permit. EPA's BMP 
regulations are found at 40 CFR 122.44(k). Section 304(e) of the CWA 
authorizes EPA to include BMPs in effluent limitation guidelines for 
certain toxic or hazardous pollutants to control ``plant site runoff, 
spillage or leaks, sludge or waste disposal, and drainage from raw 
material storage.'' CWA section 402(a)(1) and NPDES regulations (40 CFR 
122.44(k)) also provide for BMPs to control or abate the discharge of 
pollutants when numeric limitations and standards are infeasible. In 
addition, CWA section 402(a)(2), read in concert with CWA section 
501(a), authorizes EPA to prescribe as wide a range of permit 
conditions as the Administrator deems appropriate in order to ensure 
compliance with applicable effluent limitations and standards and such 
other requirements as the Administrator deems appropriate.
    There are no BMPs specified in today's final rule. However, 
existing NPDES permits for airports include BMP requirements, and some 
permits may have included, as required BMPs, the technologies that EPA 
has identified as a basis for BAT or NSPS in today's rule. Other BMPs 
included in airport permits include dikes, curbs, and other control 
measures to contain leaks and spills as part of good ``housekeeping'' 
practices. Under section 510 of the CWA or section 301(b)(1)(C), a 
permitting authority on a facility-by-facility basis may choose to 
incorporate BMPs into the permit. See the TDD for a detailed discussion 
of P2 and BMPs used by airports and airlines.

G. Upset and Bypass Provisions

    A ``bypass'' is an intentional diversion of the streams from any 
portion of a treatment facility. An ``upset'' is an exceptional 
incident in which there is unintentional and temporary noncompliance 
with technology-based permit effluent limitations because of factors 
beyond the reasonable control of the permittee. EPA's regulations 
concerning bypasses and upsets for direct dischargers are set forth at 
40 CFR 122.41(m) and (n). The bypass

[[Page 29200]]

provisions could be used to address situations where an emergency 
application of ADF or pavement deicer was necessary to ensure safe 
operation of an aircraft or airfield, provided the conditions for its 
use are met.

H. Variances and Modifications

    The CWA requires application of effluent limitations established 
pursuant to Section 301 to all direct dischargers. However, the statute 
provides for the modification of these national requirements in a 
limited number of circumstances. The Agency has established 
administrative mechanisms to provide an opportunity for relief from the 
application of the national effluent limitations guidelines for 
categories of existing sources for toxic, conventional, and 
nonconventional pollutants.
1. Fundamentally Different Factors (FDF) Variance
    EPA, with the concurrence of the state, may develop effluent 
limitations different from the otherwise applicable requirements if an 
individual discharger is fundamentally different with respect to 
factors considered in establishing the limitation of standards 
applicable to the individual discharger. Such a modification is known 
as an FDF variance. EPA, in its initial implementation of the effluent 
guidelines program, provided for the FDF modifications in regulations, 
which were variances from the BCT effluent limitations, BAT limitations 
for toxic and nonconventional pollutants, and BPT limitations for 
conventional pollutants for direct dischargers. FDF variances for toxic 
pollutants were challenged judicially and ultimately sustained by the 
Supreme Court (Chemical Manufacturers Association v. Natural Resources 
Defense Council, 479 U.S. 116 (1985)).
    Subsequently, in the Water Quality Act of 1987, Congress added new 
CWA Section 301(n). This provision explicitly authorizes modifications 
of the otherwise applicable BAT effluent limitations, if a discharger 
is fundamentally different with respect to the factors specified in CWA 
Section 304 (other than costs) from those considered by EPA in 
establishing the effluent limitations. CWA Section 301(n) also defined 
the conditions under which EPA may establish alternative requirements. 
Under Section 301(n), an application for approval of a FDF variance 
must be based solely on (1) information submitted during rulemaking 
raising the factors that are fundamentally different or (2) information 
the applicant did not have an opportunity to submit. The alternate 
limitation must be no less stringent than justified by the difference 
and must not result in markedly more adverse non-water quality 
environmental impacts than the national limitation.
    EPA regulations at 40 CFR part 125, subpart D, authorizing the 
regional administrators to establish alternative limitations, further 
detail the substantive criteria used to evaluate FDF variance requests 
for direct dischargers. Thus, 40 CFR 125.31(d) identifies six factors 
(e.g., volume of process wastewater, age and size of a discharger's 
facility) that may be considered in determining if a discharger is 
fundamentally different. The Agency must determine whether, based on 
one or more of these factors, the discharger in question is 
fundamentally different from the dischargers and factors considered by 
EPA in developing the nationally applicable effluent guidelines. The 
regulation also lists four other factors (e.g., inability to install 
equipment within the time allowed or a discharger's ability to pay) 
that may not provide a basis for an FDF variance. In addition, under 40 
CFR 125.31(b) (3), a request for limitations less stringent than the 
national limitation may be approved only if compliance with the 
national limitations would result in either (a) a removal cost wholly 
out of proportion to the removal cost considered during development of 
the national limitations, or (b) a non-water quality environmental 
impact (including energy requirements) fundamentally more adverse than 
the impact considered during development of the national limits. The 
legislative history of Section 301(n) underscores the necessity for the 
FDF variance applicant to establish eligibility for the variance. EPA's 
regulations at 40 CFR 125.32(b)(1) are explicit in imposing this burden 
upon the applicant. The applicant must show that the factors relating 
to the discharge controlled by the applicant's permit which are claimed 
to be fundamentally different are, in fact, fundamentally different 
from those factors considered by EPA in establishing the applicable 
guidelines. In practice, very few FDF variances have been granted for 
past ELGs. An FDF variance is not available to a new source subject to 
NSPS.
2. Economic Variances
    Section 301(c) of the CWA authorizes a variance from the otherwise 
applicable BAT effluent guidelines for nonconventional pollutants due 
to economic factors. The request for a variance from effluent 
limitations developed from BAT guidelines must normally be filed by the 
discharger during the public notice period for the draft permit. Other 
filing periods may apply, as specified in 40 CFR 122.21(m)(2). Specific 
guidance for this type of variance is provided in ``Draft Guidance for 
Application and Review of Section 301(c) Variance Requests,'' dated 
August 21, 1984, available on EPA's Web site at http://www.epa.gov/npdes/pubs/OWM0469.pdf.
3. Water Quality Variances
    Section 301(g) of the CWA authorizes a variance from BAT effluent 
guidelines for certain nonconventional pollutants due to localized 
environmental factors. These pollutants include ammonia, chlorine, 
color, iron, and total phenols.

I. Information Resources

    The Transportation Research Board (TRB), a division of the National 
Academies of Science, established a research panel to develop fact 
sheets on deicing practices to assist airports in reducing their 
deicing chemical usage and discharges. A report was prepared in 2009 
under TRB's Airport Cooperative Research Program, titled ``Deicing 
Planning Guidelines and Practices for Stormwater Management Systems.'' 
This report (DCN AD01191) and the fact sheets (DCN AD01192) are 
available in the docket for today's rule.

XI. Statutory and Executive Order (EO) Reviews

A. EO 12866: Regulatory Planning and Review and EO 13563: Improving 
Regulation and Regulatory Review

    EPA submitted this action to OMB for review under EO 12866 (58 FR 
51735, October 4, 1993) and EO 13563 (76 FR 3821, January 21, 2011) and 
any changes made in response to OMB recommendations have been 
documented in the docket for this action.

B. Paperwork Reduction Act

    OMB has approved the information collection requirements contained 
in this rule under the provisions of the Paperwork Reduction Act, 44 
U.S.C. 3501 et seq. and has assigned OMB control number 2040-0285. 
Section 449.10(a) requires that airports certify annually on the non-
use of airfield pavement deicers containing urea (unless they choose to 
comply with a numeric limit for ammonia instead).
    EPA estimates it will take an annual average of 198 hours and 
$6,534 for permittees to collect and report the information required by 
the rule. This estimate is based on average labor rates obtained from 
EPA's airport questionnaire. EPA estimates that the

[[Page 29201]]

time and cost for permit authorities to review the information 
submitted in response to requirements in the rule is negligible. EPA 
estimates that there will be no start-up or capital cost associated 
with the information described above. Burden is defined at 5 CFR 
1320(b).
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9. In addition, EPA is 
amending the table in 40 CFR part 9 of currently approved OMB control 
numbers for various regulations to list the regulatory citations for 
the information requirements contained in this final rule.

C. Regulatory Flexibility Act

    The RFA generally requires an agency to prepare a regulatory 
flexibility analysis of any rule subject to notice and comment 
rulemaking requirements under the Administrative Procedure Act or any 
other statute unless the agency certifies that the rule will not have a 
significant economic impact on a substantial number of small entities. 
Small entities include small businesses, small organizations, and small 
governmental jurisdictions.
    For the purposes of assessing the impacts of today's final rule on 
small entities, EPA determined that all airports expected to be subject 
to BAT requirements are owned by government entities. The RFA defines a 
small government entity as governments of cities, counties, towns, 
townships, villages, school districts, or special districts, with a 
population of less than 50,000 (5 U.S.C. 601 (5)). After considering 
the economic impact of today's final rule on small entities, including 
consideration of alternative regulatory approaches, I certify that this 
action will not have a significant economic impact on a substantial 
number of small entities. After matching each airport-owning 
governmental entity with its population, EPA estimates that 20 of 198 
airports subject to BAT, or 10 percent, are owned by small government 
entities. EPA projected impacts on these small airports using the 
revenue test described in Section VII.C.2.a. EPA found that one of the 
20 small BAT airports are expected to incur annualized compliance costs 
exceeding 3 percent of airport operating revenues.
    In general, airlines are not directly subject to the final rule. In 
a small number of cases, airlines are co-permittees on NPDES permits at 
certain airports, and such co-permittee airlines are therefore subject 
to the final rule. EPA determined that 18 airlines considered small by 
SBA standards are co-permittees, but based on the analytic approach 
described in Section VII.C.3, none are expected to be significantly 
impacted by the rule
    Although this final rule will not have a significant economic 
impact on a substantial number of small entities, EPA undertook a 
number of steps to minimize the impact of this rule on small entities. 
According to the FAA NPIAS (2007-2011), there are almost 3,000 public 
use general aviation and reliever airports in the United States, some 
of which have substantial cargo service. Many, if not most, of these 
airports are likely to be owned by small government entities. Also 
likely to be owned by small governmental entities are approximately 135 
non-primary commercial service airports. EPA has chosen not to regulate 
any general aviation, reliever, or non-primary commercial service 
airports under today's final rule. EPA also estimates that in addition 
to the 20 small government-owned primary commercial airports, another 
52 primary commercial airports are owned by small government entities, 
but will be out-of-scope of the regulation because little or no ADF is 
used at those airports.

D. Unfunded Mandates Reform Act (UMRA)

    This rule does not contain a federal mandate that may result in 
expenditures of $100 million or more for state, local, and tribal 
governments, in the aggregate, or the private sector in any one year. 
As explained in Section VII and the TDD, the annual cost of the rule is 
$3.5 million. Thus, this rule is not subject to the requirements of 
sections 202 or 205 of UMRA.
    By statute, a small government jurisdiction is defined as a 
government with a population less than 50,000 (5 U.S.C. 601). Because 
all in-scope airports are owned by a government or governmental agency, 
the definition for a small airport is identical for the purposes of 
both UMRA and SBREFA. If the rule exceeds annual compliance costs of 
$100 million in aggregate, all provisions of UMRA will need to be met. 
If the rule does not exceed $100 million in aggregate costs, but small 
airports are significantly or uniquely affected by the rule, EPA will 
be required to develop the small government agency plan required under 
section 203 of UMRA because these airports are owned by small 
governments.
    This rule is also not subject to the requirements of section 203 of 
UMRA because it contains no regulatory requirements that might 
significantly or uniquely affect small governments. The scope of the 
rule focuses on the airports that are the largest users of ADF. The 
rule is not projected to exceed $100 million in aggregate annual 
compliance costs. Further, as discussed in Section XI.C, EPA has 
determined the rule will not have significant economic impact on a 
substantial number of small entities.

E. EO 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government, as 
specified in EO 13132 (64 FR 43255, August 10, 1999). Today's final 
rule requires airports to implement water pollution control 
requirements through a long-established regulatory mechanism (i.e., 
NPDES) which is jointly administered by EPA and states. EPA expects the 
rule will have little effect on the relationship between, or the 
distribution of power and responsibilities among, the federal and state 
governments. Thus, EO 13132 does not apply to this action. In the 
spirit of EO 13132 and consistent with EPA policy to promote 
communications between EPA and state and local governments, EPA 
specifically solicited comment on the proposed action from state and 
local officials, however, none were received on the topic of 
federalism.

F. EO 13175: Consultation and Coordination With Indian Tribal 
Governments

    This rule does not have tribal implications, as specified in EO 
13175 (65 FR 67249, November 6, 2000). It will not have substantial 
direct effects on tribal governments, on the relationship between the 
federal government and Indian tribes, or on the distribution of power 
and responsibilities between the federal government and Indian tribes. 
Today's rule contains no federal mandates for tribal governments and 
does not impose any enforceable duties on tribal governments. Thus, EO 
13175 does not apply to this rule. In the spirit of EO 13175 and 
consistent with EPA policy to promote communications between EPA and 
tribal governments, EPA specifically solicited comment on the proposed 
rule on tribal impacts. No comments were received on this topic.

[[Page 29202]]

G. EO 13045: Protection of Children From Environmental Health and 
Safety Risks

    This rule is not subject to EO 13045 (62 FR 19885, April 23, 1997) 
because it is not an economically significant rule pursuant to EO 
12866.

H. EO 13211: Energy Effects

    This rule is not a ``significant energy action'' as defined in EO 
13211, ``Actions Concerning Regulations That Significantly Affect 
Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001) 
because it is not likely to have a significant adverse effect on the 
supply, distribution, or use of energy. As explained in Section IX.A, 
EPA determined that today's final rule will not require any additional 
energy usage.

I. National Technology Transfer Advancement Act (NTTAA)

    Section 12(d) of the NTTAA of 1995, (Pub. L. 104-113, sec. 12(d); 
15 U.S.C. 272) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standard bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    The rulemaking involves technical standards. Therefore, the Agency 
conducted a search to identify potentially applicable voluntary 
consensus standards. However, EPA identified no such standards, and 
none were brought to EPA's attention in comments. Therefore, EPA 
decided to use the technology-based controls for aircraft and airfield 
pavement deicing discharges described in Section V.

J. EO 12898: Federal Actions To Address Environmental Justice in 
Minority Populations and Low-Income Populations

    EO 12898 (59 FR 7629, February 16, 1994) establishes federal 
executive policy on environmental justice. Its main provision directs 
federal agencies, to the greatest extent practicable and permitted by 
law, to make environmental justice part of their mission by identifying 
and addressing, as appropriate, disproportionately high and adverse 
human health or environmental effects of their programs, policies, and 
activities on minority populations and low-income populations in the 
United States.
    EPA has determined that this final rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it increases the 
level of environmental protection for all affected populations without 
having any disproportionately high and adverse human health or 
environmental effects on any population, including any minority or low-
income population. The rule will reduce the negative effects of 
discharges from airports to the nation's waters, to benefit all of 
society, including minority communities.

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the FR. A major rule cannot take effect 
until 60 days after it is published in the FR. This action is not a 
``major rule'' as defined by 5 U.S.C. 804(2). This rule will be 
effective June 15, 2012.

Appendix A to the Preamble: Abbreviations and Definitions Used in This 
Document

AAIA: Airport and Airway Improvement Act
ACI-NA: Airports Council International-North America
ADF: Aircraft deicing fluid (includes anti-icing fluid)
AFB: Anaerobic fluidized bed
AIP: Airport Improvement Program
ALB: Albany International Airport
ATA: Air Transport Association
BADCT: Best available demonstrated control technology
BAT: Best available technology economically achievable, as defined 
by sec. 301(b)(2)(A) and sec. 304(b)(2)(B) of the CWA
BCT: Best conventional pollutant control technology
BMP: Best management practice
BOD5: Biochemical oxygen demand
BPJ: Best Professional Judgment
BPT: Best conventional pollutant control technology
CBI: Confidential Business Information
CDP: Centralized deicing pad
CO2: Carbon dioxide
COD: Chemical oxygen demand
CWA: Clean Water Act
CWT: Centralized waste treatment
DIA: Denver International Airport
DSCR: Debt service coverage ratio
EA: Economic Analysis
EIB: Environmental Impact and Benefit
EO: Executive Order
EPA: U.S. Environmental Protection Agency
ELG: Effluent limitation guideline
FAA: Federal Aviation Administration
FDF: Fundamentally different factor
GARB: General airport revenue bonds
HDD: Heating degree day
IR: Infrared
GCV: Glycol collection vehicle
MSGP: Multi-Sector General Permit
Net income: Operating profit minus interest, taxes, depreciation, 
and non-operating profits and losses
NOAA: National Oceanic and Atmospheric Administration
NOI: Notice of Intent to discharge under a general permit (40 CFR 
122.28(b)(2))
Normalized ADF: ADF less any water added by the manufacturer or 
customer before ADF application.
NPDES: National Pollutant Discharge Elimination System, as defined 
by sec. 402 of the CWA
NPIAS: National Plan of Integrated Airport Systems
NSPS: New Source Performance Standards, as defined by sec. 306 of 
the CWA
NTTAA: National Technology Transfer Advancement Act
O&M: Operations and maintenance
Operating profit: Revenues minus cost of providing those services
P2: Pollution prevention
PFC: Passenger Facility Charges
POTW: Publicly owned treatment works
PSES: Pretreatment standards for existing sources
PSNS: Pretreatment standards for new sources
PV: Present value
RAS: Rural Aviation System
Revenues: Money received for services rendered
RFA: Regulatory Flexibility Act
SBA: Small Business Administration
TDD: Technical Development Document
ThOD: Theoretical oxygen demand
TRB: Transportation Research Board
UMRA: Unfunded Mandates Reform Act
U.S.C.: United States Code

List of Subjects

40 CFR Part 9

    Reporting and recordkeeping requirements.

40 CFR Part 449

    Environmental protection, Airline, Airport deicing, Airports, Waste 
treatment and disposal, Water pollution control.

    Dated: April 25, 2012.
Lisa P. Jackson,
Administrator.

    For the reasons set out in the preamble, 40 CFR chapter I is 
amended as follows:

[[Page 29203]]

PART 9--[AMENDED]

0
1. The authority citation for part 9 continues to read as follows:

    Authority:  7 United States Code (U.S.C.) 135 et seq., 136-136y; 
15 U.S.C. 2001, 2003, 2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 
348; 31 U.S.C. 9701; 33 U.S.C. 1251 et seq., 1311, 1313d, 1314, 
1318, 1321, 1326, 1330, 1342, 1344, 1345 (d) and (e), 1361; E.O. 
11735, 38 FR 21243, 3 CFR, 1971-1975 Comp. p. 973; 42 U.S.C. 241, 
242b, 243, 246, 300f, 300g, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 
300g-6, 300j-1, 300j-2, 300j-3, 300j-4, 300j-9, 1857 et seq., 6901-
6992k, 7401-7671q, 7542, 9601-9657, 11023, 11048.


0
2. In Sec.  9.1, the table is amended by adding a new heading and entry 
to read as follows:


Sec.  9.1  OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------
                                                            OMB control
                     40 CFR citation                            No.
------------------------------------------------------------------------
 
                                * * * * *
                  Airport Deicing Point Source Category
------------------------------------------------------------------------
449.10(a)...............................................       2040-0285
------------------------------------------------------------------------

* * * * *

0
3. Part 449 is added to read as follows:

PART 449--AIRPORT DEICING POINT SOURCE CATEGORY

Subpart A--Airport Deicing Category
Sec.
449.1 Applicability.
449.2 General definitions.
449.10 Effluent limitations representing the best available 
technology economically achievable (BAT).
449.11 New source performance standards (NSPS).
449.20 Monitoring, reporting and recordkeeping requirements.
Subpart B--[Reserved]
Appendix A to Part 449--Sampling Protocol for Soluble COD

    Authority:  33 U.S.C. 1311, 1314, 1316, 1318, 1342, 1361 and 
1370.

Subpart A--Airport Deicing Category


Sec.  449.1  Applicability.

    This part applies to discharges of pollutants from deicing 
operations at Primary Airports.


Sec.  449.2  General definitions.

    The following definitions apply to this part:
    Aircraft deicing fluid (ADF) means a fluid (other than hot water) 
applied to aircraft to remove or prevent any accumulation of snow or 
ice on the aircraft. This includes deicing and anti-icing fluids.
    Airfield pavement means all paved surfaces on the airside of an 
airport.
    Airside means the part of an airport directly involved in the 
arrival and departure of aircraft, including runways, taxiways, aprons, 
and ramps.
    Annual non-propeller aircraft departures means the average number 
of commercial turbine-engine aircraft that are propelled by jet, i.e., 
turbojet or turbofan, that take off from an airport on an annual basis, 
as tabulated by the Federal Aviation Administration (FAA).
    Available ADF means 75 percent of the normalized Type I aircraft 
deicing fluid and 10 percent of the normalized Type IV aircraft deicing 
fluid, excluding aircraft deicing fluids used for defrosting or deicing 
for safe taxiing.
    Centralized deicing pad means a facility on an airfield designed 
for aircraft deicing operations, typically constructed with a drainage 
system separate from the airport main storm drain system.
    COD means Chemical Oxygen Demand.
    Collection requirement means the requirement in Sec.  449.11 for 
the permittee to collect available ADF.
    Defrosting means the removal of frost contamination from an 
aircraft when there has been no active precipitation.
    Deicing mean procedures and practices to remove or prevent any 
accumulation of snow or ice on:
    (1) An aircraft; or
    (2) Airfield pavement.
    Deicing for safe taxiing means the application of ADF necessary to 
remove snow or ice to prevent damage to a taxiing aircraft.
    FAA Advisory Circular means a guidance document issued by the FAA 
on methods, procedures, or facility design.
    Heating degree day means the number of degrees per day the daily 
average temperature is below 65 degrees Fahrenheit. The daily average 
temperature is the mean of the maximum and minimum temperature for a 
24-hour period. The annual heating degree day value is derived by 
summing the daily heating degree days over a calendar year period.
    Normalized Type I or Type IV aircraft deicing fluid means ADF less 
any water added by the manufacturer or customer before ADF application.
    Primary Airport means an airport defined at 49 U.S.C. 47102 (15).


Sec.  449.10  Effluent limitations representing the best available 
technology economically achievable (BAT).

    Except as provided in 40 CFR 125.30 through 125.32, any existing 
point source with at least 1,000 annual non-propeller aircraft 
departures must comply with the following requirements representing the 
degree of effluent reduction attainable by the application of BAT. The 
BAT requirements for point sources with less than 1,000 annual non-
propeller aircraft departures are beyond the scope of this regulation 
and shall be determined by the permit authority on a site-specific 
basis.
    (a) Airfield pavement deicing. There shall be no discharge of 
airfield pavement deicers containing urea. To comply with this 
limitation, any existing point source must certify annually that it 
does not use airfield deicing products that contain urea or 
alternatively, airfield pavement discharges at every discharge point 
must achieve the numeric limitations for ammonia in Table I, prior to 
any dilution or commingling with any non-deicing discharge.

                        Table I--BAT Limitations
------------------------------------------------------------------------
         Wastestream                Pollutant           Daily maximum
------------------------------------------------------------------------
Airfield Pavement Deicing...  Ammonia as Nitrogen.  14.7 mg/L.
------------------------------------------------------------------------

     (b) [Reserved]


Sec.  449.11  New source performance standards (NSPS).

    New sources with at least 1,000 annual non-propeller aircraft 
departures must achieve the following new source performance standards. 
The new source performance standards for point sources with less than 
1,000 annual non-propeller aircraft departures are beyond the scope of 
this part and shall be determined by the permit authority on a site-
specific basis.
    (a) Aircraft deicing. Except for new airports located in Alaska, 
all new sources located in an area that, at the time of construction, 
had more than

[[Page 29204]]

3,000 annual heating degree days, and are estimated, within five years 
of commencing operations, to exceed 10,000 annual departures, must 
comply with the following requirements upon the date the facility 
exceeds 10,000 annual departures. New source performance standards that 
apply prior to that date, new source performance standards for sources 
that project they will not exceed 10,000 annual departures within five 
years of commencing operations, and new performance standards for 
airports in Alaska, are beyond the scope of this regulation and shall 
be determined by the permit authority on a site-specific basis.
    (1) Collection requirement. The new source must collect at least 60 
percent of available ADF.
    (2) Numerical effluent limitation. The new source must achieve the 
performance standards in Table II for available ADF collected pursuant 
to paragraph (a)(1) of this section. The limitation must be met at the 
location where the effluent leaves the onsite treatment system utilized 
for meeting these requirements and before commingling with any non-
deicing discharge.

                                                 Table II--NSPS
----------------------------------------------------------------------------------------------------------------
           Wastestream                     Pollutant                Daily maximum            Weekly average
----------------------------------------------------------------------------------------------------------------
Aircraft Deicing.................  COD......................  271 mg/L................  154 mg/L.
----------------------------------------------------------------------------------------------------------------

     (b) Airfield pavement deicing. There shall be no discharge of 
airfield pavement deicers containing urea. To comply with this 
limitation, any new source must certify annually that it does not use 
airfield deicing products that contain urea or alternatively, airfield 
pavement discharges at every discharge point must achieve the numeric 
limitations for ammonia in Table III, prior to any dilution or 
commingling with any non-deicing discharge.

                             Table III--NSPS
------------------------------------------------------------------------
         Wastestream                Pollutant           Daily maximum
------------------------------------------------------------------------
Airfield Pavement Deicing...  Ammonia as Nitrogen.  14.7 mg/L.
------------------------------------------------------------------------

Sec.  449.20  Monitoring, reporting and recordkeeping requirements.

    (a) Demonstrating compliance with the ADF collection requirement 
for dischargers subject to NSPS collection requirements in Sec.  
449.11. Except as provided in 40 CFR 125.30 through 125.32, an 
individual permittee shall select a procedure under either paragraphs 
(a)(1), (2), or (3) of this section in its permit application as the 
procedure for the permittee to demonstrate compliance with the 
applicable collection, reporting and recordkeeping requirements of this 
Part. A procedure selected by the permittee under paragraph (a)(2) of 
this section may be included in the permit only with the Director's 
approval, as described in paragraph (a)(2) of this section. For general 
permits, use of alternative methods for determining compliance with the 
ADF collection requirement for dischargers subject to NSPS collection 
requirements in this part will be at the discretion of the Director.
    (1) The permittee shall maintain records to demonstrate, and 
certify annually, that it is operating and maintaining one or more 
centralized deicing pads. This technology shall be operated and 
maintained according to the technical specifications set forth in 
paragraphs (a)(1)(i) through (iv) of this section. For both individual 
and general permits, these technical specifications shall be expressly 
set forth as requirements in the permit. The permittee's demonstration 
and valid certification are sufficient to meet the applicable NSPS 
collection requirement without the permittee having to determine the 
numeric percentage of available ADF collected.
    (i) Each centralized deicing pad shall be sized and sited in 
accordance with all applicable FAA advisory circulars.
    (ii) Drainage valves associated with the centralized deicing pad 
shall be activated before deicing activities commence, to collect 
available ADF.
    (iii) The centralized deicing pad and associated collection 
equipment shall be installed and maintained per any applicable 
manufacturers' instructions, and shall be inspected, at a minimum, at 
the beginning of each deicing season to ensure that the pad and 
associated equipment are in working condition.
    (iv) All aircraft deicing shall take place on a centralized deicing 
pad, with the exception of defrosting and deicing for safe taxiing.
    (2) Alternative technology or specifications. (i) An individual 
permit (or a general permit at the discretion of the Director) may 
allow one of the following alternative procedures for demonstrating 
compliance with its collection requirement, instead of the procedure in 
paragraph (a)(1) of this section. The permittee must submit all 
information and documentation necessary to support this request. An 
individual permittee may request this alternative procedure in its 
initial permit application or permit renewal application. During the 
term of an individual permit, the permittee may also request this 
alternative procedure as a permit modification, subject to the 
requirements and procedures at 40 CFR 122.62 and 40 CFR part 124. If 
the Director determines, in his or her discretion, that the requested 
alternative procedure will achieve the collection requirement in the 
permit, the Director shall approve the request:
    (A) The use of a different ADF collection technology from the 
centralized deicing pad technology specified in paragraph (a)(1) of 
this section; or
    (B) The use of the same ADF collection technology, but with 
different specifications for operation and/or maintenance.
    (ii) Pollution prevention credit. A permittee may apply for, and 
obtain, full or partial credit towards compliance with the available 
ADF collection requirement. To obtain credit the permittee must 
demonstrate to the Director's satisfaction that it employs a pollution 
prevention technique that reduces the volume of, or quantity of, 
pollutants in, available ADF. The credit shall be equivalent to the 
demonstrated reduction, as determined by the Director.
    (iii) The Director shall set forth technical specifications for 
proper operation and maintenance of the chosen collection technology, 
as

[[Page 29205]]

appropriate, and compliance with these technical specifications must be 
required by the permit. The permit shall also require the permittee to 
maintain records sufficient to demonstrate compliance with these 
requirements. This demonstration constitutes compliance by the 
permittee with the percent capture requirement without the permittee 
having to determine the numeric percentage of ADF that it has 
collected. Before the Director may approve an alternate technology 
under this subsection, the permittee must demonstrate to the Director's 
satisfaction that the alternate technology will achieve the applicable 
percent capture requirement.
    (3) The permittee shall maintain records, by means deemed 
acceptable by the Director, and report at a frequency determined by the 
Director, on the volume of ADF sprayed and the amount of available ADF 
collected in order to determine the compliance with the collection 
requirement.
    (b) Monitoring requirements--(1) COD limitation. Permittees subject 
to the ADF collection and discharge requirements specified in Sec.  
449.11 must conduct effluent monitoring to demonstrate compliance with 
the COD limitation for all ADF that is collected. Compliance must be 
demonstrated at the location where the effluent leaves the on-site 
treatment system utilized for meeting these requirements and before 
commingling with any non-deicing discharge. Effluent samples must be 
collected following the protocol in Appendix A to this part.
    (2) Ammonia limitation. If a permittee chooses to comply with the 
compliance alternative specified in Sec.  449.10(a) or Sec.  449.11(b), 
the permittee must conduct effluent monitoring at all locations where 
pavement deicing with a product that contains urea is occurring, prior 
to any dilution or commingling with any non-deicing discharge.
    (c) Recordkeeping. (1) The permit shall provide that the permittee 
must maintain on site, during the term of the permit, up to five years, 
records documenting compliance with paragraphs (a) through (b) of this 
section. These records include, but are not limited to, documentation 
of wastewater samples collected and analyzed, certifications, and 
equipment maintenance schedules and agreements.
    (2) At the Director's discretion, a requirement may be included in 
the permit for the permittee to collect, and maintain on site during 
the term of the permit, up to five (5) years of data on the annual 
volume of ADF used.

Subpart B--[Reserved]

Appendix A to Part 449--Sampling Protocol for Soluble COD

    This sampling protocol applies only to samples collected for use 
in measurement of COD when demonstrating compliance with the 
regulations set forth in this part. Collect a representative sample 
of the effluent from the airport deicing treatment system, based on 
the discharge permit requirements (e.g., a grab sample or a 
composite sample). Because only the COD sample is filtered, do not 
use in-line filters if collecting a sample with a compositing 
device.

A. Grab Samples

    1. Cap the container and shake the grab sample vigorously to mix 
it. Remove the plunger from a 10-milliliter (mL) or larger Luer-lock 
plastic syringe equipped with an Acrodisc Luer-lock filter 
containing a 1.5-[mu]m glass fiber filter (Whatman 934-AH, or 
equivalent), and fill the syringe body with sample.
    2. Replace the plunger and filter the sample into a clean 50-mL 
screw-cap glass, plastic, or fluoropolymer bottle.
    Note: If testing is being done in the field, or with a test kit 
product (e.g., Hach Method 8000), the filtrate may be collected in 
the test kit vial or container.
    3. Additional 10-mL volumes of sample may be filtered and the 
filtrate added to the same sample bottle. This additional volume may 
be used to repeat sample analyses or to prepare Quality Control (QC) 
samples, as needed.
    4. Unless the filtered sample will be analyzed within 15 
minutes, preserve the filtered sample with 
H2SO4 to pH <2. Cap the bottle and label with 
the sample number. Place in a cooler on ice prior to shipping.
    5. Once at the analytical laboratory, the sample must be stored 
at <=6 degrees Celsius and analyzed within 28 days of collection 
(see the requirements for COD in Table II at 40 CFR part 136).
    6. Analyze the sample using a method approved for COD in Table 
IB at 40 CFR part 136.
    Note: Because this procedure is specific to this point source 
category, it does not appear by name in 40 CFR part 136.
    7. Report the sample results as Soluble COD in units of 
milligrams per liter (mg/L). There is no Chemical Abstracts Service 
(CAS) Registry Number for soluble COD.

B. Composite Samples

    1. If the sample will be analyzed in a fixed laboratory (as 
opposed to field testing), transfer at least 50 mL of well-mixed 
sample from the compositing device into a clean 50-mL screw-cap 
glass, plastic, or fluoropolymer bottle. Preserve the sample with 
H2SO4 to pH <2. Cap the bottle and label with 
the sample number. Place in a cooler on ice prior to shipping.
    2. Once at the analytical laboratory, the sample must be stored 
at <=6 degrees Celsius and analyzed within 28 days of collection 
(see the requirements for COD in Table II at 40 CFR part 136).
    3. Prior to analysis, remove the sample from cold storage and 
allow it to warm to room temperature. Shake the sample vigorously to 
mix it.
    4. Remove the plunger from a 10-mL or larger Luer-lock plastic 
syringe equipped with an Acrodisc Luer-lock filter containing a 1.5-
[mu]m glass fiber filter (Whatman 934-AH, or equivalent), and fill 
the syringe body with sample.
    5. Replace the plunger and filter the sample into a clean COD 
vial or other suitable container.
    6. Additional 10-mL volumes of sample may be filtered and the 
filtrate added to separate containers, as needed, to provide samples 
for repeat analyses or to prepare QC samples.
    7. Analyze the sample using a method approved for COD in Table 
1B at 40 CFR part 136.
    Note: Because this procedure is specific to this point source 
category, it does not appear by name in 40 CFR part 136.
    8. Report the sample results as Soluble COD in units of mg/L. 
There is no CAS Registry Number for soluble COD.

[FR Doc. 2012-10633 Filed 5-15-12; 8:45 am]
BILLING CODE 6560-50-P