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

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

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.

    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

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

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

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.

   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

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

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

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

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

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

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

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

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

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.

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